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1.
J Virol ; 96(7): e0216121, 2022 04 13.
Article in English | MEDLINE | ID: mdl-35297660

ABSTRACT

Vaccine-induced protective T cell immunity is necessary for HIV-1 functional cure. We previously reported that rhesus PD1-Gag-based DNA vaccination sustained simian-human immunodeficiency virus (SHIV) suppression by inducing effector-memory CD8+ T cells. Here, we investigated a human PD1-Gag-based DNA vaccine, namely, ICVAX, for clinical translation. PD1-based dendritic cell targeting and mosaic antigenic designs were combined to generate the ICVAX by fusing the human soluble PD1 domain with a bivalent HIV-1 Gag-p41 mosaic antigen. The mosaic antigen was cross-reactive with patients infected with B, CRF07/08_BC, and CRF01_AE variants. In mice, ICVAX elicited stronger, broader, and more polyfunctional T cell responses than mosaic Gag-p41 alone, and suppressed EcoHIV infection more efficiently. In macaques, ICVAX elicited polyfunctional effector-memory T cell responses that targeted multiple nonoverlapping epitopes of the Gag-p41 antigen. Furthermore, ICVAX manufactured following good manufacturing practices proved potent immunogenicity in macaques after biannual homologous vaccination, warranting clinical evaluation of ICVAX as an immunotherapy against HIV-1. IMPORTANCE This study presents that ICVAX, a PD1-based DNA vaccine against HIV-1, could induce broad and polyfunctional T cell responses against different HIV-1 subtypes. ICVAX encodes a recombinant antigen consisting of the human soluble PD1 domain fused with two mosaic Gag-p41 antigens. The mosaic antigens cover more than 500 HIV-1 strains circulating in China including the subtypes B/B', CRF01_AE, and CRF07/08_BC. In mice, ICVAX elicited stronger, broader, and more polyfunctional T cell responses, with better EcoHIV suppression than the nontargeting mosaic Gag-p41 DNA vaccine. Moreover, both lab-generated and GMP-grade ICVAX also elicited strong polyfunctional effector-memory T cell responses in rhesus macaques with good immunogenicity against multiple nonoverlapping epitopes of the Gag-p41 antigen. This study therefore highlights the great potential to translate the PD1-based DNA vaccine approach into clinical use, and opens up new avenues for alternative HIV-1 vaccine design for HIV-1 preventive and functional cure.


Subject(s)
HIV Infections , HIV-1 , Vaccines, Combined , Vaccines, DNA , Viral Vaccines , AIDS Vaccines/immunology , Animals , Antigens, Viral , CD48 Antigen , CD8-Positive T-Lymphocytes , Epitopes/immunology , Gene Products, gag/genetics , Gene Products, gag/immunology , HIV Infections/prevention & control , HIV-1/genetics , Humans , Macaca mulatta , Memory T Cells , Mice , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, DNA/genetics , Vaccines, DNA/immunology , Viral Vaccines/genetics , Viral Vaccines/immunology
2.
Infect Immun ; 89(7): e0010621, 2021 06 16.
Article in English | MEDLINE | ID: mdl-33875477

ABSTRACT

There are no vaccines licensed for enterotoxigenic Escherichia coli (ETEC), a leading cause of diarrhea for children in developing countries and international travelers. Virulence heterogeneity among strains and difficulties identifying safe antigens for protective antibodies against STa, a potent but poorly immunogenic heat-stable toxin which plays a key role in ETEC diarrhea, are challenges in ETEC vaccine development. To overcome these challenges, we applied a toxoid fusion strategy and a novel epitope- and structure-based multiepitope fusion antigen (MEFA) vaccinology platform to construct two chimeric multivalent proteins, toxoid fusion 3xSTaN12S-mnLTR192G/L211A and adhesin CFA/I/II/IV MEFA, and demonstrated that the proteins induced protective antibodies against STa and heat-labile toxin (LT) produced by all ETEC strains or the seven most important ETEC adhesins (CFA/I and CS1 to CS6) expressed by the ETEC strains causing 60 to 70% of diarrheal cases and moderate to severe cases. Combining two proteins, we prepared a protein-based multivalent ETEC vaccine, MecVax. MecVax was broadly immunogenic; mice and pigs intramuscularly immunized with MecVax developed no apparent adverse effects but had robust antibody responses to the target toxins and adhesins. Importantly, MecVax-induced antibodies were broadly protective, demonstrated by significant adherence inhibition against E. coli bacteria producing any of the seven adhesins and neutralization of STa and cholera toxin (CT) enterotoxicity. Moreover, MecVax protected against watery diarrhea and provided over 70% and 90% protection against any diarrhea from an STa-positive or an LT-positive ETEC strain in a pig challenge model. These results indicated that MecVax induces broadly protective antibodies and prevents diarrhea preclinically, signifying that MecVax is potentially an effective injectable vaccine for ETEC. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) bacteria are a top cause of children's diarrhea and travelers' diarrhea and are responsible for over 220 million diarrheal cases and more than 100,000 deaths annually. A safe and effective ETEC vaccine can significantly improve public health, particularly in developing countries. Data from this preclinical study showed that MecVax induces broadly protective antiadhesin and antitoxin antibodies, becoming the first ETEC vaccine candidate to induce protective antibodies inhibiting adherence of the seven most important ETEC adhesins and neutralizing the enterotoxicity of not only LT but also STa toxin. More importantly, MecVax is shown to protect against clinical diarrhea from STa-positive or LT-positive ETEC infection in a pig challenge model, recording protection from antibodies induced by the protein-based, injectable, subunit vaccine MecVax against ETEC diarrhea and perhaps the possibility of intramuscularly administered protein vaccines for protection against intestinal mucosal infection.


Subject(s)
Diarrhea/microbiology , Diarrhea/prevention & control , Enterotoxigenic Escherichia coli/immunology , Escherichia coli Infections/prevention & control , Escherichia coli Vaccines/immunology , Animals , Antibodies, Bacterial/immunology , Antibodies, Neutralizing/immunology , Antigens, Bacterial/immunology , Bacterial Toxins/immunology , Diarrhea/immunology , Disease Models, Animal , Epitopes/immunology , Escherichia coli Proteins/immunology , Escherichia coli Vaccines/administration & dosage , Escherichia coli Vaccines/adverse effects , Mice , Recombinant Fusion Proteins/immunology , Swine , Vaccines, Combined/genetics , Vaccines, Combined/immunology
3.
Int J Mol Sci ; 22(6)2021 Mar 23.
Article in English | MEDLINE | ID: mdl-33807097

ABSTRACT

Enteric fever is a major global healthcare issue caused largely by Salmonella enterica serovars Typhi and Paratyphi A. The objective of this study was to develop a novel, bivalent oral vaccine capable of protecting against both serovars. Our approach centred on genetically engineering the attenuated S. Typhi ZH9 strain, which has an excellent safety record in clinical trials, to introduce two S. Paratyphi A immunogenic elements: flagellin H:a and lipopolysaccharide (LPS) O:2. We first replaced the native S. Typhi fliC gene encoding flagellin with the highly homologous fliC gene from S. Paratyphi A using Xer-cise technology. Next, we replaced the S. Typhi rfbE gene encoding tyvelose epimerase with a spacer sequence to enable the sustained expression of O:2 LPS and prevent its conversion to O:9 through tyvelose epimerase activity. The resulting new strain, ZH9PA, incorporated these two genetic changes and exhibited comparable growth kinetics to the parental ZH9 strain. A formulation containing both ZH9 and ZH9PA strains together constitutes a new bivalent vaccine candidate that targets both S. Typhi and S. Paratyphi A antigens to address a major global healthcare gap for enteric fever prophylaxis. This vaccine is now being tested in a Phase I clinical trial (NCT04349553).


Subject(s)
Bioengineering , Salmonella Vaccines/immunology , Salmonella typhi/immunology , Typhoid Fever/prevention & control , Vaccines, Combined/immunology , Administration, Oral , Animals , Disease Models, Animal , Female , Flagellin/immunology , Genetic Vectors/genetics , Humans , Immunogenicity, Vaccine , Lipopolysaccharides/immunology , Mice , Salmonella Vaccines/administration & dosage , Salmonella Vaccines/genetics , Salmonella typhi/genetics , Vaccines, Combined/administration & dosage , Vaccines, Combined/genetics
4.
Retrovirology ; 14(1): 8, 2017 02 06.
Article in English | MEDLINE | ID: mdl-28166802

ABSTRACT

BACKGROUND: In the Friend retrovirus mouse model we developed potent adenovirus-based vaccines that were designed to induce either strong Friend virus GagL85-93-specific CD8+ T cell or antibody responses, respectively. To optimize the immunization outcome we evaluated vaccination strategies using combinations of these vaccines. RESULTS: While the vaccines on their own confer strong protection from a subsequent Friend virus challenge, the simple combination of the vaccines for the establishment of an optimized immunization protocol did not result in a further improvement of vaccine effectivity. We demonstrate that the co-immunization with GagL85-93/leader-gag encoding vectors together with envelope-encoding vectors abrogates the induction of GagL85-93-specific CD8+ T cells, and in successive immunization protocols the immunization with the GagL85-93/leader-gag encoding vector had to precede the immunization with an envelope encoding vector for the efficient induction of GagL85-93-specific CD8+ T cells. Importantly, the antibody response to envelope was in fact enhanced when the mice were adenovirus-experienced from a prior immunization, highlighting the expedience of this approach. CONCLUSIONS: To circumvent the immunosuppressive effect of envelope on immune responses to simultaneously or subsequently administered immunogens, we developed a two immunizations-based vaccination protocol that induces strong immune responses and confers robust protection of highly Friend virus-susceptible mice from a lethal Friend virus challenge.


Subject(s)
Adenoviridae/genetics , Retroviridae Infections/immunology , Retroviridae Infections/prevention & control , Vaccination/methods , Viral Vaccines/administration & dosage , Viral Vaccines/immunology , Adenoviridae/immunology , Animals , Antibodies, Viral/immunology , CD8-Positive T-Lymphocytes/immunology , Disease Models, Animal , Friend murine leukemia virus/genetics , Friend murine leukemia virus/immunology , Genetic Vectors , HEK293 Cells , Humans , Mice , Retroviridae Infections/virology , Vaccines, Combined/administration & dosage , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, Synthetic/immunology , Viral Vaccines/genetics
5.
Arch Virol ; 161(5): 1209-16, 2016 May.
Article in English | MEDLINE | ID: mdl-26873815

ABSTRACT

Infectious bronchitis (IB) and Newcastle disease (ND) are common viral diseases of chickens, which are caused by infectious bronchitis virus (IBV) and Newcastle disease virus (NDV), respectively. Vaccination with live attenuated strains of IBV-H120 and NDV-LaSota are important for the control of IB and ND. However, conventional live attenuated vaccines are expensive and result in the inability to differentiate between infected and vaccinated chickens. Therefore, there is an urgent need to develop new efficacious vaccines. In this study, using a previously established reverse genetics system, we generated a recombinant IBV virus based on the IBV H120 vaccine strain expressing the haemagglutinin-neuraminidase (HN) protein of NDV. The recombinant virus, R-H120-HN/5a, exhibited growth dynamics, pathogenicity and viral titers that were similar to those of the parental IBV H120, but it had acquired hemagglutination activity from NDV. Vaccination of SPF chickens with the R-H120-HN/5a virus induced a humoral response at a level comparable to that of the LaSota/H120 commercial bivalent vaccine and provided significant protection against challenge with virulent IBV and NDV. In summary, the results of this study indicate that the IBV H120 strain could serve as an effective tool for designing vaccines against IB and other infectious diseases, and the generation of IBV R-H120-HN/5a provides a solid foundation for the development of an effective bivalent vaccine against IBV and NDV.


Subject(s)
Coronavirus Infections/veterinary , Infectious bronchitis virus/immunology , Newcastle Disease/prevention & control , Newcastle disease virus/immunology , Poultry Diseases/prevention & control , Viral Vaccines , Animals , Chickens/virology , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Hemagglutinins/genetics , Hemagglutinins/immunology , Neuraminidase/genetics , Neuraminidase/immunology , Newcastle Disease/immunology , Newcastle Disease/virology , Newcastle disease virus/genetics , Poultry Diseases/immunology , Poultry Diseases/virology , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Viral Vaccines/genetics , Viral Vaccines/immunology
6.
Avian Dis ; 57(1): 65-70, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23678731

ABSTRACT

A limited outbreak of nephropathogenic infectious bronchitis (NIB) occurred in three Delmarva (DMV) commercial broiler chicken flocks in 2011. Isolates of NIB virus (NIBV)--DMV/1639/11, DMV/3432/11, and DMV/3902/11--were characterized by sequence analysis of the N-terminal subunit (S1) of the spike (S) gene. Findings indicated that the isolates were identical to each other and to PA/9579A/10, a 2010 isolate from poultry in Pennsylvania. The 2010 and 2011 isolates appear to have originated from a 1997-2000 NIB outbreak in Pennsylvania. DMV/1639/11 and PA/9579A/10 were determined to be nephropathogenic in susceptible chickens, yielding virus reisolations from kidney and inducing characteristic interstitial nephritis microscopic lesions. In a controlled laboratory study, 40% of chickens vaccinated with a combination live vaccine containing infectious bronchitis virus (IBV) strains Massachusetts (Mass) + Connecticut (Conn) were positive on virus isolation attempts after challenge with DMV/1639/11, compared with only 13% of Mass + Arkansas (Ark) vaccinates. Both combination vaccines gave partial protection against the development of DMV/1639/11-induced renal lesions. Although numerically fewer chickens vaccinated with Mass + Conn had interstitial nephritis compared with those vaccinated with Mass + Ark, neither vaccine combination offered greater protection (P < 0.05) than observed in unvaccinated chickens challenged with DMV/1639/11. Mass + Ark vaccinations, applied under commercial conditions in the hatchery (spray) and on-farm (spray), did not protect the trachea or kidney from DMV/1639/11 challenge. Serologic testing of broiler flocks found < 3% (2 of 69) tested to possess specific antibodies to DMV/1639/11, indicating the virus had not become established in the region.


Subject(s)
Chickens , Coronavirus Infections/veterinary , Infectious bronchitis virus/genetics , Infectious bronchitis virus/pathogenicity , Poultry Diseases/virology , Viral Vaccines/immunology , Animals , Antibodies, Viral/blood , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Delaware/epidemiology , Infectious bronchitis virus/classification , Infectious bronchitis virus/isolation & purification , Kidney/pathology , Kidney/virology , Molecular Sequence Data , Phylogeny , Poultry Diseases/epidemiology , Poultry Diseases/prevention & control , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Sequence Analysis, DNA/veterinary , Sequence Analysis, Protein/veterinary , Sequence Homology , Specific Pathogen-Free Organisms , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Viral Vaccines/genetics , Virulence
7.
Nat Med ; 11(7): 786-90, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15937495

ABSTRACT

Vaccines and therapies are urgently needed to address public health needs stemming from emerging pathogens and biological threat agents such as the filoviruses Ebola virus (EBOV) and Marburg virus (MARV). Here, we developed replication-competent vaccines against EBOV and MARV based on attenuated recombinant vesicular stomatitis virus vectors expressing either the EBOV glycoprotein or MARV glycoprotein. A single intramuscular injection of the EBOV or MARV vaccine elicited completely protective immune responses in nonhuman primates against lethal EBOV or MARV challenges. Notably, vaccine vector shedding was not detectable in the monkeys and none of the animals developed fever or other symptoms of illness associated with vaccination. The EBOV vaccine induced humoral and apparent cellular immune responses in all vaccinated monkeys, whereas the MARV vaccine induced a stronger humoral than cellular immune response. No evidence of EBOV or MARV replication was detected in any of the protected animals after challenge. Our data suggest that these vaccine candidates are safe and highly efficacious in a relevant animal model.


Subject(s)
Ebolavirus/immunology , Marburgvirus/immunology , Vaccines, Attenuated/immunology , Vaccines, Combined/immunology , Viral Vaccines/immunology , Animals , Antibody Formation , Cross Reactions , Ebola Vaccines/immunology , Ebola Vaccines/pharmacology , Primates , Vaccines, Attenuated/genetics , Vaccines, Attenuated/pharmacology , Vaccines, Combined/genetics , Vaccines, Combined/pharmacology , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Vaccines, Synthetic/pharmacology , Vesicular stomatitis Indiana virus/genetics , Viral Vaccines/genetics , Viral Vaccines/pharmacology , Viremia/immunology , Viremia/virology , Virus Replication
8.
Science ; 378(6622): 899-904, 2022 11 25.
Article in English | MEDLINE | ID: mdl-36423275

ABSTRACT

Seasonal influenza vaccines offer little protection against pandemic influenza virus strains. It is difficult to create effective prepandemic vaccines because it is uncertain which influenza virus subtype will cause the next pandemic. In this work, we developed a nucleoside-modified messenger RNA (mRNA)-lipid nanoparticle vaccine encoding hemagglutinin antigens from all 20 known influenza A virus subtypes and influenza B virus lineages. This multivalent vaccine elicited high levels of cross-reactive and subtype-specific antibodies in mice and ferrets that reacted to all 20 encoded antigens. Vaccination protected mice and ferrets challenged with matched and mismatched viral strains, and this protection was at least partially dependent on antibodies. Our studies indicate that mRNA vaccines can provide protection against antigenically variable viruses by simultaneously inducing antibodies against multiple antigens.


Subject(s)
Influenza A virus , Influenza B virus , Orthomyxoviridae Infections , Vaccines, Combined , Vaccines, Synthetic , mRNA Vaccines , Animals , Mice , Ferrets , Nucleosides/chemistry , Nucleosides/genetics , Orthomyxoviridae Infections/prevention & control , Vaccines, Combined/genetics , Vaccines, Combined/immunology , mRNA Vaccines/genetics , mRNA Vaccines/immunology , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Influenza A virus/immunology , Influenza B virus/immunology , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Cross Reactions
9.
J Immunol ; 182(9): 5331-41, 2009 May 01.
Article in English | MEDLINE | ID: mdl-19380780

ABSTRACT

Cytokine-Ag fusion proteins represent a novel approach for induction of Ag-specific tolerance and may constitute an efficient therapy for autoimmune disease. This study addressed whether a fusion protein containing rat IFN-beta and the encephalitogenic 73-87 determinant of myelin basic protein (i.e., the neuroantigen, or NAg) could prevent or treat experimental autoimmune encephalomyelitis (EAE) in Lewis rats. The optimal structure of the fusion protein was comprised of the rat IFN-beta cytokine as the N-terminal domain with an enterokinase (EK) linker to the NAg domain. Both cytokine and NAg domains had full biological activity. Subcutaneous administration of 1 nmol of IFNbeta-NAg fusion protein in saline on days -21, -14, and -7 before encephalitogenic challenge on day 0 resulted in a substantial attenuation of EAE. In contrast, administration of IFN-beta or NAg alone did not affect susceptibility to EAE. The covalent attachment of IFN-beta and NAg was not necessary, because separate injections of IFN-beta and NAg at adjacent sites were as effective as injection of IFNbeta-NAg for prevention of disease. When treatment was initiated after disease onset, the rank order of inhibitory activity was as follows: the IFNbeta-NAg fusion protein > or = a mixture of IFN-beta plus NAg > IFN-beta > NAg. The novel finding that IFN-beta acts as a tolerogenic adjuvant as well as a tolerogenic fusion partner may have significance for development of tolerogenic vaccines.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Encephalomyelitis, Autoimmune, Experimental/immunology , Encephalomyelitis, Autoimmune, Experimental/prevention & control , Immune Tolerance , Interferon-beta/administration & dosage , Myelin Basic Protein/administration & dosage , Recombinant Fusion Proteins/administration & dosage , Adjuvants, Immunologic/genetics , Amino Acid Sequence , Animals , Cell Line , Cells, Cultured , Encephalomyelitis, Autoimmune, Experimental/pathology , Guinea Pigs , Humans , Immune Tolerance/genetics , Immunity, Innate/genetics , Interferon-beta/genetics , Interferon-beta/immunology , Molecular Sequence Data , Myelin Basic Protein/genetics , Myelin Basic Protein/physiology , Rats , Rats, Inbred Lew , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , Vaccines, Combined/administration & dosage , Vaccines, Combined/genetics , Vaccines, Combined/immunology
10.
Hum Vaccin ; 7(9): 941-4, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21921700

ABSTRACT

AIM: Because of the high mother-to-infant transmissibility of hepatitis B (HB) infection, neonatal vaccination is necessary, but the further doses of HB vaccines can be combined with conventional diphtheria-tetanus-whole cell pertussis (DTPw) vaccines. We compared immunogenicity and reactogenicity of two tetravalent vaccines in Indian children, who after neonatal HB immunization, were vaccinated thrice with one of these vaccines. METHODS: In this open-label randomized study, 287 infants received a dose of an Indian- (Q-Vac (TM )) or European-made (Tritanrix-HB (TM )) tetravalent vaccine at age 6, 10, and 14 weeks. The ELISA antibodies were measured prior to the first and one month after the third dose. Immunogenicity was determined by measuring the seroprotection/seropositivity rates and geometric mean titres (GMT), whereas vaccine reactogenicity was elucidated with diary cards for 7 days following each dose. The potential unsolicited events were queried throughout the whole 3-month study period. RESULTS: Out of the 250 subjects who completed the study, 123 received the Indian and 127 the European vaccine. After 3 doses, the seroprotection/seropositivity rates were 99 % and 100% for diphtheria, 98% and 95% for tetanus, 89% and 94% for pertussis, and 100% and 100% for hepatitis B, respectively. GMT of tetanus antibodies was significantly higher with the Indian vaccine. Low-grade reactogenicity was rather similar in the two vaccine groups, the most common events being local pain, redness, swelling, fever, irritability, unusual crying, drowsiness, and non-specific gastrointestinal symptoms. CONCLUSIONS: Since both immunogenicity and reactogenicity of the two vaccines were almost identical, the Indian vaccine poses a good alternative to the costlier competitor vaccines.


Subject(s)
Diphtheria-Tetanus-Pertussis Vaccine/immunology , Diphtheria-Tetanus-Pertussis Vaccine/therapeutic use , Hepatitis B Vaccines/immunology , Hepatitis B Vaccines/therapeutic use , Antibodies, Bacterial/blood , Antibodies, Viral/blood , Diphtheria/prevention & control , Diphtheria-Tetanus-Pertussis Vaccine/genetics , Female , Hepatitis B/prevention & control , Hepatitis B Vaccines/genetics , Humans , Immunization Schedule , Infant , Male , Tetanus/prevention & control , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, Combined/therapeutic use , Whooping Cough/prevention & control
11.
Parasit Vectors ; 14(1): 241, 2021 May 07.
Article in English | MEDLINE | ID: mdl-33962671

ABSTRACT

BACKGROUND: Transmission-blocking vaccine (TBV) is a promising strategy for malaria elimination. It is hypothesized that mixing or fusing two antigens targeting different stages of sexual development may provide higher transmission-blocking activity than these antigens used individually. METHODS: A chimeric protein composed of fragments of Pbg37 and PSOP25 was designed and expressed the recombinant protein in Escherichia coli Rosetta-gami B (DE3). After immunizing mice with individual recombinant proteins Pbg37 and PSOP25, mixed proteins (Pbg37+PSOP25), or the fusion protein (Pbg37-PSOP25), the antibody titers of individual sera were analyzed by ELISA. IFA and Western blot were performed to test the reactivity of the antisera with the native proteins in the parasite. The transmission-blocking activity of the different immunization schemes was assessed using in vitro and in vivo assays. RESULTS: When Pbg37 and PSOP25 were co-administered in a mixture or as a fusion protein, they elicited similar antibody responses in mice as single antigens without causing immunological interference with each other. Antibodies against the mixed or fused antigens recognized the target proteins in the gametocyte, gamete, zygote, and ookinete stages. The mixed proteins or the fusion protein induced antibodies with significantly stronger transmission-reducing activities in vitro and in vivo than individual antigens. CONCLUSIONS: There was no immunological interference between Pbg37 and PSOP25. The bivalent vaccines, which expand the portion of the sexual development during which the transmission-blocking antibodies act, produced significantly stronger transmission-reducing activities than single antigens. Altogether, these data provide the theoretical basis for the development of combination TBVs targeting different sexual stages.


Subject(s)
Malaria Vaccines/administration & dosage , Malaria/prevention & control , Plasmodium berghei/growth & development , Plasmodium berghei/immunology , Protozoan Proteins/administration & dosage , Vaccines, Combined/administration & dosage , Animals , Antibodies, Protozoan/blood , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Humans , Immunization , Malaria/blood , Malaria/parasitology , Malaria/transmission , Malaria Vaccines/genetics , Malaria Vaccines/immunology , Mice , Mice, Inbred BALB C , Plasmodium berghei/genetics , Protozoan Proteins/genetics , Protozoan Proteins/immunology , Vaccines, Combined/genetics , Vaccines, Combined/immunology
12.
Vet Microbiol ; 257: 109076, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33957572

ABSTRACT

The Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne hemorrhagic zoonotic disease, which is potentially fatal in human with mortality rates ranging from 16.2%-32%. The rabies virus (RABV) LBNSE vector expressing foreign antigens have shown considerable promise as vaccines against viral diseases, which is effective and safe. In the present study, we generated a recombinant RABV rLBNSE-Gn expressing a SFTSV glycoprotein Gn by reverse genetic technology to control rabies and SFTS in animals. An extra insertion of Gn gene did not impact replication of the recombinant virus rLBNSE-Gn in NA and BHK-21 cells compared to the parent rLBNSE strain. The SFTSV Gn gene together with RABV N and G genes were efficiently expressed in rLBNSE-infected Vero cells by immunostaining and immune blots. A single dose of 107 FFU of the rLBNSE-Gn intramuscularly inoculated in BALB/c mice induced rapid and robust humoral responses against both RABV and SFTSV without any signs of disease or weight loss. Compared to the rLBNSE and DMEM groups, the extra Gn expression contributed to the recruitments and/or activations of the dendritic cells and B cells from inguinal lymph nodes of BALB/c mice vaccinated with rLBNSE-Gn. The protective efficacy of rLBNSE-Gn against SFTSV in C57BL/6 mice was evaluated, and the virus loading in the spleens reduced to 10 TCID50/mg at 7 days post SFTSV infections, which indicated that the rLBNSE-Gn conferred efficacious protective immune responses from SFTSV in C57BL/6 mice. All the mice immunization with rLBNSE-Gn and rLBNSE survived after a lethal RABV challenge, suggesting a 100 % protection from RABV. Therefore, the rLBNSE-Gn would be a promising bivalent candidate vaccine against SFTS and rabies in animals.


Subject(s)
Antibodies, Viral/blood , Genetic Vectors , Phlebovirus/immunology , Rabies virus/genetics , Rabies/prevention & control , Severe Fever with Thrombocytopenia Syndrome/prevention & control , Viral Vaccines/immunology , Animals , Female , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Phlebovirus/genetics , Rabies Vaccines/administration & dosage , Rabies Vaccines/immunology , Rabies virus/immunology , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/immunology , Vaccines, Combined/administration & dosage , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, Inactivated/administration & dosage , Vaccines, Inactivated/immunology , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/immunology , Viral Vaccines/administration & dosage , Viral Vaccines/genetics
13.
Front Immunol ; 12: 736360, 2021.
Article in English | MEDLINE | ID: mdl-34671354

ABSTRACT

Bacterial infections cause huge losses in aquaculture and a wide range of health issues in humans. A vaccine is the most economical, efficient, and environment-friendly agent for protecting hosts against bacterial infections. This study aimed to identify broad, cross-protective antigens from the extracellular secretory proteome of the marine bacterium Vibrio alginolyticus. Of the 69 predicted extracellular secretory proteins in its genome, 16 were randomly selected for gene cloning to construct DNA vaccines, which were used to immunize zebrafish (Danio rerio). The innate immune response genes were also investigated. Among the 16 DNA vaccines, 3 (AT730_21605, AT730_22220, and AT730_22910) were protective against V. alginolyticus infection with 47-66.7% increased survival compared to the control, while other vaccines had lower or no protective effects. Furthermore, AT730_22220, AT730_22910, and AT730_21605 also exhibited cross-immune protective effects against Pseudomonas fluorescens and/or Aeromonas hydrophila infection. Mechanisms for cross-protective ability was explored based on conserved epitopes, innate immune responses, and antibody neutralizing ability. These results indicate that AT730_21605, AT730_22220, and AT730_22910 are potential polyvalent vaccine candidates against bacterial infections. Additionally, our results suggest that the extracellular secretory proteome is an antigen pool that can be used for the identification of cross-protective immunogens.


Subject(s)
Antigens, Bacterial/pharmacology , Bacterial Infections/prevention & control , Bacterial Vaccines/pharmacology , Vaccine Development , Vaccines, Combined/pharmacology , Vibrio alginolyticus/immunology , Animals , Antibodies, Bacterial/metabolism , Antibodies, Neutralizing/metabolism , Antigens, Bacterial/genetics , Antigens, Bacterial/immunology , Bacterial Infections/immunology , Bacterial Infections/microbiology , Bacterial Vaccines/genetics , Bacterial Vaccines/immunology , Cross Reactions , Disease Models, Animal , Gram-Negative Bacterial Infections/immunology , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/prevention & control , Immunity, Innate/drug effects , Immunization , Immunogenicity, Vaccine , Pseudomonas Infections/immunology , Pseudomonas Infections/microbiology , Pseudomonas Infections/prevention & control , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vibrio Infections/immunology , Vibrio Infections/microbiology , Vibrio Infections/prevention & control , Vibrio alginolyticus/genetics , Zebrafish
14.
J Immunother Cancer ; 9(3)2021 03.
Article in English | MEDLINE | ID: mdl-33762322

ABSTRACT

BACKGROUND: Antitumor vaccines targeting tumor-associated antigens (TAAs) can generate antitumor immune response. A novel vaccine platform using adenovirus 5 (Ad5) vectors [E1-, E2b-] targeting three TAAs-prostate-specific antigen (PSA), brachyury, and MUC-1-has been developed. Both brachyury and the C-terminus of MUC-1 are overexpressed in metastatic castration-resistant prostate cancer (mCRPC) and have been shown to play an important role in resistance to chemotherapy, epithelial-mesenchymal transition, and metastasis. The transgenes for PSA, brachyury, and MUC-1 all contain epitope modifications for the expression of CD8+ T-cell enhancer agonist epitopes. We report here the first-in-human trial of this vaccine platform. METHODS: Patients with mCRPC were given concurrently three vaccines targeting PSA, brachyury, and MUC-1 at 5×1011 viral particles (VP) each, subcutaneously every 3 weeks for a maximum of three doses (dose de-escalation cohort), followed by a booster vaccine every 8 weeks for 1 year (dose-expansion cohort only). The primary objective was to determine the safety and the recommended phase II dose. Immune assays and clinical responses were evaluated. RESULTS: Eighteen patients with mCRPC were enrolled between July 2018 and September 2019 and received at least one vaccination. Median PSA was 25.58 ng/mL (range, 0.65-1006 ng/mL). The vaccine was tolerable and safe, and no grade >3 treatment-related adverse events or dose-limiting toxicities (DLTs) were observed. One patient had a partial response, while five patients had confirmed PSA decline and five had stable disease for >6 months. Median progression-free survival was 22 weeks (95% CI: 19.1 to 34). Seventeen (100%) of 17 patients mounted T-cell responses to at least one TAA, whereras 8 (47%) of 17 patients mounted immune responses to all three TAAs. Multifunctional T-cell responses to PSA, MUC-1, and brachyury were also detected after vaccination in the majority of the patients. CONCLUSIONS: Ad5 PSA/MUC-1/brachyury vaccine is well tolerated. The primary end points were met and there were no DLTs. The recommended phase II dose is 5×1011 VP. The vaccine demonstrated clinical activity, including one partial response and confirmed PSA responses in five patients. Three patients with prolonged PSA responses received palliative radiation therapy. Further research is needed to evaluate the clinical benefit and immunogenicity of this vaccine in combination with other immuno-oncology agents and/or palliative radiation therapy. TRIAL REGISTRATION NUMBER: NCT03481816.


Subject(s)
Adenoviridae/immunology , Cancer Vaccines/therapeutic use , Fetal Proteins/immunology , Kallikreins/immunology , Mucin-1/immunology , Prostate-Specific Antigen/immunology , Prostatic Neoplasms, Castration-Resistant/therapy , T-Box Domain Proteins/immunology , Vaccines, Combined/therapeutic use , Adenoviridae/genetics , Aged , Aged, 80 and over , Cancer Vaccines/adverse effects , Cancer Vaccines/genetics , Cancer Vaccines/immunology , Fetal Proteins/genetics , Genetic Vectors , Humans , Kallikreins/genetics , Male , Middle Aged , Mucin-1/genetics , Progression-Free Survival , Prostate-Specific Antigen/genetics , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/immunology , T-Box Domain Proteins/genetics , Time Factors , Vaccination , Vaccine Efficacy , Vaccines, Combined/adverse effects , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Viral Vaccines
15.
Commun Biol ; 4(1): 597, 2021 05 19.
Article in English | MEDLINE | ID: mdl-34011948

ABSTRACT

The COVID-19 pandemic continues to wreak havoc as worldwide SARS-CoV-2 infection, hospitalization, and death rates climb unabated. Effective vaccines remain the most promising approach to counter SARS-CoV-2. Yet, while promising results are emerging from COVID-19 vaccine trials, the need for multiple doses and the challenges associated with the widespread distribution and administration of vaccines remain concerns. Here, we engineered the coat protein of the MS2 bacteriophage and generated nanoparticles displaying multiple copies of the SARS-CoV-2 spike (S) protein. The use of these nanoparticles as vaccines generated high neutralizing antibody titers and protected Syrian hamsters from a challenge with SARS-CoV-2 after a single immunization with no infectious virus detected in the lungs. This nanoparticle-based vaccine platform thus provides protection after a single immunization and may be broadly applicable for protecting against SARS-CoV-2 and future pathogens with pandemic potential.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/immunology , COVID-19/prevention & control , Pandemics , SARS-CoV-2 , Animals , Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , COVID-19 Vaccines/genetics , COVID-19 Vaccines/immunology , Drug Delivery Systems , Female , Humans , Immunization/methods , Levivirus/genetics , Levivirus/immunology , Mesocricetus , Microscopy, Electron, Transmission , Models, Animal , Nanoparticles/administration & dosage , Nanoparticles/ultrastructure , Nanotechnology , Pandemics/prevention & control , Protein Engineering , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/administration & dosage , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Combined/administration & dosage , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, Virus-Like Particle/administration & dosage , Vaccines, Virus-Like Particle/genetics , Vaccines, Virus-Like Particle/immunology
16.
Front Immunol ; 12: 692937, 2021.
Article in English | MEDLINE | ID: mdl-34497604

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) kills thousands of people worldwide every day, thus necessitating rapid development of countermeasures. Immunoinformatics analyses carried out here in search of immunodominant regions in recently identified SARS-CoV-2 unannotated open reading frames (uORFs) have identified eight linear B-cell, one conformational B-cell, 10 CD4+ T-cell, and 12 CD8+ T-cell promising epitopes. Among them, ORF9b B-cell and T-cell epitopes are the most promising followed by M.ext and ORF3c epitopes. ORF9b40-48 (CD8+ T-cell epitope) is found to be highly immunogenic and antigenic with the highest allele coverage. Furthermore, it has overlap with four potent CD4+ T-cell epitopes. Structure-based B-cell epitope prediction has identified ORF9b61-68 to be immunodominant, which partially overlaps with one of the linear B-cell epitopes (ORF9b65-69). ORF3c CD4+ T-cell epitopes (ORF3c2-16, ORF3c3-17, and ORF3c4-18) and linear B-cell epitope (ORF3c14-22) have also been identified as the candidate epitopes. Similarly, M.ext and 7a.iORF1 (overlap with M and ORF7a) proteins have promising immunogenic regions. By considering the level of antigen expression, four ORF9b and five M.ext epitopes are finally shortlisted as potent epitopes. Mutation analysis has further revealed that the shortlisted potent uORF epitopes are resistant to recurrent mutations. Additionally, four N-protein (expressed by canonical ORF) epitopes are found to be potent. Thus, SARS-CoV-2 uORF B-cell and T-cell epitopes identified here along with canonical ORF epitopes may aid in the design of a promising epitope-based polyvalent vaccine (when connected through appropriate linkers) against SARS-CoV-2. Such a vaccine can act as a bulwark against SARS-CoV-2, especially in the scenario of emergence of variants with recurring mutations in the spike protein.


Subject(s)
Antigens, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Coronavirus Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , Amino Acid Sequence/genetics , Antigens, Viral/genetics , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/genetics , COVID-19 Vaccines/therapeutic use , Computational Biology , Coronavirus Nucleocapsid Proteins/genetics , Drug Design , Epitope Mapping , Epitopes, B-Lymphocyte/genetics , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , Humans , Open Reading Frames/genetics , Open Reading Frames/immunology , SARS-CoV-2/genetics , Sequence Analysis, Protein , Vaccines, Combined/genetics , Vaccines, Combined/immunology
17.
Curr Top Microbiol Immunol ; 329: 129-62, 2009.
Article in English | MEDLINE | ID: mdl-19198565

ABSTRACT

An overview is given on the development of technologies to allow reverse genetics of RNA viruses, i.e., the rescue of viruses from cDNA, with emphasis on nonsegmented negative-strand RNA viruses (Mononegavirales), as exemplified for measles virus (MV). Primarily, these technologies allowed site-directed mutagenesis, enabling important insights into a variety of aspects of the biology of these viruses. Concomitantly, foreign coding sequences were inserted to (a) allow localization of virus replication in vivo through marker gene expression, (b) develop candidate multivalent vaccines against measles and other pathogens, and (c) create candidate oncolytic viruses. The vector use of these viruses was experimentally encouraged by the pronounced genetic stability of the recombinants unexpected for RNA viruses, and by the high load of insertable genetic material, in excess of 6 kb. The known assets, such as the small genome size of the vector in comparison to DNA viruses proposed as vectors, the extensive clinical experience of attenuated MV as vaccine with a proven record of high safety and efficacy, and the low production cost per vaccination dose are thus favorably complemented.


Subject(s)
Genetic Engineering , Measles Vaccine/immunology , Measles virus/genetics , Measles/immunology , Animals , Genome, Viral , Humans , Measles/prevention & control , Measles/virology , Measles Vaccine/administration & dosage , Measles Vaccine/genetics , Measles virus/immunology , Mutagenesis, Site-Directed , Vaccines, Combined/administration & dosage , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology
18.
Med Parazitol (Mosk) ; (2): 36-9, 2010.
Article in Russian | MEDLINE | ID: mdl-20608183

ABSTRACT

RT-PCR evaluation of the activity of eight Ixodes persulcatus salivary gland genes shows clear distinctions in their expression depending of the stage of tick feeding. Out of them, only Salp 10 and Salp 15 proteins may be regarded as candidates for protective antigens to develop anti-tick and anti-Borrelia vaccines. Firstly they play an important role in feeding a tick and modifying a host's immune response. Secondly, the increasing expression of the salp 10 and salp 10 genes begins at early tick feeding stages. Thirdly, the activity of these genes increases with the beginning of feeding by tens and hundreds times and keeps at this level until the third tick feeding stage is over.


Subject(s)
Immunodominant Epitopes/genetics , Ixodes/genetics , Lyme Disease Vaccines/genetics , Salivary Glands/metabolism , Salivary Proteins and Peptides/genetics , Animals , Female , Gene Expression Regulation , Ixodes/physiology , Lyme Disease/prevention & control , Reverse Transcriptase Polymerase Chain Reaction , Vaccines, Combined/genetics
19.
Vaccine ; 38(14): 2949-2959, 2020 03 23.
Article in English | MEDLINE | ID: mdl-32111526

ABSTRACT

Junin (JUNV) and Machupo (MACV), two mammalian arenaviruses placed on the 2018 WHO watch list, are prevalent in South America causing Argentine and Bolivian hemorrhagic fevers (AHF and BHF), respectively. The live attenuated JUNV vaccine, Candid #1, significantly reduced the incidence of AHF. Vaccination induces neutralizing antibody (nAb) responses which effectively target GP1 (the viral attachment glycoprotein) pocket which accepts the tyrosine residue of the cellular receptor, human transferrin receptor 1 (TfR1). In spite of close genetic relationships between JUNV and MACV, variability in the GP1 receptor binding site (e.g., MACV GP1 loop 10) results in poor MACV neutralization by Candid #1-induced nAbs. Candid #1 is not recommended for vaccination of children younger than 15 years old (a growing "at risk" group), pregnant women, or other immunocompromised individuals. Candid #1's primary reliance on limited missense mutations for attenuation, genetic heterogeneity, and potential stability concerns complicate approval of this vaccine in the US. To address these issues, we applied alphavirus RNA replicon vector technology based on the human Venezuelan equine encephalitis vaccine (VEEV) TC-83 to generate replication restricted virus-like-particles vectors (VLPVs) simultaneously expressing cellular glycoprotein precursors (GPC) of both viruses, JUNV and MACV. Resulting JV&MV VLPVs were found safe and immunogenic in guinea pigs. Immunization with VLPVs induced humoral responses which correlated with complete protection against lethal disease after challenge with pathogenic strains of JUNV (Romero) and MACV (Carvallo).


Subject(s)
Alphavirus , Hemorrhagic Fever, American , Replicon , Viral Vaccines/immunology , Alphavirus/genetics , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Arenaviruses, New World , Guinea Pigs , Hemorrhagic Fever, American/prevention & control , Immunity, Humoral , Junin virus , RNA , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Viral Vaccines/genetics
20.
Vaccine ; 38(7): 1690-1699, 2020 02 11.
Article in English | MEDLINE | ID: mdl-31937412

ABSTRACT

Newcastle disease virus (NDV) has been used as a vector in the development of vaccines and gene delivery. In the present study, we generated the thermostable recombinant NDV (rNDV) expressing the different forms of hemagglutinin (HA) of highly pathogenic avian influenza virus (HPAIV) H5N1 based on the full-length cDNA clone of thermostable TS09-C strain. The recombinant thermostable Newcastle disease viruses, rTS-HA, rTS-HA1 and rTS-tPAs/HA1, expressed the HA, HA1 or modified HA1 protein with the tissue plasminogen activator signal sequence (tPAs), respectively. The rNDVs displayed similar thermostability, growth kinetics and pathogenicity compared with the parental TS09-C virus. The tPAs facilitated the expression and secretion of HA1 protein in cells infected with rNDV. Animal studies demonstrated that immunization with rNDVs elicited effective H5N1- and NDV-specific antibody responses and conferred immune protection against lethal H5N1 and NDV challenges in chickens and mice. Importantly, vaccination of rTS-tPAs/HA1 resulted in enhanced protective immunity in chickens and mice. Our study thus provides a novel thermostable NDV-vectored vaccine candidate expressing a soluble form of a heterologous viral protein, which will greatly aid the poultry industry in developing countries.


Subject(s)
Hemagglutinin Glycoproteins, Influenza Virus/immunology , Influenza Vaccines , Influenza in Birds , Newcastle Disease , Animals , Antibodies, Viral/blood , Chickens/immunology , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Influenza A Virus, H5N1 Subtype , Influenza Vaccines/genetics , Influenza in Birds/prevention & control , Mice , Newcastle Disease/prevention & control , Newcastle disease virus , Tissue Plasminogen Activator/genetics , Vaccines, Combined/genetics
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