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1.
Microb Cell Fact ; 22(1): 260, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38110987

RESUMO

BACKGROUND: RNA-dependent RNA polymerase (RdRp) is a good target of anti-RNA virus agents; not only it is pivotal for the RNA virus replication cycle and highly conserved among RNA viruses across different families, but also lacks human homolog. Recently, human single-chain antibody (HuscFv) that bound to thumb domain of hepatitis C virus (HCV) RNA-dependent RNA polymerase (functionalized NS5B protein) was produced and engineered into cell-penetrating antibody (super antibody) in the form of cell-penetrating peptide (penetratin, PEN)-linked HuscFv (PEN-HuscFv34). The super antibody was produced and purified from inclusion body (IB) of a pen-huscfv34-vector-transformed Escherichia coli. The super antibody inhibited replication of alpha- and beta- coronaviruses, flaviviruses, and picornaviruses that were tested (broadly effective); thus, it has high potential for developing further towards a pan-anti-RNA virus agent. However, production, purification, and refolding of the super antibody molecules from the bacterial IB are laborious and hurdles to large-scale production. Therefore, in this study, Sortase-self-cleave method and bacteria surface display system were combined and modified for the super antibody production. METHODS AND RESULTS: BL21 (DE3) ΔA E. coli, a strain lacking predominant outer membrane protein (OmpA) and ion and OmpT proteases, that displayed a membrane-anchored fusion protein, i.e., chimeric lipoprotein (Lpp')-OmpA', SUMO, Sortase protease, Sortase cleavage site (LPET↓G) and PEN-HuscFv34-6× His was generated. The soluble PEN-HuscFv34-6× His with glycine at the N-terminus could be released from the E. coli surface, simply by incubating the bacterial cells in a Sortase-cleavage buffer. After centrifugation, the G-PEN-HuscFv34-6× His could be purified from the supernatant. The purified G-PEN-HuscFv34-6× retained original cell-penetrating ability (being super antibody) and the broadly effective anti-RNA virus activity of the original IB-derived-PEN-HuscFv34. CONCLUSION: The functionalized super antibody to RNA virus RdRp was successfully produced by using combined Sortase self-cleave and bacterial surface display systems with modification. The display system is suitable for downstream processing in a large-scale production of the super antibody. It is applicable also for production of other recombinant proteins in soluble free-folding form.


Assuntos
Escherichia coli , Anticorpos de Cadeia Única , Humanos , Escherichia coli/metabolismo , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Anticorpos de Cadeia Única/genética , Proteínas Recombinantes , Proteínas de Membrana
2.
Eur J Immunol ; 51(4): 848-863, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33345332

RESUMO

Upon generation of monoclonal antibodies to the T cell antigen receptor/CD3 (TCR/CD3) complex, we isolated mAb MT3, whose reactivity correlates inversely with the production of IFN-γ by human peripheral blood T lymphocytes. Using eukaryotic expression cloning, we identified the MT3 antigen as myelin-and-lymphocyte (MAL) protein. Flow cytometry analysis demonstrates high surface expression of MAL on all naïve CD4+ T cells whereas MAL expression is diminished on central memory- and almost lost on effector memory T cells. MAL- T cells proliferate strongly in response to stimulation with CD3/CD28 antibodies, corroborating that MAL+ T cells are naïve and MAL- T cells memory subtypes. Further, resting MAL- T cells harbor a larger pool of Ser59- and Tyr394- double phosphorylated lymphocyte-specific kinase (Lck), which is rapidly increased upon in vitro restimulation. Previously, lack of MAL was reported to prevent transport of Lck, the key protein tyrosine kinase of TCR/CD3 signaling to the cell membrane, and to result in strongly impaired human T cell activation. Here, we show that knocking out MAL did not significantly affect Lck membrane localization and immune synapse recruitment, or transcriptional T cell activation. Collectively, our results indicate that loss of MAL is associated with activation-induced differentiation of human T cells but not with impaired membrane localization of Lck or TCR signaling capacity.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Ativação Linfocitária/imunologia , Proteínas Proteolipídicas Associadas a Linfócitos e Mielina/imunologia , Animais , Antígenos CD28/imunologia , Antígenos CD28/metabolismo , Complexo CD3/imunologia , Complexo CD3/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/genética , Linhagem Celular Tumoral , Citometria de Fluxo , Expressão Gênica/imunologia , Humanos , Interferon gama/imunologia , Interferon gama/metabolismo , Células Jurkat , Ativação Linfocitária/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/imunologia , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Camundongos , Proteínas Proteolipídicas Associadas a Linfócitos e Mielina/genética , Proteínas Proteolipídicas Associadas a Linfócitos e Mielina/metabolismo , Fosforilação , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
3.
Int J Mol Sci ; 23(12)2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35743031

RESUMO

Broadly effective and safe anti-coronavirus agent is existentially needed. Major protease (3CLpro) is a highly conserved enzyme of betacoronaviruses. The enzyme plays pivotal role in the virus replication cycle. Thus, it is a good target of a broadly effective anti-Betacoronavirus agent. In this study, human single-chain antibodies (HuscFvs) of the SARS-CoV-2 3CLpro were generated using phage display technology. The 3CLpro-bound phages were used to infect Escherichia coli host for the production the 3CLpro-bound HuscFvs. Computerized simulation was used to guide the selection of the phage infected-E. coli clones that produced HuscFvs with the 3CLpro inhibitory potential. HuscFvs of three phage infected-E. coli clones were predicted to form contact interface with residues for 3CLpro catalytic activity, substrate binding, and homodimerization. These HuscFvs were linked to a cell-penetrating peptide to make them cell-penetrable, i.e., became superantibodies. The superantibodies blocked the 3CLpro activity in vitro, were not toxic to human cells, traversed across membrane of 3CLpro-expressing cells to co-localize with the intracellular 3CLpro and most of all, they inhibited replication of authentic SARS-CoV-2 Wuhan wild type and α, ß, δ, and Omicron variants that were tested. The superantibodies should be investigated further towards clinical application as a safe and broadly effective anti-Betacoronavirus agent.


Assuntos
Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Proteases 3C de Coronavírus , Escherichia coli , Humanos , Inibidores de Proteases/farmacologia
4.
Molecules ; 26(21)2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34770845

RESUMO

Proviral integration site of Moloney virus-2 (PIM2) is overexpressed in multiple human cancer cells and high level is related to poor prognosis; thus, PIM2 kinase is a rational target of anti-cancer therapeutics. Several chemical inhibitors targeting PIMs/PIM2 or their downstream signaling molecules have been developed for treatment of different cancers. However, their off-target toxicity is common in clinical trials, so they could not be advanced to official approval for clinical application. Here, we produced human single-chain antibody fragments (HuscFvs) to PIM2 by using phage display library, which was constructed in a way that a portion of phages in the library carried HuscFvs against human own proteins on their surface with the respective antibody genes in the phage genome. Bacterial derived-recombinant PIM2 (rPIM2) was used as an antigenic bait to fish out the rPIM2-bound phages from the library. Three E. coli clones transfected with the HuscFv genes derived from the rPIM2-bound phages expressed HuscFvs that bound also to native PIM2 from cancer cells. The HuscFvs presumptively interact with the PIM2 at the ATP binding pocket and kinase active loop. They were as effective as small chemical drug inhibitor (AZD1208, which is an ATP competitive inhibitor of all PIM isoforms for ex vivo use) in inhibiting PIM kinase activity. The HuscFvs should be engineered into a cell-penetrating format and tested further towards clinical application as a novel and safe pan-anti-cancer therapeutics.


Assuntos
Engenharia Genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Recombinantes , Anticorpos de Cadeia Única/farmacologia , Afinidade de Anticorpos , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/farmacologia , Técnicas de Visualização da Superfície Celular , Cromatografia em Gel , Ativação Enzimática/efeitos dos fármacos , Modelos Moleculares , Biblioteca de Peptídeos , Ligação Proteica , Conformação Proteica , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas/metabolismo , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/genética , Relação Estrutura-Atividade
5.
Int Immunol ; 31(8): 515-530, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-30859183

RESUMO

Natural killer (NK) cells are innate lymphoid cells having potent cytolytic function that provide host defense against microbial infections and tumors. Using our generated monoclonal antibody (mAb), named FE-1H10, new NK cell sub-populations in peripheral blood were identified. The molecules recognized by mAb FE-1H10 were expressed on a sub-population of CD3-CD56dim NK cells. The epitope recognized by mAb FE-1H10 was demonstrated to be N-glycan and proven to be different from CD57. Upon K562 stimulation, the CD56dimFE-1H10+ NK cell sub-population exhibited significantly lower cytolytic function with low ability to degranulate and release cytolytic granules compared to the CD56dimFE-1H10- NK cell sub-population. Moreover, the CD56dimFE-1H10+ NK cells produced less IFN-γ and TNF-α than the CD56dimFE-1H10- NK cells. We demonstrated here that mAb FE-1H10 could identify two sub-populations of circulating CD56dim NK cells with different functions. Our discovery of new sub-populations of NK cells improves our understanding of NK cell biology and may lead to the development of new approaches for NK cell therapy.


Assuntos
Células Matadoras Naturais/citologia , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/imunologia , Linhagem Celular , Humanos , Células Matadoras Naturais/imunologia , Camundongos , Camundongos Endogâmicos BALB C
6.
Asian Pac J Allergy Immunol ; 33(2): 107-16, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26141031

RESUMO

BACKGROUND: Several molecules are known to be involved in T-cell activation via the TCR/CD3 complex and while the mechanisms of late T cell signaling have been well characterized, the very early events are still not fully understood. OBJECTIVE: The aim of this study was to identify yet unknown molecules associated with the TCR/CD3 complex. RESULTS: To identify new molecules associated with the TCR/CD3 complex, a monoclonal antibody termed MT3 was produced by immunoprecipitated beads immunization. Colocalization of the MT3 mAb recognizing molecules with the TCR/CD3 complexes was verified by confocal microscopic analysis. The surface antigen recognized by MT3 antibody was expressed on a subpopulation of CD3+ T cells, and on both CD4+ and CD8+ lymphocytes. The antigen was also expressed on na?ve CD4+ T cells and on a subset of memory CD4+ T cells. In contrast, in the CD8 population, the majority of MT3+ cells were found in the na?ve population. The MT3 mAb recognizing molecules were also expressed on red blood cells but only in particular subjects. Similar to peripheral blood leukocytes, MT3 mAb recognizing molecules are exclusively expressed on T cell lines. CONCLUSIONS: Based on the cellular distribution patterns and confocal microscopic analysis, the MT3 mAb recognizing molecule that we investigated is proposed to be a TCR/CD3 associated molecule and might be involved in the antigen recognition of T cells.


Assuntos
Anticorpos Monoclonais/imunologia , Imunização , Ativação Linfocitária , Complexo Receptor-CD3 de Antígeno de Linfócitos T/imunologia , Linfócitos T/imunologia , Animais , Anticorpos Monoclonais/metabolismo , Linhagem Celular Tumoral , Epitopos , Humanos , Hibridomas , Imunoprecipitação , Camundongos Endogâmicos BALB C , Microscopia Confocal , Complexo Receptor-CD3 de Antígeno de Linfócitos T/administração & dosagem , Complexo Receptor-CD3 de Antígeno de Linfócitos T/metabolismo , Transdução de Sinais , Linfócitos T/metabolismo
7.
Viruses ; 15(6)2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-37376552

RESUMO

Engineered nanobodies (VHs) to the SARS-CoV-2 receptor-binding domain (RBD) were generated using phage display technology. A recombinant Wuhan RBD served as bait in phage panning to fish out nanobody-displaying phages from a VH/VHH phage display library. Sixteen phage-infected E. coli clones produced nanobodies with 81.79-98.96% framework similarity to human antibodies; thus, they may be regarded as human nanobodies. Nanobodies of E. coli clones 114 and 278 neutralized SARS-CoV-2 infectivity in a dose-dependent manner; nanobodies of clones 103 and 105 enhanced the virus's infectivity by increasing the cytopathic effect (CPE) in an infected Vero E6 monolayer. These four nanobodies also bound to recombinant Delta and Omicron RBDs and native SARS-CoV-2 spike proteins. The neutralizing VH114 epitope contains the previously reported VYAWN motif (Wuhan RBD residues 350-354). The linear epitope of neutralizing VH278 at Wuhan RBD 319RVQPTESIVRFPNITN334 is novel. In this study, for the first time, we report SARS-CoV-2 RBD-enhancing epitopes, i.e., a linear VH103 epitope at RBD residues 359NCVADVSVLYNSAPFFTFKCYG380, and the VH105 epitope, most likely conformational and formed by residues in three RBD regions that are spatially juxtaposed upon the protein folding. Data obtained in this way are useful for the rational design of subunit SARS-CoV-2 vaccines that should be devoid of enhancing epitopes. VH114 and VH278 should be tested further for clinical use against COVID-19.


Assuntos
COVID-19 , Anticorpos de Domínio Único , Animais , Humanos , SARS-CoV-2 , Epitopos , Anticorpos Antivirais , Vacinas contra COVID-19 , Escherichia coli/metabolismo , Anticorpos Neutralizantes , Glicoproteína da Espícula de Coronavírus
9.
Vaccines (Basel) ; 11(12)2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38140230

RESUMO

(1) Background: Understanding how advanced cancers evade host innate and adaptive immune opponents has led to cancer immunotherapy. Among several immunotherapeutic strategies, the reversal of immunosuppression mediated by regulatory T cells in the tumor microenvironment (TME) using blockers of immune-checkpoint signaling in effector T cells is the most successful treatment measure. Furthermore, agonists of T cell costimulatory molecules (CD40, 4-1BB, OX40) play an additional anti-cancer role to that of checkpoint blocking in combined therapy and serve also as adjuvant/neoadjuvant/induction therapy to conventional cancer treatments, such as tumor resection and radio- and chemo- therapies. (2) Methods and Results: In this study, novel agonistic antibodies to the OX40/CD134 ectodomain (EcOX40), i.e., fully human bivalent single-chain variable fragments (HuscFvs) linked to IgG Fc (bivalent HuscFv-Fcγ fusion antibodies) were generated by using phage-display technology and genetic engineering. The HuscFvs in the fusion antibodies bound to the cysteine-rich domain-2 of the EcOX40, which is known to be involved in OX40-OX40L signaling for NF-κB activation in T cells. The fusion antibodies caused proliferation, and increased the survival and cytokine production of CD3-CD28-activated human T cells. They showed enhancement trends for other effector T cell activities like granzyme B production and lysis of ovarian cancer cells when added to the activated T cells. (3) Conclusions: The novel OX40 agonistic fusion antibodies should be further tested step-by-step toward their safe use as an adjunctive non-immunogenic cancer immunotherapeutic agent.

10.
Vaccines (Basel) ; 11(9)2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37766091

RESUMO

Many patients develop post-acute COVID syndrome (long COVID (LC)). We compared the immune response of LC and individuals with post-COVID full recovery (HC) during the Omicron pandemic. Two hundred ninety-two patients with confirmed COVID infections from January to May 2022 were enrolled. We observed anti-SARS-CoV-2 receptor-binding domain immunoglobulin G, surrogate virus neutralization test, T cell subsets, and neutralizing antibodies against Wuhan, BA.1, and BA.5 viruses (NeuT). NeuT was markedly reduced against BA.1 and BA.5 in HC and LC groups, while antibodies were more sustained with three doses and an updated booster shot than ≤2-dose vaccinations. The viral neutralization ability declined at >84-days after COVID-19 onset (PC) in both groups. PD1-expressed central and effector memory CD4+ T cells, and central memory CD8+ T cells were reduced in the first months PC in LC. Therefore, booster vaccines may be required sooner after the most recent infection to rescue T cell function for people with symptomatic LC.

11.
Front Microbiol ; 13: 926929, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35935185

RESUMO

RNA-dependent RNA polymerase (RdRp) is a unique and highly conserved enzyme across all members of the RNA virus superfamilies. Besides, humans do not have a homolog of this protein. Therefore, the RdRp is an attractive target for a broadly effective therapeutic agent against RNA viruses. In this study, a formerly generated cell-penetrating human single-chain antibody variable fragment (superantibody) to a conformational epitope of hepatitis C virus (HCV) RdRp, which inhibited the polymerase activity leading to the HCV replication inhibition and the host innate immunity restoration, was tested against emerging/reemerging RNA viruses. The superantibody could inhibit the replication of the other members of the Flaviviridae (DENV serotypes 1-4, ZIKV, and JEV), Picornaviridae (genus Enterovirus: EV71, CVA16), and Coronaviridae (genus Alphacoronavirus: PEDV, and genus Betacoronavirus: SARS-CoV-2 (Wuhan wild-type and the variants of concern), in a dose-dependent manner, as demonstrated by the reduction of intracellular viral RNAs and numbers of the released infectious particles. Computerized simulation indicated that the superantibody formed contact interfaces with many residues at the back of the thumb domain (thumb II site, T2) of DENV, ZIKV, JEV, EV71, and CVA16 and fingers and thumb domains of the HCV and coronaviruses (PEDV and SARS-CoV-2). The superantibody binding may cause allosteric change in the spatial conformation of the enzyme and disrupt the catalytic activity, leading to replication inhibition. Although the speculated molecular mechanism of the superantibody needs experimental support, existing data indicate that the superantibody has high potential as a non-chemical broadly effective anti-positive sense-RNA virus agent.

12.
Front Microbiol ; 13: 933249, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35935230

RESUMO

Porcine epidemic diarrhea virus (PEDV) is the causative agent of a highly contagious enteric disease of pigs characterized by diarrhea, vomiting, and severe dehydration. PEDV infects pigs of all ages, but neonatal pigs during the first week of life are highly susceptible; the mortality rates among newborn piglets may reach 80-100%. Thus, PEDV is regarded as one of the most devastating pig viruses that cause huge economic damage to pig industries worldwide. Vaccination of sows and gilts at the pre-fertilization or pre-farrowing stage is a good strategy for the protection of suckling piglets against PEDV through the acquisition of the lactating immunity. However, vaccination of the mother pigs for inducing a high level of virus-neutralizing antibodies is complicated with unstandardized immunization protocol and unreliable outcomes. Besides, the vaccine may also induce enhancing antibodies that promote virus entry and replication, so-called antibody-dependent enhancement (ADE), which aggravates the disease upon new virus exposure. Recognition of the virus epitope that induces the production of the enhancing antibodies is an existential necessity for safe and effective PEDV vaccine design. In this study, the enhancing epitope of the PEDV spike (S) protein was revealed for the first time, by using phage display technology and mouse monoclonal antibody (mAbG3) that bound to the PEDV S1 subunit of the S protein and enhanced PEDV entry into permissive Vero cells that lack Fc receptor. The phages displaying mAbG3-bound peptides derived from the phage library by panning with the mAbG3 matched with several regions in the S1-0 sub-domain of the PEDV S1 subunit, indicating that the epitope is discontinuous (conformational). The mAbG3-bound phage sequence also matched with a linear sequence of the S1-BCD sub-domains. Immunological assays verified the phage mimotope results. Although the molecular mechanism of ADE caused by the mAbG3 via binding to the newly identified S1 enhancing epitope awaits investigation, the data obtained from this study are helpful and useful in designing a safe and effective PEDV protein subunit/DNA vaccine devoid of the enhancing epitope.

13.
Vaccines (Basel) ; 9(8)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34452018

RESUMO

HIV-1 progeny are released from infected cells as immature particles that are unable to infect new cells. Gag-Pol polyprotein dimerization via the reverse transcriptase connection domain (RTCDs) is pivotal for proper activation of the virus protease (PR protein) in an early event of the progeny virus maturation process. Thus, the RTCD is a potential therapeutic target for a broadly effective anti-HIV agent through impediment of virus maturation. In this study, human single-chain antibodies (HuscFvs) that bound to HIV-1 RTCD were generated using phage display technology. Computerized simulation guided the selection of the transformed Escherichia coli-derived HuscFvs that bound to the RTCD dimer interface. The selected HuscFvs were linked molecularly to human-derived-cell-penetrating peptide (CPP) to make them cell-penetrable (i.e., become transbodies). The CPP-HuscFvs/transbodies produced by a selected transformed E. coli clone were tested for anti-HIV-1 activity. CPP-HuscFvs of transformed E. coli clone 11 (CPP-HuscFv11) that presumptively bound at the RTCD dimer interface effectively reduced reverse transcriptase activity in the newly released virus progeny. Infectiousness of the progeny viruses obtained from CPP-HuscFv11-treated cells were reduced by a similar magnitude to those obtained from protease/reverse transcriptase inhibitor-treated cells, indicating anti-HIV-1 activity of the transbodies. The CPP-HuscFv11/transbodies to HIV-1 RTCD could be an alternative, anti-retroviral agent for long-term HIV-1 treatment.

14.
Front Immunol ; 12: 676558, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34135902

RESUMO

Allergen-specific-immunotherapy (ASIT) can cause long-term resolution of allergic diseases, reduces drug use and chances of new allergen sensitization. Nevertheless, therapeutic vaccine and data on ASIT efficacy for cockroach (CR) allergy are relatively scarce. In this study, efficacy and mechanism of a novel intranasal vaccine consisting of liposome (L)-entrapped mixture of American CR (Periplaneta americana) major allergen (Per a 9) and immunosuppressive protein of Brugia malayi nematode named transforming growth factor-beta homologue (TGH) in treatment of CR allergy were investigated along with two other vaccines (L-Per a 9 alone and L-TGH alone). All three vaccines could reduce pathogenic type 2 response and lung immunopathology in the vaccines-treated CR-allergic mice, but by different mechanisms. L-Per a 9 caused a deviation of the pathogenic type 2 to type 1 response (IFN-γ-upregulation), whereas the L-(TGH + Per a 9) and L-TGH generated regulatory immune responses including up-expression of immunosuppressive cytokine genes and increment of serum adenosine and lung indoleamine-2,3-dioxygenase-1 which are signatures of regulatory T cells (Tregs) and tolerogenic dendritic cells, respectively. The L-(TGH + Per a 9) should be further evaluated towards clinical application, as this vaccine has a propensity to induce broadly effective therapeutic effects for inhalant allergies.


Assuntos
Alérgenos/imunologia , Arginina Quinase/imunologia , Brugia Malayi/imunologia , Dessensibilização Imunológica/métodos , Hipersensibilidade/imunologia , Hipersensibilidade/prevenção & controle , Imunossupressores/imunologia , Proteínas de Insetos/imunologia , Periplaneta/imunologia , Fator de Crescimento Transformador beta/imunologia , Vacinas/imunologia , Administração Intranasal , Alérgenos/sangue , Animais , Arginina Quinase/sangue , Células Dendríticas/imunologia , Modelos Animais de Doenças , Hipersensibilidade/sangue , Hipersensibilidade/parasitologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Lipossomos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/sangue , Resultado do Tratamento , Vacinas/administração & dosagem
15.
Front Microbiol ; 11: 1172, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32670218

RESUMO

The quorum sensing (QS) signaling molecule, N-(3-oxododecanoyl)-L-homoserine lactone (3O-C12-HSL), contributes to the pathogenesis of Pseudomonas aeruginosa by regulating expression of the bacterial virulence factors that cause intense inflammation and toxicity in the infected host. As such, the QS molecule is an attractive therapeutic target for direct-acting inhibitors. Several substances, both synthetic and naturally derived products, have shown effectiveness against detrimental 3O-C12-HSL activity. Unfortunately, these compounds are relatively toxic to mammalian cells, which limits their clinical application. In this study, fully human single-chain variable fragments (HuscFvs) that bind to P. aeruginosa haptenic 3O-C12-HSL were generated based on the principle of antibody polyspecificity and molecular mimicry of antigenic molecules. The HuscFvs neutralized 3O-C12-HSL activity and prevented mammalian cells from the HSL-mediated apoptosis, as observed by Annexin V/PI staining assay, sub-G1 arrest population investigation, transmission electron microscopy for ultrastructural morphology of mitochondria, and confocal microscopy for nuclear condensation and DNA fragmentation. Computerized homology modeling and intermolecular docking predicted that the effective HuscFvs interacted with several regions of the bacterially derived ligand that possibly conferred neutralizing activity. The effective HuscFvs should be tested further in vitro on P. aeruginosa phenotypes as well as in vivo as a sole or adjunctive therapeutic agent against P. aeruginosa infections, especially in antibiotic-resistant cases.

16.
Mol Immunol ; 114: 591-599, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31536880

RESUMO

Human CD63 has been reported to play a role either as an inhibitor or as a co-stimulator of T- cell responses, although the mechanism of this is unclear. In this study, an anti-human CD63 monoclonal antibody (mAb) COS3A was used to monitor the role of CD63 in T-cell activation. MAb COS3A could inhibit CD3-mediated T-cell proliferation and CD25 expression in peripheral blood mononuclear cells (PBMCs), used as a study model, but the suppressive effect was not observed when purified T-cells were used instead of PBMCs. The inhibitory phenomenon was associated with downregulation of IL-2 and IFN-γ by T-cells, but upregulation of IL-10 by monocytes. Neutralizing IL-10 with anti-IL-10 mAb improved the T-cell response, indicating the role of IL-10 in T-cell suppression. In this study, monocytes were demonstrated to play a role in impeding T-cell activation by the anti-CD63 mAb COS3A. This is the first evidence that anti-CD63 mAb induces IL-10 secretion by monocytes, which later play a role in T-cell hypo-responsiveness.


Assuntos
Anticorpos Monoclonais/imunologia , Complexo CD3/imunologia , Interleucina-10/imunologia , Monócitos/imunologia , Linfócitos T/imunologia , Tetraspanina 30/imunologia , Regulação para Cima/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Células Cultivadas , Regulação para Baixo/imunologia , Humanos , Interleucina-2/imunologia , Leucócitos Mononucleares/imunologia , Ativação Linfocitária
17.
Sci Rep ; 9(1): 14928, 2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624289

RESUMO

Targeting bacterial virulence factors directly provides a new paradigm for the intervention and treatment of bacterial diseases. Pseudomonas aeruginosa produces a myriad of virulence factors to cause fatal diseases in humans. In this study, human single-chain antibodies (HuscFvs) that bound to P. aeruginosa exotoxin A (ETA) were generated by phage display technology using recombinant ETA, ETA-subdomains and the synthetic peptide of the ETA-catalytic site as baits for selecting ETA-bound-phages from the human-scFv phage display library. ETA-bound HuscFvs derived from three phage-transfected E. coli clones neutralized the ETA-induced mammalian cell apoptosis. Computerized simulation demonstrated that these HuscFvs used several residues in their complementarity-determining regions (CDRs) to form contact interfaces with the critical residues in ETA-catalytic domain essential for ADP-ribosylation of eukaryotic elongation factor 2, which should consequently rescue ETA-exposed-cells from apoptosis. The HuscFv-treated ETA-exposed cells also showed decremented apoptosis-related genes, i.e., cas3 and p53. The effective HuscFvs have high potential for future evaluation in animal models and clinical trials as a safe, novel remedy for the amelioration of exotoxin A-mediated pathogenesis. HuscFvs may be used either singly or in combination with the HuscFv cognates that target other P. aeruginosa virulence factors as an alternative therapeutic regime for difficult-to-treat infections.


Assuntos
ADP Ribose Transferases/antagonistas & inibidores , Antibacterianos/farmacologia , Toxinas Bacterianas/antagonistas & inibidores , Exotoxinas/antagonistas & inibidores , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Anticorpos de Cadeia Única/farmacologia , Fatores de Virulência/antagonistas & inibidores , ADP Ribose Transferases/genética , ADP Ribose Transferases/imunologia , ADP Ribose Transferases/metabolismo , Antibacterianos/imunologia , Antibacterianos/uso terapêutico , Apoptose/efeitos dos fármacos , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Toxinas Bacterianas/metabolismo , Domínio Catalítico/genética , Regiões Determinantes de Complementaridade/imunologia , Regiões Determinantes de Complementaridade/farmacologia , Exotoxinas/genética , Exotoxinas/imunologia , Exotoxinas/metabolismo , Células HeLa , Humanos , Simulação de Acoplamento Molecular , Biblioteca de Peptídeos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/imunologia , Pseudomonas aeruginosa/patogenicidade , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/uso terapêutico , Fatores de Virulência/genética , Fatores de Virulência/imunologia , Fatores de Virulência/metabolismo , Exotoxina A de Pseudomonas aeruginosa
18.
Sci Rep ; 8(1): 15480, 2018 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-30341299

RESUMO

Allergen-specific immunotherapy (AIT) facilitates long-term resolution of allergic morbidity resulting in reduced drug use and increased refractoriness to new sensitization. AIT effectiveness has been demonstrated in seasonal and perennial allergies, and insect stings. However, data and studies in AIT relative to cockroach (CR) allergy are relatively scarce. In this study, mice allergic to American CR (Periplaneta americana) were treated with a liposome (L)-entrapped vaccine made of mouse Tregitope289-Per a 9 of the CR, Tregitope167-Per a 9, or Per a 9 alone - or placebo. Allergic mice that received an individual vaccine intranasally had reduced Th2 response, reduced lung inflammation, and reduced respiratory tissue remodeling. However, only L-Tregitope289-Per a 9 and L-Tregitope167-Per a 9 induced expression of immunosuppressive cytokine genes (IL-10, TGF-ß, and IL-35 for L-Tregitope289-Per a 9, and IL-10 and TGF-ß for L-Tregitope167-Per a 9) and increment of idoleamine-2,3-dioxygenase 1 (IDO1), indicating that these vaccines caused allergic disease suppression and reversal of respiratory tissue remodeling via generation of regulatory lymphocytes. Liposome entrapped-recombinant Per a 9 (L-Per a 9) did not cause upregulation of immunosuppressive cytokine genes and IDO1 increment; rather, L-Per a 9 induced high expression of IFN-γ in lungs of treated mice, which resulted in mitigation of allergic manifestations. This study provides compelling evidence that both liposome-entrapped vaccines made of single refined major allergen alone and single refined major allergen linked with Tregitopes are effective for reducing allergen-mediated respiratory tissue inflammation and remodeling, but through different mechanisms.


Assuntos
Dessensibilização Imunológica/métodos , Hipersensibilidade/imunologia , Linfócitos T Reguladores/imunologia , Vacinas/imunologia , Administração Intranasal , Alérgenos/imunologia , Animais , Proteínas do Capsídeo/imunologia , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Epitopos de Linfócito T/imunologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Periplaneta
19.
PLoS One ; 11(1): e0145983, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26727515

RESUMO

Autoantibodies against interferon-gamma (IFN-γ) can cause immunodeficiency and are associated with various opportunistic infections. In the present study, we investigated other cellular immune parameters for a better understanding of the immunodeficiency condition in the patients. The numbers of WBC, monocytes and NK cells were increased in patients with anti-IFN-γ autoantibodies (AAbs). Upon TCR activation, T cell proliferation and IL-2 receptor of the patients remained intact. Nonetheless, the Th1 cytokine (IFN-γ and TNF-α) production was up-regulated. The production of Th2 (IL-4) and Th17 (IL-17) cytokines was unchanged. We suggest that, in addition to the presence of anti-IFN-γ autoantibodies, alterations in the cellular immune functions may also contribute to this immunodeficiency.


Assuntos
Autoanticorpos/sangue , Síndromes de Imunodeficiência/imunologia , Interferon gama/imunologia , Estudos de Casos e Controles , Citocinas/biossíntese , Humanos , Imunidade Celular , Linfócitos T/imunologia
20.
Immunobiology ; 220(5): 634-40, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25678464

RESUMO

Na,K ATPase plays an important role in the regulation of Na(+) and K(+) ions that are required for normal resting membrane potential and various cellular functions. Na,K ATPase is composed of two subunits, α and ß subunits. Engagement of the ß subunit by an agonistic monoclonal antibody (mAb) P-3E10 inhibited T cell activation and induced the G0/G1 cell cycle arrest. In addition, mAb P-3E10 decreased CD25 expression. The mAb P-3E10, however, did not inhibit the proliferation of cell lines and the phagocytosis activity of phagocytes, and did not interfere with the Na,K ATPase activity. These results indicate that mAb P-3E10 reacts to the ß subunit and, as a consequence, brings about the regulation of the T cell activation without disturbing the Na,K pump activity. By sequential immunoprecipitation, we demonstrated the expression of the ß3 subunit free form apart from the α subunit. In this study, we propose that the ß3 subunits of Na,K ATPase are expressed separately from the α subunit, and play a role in regulation of the immune response.


Assuntos
Membrana Celular/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Linfócitos T/imunologia , Anticorpos Monoclonais/metabolismo , Ciclo Celular , Proliferação de Células , Humanos , Transporte de Íons , Células Jurkat , Ativação Linfocitária , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/imunologia
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