RESUMO
AIMS: To generate different larval stages of Strongylus vulgaris and to study cytokine responses in cultures of eqPBMC exposed to defined larval stages of S. vulgaris and cyathostomins with the aim to understand the early immune reaction to these parasites. METHODS AND RESULTS: EqPBMC were exposed to S. vulgaris larvae (L3, exsheated L3 and L4) and cyathostomin L3 and analysed for cytokine gene expression. Procedures for decontamination, culturing and attenuation of larvae were established. Transcription of IL-4, IL-5 and IL-13 was induced by both S. vulgaris and cyathostomin L3. Moulting of S. vulgaris from L3 to L4 stage was accompanied by a shift to high expression of IL-5 and IL-9 (exsheated L3 and L4) and IFN-γ (L4 only). In parallel, the adjuvant G3 modified the cytokine profile induced by both parasites by reducing the expression of IL-4, IL-5 and IL-10 while concomitantly enhancing the expression of IFN-γ. CONCLUSION: The L4 stage of S. vulgaris generated a cytokine profile different from that induced by the earlier L3 stage of S. vulgaris and cyathostomins. This diversity depending on the life cycle stage will have implications for the choice of antigen and adjuvant in future vaccine design.
Assuntos
Citocinas/metabolismo , Doenças dos Cavalos/imunologia , Larva/imunologia , Infecções Equinas por Strongyloidea/parasitologia , Strongylus/imunologia , Adjuvantes Imunológicos/metabolismo , Animais , Doenças dos Cavalos/parasitologia , Cavalos , Estágios do Ciclo de Vida , Strongylus/efeitos dos fármacos , Strongylus/metabolismoRESUMO
The immunomodulatory effect of a new particulate adjuvant, G3, alone or in combination with agonists to TLR2/1 or TLR5 was evaluated in cultures of equine PBMC. Exposure to the G3 adjuvant up-regulated genes encoding IFN-γ, IL-1ß, IL-6, IL-8, IL-12p40 and IL-23p19 in the majority of the horses tested, indicating that the G3 adjuvant induced a pro-inflammatory and Th1 dominated profile. In accordance, genes encoding IL-13, IL-4, IL-10 and TGF-ß remained unaffected and genes encoding IFN-α, IL-17A and TNF-α were only occasionally and weakly induced. The two TLR agonists Pam3CSK4 (TLR2/1) and FliC (TLR5) induced cytokine profiles characterized by a clear induction of IL-10 as well as up-regulation of the genes encoding IL-1ß, IL-6 and IL-8. The presence of G3 modified this response, in particular by reducing the FliC and Pam3CSK4 induced production of IL-10. Furthermore, G3 acted in synergy with Pam3CSK4 in enhancing the production of IFN-γ whereas G3 combined with FliC increased the gene expression of IL-8. Thus, the G3 adjuvant seems to have the capacity to promote a Th1 polarizing innate immune response in eqPBMC, both by favouring IFN-γ production and by reducing production of IL-10 induced by co-delivered molecules. These features make G3 an interesting candidate to further evaluate for its potential as an adjuvant in equine vaccines.
Assuntos
Adjuvantes Imunológicos/farmacologia , Cavalos/sangue , Cavalos/imunologia , Imunidade Inata/efeitos dos fármacos , Leucócitos Mononucleares/fisiologia , Animais , Citocinas/genética , Citocinas/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Lipopeptídeos/farmacologia , Masculino , Receptores Toll-LikeRESUMO
A preferred adjuvant should promote both Th1 and Th2 responses. However, most adjuvants in common use are biased towards a Th2-driven response. Therefore, the ability of a novel saponin-based adjuvant G3 to inducing balanced Th1 and Th2 responses in BALB/c mice immunized with a split trivalent seasonal influenza vaccine was evaluated in comparison to that of the adjuvant Al(OH)3. Clear differences in the IgG profiles induced by G3, Al(OH)3 or non-adjuvanted vaccine were recorded. Both adjuvants enhanced high and similar levels of the Th2 associated IgG1 subtype compared to mice given vaccine alone. Only G3 enhanced the IgG2a subclass reflecting a Th1 response, whereas Al(OH)3 even abrogated the IgG2a production. Accordingly, G3 enhanced the production of IL-2 and IFN-γ and also of IL-2/IFN-γ double secreting cells, emphasizing the strong Th1 driving effect of G3. Only Al(OH)3 increased splenocyte production of IL-17. Taken together, the results indicate a strong propensity for G3 to induce both Th1 and Th2 driven immune responses.
Assuntos
Adjuvantes Imunológicos/farmacologia , Vacinas contra Influenza/imunologia , Células Th1/imunologia , Células Th2/imunologia , Hidróxido de Alumínio/imunologia , Hidróxido de Alumínio/farmacologia , Animais , Citocinas/imunologia , Citocinas/metabolismo , Imunoglobulina G/sangue , Camundongos Endogâmicos BALB C , Baço/citologia , Baço/imunologia , Células Th1/efeitos dos fármacos , Células Th2/efeitos dos fármacos , Vírion/imunologiaRESUMO
The aim of the present study was to evaluate the immunogenicity and protective efficacy of rNcSAG1, rNcHSP20 and rNcGRA7 recombinant proteins formulated with immune stimulating complexes (ISCOMs) in pregnant heifers against vertical transmission of Neospora caninum. Twelve pregnant heifers were divided into 3 groups of 4 heifers each, receiving different formulations before mating. Immunogens were administered twice subcutaneously: group A animals were inoculated with three recombinant proteins (rNcSAG1, rNcHSP20, rNcGRA7) formulated with ISCOMs; group B animals received ISCOM-MATRIX (without antigen) and group C received sterile phosphate-buffered saline (PBS) only. The recombinant proteins were expressed in Escherichia coli and purified nickel resin. All groups were intravenously challenged with the NC-1 strain of N. caninum at Day 70 of gestation and dams slaughtered at week 17 of the experiment. Heifers from group A developed specific antibodies against rNcSAG1, rNcHSP20 and rNcGRA7 prior to the challenge. Following immunization, an statistically significant increase of antibodies against rNcSAG1 and rNcHSP20 in all animals of group A was detected compared to animals in groups B and C at weeks 5, 13 and 16 (P<0.001). Levels of antibodies against rNcGRA7 were statistical higher in group A animals when compared with groups B and C at weeks 5 and 16 (P>0.001). There were no differences in IFN-γ production among the experimental groups at any time point (P>0.05). Transplacental transmission was determined in all foetuses of groups A, B and C by Western blot, immunohistochemistry and nested PCR. This work showed that rNcSAG1, rNcHSP20 and rNcGRA7 proteins while immunogenic in cattle failed to prevent the foetal infection in pregnant cattle challenged at Day 70 of gestation.
Assuntos
Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Transmissão Vertical de Doenças Infecciosas/veterinária , Neospora/imunologia , Vacinas Protozoárias/imunologia , Vacinas Sintéticas/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Western Blotting/veterinária , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/transmissão , Coccidiose/imunologia , Coccidiose/parasitologia , Coccidiose/transmissão , DNA de Protozoário/química , DNA de Protozoário/genética , Feminino , Feto , Proteínas de Choque Térmico HSP20/genética , Proteínas de Choque Térmico HSP20/imunologia , ISCOMs/farmacologia , Imuno-Histoquímica/veterinária , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Reação em Cadeia da Polimerase/veterinária , Gravidez , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Distribuição Aleatória , Estatísticas não Paramétricas , Vacinas Sintéticas/normasRESUMO
Vaccines used against seasonal influenza are poorly effective against influenza A viruses of novel subtypes that may have pandemic potential. Furthermore, pre(pandemic) influenza vaccines are poorly immunogenic, which can be overcome by the use of adjuvants. A limited number of adjuvants has been approved for use in humans, however there is a need for alternative safe and effective adjuvants that can enhance the immunogenicity of influenza vaccines and that promote the induction of broad-protective T cell responses. Here we evaluated a novel nanoparticle, G3, as an adjuvant for a seasonal trivalent inactivated influenza vaccine in a mouse model. The G3 adjuvant was formulated with or without steviol glycosides (DT, for diterpenoid). The use of both formulations enhanced the virus-specific antibody response to all three vaccine strains considerably. The adjuvants were well tolerated without any signs of discomfort. To assess the protective potential of the vaccine-induced immune responses, an antigenically distinct influenza virus strain, A/Puerto Rico/8/34 (A/PR/8/34), was used for challenge infection. The vaccine-induced antibodies did not cross-react with strain A/PR/8/34 in HI and VN assays. However, mice immunized with the G3/DT-adjuvanted vaccine were partially protected against A/PR/8/34 infection, which correlated with the induction of anamnestic virus-specific CD8(+) T cell responses that were not observed with the use of G3 without DT. Both formulations induced maturation of human dendritic cells and promoted antigen presentation to a similar extent. In conclusion, G3/DT is a promising adjuvant formulation that not only potentiates the antibody response induced by influenza vaccines, but also induces T cell immunity which could afford broader protection against antigenically distinct influenza viruses.
Assuntos
Adjuvantes Imunológicos/farmacologia , Linfócitos T CD8-Positivos/imunologia , Vacinas contra Influenza/imunologia , Nanopartículas/administração & dosagem , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Anticorpos Antivirais/sangue , Formação de Anticorpos , Apresentação de Antígeno , Reações Cruzadas/imunologia , Células Dendríticas/imunologia , Diterpenos/farmacologia , Feminino , Humanos , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza B , Camundongos Endogâmicos C57BL , Vacinas de Produtos Inativados/imunologiaRESUMO
Cancer cells are characterized by uncontrolled replication involving loss of control of cyclin dependent kinases (CDKs) and cyclins, and by abolished differentiation. In this study we introduce KGI, which is a nanoparticle with a Quillaja saponin as an active molecule. By the use of RNA array analysis and confirmation at the protein level, we show that KGI affects myeloid leukemia cells (in particular, the U937 monoblast cancer cell) by the following mechanisms: (A) ceasing cell replication via proteasome degradation, (B) down-regulation of key molecules at check points between G1/S and G2/M phases, (C) reduction of thymidine kinase activity, followed by (D) exit to differentiation and production of interleukin-8 (IL-8), eventually leading to apoptosis. Leukemia cell lines (U937 and HL-60 cells) were exposed to KGI for 8 h, after which the drug was removed. The cancer cells did not revert to replication over the following 10 days. Thus our findings suggest that the nanoparticle KGI inhibits proliferation and promotes differentiation in leukemic cells by interfering with the cell cycle process.
Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/química , Nanopartículas/administração & dosagem , Nanopartículas/química , Saponinas de Quilaia/química , Apoptose/efeitos dos fármacos , Apoptose/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quinases Ciclina-Dependentes/antagonistas & inibidores , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Células HL-60 , Humanos , Purinas/farmacologia , Roscovitina , Células U937RESUMO
Staphylococcus aureus is the most frequently isolated pathogen from bovine intramammary infections worldwide. Commercially available vaccines for mastitis control are composed either of S. aureus lysates or whole-cells formulated with traditional adjuvants. We recently showed the ability of a S. aureus CP5 whole-cell vaccine adjuvanted with ISCOM Matrix to increase specific antibodies production in blood and milk, improving opsonic capacity, compared with the same vaccine formulated with Al(OH)3. However, there is no information about the use of ISCOM Matrix for the formulation of bacterial lysates. The aim of this study was to characterize the innate and humoral immune responses induced by a S. aureus CP5 whole-cell or lysate vaccine, formulated with ISCOM Matrix after immunization of pregnant heifers. Both immunogens stimulated strong humoral immune responses in blood and milk, raising antibodies that increased opsonic capacity. Lysate formulation generated a higher and longer lasting antibody titer and stimulated a higher expression of regulatory and pro-inflammatory cytokines compared with the whole-cell vaccine.
Assuntos
Adjuvantes Imunológicos/farmacologia , Vacinas Bacterianas/imunologia , ISCOMs/farmacologia , Mastite Bovina/imunologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/imunologia , Animais , Anticorpos Antibacterianos/sangue , Bovinos , Contagem de Colônia Microbiana/veterinária , Citocinas/sangue , Citocinas/genética , Feminino , Imunização/normas , Imunização/veterinária , Mastite Bovina/microbiologia , Mastite Bovina/prevenção & controle , Leite/microbiologia , Gravidez , RNA/química , RNA/genética , Distribuição Aleatória , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/genética , Estatísticas não ParamétricasRESUMO
AIM: To characterize the cytotoxic effect of BBE, the particulate of desacyl-saponin, in model systems of solid tumours. MATERIALS AND METHODS: Cytotoxic activity of BBE was investigated in solid human tumour cell lines, in tumour cells from patients with renal cell carcinoma, in normal human renal cells and in peripheral blood mononuclear cells. The BBE mode of cell death was assessed in vitro. In vivo effect of BBE was evaluated in xenograft-bearing mice. RESULTS: BBE was selectively active against renal cell carcinoma, with no or little effect on normal cells. BBE induced caspase activity and apoptosis. An inhibitory activity of BBE on xenograft tumour growth, with no apparent signs of haematological toxicity was shown. In the non-proliferative model of patient tumour cells, BBE was active on only 1/5 patient samples, suggesting association of BBE effect with cell proliferation. CONCLUSION: BBE has interesting activities against renal cell carcinoma and should be further explored as a drug against this resistant tumour type.
Assuntos
Proliferação de Células/efeitos dos fármacos , Extratos Vegetais , Saponinas de Quilaia/administração & dosagem , Quillaja/química , Animais , Apoptose/efeitos dos fármacos , Carcinoma de Células Renais/tratamento farmacológico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Neoplasias Renais/tratamento farmacológico , Camundongos , Camundongos Nus , Nanopartículas/administração & dosagem , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Transplante HeterólogoRESUMO
The shortcomings of Staphylococcus aureus vaccines to control bovine mastitis have been attributed to insufficient capacity of the vaccines to induce opsonizing antibodies and to stimulate cellular immune responses. Types of antigen, administration route and adjuvant used in a vaccine formulation have been identified as critical factors for the development of opsonic antibodies. Current commercially available vaccines for Staph. aureus bovine mastitis control are formulated with Al(OH)3 and oil-based adjuvants. The aim of this study was to evaluate the immune response of heifers immunized with a Staph. aureus CP5 whole cell vaccine formulated either with Al(OH)3 or ISCOMATRIX™. Twenty primigravid Holstein dairy heifers in the last trimester of gestation were immunized either with a vaccine formulated with ISCOMATRIX™ (n = 6), Al(OH)3 (n = 7), or saline solution (placebo) (n = 7). Immunization was carried out 38 and 10 d before calving. Heifers vaccinated with Staph. aureus adjuvanted with ISCOMATRIX™ responded with significantly higher levels of anti-bacterin and anti-CP5 IgG and IgG2 in sera than animals in the Al(OH)3 or control groups. Animals in the ISCOMATRIX™ group responded with significantly higher anti-bacterin specific IgG in whey than animals in the Al(OH)3 and control groups, detected from the first week post calving until 60 d of lactation. Sera from animals inoculated with Staph. aureus in ISCOMATRIX™, obtained 7 d post partum, significantly increased both the number of neutrophils ingesting bacteria and the number of bacteria being ingested by the neutrophils, compared with sera obtained from heifers vaccinated with Al(OH)3 or non-vaccinated controls. These features coupled to safety of the ISCOMATRIX™ formulation, warrant additional studies.
Assuntos
Adjuvantes Imunológicos , Bovinos/imunologia , Colesterol/imunologia , Fosfolipídeos/imunologia , Saponinas/imunologia , Vacinas Antiestafilocócicas/imunologia , Staphylococcus aureus/imunologia , Animais , Anticorpos Antibacterianos/sangue , Combinação de Medicamentos , Feminino , Imunoglobulina G/sangue , Mastite Bovina/prevenção & controle , Leite/imunologia , Neutrófilos/imunologia , Fagocitose , GravidezRESUMO
Objective To investigate the effect of Iscom matrix on the immunogenicity of recombinant hepatitis B surface antigen containing PreS epitopes(SS1S2). Methods SS1S2+ Al(OH)3 and SS1S2+Iscom vaccines were made by combining purified SS1S2 antigen with Al( OH)3 adjuvant or Iscom matrix.Groups of BALB/c mice were injected i. m or s. c by either of the two vaccines at day 0 and day 14. Half of the mice were sacrificed and sera were taken and spleen cells separated from the mice 14 days after each injection. Anti-S, anti-PreS1, and anti-PreS2 antibody titers were measured, and total IgG1 and IgG2a titers were further detected for each serum sample. IFN-γ ELISPOT assay was performed to detect IFN-γsecreting cells from the pooled spleen cells for each vaccine group. Results The seroconversion rates and geometric mean titers(GMTs) and the numbers of IFN-γ secreting cells were approximately at the same level for the differently formulated vaccines after the first injection except that the ratio of IgG2a to IgG1 in the Iscom group was higher than the Al(OH)3 group. After boost injection, the GMTs of total IgG rise slightly in the Al(OH)3 group but significantly in the Iscom group. The IgG2a to IgG1 ratio in the Iscom group kept balanced while dropped further in the Al(OH)3 group. The number of specific IFN-γsecreting cells triggered by the Iscom vaccine exceeded significantly the number of Al( OH)3 vaccine, showinga stronger cellular response. Conclusion The results in this study shows that Iscom matrix is more potent in enhancing the immunogenicity of recombinant hepatitis B virus surface antigen containing PreS epitopes than Al( OH)3 adjuvant.
RESUMO
Saponin fractions of Quillaja saponaria Molina (QS) have cytotoxic activity against cancer cells in vitro, but are too toxic to be useful in the clinic. The toxic effect was abolished by converting QS fractions into stable nanoparticles through the binding of QS to cholesterol. Two fractions of QS were selected for particle formation, one with an acyl-chain (ASAP) was used to form killing and growth-inhibiting (KGI) particles, and the other without the acyl-chain (DSAP) was used to formulate blocking and balancing effect (BBE) particles. KGI showed significant growth inhibiting and cancer cell-killing activities in nine of 10 cell lines while BBE showed that on one cell line. The monoblastoid lymphoma cell line U937 was selected for analyzing the mode of action. Low concentrations of KGI (0.5 and 2 microg/mL) induced irreversible exit from the cell cycle, differentiation measured by cytokine production, and eventually programmed cell death (apoptosis). Compared to normal human monocytes, the U937 cells were 30-fold more sensitive to KGI. The nontoxic BBE blocked the cell killing effect of KGI in a concentration-dependent manner. In conclusion, the formulation of QS into nanoparticles has the potential of becoming a new class of anticancer agents.
Assuntos
Apoptose/efeitos dos fármacos , Nanopartículas/administração & dosagem , Nanopartículas/química , Fitoterapia/métodos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Quillaja/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Composição de Medicamentos/métodos , Humanos , Células Jurkat , Tamanho da Partícula , Resultado do Tratamento , Células U937RESUMO
We determined the impact of mucosal prime/boost regimens and vaccine type (attenuated Wa human rotavirus [AttHRV] or nonreplicating Wa 2/6 rotavirus-like particles [VLP]) on protection and antibody-secreting cell (ASC) responses to HRV in a neonatal gnotobiotic pig disease model. Comparisons of delivery routes for AttHRV and evaluation of nonreplicating VLP vaccines are important as alternative vaccine approaches to overcome risks associated with live oral vaccines. Groups of neonatal gnotobiotic pigs were vaccinated using combinations of oral (PO) and intranasal (IN) inoculation routes as follows: (i) 3 oral doses of AttHRV (AttHRV3xPO); (ii) AttHRV3xIN; (iii) AttHRVPO, then 2/6VLP2xIN; (iv) AttHRVIN, then 2/6VLP2xIN; and (v) mock-inoculated controls. Subsets of pigs from each group were challenged with virulent Wa HRV [P1A(8) G1] (4 weeks post-primary inoculation) to assess protection. The AttHRVPO+2/6VLP2xIN pigs had the highest protection rates against virus shedding and diarrhea (71% each); however, these rates did not differ statistically among the vaccine groups, except for the AttHRVIN+2/6VLPIN group, which had a significantly lower protection rate (17%) against diarrhea. The isotype, magnitude, and tissue distribution of ASCs were analyzed by enzyme-linked immunospot assay. The highest mean numbers of virus-specific IgG and IgA ASCs were observed pre- and postchallenge in both intestinal and systemic lymphoid tissues of the AttHRVPO+2/6VLPIN group. Thus, the AttHRVPO+2/6VLPIN vaccine regimen using immunostimulating complexes (ISCOM) and multiple mucosal inductive sites, followed by AttHRV3xPO or IN regimens, were the most effective vaccine regimens, suggesting that either AttHRVPO+2/6VLPIN or AttHRV3xIN may be an alternative approach to AttHRV3xPO for inducing protective immunity against rotavirus diarrhea.
Assuntos
Células Produtoras de Anticorpos/imunologia , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Vacinas contra Rotavirus/administração & dosagem , Administração Intranasal , Administração Oral , Animais , Animais Recém-Nascidos , Vida Livre de Germes , Humanos , Imunização Secundária , Rotavirus/imunologia , Vacinas contra Rotavirus/imunologia , Suínos , Vacinação , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vírion/imunologiaRESUMO
We investigated maternal antibody (MatAb) effects on protection and immune responses to rotavirus vaccines. Gnotobiotic pigs were injected intraperitoneally at birth with pooled serum from sows hyperimmunized with human rotavirus (HRV); control pigs received no sow serum. Pigs with or without MatAbs received either sequential attenuated HRV (AttHRV) oral priming and intranasal boosting with VP2/VP6 virus-like particle (VLP)-immunostimulating complex (ISCOM) (AttHRV/VLP) or intranasal VLP-ISCOM prime/boost (VLP) vaccines at 3 to 5 days of age. Subsets of pigs were challenged at 28 or 42 days postinoculation with virulent Wa HRV to assess protection. Isotype-specific antibody-secreting cell (ASC) responses to HRV were quantitated by enzyme-linked immunospot assay to measure effector and memory B-cell responses in intestinal and systemic lymphoid tissues pre- and/or postchallenge. Protection rates against HRV challenge (contributed by active immunity and passive circulating MatAbs) were consistently (but not significantly) lower in the MatAb-AttHRV/VLP groups than in the corresponding groups without MatAbs. Intestinal B-cell responses in the MatAb-AttHRV/VLP group were most suppressed with significantly reduced or no intestinal immunoglobulin A (IgA) and IgG effector and memory B-cell responses or antibody titers pre- and postchallenge. This suppression was not alleviated but was enhanced after extending vaccination/challenge from 28 to 42 days. In pigs vaccinated with nonreplicating VLP alone that failed to induce protection, MatAb effects differed, with intestinal and systemic IgG ASCs and prechallenge memory B cells suppressed but the low intestinal IgA and IgM ASC responses unaffected. Thus, we demonstrate that MatAbs differentially affect both replicating and nonreplicating HRV vaccines and suggest mechanisms of MatAb interference. This information should facilitate vaccine design to overcome MatAb suppression.
Assuntos
Anticorpos Antivirais/sangue , Linfócitos B/imunologia , ISCOMs/imunologia , Imunidade Materno-Adquirida , Imunização Secundária , Memória Imunológica , Vacinas contra Rotavirus/imunologia , Vírion/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Antivirais/administração & dosagem , Linfócitos B/virologia , Diarreia/imunologia , Diarreia/prevenção & controle , Diarreia/virologia , Feminino , Humanos , ISCOMs/administração & dosagem , Lactente , Recém-Nascido , Injeções Intraperitoneais , Rotavirus/imunologia , Vacinas contra Rotavirus/administração & dosagem , Suínos , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologiaRESUMO
We investigated effects of low titer (Lo) circulating MatAb on protection and immunogenicity of attenuated (Att) human rotavirus (HRV) priming and 2/6-virus-like particle (VLP)-immunostimulating complex (ISCOM) boosting (AttHRV/VLP) or VLP-ISCOM alone vaccines. LoMatAb had both enhancing and suppressing effects on B cell responses, depending on tissue, antibody isotype and vaccine. Differential effects of LoMatAb on IgA responses in different tissues suggest that LoMatAb did not suppress induction of IgA effector and memory B cells but impaired homing of these cells to secondary lymphoid or effector tissues, reducing IgA antibody secreting cells and antibodies at these sites. The AttHRV/VLP vaccine partially overcame LoMatAb suppression, conferred moderate protection against virulent HRV (as measured by reduced viral shedding and diarrhea) and represents a new candidate for rotavirus vaccines for both humans and animals.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Linfócitos B/imunologia , ISCOMs/administração & dosagem , Imunidade Materno-Adquirida , Vacinas contra Rotavirus/imunologia , Vírion/imunologia , Animais , Anticorpos Antivirais/biossíntese , Humanos , Memória Imunológica , Injeções Intraperitoneais , Suínos , Vacinas Atenuadas/imunologia , Eliminação de Partículas ViraisRESUMO
A successful vaccine against human RSV (HRSV) is likely to induce a Th1 or a balanced Th1/TH2 cytokine response. We tested a panel of HRSV immunostimulating complexes (ISCOMs) containing different Quillaja saponin fractions (QH-A, QH-C, and 703: a mixture of 70% QH-A and 30% QH-C) with different immunological properties for their capacity of inducing innate and acquired immune responses. The HRSV 703 ISCOMs induced the strongest innate and acquired immune responses, followed by RSV QH-C and QH-A ISCOMs. All three formulations induced various degrees of Th1 bias response with prominent production of IFN-gamma being 10-50 times higher than that of IL-4 and IL-5. The HRSV specific IgG isotype profile correlated with the predominant secretion of Th1 cytokines, with strong induction of IgG2a antibodies. The 703 ISCOMs induced the most pronounced Th1 profile followed by QH-C and QH-A ISCOMs. The high incorporation of F protein in these ISCOMs compared to G protein combined with the Th1 biased nature of ISCOM are likely to be the causes to promote a Th1 type of profile. The prospect to formulate an RSV ISCOM formulation with an optimal Th1/Th2 balance is in reach particularly in view of the versatile properties of the ISCOM concept.
Assuntos
Adjuvantes Imunológicos , ISCOMs/imunologia , Quillaja/química , Quillaja/imunologia , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Animais , Anticorpos Antivirais/sangue , Feminino , Imunoglobulina G/sangue , Interferon gama/análise , Interleucina-4/análise , Interleucina-5/análise , Camundongos , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinação/métodos , Proteínas Virais/imunologiaRESUMO
The protection induced by immunostimulating complexes (ISCOMs) against bovine respiratory syncytial virus (BRSV) was evaluated and compared to that of a commercial inactivated vaccine (CV) in calves with BRSV-specific maternal antibodies. Following experimental challenge, controls (n = 4) and animals immunized with CV (n = 5) developed moderate to severe respiratory disease, whereas calves immunized with ISCOMs (n = 5) remained clinically healthy. BRSV was re-isolated from the nasopharynx of all controls and from all calves immunized with CV, but from none of the calves immunized with ISCOMs. BRSV-RNA was detected by real-time PCR from a single animal in this group. Significantly higher BRSV-specific nasal IgG, serum IgG1 and IgG2 titers were detected before and after challenge in animals immunized with ISCOMs versus CV. In conclusion, the ISCOMs overcame the suppressive effect of maternal antibodies in calves and induced strong clinical and virological protection against a BRSV challenge.
Assuntos
Doenças dos Bovinos/prevenção & controle , ISCOMs/administração & dosagem , Infecções por Vírus Respiratório Sincicial/veterinária , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vírus Sincicial Respiratório Bovino/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/sangue , Bovinos , Ensaio de Imunoadsorção Enzimática , ISCOMs/imunologia , Imunidade Materno-Adquirida , Imunoglobulina G/sangue , Masculino , Nasofaringe/virologia , RNA Viral/análise , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Bovino/isolamento & purificação , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologiaRESUMO
The immune stimulating complex (ISCOM) is a 40 nm nanoparticle used as a delivery system for vaccine antigens, targeting the immune system both after parenteral and mucosal administration. The ISCOM is made up of saponin, lipids and antigen usually held together by hydrophobic interaction between these three components. The compulsory elements to form the ISCOM structure are cholesterol and saponin. When the antigen is omitted the ISCOM-MATRIX is formed. There are a number of saponins that can form ISCOMs, and many other substances (including antigens, targeting and immuno-modulating molecules) can be incorporated into the ISCOM provided they are hydrophobic or rendered to be hydrophobic. Thus, it is possible to create ISCOM particles with different properties. After parenteral immunisation of the ISCOM, the T cell response is first detected in the draining lymph node. Subsequently, the T cell response is localised to the spleen, while the B cell response is first found both in the draining lymph nodes and in the spleen. Up to 50 days later, the majority of the antibody producing cells is found in the bone marrow (BM). In contrast, antigens that have been adjuvanted in an oil emulsion, limit the T cell response to the draining lymph nodes while the B cell response is found in the draining lymph nodes and spleen, but not in the BM. The ISCOM efficiently evokes CD8+, MHC class 1 restricted T cell response. The deposit of antigens both to the endosomal vesicles and to the cytosol of antigen presenting cells (APCs) explains why both T helper cells (vesicles) and cytotoxic T lymphocytes (cytosol) are efficiently induced by ISCOMs. The T helper (Th) cell response is balanced in the sense that both Th1 and Th2 cells are induced. Prominent IL-12 production by cells in the innate system is a characteristic reaction induced by ISCOMs, promoting the development of a strong Th1 response. After mucosal administration by the intranasal or the intestinal routes, the ISCOM induces strong specific mucosal IgA responses in local and remote mucosal surfaces. Also T cell responses are evoked by the mucosal administration. A large number of experimental ISCOM vaccines have been tested and protection has been induced against a number of pathogens in various species including chronic and persistent infections exemplified by human immune deficiency virus 1 (HIV-1), and 2 (HIV-2) and simian immune deficiency virus (SIV) in primates, and various herpes virus infections in several species. In contrast to a conventional rabies virus vaccine the ISCOM rabies formulation protected mice after exposure to the virulent virus. Recently, experimental ISCOM vaccines were shown to efficiently induce immune response in newborns of murine and bovine species in the presence of maternal antibodies, while conventional vaccines have failed. ISCOM vaccines are on the market for horses and cattle and several other ISCOM vaccines are under development. Since the ISCOM and the ISCOM-MATRIX can be blended with live attenuated vaccine antigens without hampering the proliferation of the live vaccine antigens, it opens the possibility to use the ISCOM adjuvant system in a mixture of live and killed vaccine antigens.
Assuntos
ISCOMs , Imunização/veterinária , Doenças dos Animais/imunologia , Doenças dos Animais/prevenção & controle , Animais , ISCOMs/administração & dosagem , ISCOMs/imunologia , Medicina VeterináriaRESUMO
To protect against human respiratory syncytial virus (hRSV)-induced bronchiolitis in early infancy, vaccines need to be designed which are effective in the neonatal period. To test the safety and efficacy of adjuvants in neonatal mice, we injected hRSV surface proteins combined with immune-stimulating complexes (ISCOMs) prepared from fractions A, C or A + C of Quillaja saponins. All were well tolerated in adults, but A + C ISCOMS proved lethal in neonates; A or C fractions alone were well tolerated by neonates up to the adult dose. hRSV-ISCOM A induced antibody responses similar to combined fractions, and potent in vitro cytotoxic T cell responses. Adult-like in vitro cytotoxicity against hRSV-infected targets and precursor cytotoxic T cell frequencies were observed within one week of neonatal priming and hRSV-ISCOM A-primed neonates showed virtually complete protection against subsequent viral challenge. hRSV challenge was associated with some pulmonary eosinophilia in both age groups, with higher IL-4 production by lung CD4+ T cells in mice primed as neonates. This was, however, accompanied by only minor (approximately 10%) and transient illness and weight loss. Thus, the identification of hRSV antigen delivery systems with an age-appropriate adjuvanticity/reactogenicity balance may be feasible even in the vulnerable early-life period.
Assuntos
Adjuvantes Imunológicos , Bronquiolite Viral/prevenção & controle , ISCOMs , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano/imunologia , Saponinas , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/efeitos adversos , Adjuvantes Imunológicos/uso terapêutico , Animais , Animais Recém-Nascidos , Anticorpos Antivirais/sangue , Bronquiolite Viral/virologia , Humanos , ISCOMs/administração & dosagem , ISCOMs/efeitos adversos , ISCOMs/uso terapêutico , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/virologia , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vacinas contra Vírus Sincicial Respiratório/efeitos adversos , Vacinas contra Vírus Sincicial Respiratório/uso terapêutico , Saponinas/administração & dosagem , Saponinas/química , Saponinas/uso terapêutico , Linfócitos T/imunologiaRESUMO
Evidence is accumulating that CD4(+) T-helper (Th) responses play a critical role in facilitating effector responses which are capable of controlling and even preventing human immunodeficiency virus (HIV) infection. The present work was undertaken to determine whether immunization with multiple antigens influenced individual Th responses and increased protection relative to a single antigen. Rhesus macaques were primed with DNA and boosted (immune-stimulating complex-formulated protein) with a combination of regulatory and structural antigens (Tat-Env-Gag) or with Tat alone. Immunization with combined antigens reduced the magnitude of the responses to Tat compared to the single-antigen immunization. Interestingly, the Th immune responses to the individual antigens were noticeably different. To determine whether the qualitative differences in vaccine-induced Th responses correlated with vaccine efficacy, animals were challenged intravenously with simian/human immunodeficiency virus (strain SHIV(89.6p)) 2 months following the final immunization. Animals that developed combined Th1- and Th2-like responses to Gag and Th2 dominant Env-specific responses were protected from disease progression. Interestingly, one animal that was completely protected from infection had the strongest IFN-gamma and interleukin-2 (IL-2) responses prior to challenge, in addition to very strong IL-4 responses to Gag and Env. In contrast, animals with only a marked vaccine-induced Tat-specific Th2 response (no IFN-gamma) were not protected from infection or disease. These data support the rationale that effective HIV vaccine-induced immunity requires a combination of potent Th1- and Th2-like responses best directed to multiple antigens.