RESUMEN
The role of T helper-17 (Th17) lymphocytes in the regulation of Schistosoma mansoni soluble egg antigen (SEA)-induced granuloma is unknown. This study examined the effect of Th17 cytokines (IL-17 and IL-22) on granulocyte recruitment and functions during SEA-induced granuloma formation in vitro in Schistosoma-infected and noninfected individuals. Granulocytes were isolated from 27 Schistosoma-infected patients and 13 controls and were used for granuloma induction using SEA-conjugated polyacrylamide beads in the presence of Th17 cytokines. Granuloma index was assessed, and granulocyte mediators such as tumour necrosis factor (TNF-α), hydrogen peroxide (H2 O2 ) and nitric oxide (NO) were measured in the culture supernatant at the 7th day using enzyme-linked immunosorbent assay (ELISA). Schistosoma-infected patients had significant larger SEA-induced granuloma than controls. IL-17 (125 pg/mL) induced the optimum size for granuloma within 3-7 days. However, IL-22 at different concentrations up to 300 pg/mL had no effect on granuloma formation. Using both cytokines simultaneously, IL-22 suppressed the effect of IL-17 and prevented granuloma formation. IL-17 significantly decreased TNF-α, H2 O2 and NO levels in Schistosoma-infected individuals. In contrast, IL-22 increased TNF-α and H2 O2 levels. In conclusion, IL-17 accelerates SEA-induced granuloma formation and inhibits granulocytes functions in Schistosoma-infected patients, while IL-22 inhibited the granuloma formation, but enhanced granulocyte functions.
Asunto(s)
Granuloma/parasitología , Interleucina-17/inmunología , Interleucinas/inmunología , Schistosoma mansoni/inmunología , Esquistosomiasis mansoni/inmunología , Células Th17/inmunología , Adulto , Animales , Antígenos Helmínticos/inmunología , Citocinas , Ensayo de Inmunoadsorción Enzimática , Femenino , Granulocitos/inmunología , Granuloma/inmunología , Granuloma/patología , Humanos , Masculino , Ratones , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa , Interleucina-22RESUMEN
Hepatitis E virus (HEV) has been reported to cause acute and chronic hepatitis in those with HIV infection and among solid organ transplant recipients in Europe. Limited data indicate that HEV is endemic in the United States, but the prevalence and significance of HEV infection among those with HIV and awaiting solid organ transplantation is unknown. We evaluated anti-HEV IgM and IgG antibodies and HEV RNA in 166 HIV-infected solid organ transplant candidates enrolled in the NIH HIV-Transplant Cohort. Overall prevalence of anti-HEV IgG approached 20% in both liver and renal transplant candidates. Evidence of recent infection was present in approximately 2% of liver transplant candidates and none of the kidney transplant candidates. HEV RNA was not detected in any patient. We conclude that markers of HEV infection are frequent among candidates for transplantation, but active, ongoing viremia is not seen. Evidence of recent infection (acute on chronic) liver disease was present in liver but not kidney recipients.
Asunto(s)
Infecciones por VIH/complicaciones , Hepatitis E/epidemiología , Hepevirus/aislamiento & purificación , Adulto , Femenino , Anticuerpos Antihepatitis/sangre , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Prevalencia , ARN Viral/sangre , Estados Unidos/epidemiologíaRESUMEN
Occult hepatitis B virus (HBV) infection is characterized by the absence of detectable hepatitis B surface antigen (HBsAg) in the serum, despite detectable HBV DNA. Investigations of the mechanisms underlying the development of occult HBV infection are lacking in the current literature, although viral mutations in the surface region, resulting in decreased HBsAg expression or secretion, represent one potential mechanism. Wild-type HBsAg expression vectors were constructed from genotype-matched chronic HBV sequences. Site-directed mutagenesis was then utilized to introduce three genotype A mutations - M103I, K122R and G145A - associated with occult HBV infection in vivo, alone and in combination, into the wild-type HBsAg vectors. Transfection of Huh7 and HepG2 cell lines was performed, and cell culture supernatants and cell lysates were collected over 7 days to assess the effects of these mutations on extracellular and intracellular HBsAg levels. The G145A mutation resulted in significantly decreased extracellular and intracellular HBsAg expression in vitro. The most pronounced reduction in HBsAg expression was observed when all three mutations were present. The mutations evaluated in vitro in the current study resulted in decreased HBsAg expression and potentially increased hepatic retention and/or decreased hepatic secretion of synthesized HBsAg, which could explain the lack of HBsAg detection that is characteristic of occult HBV infection in vivo.
Asunto(s)
Antígenos de Superficie de la Hepatitis B/biosíntesis , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Hepatitis B/patología , Hepatitis B/virología , Mutación Missense , Línea Celular , Hepatocitos/virología , Humanos , Mutagénesis Sitio-DirigidaRESUMEN
Hepatitis E virus (HEV) is a common cause of acute viral hepatitis (AVH) in developing countries. In Egypt; where up to 80% of the inhabitants of rural villages have anti-HEV antibodies denoting past infection, most of these infections are asymptomatic with little evidence that the infection causes AVH. There are accumulating reports which suggest potential risk of HEV transmission by blood transfusion. However, detection of serological markers for HEV infection or HEV RNA in Egyptian blood banks is not routinely performed. 760 blood samples from apparently healthy donors at the National blood bank were tested for markers of acute HEV infection to estimate the seroprevalence of acute HEV infection, and potential risk of infection by blood transfusion. They included 124 females (16.82%) and 636 males (83.68%), with a mean age of 23.8 +/- 5.3 years and mean ALT value of 23.3 +/- 13.2 IU/ml. Samples were tested as pools of 10 subjects. Pools with highest reactivity were retested individually to determine the frequency of positive subjects. Out of the 760 samples, three (0.45%) samples were positive for anti-HEV IgM and two of them had HEV RNA as determined by RT-PCR. In conclusion, this study suggests that the tested blood donors have low prevalence of ongoing subclinical infection with HEV and that the potential risk of transfusion may be low.
Asunto(s)
Donantes de Sangre/estadística & datos numéricos , Virus de la Hepatitis E/aislamiento & purificación , Hepatitis E/epidemiología , Inmunoglobulina M/sangre , Adolescente , Adulto , Egipto/epidemiología , Femenino , Hepatitis E/sangre , Hepatitis E/inmunología , Hepatitis E/virología , Virus de la Hepatitis E/genética , Virus de la Hepatitis E/inmunología , Humanos , Masculino , Persona de Mediana Edad , ARN Viral/química , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estudios Seroepidemiológicos , Adulto JovenRESUMEN
Hepatitis E virus (HEV) infection is a common cause of acute viral hepatitis (AVH) in Egypt. We aimed to identify risk factors of HEV among acute hepatitis cases, measure HEV specific immune response to differentiate between symptomatic and asymptomatic infections. The study included symptomatic acute hepatitis (AH) patients (n = 235) and asymptomatic contacts (n = 200) to HEV cases. They completed a lifestyle questionnaire, screened for common hepatotropic viruses. Blood and serum samples were collected from patients and contacts after onset of disease and follow-up samples collected until convalescence. PBMC were separated and tested for specific HEV T-cell response by INF-gamma ELISPOT assay. Serum samples were tested for IgM and IgG anti-hepatitis E virus by ELISA. IgM antibodies to HAV were detected in 19 patients (8.1%), 37 (15.7%) with HBV, 10 (4.3%) with HCV. HEV infection was identified in 42 (16%) patients with AVH. Of the 200 contacts, 14 (7%) had serological evidence of recent HEV asymptomatic infection, showed stronger CMI responses than HEV infected subjects (2540 +/- 28 and 182 +/- 389 ISCs/106 cells, respectively; P < 0.05). In conclusion, HEV is a major cause of AVH in Egypt. Asymptomatic HEV patients are likely to have stronger immune responses including CMI responses, than symptomatic cases.
Asunto(s)
Virus de la Hepatitis E/inmunología , Hepatitis E/inmunología , Enfermedad Aguda , Infecciones Asintomáticas , Egipto , Ensayo de Immunospot Ligado a Enzimas/métodos , Femenino , Estudios de Seguimiento , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Masculino , Factores de Riesgo , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Occult hepatitis B virus (O-HBV) infection is characterized by the presence of HBV DNA without detectable hepatitis B surface antigen (HBV DNA+/HBsAg-) in the serum. Although O-HBV is more prevalent during HBV/HIV co-infection, analysis of HBV mutations in co-infected patients is limited. In this preliminary study, HBV PreSurface (PreS) and surface (S) regions were amplified from 33 HIV-positive patient serum samples - 27 chronic HBV (C-HBV) and six O-HBV infections. HBV genotype was determined by phylogenetic analysis, while quasispecies diversity was quantified for the PreS, S and overlapping polymerase regions. C-HBV infections harboured genotypes A, D and G, compared to A, E, G and one mixed A/G infection for O-HBV. Interestingly, nonsynonymous-synonymous mutation values indicated positive immune selection in three regions for O-HBV vs one for C-HBV. Sequence analysis further identified new O-HBV mutations, in addition to several previously reported mutations within the HBsAg antigenic determinant. Several of these O-HBV mutations likely contribute to the lack of detectable HBsAg in O-HBV infection by interfering with detection in serologic assays, altering antigen secretion and/or decreasing replicative fitness.
Asunto(s)
Infecciones por VIH/complicaciones , VIH/inmunología , Antígenos de Superficie de la Hepatitis B/inmunología , Virus de la Hepatitis B/inmunología , Hepatitis B/complicaciones , Filogenia , Adulto , Secuencia de Bases , Estudios de Cohortes , ADN Viral/química , ADN Viral/genética , Variación Genética , Genotipo , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Hepatitis B/inmunología , Hepatitis B/virología , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Humanos , Persona de Mediana Edad , Datos de Secuencia Molecular , Proyectos Piloto , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , ADN Polimerasa Dirigida por ARN/química , ADN Polimerasa Dirigida por ARN/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Proteínas Estructurales Virales/química , Proteínas Estructurales Virales/genética , Adulto JovenRESUMEN
We evaluated the effect of low-dose IL-2 therapy (daily 1.2 MIU/m(2), subcutaneously) on the number and phenotype of regulatory T cells (T(regs)) and natural killer (NK) cells in HIV/HCV-coinfected patients taking antiretroviral therapy. The frequency and phenotype of circulating T(regs) (defined as CD3(+) CD4(+) CD25(high) or CD3(+) CD4(+) FOXP3(+)) and NK cells (CD3(-) CD16(+)/CD56(+)) were evaluated at baseline and after 12 weeks of treatment. The expression of CD25, CTLA-4, and granzymes A and B by CD4(+) FOXP3(+) cells, as well as the expression of KIR receptors (NKB1, CD158a, and NKAT2) on NK cells, was evaluated. Low doses of IL-2 resulted in the augmented frequency and absolute number of T(regs) in coinfected individuals. FOXP3 levels per cell as well as augmented CD25 and CTLA-4 expression by T(regs) suggested that IL-2 may lead to both expansion and activation of T(regs), although changes in the proportion of CD4(+) FOXP3(+) cells were not associated with changes in HCV viral load and CD4(+) cells between baseline and week 12. NK cell frequency also increased after IL-2 therapy. Interestingly, the pattern of expression of KIR receptors was changed by IL-2 treatment, since the frequency of NK cells expressing NKB1 augmented whereas the frequency of NK expressing CD158a and NKAT2 decreased.
Asunto(s)
Antivirales/administración & dosificación , Infecciones por VIH , Hepatitis C , Inmunoterapia , Interleucina-2/administración & dosificación , Células Asesinas Naturales/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Terapia Antirretroviral Altamente Activa , Antivirales/uso terapéutico , Quimioterapia Combinada , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/inmunología , Infecciones por VIH/terapia , VIH-1 , Hepacivirus , Hepatitis C/complicaciones , Hepatitis C/inmunología , Hepatitis C/terapia , Humanos , Inmunofenotipificación , Interferones/administración & dosificación , Interferones/uso terapéutico , Interleucina-2/inmunología , Interleucina-2/uso terapéutico , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Polietilenglicoles/uso terapéutico , Ribavirina/administración & dosificación , Ribavirina/uso terapéutico , Linfocitos T Reguladores/clasificación , Resultado del TratamientoRESUMEN
In developing countries, hepatitis E (HEV) and hepatitis A (HAV) are the major causes of acute viral hepatitis with similar feco-oral modes of transmission. In contrast to the high seroprevalence of hepatitis A infection, a low seroprevalence of HEV among children in endemic areas has been reported. These data suggest the possibility that silent HEV infection is undiagnosed by the current available methods. Many of the serological tests used for HEV diagnosis have poor specificity and are unable to differentiate among different genotypes of HEV. Moreover, the RT-PCR used for HEV isolation is only valid for a brief period during the acute stage of infection. Cell-mediated immune (CMI) responses are highly sensitive, and long lasting after sub-clinical infections as shown in HCV and HIV. Our objective was to develop a quantitative assay for cell-mediated immune (CMI) responses in HEV infection as a surrogate marker for HEV exposure in silent infection. Quantitative assessment of the CMI responses in HEV will also help us to evaluate the role of CMI in HEV morbidity. In this study, an HEV-specific interferon-gamma (IFN-gamma) ELISPOT assay was optimized to analyze HEV-specific CMI responses. We used peripheral blood mononuclear cells (PBMC) and sera from experimentally infected chimpanzees and from seroconverted and control human subjects to validate the assay. The HEV-specific IFN-gamma ELISPOT responses correlated strongly and significantly with anti-HEV ELISA positive/negative results (rho=0.73, p=0.02). Moreover, fine specificities of HEV-specific T cell responses could be identified using overlapping HEV ORF2 peptides.
Asunto(s)
Hepatitis E/diagnóstico , Inmunidad Celular/inmunología , Inmunoensayo , Interferón gamma/análisis , Leucocitos Mononucleares/inmunología , Animales , Anticuerpos Antivirales/análisis , Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática , Hepatitis E/sangre , Hepatitis E/inmunología , Humanos , Epítopos Inmunodominantes , Memoria Inmunológica , Interferón gamma/inmunología , Leucocitos Mononucleares/metabolismo , Pan troglodytesRESUMEN
Patients coinfected with hepatitis C virus (HCV) and the trematode, Schistosoma mansoni, have an increased incidence of viral persistence and accelerated fibrosis. To investigate immunological mechanisms responsible for this more aggressive natural history of HCV, the core HCV-specific T-cell responses were analysed in 44 donated blood units rejected because they had antibodies to HCV (anti-HCV). Half also had anti-S. mansoni antibodies, evidence of past or active infection. HCV-specific ELISPOT responses were examined using pools of 180 overlapping 9-mer peptides with offsets of one covering the core of HCV genotype 4a. Comparison of T-cell responses in blood units positive for both anti-HCV and anti-Schistosoma antibodies with blood units positive only for anti-HCV antibodies showed a significant decrease in core-specific T-cell IFN-gamma (505+/- 46 vs. 803 +/- 66 ISC/10(6) cells, P < 0.001), IL-4 (2 +/- 108 vs. 641 +/- 131 ISC/10(6) cells, P < 0.001), and IL-10 (159 +/- 105 vs. 466 +/- 407 ISC/10(6) cells, P < 0.002) responses. In contrast, there was no significant difference in cell-mediated immune response (CMI) to PHA mitogen between these two groups. Therefore, we concluded T cells from persons with anti-Schistosoma have reduced IFN-gamma, IL-4, and IL-10 secreting HCV-specific T-cell responses. This may explain why Schistosoma coinfection increases persistence and severity of HCV infection.
Asunto(s)
Hepatitis C/inmunología , Péptidos/inmunología , Esquistosomiasis mansoni/inmunología , Linfocitos T/inmunología , Proteínas del Núcleo Viral/inmunología , Animales , Citocinas/metabolismo , Hepacivirus/inmunología , Hepatitis C/complicaciones , Hepatitis C/virología , Anticuerpos contra la Hepatitis C/sangre , Humanos , Inmunidad Celular , Terapia de Inmunosupresión , Activación de Linfocitos , Péptidos/síntesis química , Péptidos/química , Schistosoma mansoni/patogenicidad , Esquistosomiasis mansoni/complicaciones , Esquistosomiasis mansoni/parasitologíaRESUMEN
The availability of molecular beacon-based, real time polymerase chain reaction (PCR) and a semi-automated sample extraction procedure have made it possible for us to retrospectively examine HCV replication kinetics in HCV naive chimpanzees infected during the past 20 years. We compared these in 17 animals that developed chronic infection, and in 21 that developed self-limited infection. No differences were found in infecting dose, or replication kinetics in the acute phase between these two types of infection. An unanticipated finding was the fact that 10 of 17 animals developing chronic infection partially controlled virus replication for 48 +/- 48 weeks after typical acute phase viraemia, and prior to development of chronic infection. Twenty-nine out of 30 (29/30) sera, which were negative by quantitative PCR during the downregulated period, were, however, positive by the more sensitive Genprobe isothermal transcription-mediated amplification (TMA) assay. Thus, downregulation was not complete. Ten animals showing self-limited infection showed complete resolution of viraemia by TMA assay. Quasispecies analysis revealed that in all, except one case, the virus reappearing after downregulation was essentially identical to that of the originally infecting virus.
Asunto(s)
Enfermedades del Simio Antropoideo/virología , Hepacivirus/fisiología , Hepatitis C/veterinaria , Pan troglodytes/virología , Animales , Hepacivirus/patogenicidad , Hepatitis C/etiología , Hepatitis C/virología , Hepatitis C Crónica/etiología , Hepatitis C Crónica/veterinaria , Hepatitis C Crónica/virología , Cinética , Factores de Tiempo , Viremia/veterinaria , Replicación ViralRESUMEN
Conformationally constrained HIV-1 Env and gp120 immunogens induce broadly cross-reactive neutralizing antibodies. Thus, it is now feasible to rationally design an HIV-1 vaccine that affords protection through humoral mechanisms. This paper reviews our progress toward the development of an oral bacterial vaccine vector that is capable of delivering an HIV-1 DNA vaccine to host lymphoid tissues and inducing broadly neutralizing antibodies to HIV-1 in the mucosal and systemic immune compartments.
Asunto(s)
Vacunas contra el SIDA/inmunología , Vacunas Bacterianas/inmunología , Productos del Gen env/inmunología , Vectores Genéticos , Anticuerpos Anti-VIH/sangre , Proteína gp120 de Envoltorio del VIH/inmunología , Administración Oral , Animales , Vacunas Bacterianas/genética , Femenino , Productos del Gen env/genética , Anticuerpos Anti-VIH/inmunología , Proteína gp120 de Envoltorio del VIH/genética , VIH-1/inmunología , Humanos , Ratones , Ratones Endogámicos BALB C , Pruebas de Neutralización , Salmonella/genética , Salmonella/inmunología , Shigella/genética , Shigella/inmunologíaRESUMEN
Passive antibody studies unequivocally demonstrate that sterilizing immunity against lentiviruses is obtainable through humoral mechanisms. In this regard, DNA vaccines represent an inexpensive alternative to subunit vaccine for mass vaccination programs designed to induce such responses to human immunodeficiency virus type I (HIV-1). At present, however, this vaccine modality has proven relatively ineffective at inducing humoral responses. In this report, we describe the immunogenicity of DNA vaccines that direct the coincident expression of the cholera toxin catalytic domain (CTA1) with that of the human immunodeficiency virus type I gp120 through genes either encoded in individual plasmids or in a single dicistronic plasmid. In BALB/cJ mice, coincident expression of CTA1 in either a separate plasmid or in the dicistronic plasmid in the DNA vaccines induced serum IgG responses to gp120 that were at least 1000-fold greater, and remained elevated longer than, the analogous responses in mice vaccinated with a DNA vaccine that expressed gp120 alone. In addition, mice vaccinated with CTA1 and gp120 produced significantly more gp120-specific IFN-gamma ELISPOTs than mice vaccinated with the gp120 DNA vaccine. Combined, these data show that the adjuvant properties of cholera toxin can be harnessed in DNA vaccine modalities.
Asunto(s)
Adyuvantes Inmunológicos/farmacología , Toxina del Cólera/farmacología , ADN Viral/genética , ADN Viral/inmunología , Proteína gp120 de Envoltorio del VIH/genética , Vacunas de ADN/inmunología , Animales , Cromo/metabolismo , Femenino , Proteína gp120 de Envoltorio del VIH/biosíntesis , Interferón gamma/biosíntesis , Recuento de Linfocitos , Ratones , Ratones Endogámicos BALB C , Plásmidos/genética , Linfocitos T Citotóxicos/inmunología , Vacunación , Vacunas de ADN/síntesis químicaRESUMEN
The immune response to hepatitis C virus (HCV) is believed to be critical in determining the outcome of the disease. In this study we have analysed epitope recognition, cytokine profile, and anti-HCV antibody responses in chronically HCV-infected and recovered chimpanzees. Quantitative measurement of anti-HCV antibody in HCV-infected chimpanzees revealed that the response in HCV- recovered chimpanzees peaked within 4-20 weeks. In contrast, the anti-HCV antibody responses in chronically HCV infected chimpanzees did not peak until 100-200 weeks after infection, and decreased gradually thereafter. T cell proliferation assays measuring responses to pooled HCV proteins revealed significant increases in the 3H-uptake during the early stages of infection in recovered chimpanzees in comparison to the chronically infected ones. Class I-restricted epitopes of the core, and NS3 proteins of HCV were analysed using 9-10 mer overlapping peptides covering the core and NS3 proteins, and IFN-gamma ELISPOT technique. Our data indicated early and broad class-I restricted core, and NS3 protein epitope recognitions in HCV-recovered chimpanzees but not in chimpanzees that had been chronically infected. Additionally, dominant epitopes recognized early in infection (8 weeks) were no longer recognized later in infection (followed up to 64 weeks). Cytokines profiling revealed a 50-fold increase in TNF-alpha secretion in the supernatant of core-specific CD8 memory cells of the chronically infected chimpanzees in comparison to the recovered ones. In summary, multiple parameters correlate with HCV recovery in chimpanzees.
Asunto(s)
Hepatitis C Crónica/inmunología , Hepatitis C/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Modelos Animales de Enfermedad , Mapeo Epitopo , Epítopos de Linfocito T , Femenino , Hepacivirus/inmunología , Hepatitis C/virología , Anticuerpos contra la Hepatitis C/sangre , Hepatitis C Crónica/virología , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Masculino , Pan troglodytes , Péptidos/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas del Núcleo Viral/química , Proteínas del Núcleo Viral/inmunología , Proteínas no Estructurales Virales/inmunologíaRESUMEN
The rational design of new therapies against HIV-1 necessitates an improved understanding of the mechanisms underlying the production of ineffective immune responses to HIV-1 in most infected individuals. This report shows that the CD8(+) T cell responses to gp120 were greatly diminished in mice vaccinated with a bicistronic gp120-Tat DNA vaccine, compared with those induced by a DNA vaccine encoding gp120 alone. The CD8(+) T cell responses induced by the latter included strong gp120-specific IFN-gamma secretion and protective antiviral immunity against challenge by a vaccinia-env pseudotype. The degree to which Tat influenced CD8(+) T cell responses depended on the bioactivity of Tat. Thus, a bicistronic DNA vaccine that expresses gp120 and a truncated Tat defective for LTR activation elicited strong IFN-gamma -secreting CD8(+) T cell responses to gp120 but conferred only marginal protection against the vaccinia-env challenge. The effect of Tat was completely blocked, however, by immunization with inactivated Tat protein before vaccination with the bicistronic gp120-Tat DNA vaccine.
Asunto(s)
Vacunas contra el SIDA/inmunología , Síndrome de Inmunodeficiencia Adquirida/inmunología , Productos del Gen tat/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Vacunas de ADN/inmunología , Animales , Especificidad de Anticuerpos , Linfocitos T CD8-positivos , Línea Celular , Femenino , Anticuerpos Anti-VIH/sangre , Proteína gp120 de Envoltorio del VIH/inmunología , Humanos , Inmunidad Celular , Inmunoglobulina G/sangre , Ratones , Ratones Endogámicos BALB C , Subunidades de Proteína , Transfección , Productos del Gen tat del Virus de la Inmunodeficiencia HumanaRESUMEN
Because hepatitis C virus is etiologically involved in about half the cases of the world's most common cancer, hepatocellular carcinoma, and because this virus is likely to continue to spread in most of the developing world for many years, the authors believe that development of a prophylactic vaccine is imperative. Numerous approaches are available to overcome the many impediments which make the development of an HCV vaccine difficult. Such impediments include the many viral genotypes and quasispecies of HCV and the association of virions with host lipids. It is likely that overcoming these impediments will require a vaccine which induces a strong cell-mediated response. The most promising approach seems to be DNA-based immunization or a prime-boost regimen with DNA priming and boosting with a viral vector. Potentiation of responses with adjuvant strategies will probably be necessary. Hepatitis C virus immunization is in an early stage of development. Given the explosive growth in the understanding of immunology, progress should be rapid.
Asunto(s)
Hepatitis C/inmunología , Hepatitis C/prevención & control , Animales , Modelos Animales de Enfermedad , Genotipo , Hepacivirus/genética , Hepacivirus/inmunología , Hepatitis C/epidemiología , Humanos , Inmunización , Ratones , Pan troglodytes , Vacunas de ADN/farmacología , Vacunas de Subunidad/farmacología , Vacunas contra Hepatitis Viral/farmacologíaRESUMEN
CD8(+) T-cell responses provide beneficial antiviral immunity against human immunodeficiency virus 1 (HIV-1). In this study, we show that intragastric vaccination with a Salmonella HIV-1 Env DNA vaccine vector generates Env-specific CD8(+) T-cells, both in mucosal and systemic lymphoid tissue. By contrast, intramuscular vaccination with the Env DNA vaccine alone only induced systemic CD8(+) T-cells. To our knowledge, this is the first report showing both mucosal and systemic CD8(+) T-cell responses following vaccination with a Salmonella vaccine vector. These data suggest that this mode of HIV-1 DNA vaccine delivery will be advantageous over parenterally administered HIV-1 DNA vaccines.
Asunto(s)
Vacunas contra el SIDA/inmunología , Linfocitos T CD8-positivos/inmunología , Productos del Gen env/inmunología , VIH-1/inmunología , Salmonella/genética , Vacunas de ADN/inmunología , Animales , Codón , Femenino , Vectores Genéticos , Humanos , Interferón gamma/biosíntesis , Ratones , Ratones Endogámicos BALB C , VacunaciónRESUMEN
A prototype Shigella human immunodeficiency virus type 1 (HIV-1) gp120 DNA vaccine vector was constructed and evaluated for immunogenicity in a murine model. For comparative purposes, mice were also vaccinated with a vaccinia virus-env (vaccinia-env) vector or the gp120 DNA vaccine alone. Enumeration of the CD8(+)-T-cell responses to gp120 after vaccination using a gamma interferon enzyme-linked spot assay revealed that a single intranasal dose of the Shigella HIV-1 gp120 DNA vaccine vector elicited a CD8(+) T-cell response to gp120, the magnitude of which was comparable to the sizes of the analogous responses to gp120 that developed in mice vaccinated intraperitoneally with the vaccinia-env vector or intramuscularly with the gp120 DNA vaccine. In addition, a single dose of the Shigella gp120 DNA vaccine vector afforded significant protection against a vaccinia-env challenge. Moreover, the number of vaccinia-env PFU recovered in mice vaccinated intranasally with the Shigella vector was about fivefold less than the number recovered from mice vaccinated intramuscularly with the gp120 DNA vaccine. Since the Shigella vector did not express detectable levels of gp120, this report confirms that Shigella vectors are capable of delivering passenger DNA vaccines to host cells and inducing robust CD8(+) T-cell responses to antigens expressed by the DNA vaccines. Furthermore, to our knowledge, this is the first documentation of antiviral protective immunity following vaccination with a live Shigella DNA vaccine vector.
Asunto(s)
Vacunas contra el SIDA/administración & dosificación , Linfocitos T CD8-positivos/inmunología , Vectores Genéticos/administración & dosificación , Proteína gp120 de Envoltorio del VIH/inmunología , Infecciones por VIH/prevención & control , VIH-1/inmunología , Shigella/genética , Vacunación , Vacunas de ADN/administración & dosificación , Vacunas contra el SIDA/inmunología , Administración Intranasal , Animales , Antígenos Virales/inmunología , Modelos Animales de Enfermedad , Femenino , Proteína gp120 de Envoltorio del VIH/genética , Infecciones por VIH/inmunología , Recuento de Linfocitos , Ratones , Ratones Endogámicos BALB C , Vacunas de ADN/inmunologíaRESUMEN
Bacille Calmette-Guerin (BCG), Listeria monocytogenes, Salmonellae and Shigellae have shown promise as vaccine vectors in experimental animal models. Although disappointing results in humans and non-human primates stalled the development of this vaccination strategy, interest in this approach was reinvigorated recently by the development of bacterial DNA-vaccine-vectors. The purpose of this review is to highlight the strengths and weaknesses of bacterial vaccine vectors, and to discuss the future prospects of these vaccine delivery systems.
Asunto(s)
Vacunas Bacterianas/genética , Vacunas Bacterianas/inmunología , Vectores Genéticos , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Animales , Antígenos/genética , Antígenos/inmunología , Vacuna BCG/genética , Vacuna BCG/inmunología , Vacunas Bacterianas/uso terapéutico , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/inmunología , Salmonella/genética , Salmonella/inmunología , Shigella/genética , Shigella/inmunología , Vacunas Atenuadas/genética , Vacunas Atenuadas/inmunología , Vacunas Atenuadas/uso terapéutico , Vacunas Sintéticas/uso terapéuticoRESUMEN
Humans chronically infected with schistosomiasis usually have impaired parasite Ag-specific lymphocyte proliferation and IFN-gamma production that may facilitate persistence of the parasite while producing little clinical disease. The mechanisms that contribute to the immunologic hyporesponsiveness in these patients remain undefined. IL-10 has been shown to exert an inhibitory effect on cell-mediated immunity. To determine whether endogenous IL-10 has a role in regulating parasite-specific anergy in schistosomiasis, neutralizing anti-IL-10 added to PBMC from Schistosoma haematobium patients' enhanced adult worm (SWAP)- or egg Ag (SEA)-driven lymphocyte proliferation and/or IFN-gamma production by 2- to >100-fold in 32 of 38 subjects. In contrast, anti-IL-10 failed to significantly augment the mycobacterial Ag, purified protein derivative (PPD)-driven lymphocyte proliferation, or IFN-gamma production in 9 or 10 of 14 individuals, respectively. SWAP or SEA triggered IL-10 release from PBMC of both patients and healthy individuals; however, CD4+ cells were a significant source of IL-10 only in infected subjects. PPD relative to SWAP induced fivefold less IL-10 release by CD4+ cells (p < 0.01). A possible mechanism whereby IL-10 suppressed Ag-specific T cell responses was demonstrated by the ability of SWAP and not PPD to suppress B7 expression on PBMC. Anti-IL-10 completely inhibited the parasite Ag-induced down-regulation of B7 expression. These studies indicate that IL-10 contributes to parasite Ag-induced T cell hyporesponsiveness observed in patients with chronic schistosomiasis hematobia.