RESUMEN
An HIV-1 vaccine must elicit a clonally diverse virus-specific CD8+ T-cell response to contain mutant virus forms, and these responses must be present in mucosal tissues, which are the site of early HIV-1 replication. We show that systemic delivery of prototype vaccine vectors in rhesus monkeys induced SIV (simian immunodeficiency virus)-specific CD8+ T-cell responses in systemic and mucosal compartments with comparable clonal compositions. Although clonal sharing was maintained between the peripheral blood and lungs, the clonal constituents of the vaccine-induced CD8+ T-cell populations in the gastrointestinal mucosal tissues evolved away from the peripheral blood population. A phenotypic characterization indicated that the divergence was a consequence of differential trafficking and retention of the vaccine-induced cells in mucosal compartments. These findings highlight the circulation of vaccine-induced CD8+ T-cell populations between systemic and mucosal compartments and the importance of the expression of specific homing molecules for localization in mucosal tissues.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T/inmunología , Membrana Mucosa/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Secuencia de Aminoácidos , Animales , Epítopos de Linfocito T/química , Mucosa Gástrica/inmunología , Productos del Gen gag/inmunología , Inmunización , Memoria Inmunológica , Mucosa Intestinal/inmunología , Macaca mulatta , Datos de Secuencia Molecular , Membrana Mucosa/virología , Receptores de Antígenos de Linfocitos T alfa-beta/química , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/genéticaRESUMEN
Vaccination strategies for protection against a number of respiratory pathogens must induce T-cell populations in both the pulmonary airways and peripheral lymphoid organs. In this study, we show that pulmonary immunization using plasmid DNA formulated with the polymer polyethyleneimine (PEI-DNA) induced antigen-specific CD8(+) T cells in the airways that persisted long after antigen local clearance. The persistence of the cells was not mediated by local lymphocyte proliferation or persistent antigen presentation within the lung or airways. These vaccine-induced CD8(+) T cells effectively mediated protective immunity against respiratory challenges with vaccinia virus and influenza virus. Moreover, this protection was not dependent upon the recruitment of T cells from peripheral sites. These findings demonstrate that pulmonary immunization with PEI-DNA is an efficient approach for inducing robust pulmonary CD8(+) T-cell populations that are effective at protecting against respiratory pathogens.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Pulmón/inmunología , Vacunas de ADN/inmunología , Virosis/inmunología , Virus/inmunología , Animales , Presentación de Antígeno/inmunología , Antígenos/genética , Antígenos/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Infecciones por VIH/inmunología , VIH-1/genética , VIH-1/inmunología , Humanos , Inmunización , Activación de Linfocitos/inmunología , Ratones , Orthomyxoviridae/inmunología , Plásmidos/genética , Plásmidos/inmunología , Mucosa Respiratoria/inmunología , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética , Virus Vaccinia/genética , Virus Vaccinia/inmunologíaAsunto(s)
Vacunas contra el SIDA , Terapia Genética/métodos , Anticuerpos Anti-VIH/genética , Infecciones por VIH/prevención & control , Vacunas contra el SIDA/inmunología , Animales , Dependovirus/genética , Técnicas de Transferencia de Gen , Vectores Genéticos , Anticuerpos Anti-VIH/biosíntesis , Infecciones por VIH/inmunología , Haplorrinos , HumanosRESUMEN
Multifocal submucosal stromal tumors were diagnosed in a 5.5-year-old rhesus macaque (Macaca mulatta) experimentally infected with simian immunodeficiency virus, strain SIVsmE660, and CD4+ T cell depleted. The animal was negative for simian retroviruses, SRV-1, -2, and -5. Polymerase chain reaction analysis of DNA from tumor and spleen tissue revealed abundant, preferential presence of retroperitoneal fibromatosis herpesvirus, the macaque homologue of the Kaposi sarcoma-associated herpesvirus (human herpesvirus-8), in the tumors. This was corroborated by demonstration of viral latent nuclear antigen-1 in the nuclei of a majority of the spindeloid tumor cells. Low levels of an additional macaque herpesvirus, rhesus rhadinovirus, were also detected in the spleen and tumor tissues. The spindeloid cells labeled positively for vimentin and CD117 but were negative for CD31, CD68, desmin, and smooth muscle cell actin. Collectively, these findings suggest a relation to but not absolute identity with simian mesenchymoproliferative disorders (MPD) or typical gastrointestinal stromal tumors (GISTs).
Asunto(s)
Tumores del Estroma Gastrointestinal/veterinaria , Macaca mulatta , Enfermedades de los Monos/patología , Enfermedades de los Monos/virología , Síndrome de Inmunodeficiencia Adquirida del Simio/complicaciones , Virus de la Inmunodeficiencia de los Simios , Animales , Antígenos Nucleares/metabolismo , Cartilla de ADN , Tumores del Estroma Gastrointestinal/complicaciones , Tumores del Estroma Gastrointestinal/patología , Herpesvirus Humano 8/metabolismo , Inmunohistoquímica/veterinaria , Reacción en Cadena de la Polimerasa/veterinaria , Retrovirus de los Simios/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Vimentina/metabolismoRESUMEN
To provide a basis for beginning to explore the CD94/NKG2 family of molecules in rhesus monkeys, we sought to characterize the expression of these inhibitory and activating cell signalling molecules in peripheral blood mononuclear cells (PBMCs) from healthy rhesus monkeys. We developed and employed a semiquantitative polymerase chain reaction (PCR)-based assay to evaluate mRNA expression levels of nine NKG2 molecules in PBMCs from the monkeys. In addition to quantitating NKG2A, NKG2B, NKG2C2, NKG2C and NKG2D expression, mRNA expression of transmembrane-deleted forms of these molecules was also evaluated. Significant variability in NKG2 mRNA expression in the PBMCs was detected, with 15 unique NKG2 expression level profiles detected in a study of 15 monkeys. We also found that the ratio of the expressed levels of mRNA of the four NKG2 splice variants, NKG2A, NKG2B, NKG2ADeltatm, and NKG2BDeltatm, was variable between the monkeys as well as in an individual monkey over a period of 1.5 years. These findings indicate the dynamic nature of NKG2 mRNA expression in the rhesus monkey.
Asunto(s)
Linfocitos/inmunología , Receptores Inmunológicos/sangre , Animales , Expresión Génica , Subgrupos Linfocitarios/inmunología , Macaca mulatta , Reacción en Cadena de la Polimerasa/métodos , Empalme del ARN/genética , ARN Mensajero , Receptores Inmunológicos/genética , Receptores de Células Asesinas Naturales , Reproducibilidad de los ResultadosRESUMEN
The polyomavirus JC (JCV) infects 85% of healthy individuals, and its reactivation in a limited number of immunosuppressed people causes progressive multifocal leukoencephalopathy (PML), a severe demyelinating disease of the central nervous system. We hypothesized that JCV-specific cytotoxic T lymphocytes (CTLs) might control JCV replication in healthy individuals, blocking the evolution of PML. Using 51Cr release and tetramer staining assays, we show that 8 of 11 HLA-A*0201+ healthy subjects (73%) harbor detectable JCV-specific CD8+ CTLs that recognize one or two epitopes of JCV VP1 protein, the HLA-A*0201-restricted VP1p36 and VPp1100 epitopes. We determined that the frequency of JCV VP1 epitope-specific CTLs varied from less than 1/100,000 to 1/2,494 peripheral blood mononuclear cells. More individuals had JCV VP1-specific than cytomegalovirus-specific CTLs (8 of 11 subjects [73%] versus 2 of 10 subjects [20%], respectively). These results show that a CD8+-T-cell response against JCV is commonly found in immunocompetent people and suggest that these cells might protect against the development of PML.
Asunto(s)
Virus JC/inmunología , Linfocitos T Citotóxicos/inmunología , Adulto , Citomegalovirus/inmunología , Proteínas de Unión al ADN/inmunología , Antígenos HLA-A/metabolismo , Antígeno HLA-A2 , Humanos , Inmunocompetencia , Epítopos Inmunodominantes , Virus JC/patogenicidad , Virus JC/fisiología , Leucoencefalopatía Multifocal Progresiva/inmunología , Leucoencefalopatía Multifocal Progresiva/prevención & control , Leucoencefalopatía Multifocal Progresiva/virología , Proteínas de Plantas , Transactivadores , Factores de Transcripción/inmunología , Replicación Viral/inmunologíaRESUMEN
Immune responses of lymphocyte populations during early phases of mycobacterial infection and reinfection have not been well characterized in humans. A non-human primate model of Mycobacterium bovis bacille Calmette-Guerin (BCG) infection was employed to characterize optimally the immune responses of mycobacteria-specific T cells. Primary BCG infection induced biphasic immune responses, characterized by initial lymphocytopenia and subsequent expansion of CD4+, CD8+ and gammadelta T cell populations in the blood, lymph nodes and the pulmonary compartment. The potency of detectable T cell immune responses appears to be influenced by the timing and route of infection as well as challenge doses of BCG organisms. Systemic BCG infection introduced by intravenous challenge induced a dose-dependent expansion of circulating CD4+, CD8+ and gammadelta T cells whereas, in the pulmonary compartment, the systemic infection resulted in a predominant increase in numbers of gammadelta T cells. In contrast, pulmonary exposure to BCG through the bronchial route induced detectable expansions of CD4+, CD8+ and gammadelta T cell populations in only the lung but not in the blood. A rapid recall expansion of these T cell populations was seen in the macaques reinfected intravenously and bronchially with BCG. The expanded alphabeta and gammadelta T cell populations exhibited their antigen specificity for mycobacterial peptides and non-peptide phospholigands, respectively. Finally, the major expansion of T cells was associated with a resolution of active BCG infection and reinfection. The patterns and kinetics of CD4+, CD8+ and gammadelta T cell immune responses during BCG infection might contribute to characterizing immune protection against tuberculosis and testing new tuberculosis vaccines in primates.
Asunto(s)
Infecciones por Mycobacterium/inmunología , Mycobacterium bovis , Subgrupos de Linfocitos T/inmunología , Animales , División Celular/inmunología , Células Cultivadas , Relación Dosis-Respuesta Inmunológica , Memoria Inmunológica , Pulmón/inmunología , Ganglios Linfáticos/inmunología , Linfopenia/inmunología , Linfopenia/microbiología , Macaca mulatta , Macaca nemestrina , RecurrenciaRESUMEN
T-cell-mediated immune effector mechanisms play an important role in the containment of human immunodeficiency virus/simian immunodeficiency virus (HIV/SIV) replication after infection. Both vaccination- and infection-induced T-cell responses are dependent on the host major histocompatibility complex classes I and II (MHC-I and MHC-II) antigens. Here we report that both inherent, host-dependent immune responses to SIVmac251 infection and vaccination-induced immune responses to viral antigens were able to reduce virus replication and/or CD4+ T-cell loss. Both the presence of the MHC-I Mamu-A*01 genotype and vaccination of rhesus macaques with ALVAC-SIV-gag-pol-env (ALVAC-SIV-gpe) contributed to the restriction of SIVmac251 replication during primary infection, preservation of CD4+ T cells, and delayed disease progression following intrarectal challenge exposure of the animals to SIV(mac251 (561)). ALVAC-SIV-gpe immunization induced cytotoxic T-lymphocyte (CTL) responses cumulatively in 67% of the immunized animals. Following viral challenge, a significant secondary virus-specific CD8+ T-cell response was observed in the vaccinated macaques. In the same immunized macaques, a decrease in virus load during primary infection (P = 0.0078) and protection from CD4 loss during both acute and chronic phases of infection (P = 0.0099 and P = 0.03, respectively) were observed. A trend for enhanced survival of the vaccinated macaques was also observed. Neither boosting the ALVAC-SIV-gpe with gp120 immunizations nor administering the vaccine by the combination of mucosal and systemic immunization routes increased significantly the protective effect of the ALVAC-SIV-gpe vaccine. While assessing the role of MHC-I Mamu-A*01 alone in the restriction of viremia following challenge of nonvaccinated animals with other SIV isolates, we observed that the virus load was not significantly lower in Mamu-A*01-positive macaques following intravenous challenge with either SIV(mac251 (561)) or SIV(SME660). However, a significant delay in CD4+ T-cell loss was observed in Mamu-A*01-positive macaques in each group. Of interest, in the case of intravenous or intrarectal challenge with the chimeric SIV/HIV strains SHIV(89.6P) or SHIV(KU2), respectively, MHC-I Mamu-A*01-positive macaques did not significantly restrict primary viremia. The finding of the protective effect of the Mamu-A*01 molecule parallels the protective effect of the B*5701 HLA allele in HIV-1-infected humans and needs to be accounted for in the evaluation of vaccine efficacy against SIV challenge models.
Asunto(s)
Productos del Gen env/administración & dosificación , Productos del Gen gag/administración & dosificación , Productos del Gen pol/administración & dosificación , Antígenos de Histocompatibilidad Clase I/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Virus de la Inmunodeficiencia de los Simios/inmunología , Vacunación , Vacunas Virales/administración & dosificación , Animales , Productos del Gen env/inmunología , Productos del Gen gag/inmunología , Productos del Gen pol/inmunología , Macaca , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus Vaccinia , Vacunas Virales/inmunologíaRESUMEN
Although systemic virus-specific cytotoxic T lymphocyte (CTL) responses are of critical importance in controlling virus replication in individuals infected with human immunodeficiency virus 1 (HIV-1), little is known about this immune response in the gastrointestinal (GI) tract. This study investigated the GI tract CTL response in a nonhuman primate model for HIV-1 infection, simian immunodeficiency virus (SIV)-infected rhesus monkeys. Lymphocytes from duodenal pinch biopsy specimens were obtained from 9 chronically SIVmac-infected rhesus monkeys and GI tract lymphocytes were harvested from the jejunum and ileum of 4 euthanized SIVmac-infected rhesus monkeys. Lymphocytes were also assessed in GI mucosal tissues by in situ staining in histologic specimens. SIVmac Gag-specific CTLs were assessed in the monkeys using the tetramer technology. These GI mucosal tissues of chronically SIVmac-infected rhesus monkeys contained levels of CTLs comparable to those found in the peripheral blood and lymph nodes. The present studies suggest that the CD8(+) CTL response in GI mucosal sites is comparable to that seen systemically in SIVmac-infected rhesus monkeys.
Asunto(s)
Sistema Digestivo/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Biopsia , Antígenos CD8/análisis , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Duodeno/inmunología , Duodeno/patología , Productos del Gen gag/análisis , Productos del Gen gag/inmunología , Productos del Gen gag/metabolismo , Íleon/inmunología , Íleon/patología , Mucosa Intestinal/inmunología , Mucosa Intestinal/patología , Yeyuno/inmunología , Yeyuno/patología , Activación de Linfocitos , Macaca mulatta , Microscopía ConfocalRESUMEN
Although high frequencies of T lymphocytes specific for certain tumor-associated antigens have been detected in some cancer patients, increasing evidence suggests that these T cells may be functionally defective in vivo and fail to induce meaningful clinical responses. One strategy to overcome this limitation is to target novel antigens that are ignored during the natural antitumor immune response but are nevertheless capable of triggering effector T-cell responses against tumors after optimal presentation by antigen-presenting cells. Here, we show that the telomerase catalytic subunit (hTERT)-a nearly universal tumor antigen identified by epitope deduction rather than from patient immune responses-is immunologically ignored by patients despite progressive tumor burden. Nevertheless, HLA-A2-restricted CTLs against hTERT are equivalently induced ex vivo from patients and healthy individuals and efficiently kill human tumor cell lines and primary tumors. Thus, telomerase-specific T cells from cancer patients are spared functional inactivation because of immunological ignorance. These findings support clinical efforts to target the hTERT as a tumor antigen with broad therapeutic potential.
Asunto(s)
Neoplasias/inmunología , Linfocitos T Citotóxicos/inmunología , Telomerasa/inmunología , Adulto , Anciano , Proteínas de Unión al ADN , Epítopos de Linfocito T/inmunología , Femenino , Antígeno HLA-A2/inmunología , Humanos , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/inmunología , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/inmunologíaRESUMEN
RNA viruses undergo rapid sequence variation as the result of error-prone RNA replication mechanisms. When viable mutations arise in RNA regions encoding B or T cell epitopes, mutant viruses that can evade immune detection may be selected. In the carefully studied CTL response to the Gag p11C(C-M) epitope in SIVmac-infected Mamu-A*01(+) rhesus monkeys, it has been shown that CTL recognition of that epitope can occur even in the face of accruing mutations. To explore the underlying mechanism for this breadth of recognition, we have constructed Mamu-A*01 tetramers which discriminate T cells specific for epitope variants. Using these reagents we have defined discrete subsets of p11C(C-M)-specific T cells that cross-react with cells presenting variant peptides. We have found that individual Mamu-A*01(+) monkeys differ functionally in their ability to recognize epitope variants despite consistently strong recognition of the p11C(C-M) epitope. This functional difference is accounted for by the relative number of variant-specific T cells and by differences in the functionally relevant TCR repertoire of the infected monkeys. We have also found that monkeys immunized with DNA vaccine constructs encoding only the wild-type epitope sequence develop p11C(C-M)-specific CTL cross-reactive with variant peptides. Thus, cross-reactive CTL do not merely arise secondary to the emergence and immune presentation of viral CTL escape mutants but rather arise de novo following priming with a dominant epitope peptide sequence. Taken together, our results support the concept that the CTL response to a dominant viral epitope, although highly focused, can be clonally diverse and recognize potential epitope variants.
Asunto(s)
Productos del Gen gag/inmunología , Epítopos Inmunodominantes , Fragmentos de Péptidos/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Reacciones Cruzadas , Antígenos de Histocompatibilidad Clase I/química , Antígenos de Histocompatibilidad Clase I/fisiología , Macaca mulatta , MutaciónRESUMEN
Cholera toxin (CT) is frequently used as an experimental adjuvant intranasally for the induction of systemic and mucosal immunity. However, CT is highly reactogenic and not approved for use in humans. To define the cytokine requirements for the nasal activation of the systemic and mucosal immune system, and to design new adjuvants with efficacy similar to CT, we defined the cytokines that were able to replace CT as a nasal adjuvant for the induction of CTL. BALB/c mice were nasally immunized with an HIV immunogen that contains an MHC class I-restricted CTL epitope +/- cytokines and tested for HIV-specific immune responses. We found that combinations of IL-1alpha plus IL-18, IL-1alpha plus IL-12, and IL-1alpha plus IL-12 plus GM-CSF each induced optimal splenocyte anti-HIV CTL responses in immunized mice (range 60-71% peptide-specific (51)Cr release). Peak H-2D(d)-peptide tetramer-binding T cell responses induced by cytokine combinations were up to 5.5% of CD8(+) PBMC. Nasal immunization with HIV immunogen and IL-1alpha, IL-12, and GM-CSF also induced Ag-specific IFN-gamma-secreting cells in the draining cervical lymph node and the lung. The use of IL-1alpha, IL-12, and GM-CSF as nasal adjuvants was associated with an increased expression of MHC class II and B7.1 on nonlymphocytes within the nasal-associated lymphoid tissue/nasal mucosa. Thus, IL-1alpha, IL-12, IL-18, and GM-CSF are critical cytokines for the induction of systemic and mucosal CTL after nasal immunization. Moreover, these cytokines may serve as effective adjuvants for nasal vaccine delivery.
Asunto(s)
Citocinas/farmacología , Linfocitos T Citotóxicos/inmunología , Administración Intranasal , Animales , Antígeno B7-1/análisis , Complejo CD3/análisis , Toxina del Cólera/inmunología , Femenino , VIH-1/inmunología , Antígenos de Histocompatibilidad Clase II/análisis , Inmunidad Mucosa/efectos de los fármacos , Inmunización , Interferón gamma/biosíntesis , Ratones , Ratones Endogámicos BALB CRESUMEN
The ability to monitor vaccine-elicited CD8(+) cytotoxic T-lymphocyte (CTL) responses in simian immunodeficiency virus (SIV)- and simian-human immunodeficiency virus (SHIV)-infected rhesus monkeys has been limited by our knowledge of viral epitopes predictably presented to those lymphocytes by common rhesus monkey MHC class I alleles. We now define an SIV and SHIV Nef CTL epitope (YTSGPGIRY) that is presented to CD8(+) T lymphocytes by the common rhesus monkey MHC class I molecule Mamu-A*02. All seven infected Mamu-A*02(+) monkeys evaluated demonstrated this response, and peptide-stimulated interferon gamma Elispot assays indicated that the response represents a large proportion of the entire CD8(+) T-lymphocyte SIV- or SHIV-specific immune response of these animals. Knowledge of this epitope and MHC class I allele substantially increases the number of available rhesus monkeys that can be used for testing prototype HIV vaccines in this important animal model.
Asunto(s)
Alelos , Productos del Gen nef/inmunología , Genes MHC Clase I , Antígenos de Histocompatibilidad Clase I/genética , Virus de la Inmunodeficiencia de los Simios/inmunología , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Animales , Epítopos , Macaca mulatta , Datos de Secuencia MolecularRESUMEN
Accumulating evidence has demonstrated the importance of cytotoxic T lymphocytes (CTLs) and helper T lymphocytes in controlling HIV-1 replication. We have elicited immune responses in rhesus monkeys utilizing DNA vaccines augmented by the administration of IL-2/Ig, a fusion protein consisting of interleukin-2 and the Fc portion of IgG2. These vaccine-elicited immune responses did not prevent infection following a high-dose intravenous challenge with SHIV(89.6P) but did control viremia to nearly undetectable levels and prevented immunodeficiency and clinical disease. In contrast, control monkeys developed high levels of viremia and exhibited a rapid loss of CD4(+) T cells, significant clinical disease progression, and death in half of the animals by day 140 following challenge. Vaccine approaches that elicit immune responses capable of reducing plasma viral loads, but not capable of inducing sterilizing immunity, may still provide substantial clinical benefits.
Asunto(s)
Vacunas contra el SIDA/farmacología , Síndrome de Inmunodeficiencia Adquirida/inmunología , Síndrome de Inmunodeficiencia Adquirida/prevención & control , Macaca mulatta/inmunología , Vacunas contra el SIDAS/farmacología , Vacunas de ADN/farmacología , Animales , Recuento de Linfocito CD4 , Anticuerpos Anti-VIH/biosíntesis , Infecciones por VIH/inmunología , Fragmentos Fc de Inmunoglobulinas/administración & dosificación , Interleucina-2/administración & dosificación , Pruebas de Neutralización , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Linfocitos T Citotóxicos/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Viremia/inmunología , Viremia/prevención & controlRESUMEN
The contribution of immune reconstitution following antiretroviral treatment to the prevention or treatment of human immunodeficiency virus-related primary or reactivation tuberculosis remains unknown. Macaque models of simian immunodeficiency virus-Mycobacterium bovis BCG (SIV/BCG) coinfection were employed to determine the extent to which anti-Mycobacterium tuberculosis immunity can be restored by antiretroviral therapy. Both SIV-infected macaques with active BCG reinfection and naive animals with simultaneous SIV/BCG coinfection were evaluated. The suppression of SIV replication by antiretroviral treatment resulted in control of the active BCG infection and blocked development of the fatal SIV-related tuberculosis-like disease. The resolution of this disease coincided with the restoration of BCG purified protein derivative (PPD)-specific T-cell immune responses. In contrast, macaques similarly coinfected with SIV/BCG but not receiving antiretroviral therapy had depressed PPD-specific primary and memory T-cell immune responses and died from tuberculosis-like disease. These results provide in vivo evidence that the restoration of anti-mycobacterial immunity by antiretroviral agents can improve the clinical outcome of an AIDS virus-related tuberculosis-like disease.
Asunto(s)
Adenina/análogos & derivados , Antivirales/uso terapéutico , Inhibidores de la Proteasa del VIH/uso terapéutico , Indinavir/uso terapéutico , Mycobacterium bovis/efectos de los fármacos , Nelfinavir/uso terapéutico , Organofosfonatos , Síndrome de Inmunodeficiencia Adquirida del Simio/tratamiento farmacológico , Tuberculosis/fisiopatología , Adenina/uso terapéutico , Animales , Células Cultivadas , Macaca mulatta , Macaca nemestrina , Compuestos Organofosforados/uso terapéutico , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/genética , Linfocitos T/citología , Linfocitos T/inmunología , Tenofovir , Tuberculosis/inmunologíaRESUMEN
Most immunosuppressed individuals who develop progressive multifocal leukoencephalopathy (PML) have a rapid fatal outcome, whereas some become long-term survivors. We explored the impact of the cellular immune response against JC virus (JCV) on the clinical outcome of 7 HIV+ and 3 HIV- individuals with PML. Of the 4 HIV+/PML survivors, all had detectable cytotoxic T lymphocytes (CTL) specific for JCV T or VP 1 proteins compared to none of the 3 HIV+/PML progressors tested. Of the 3 HIV-/PML patients, 1 was recently diagnosed with PML and showed evidence of neurologic improvement without any treatment. This patient had CTL specific for the VP1 protein of JCV. The other 2 HIV-/PML survivors were stable 3-8 years after the diagnosis of PML. They did not have any detectable CTL against JCV. These findings suggest that JCV-specific immune response is associated with favorable outcome in HIV+ individuals with PML. The lack of detectable JCV-specific CTL in 2 HIV-/PML survivors might indicate a burnt-out disease without sufficient antigenic stimulation to maintain the cellular immune response. The detection of JCV-specific CTL in an HIV- patient recently diagnosed with PML, who was showing evidence of neurological improvement without any treatment, indicates that this finding may be used as a favorable prognostic marker of disease evolution in the clinical management of patients with PML. As the quest for an effective treatment of PML continues, JCV-specific cellular immune response deserves further attention because it appears to play a crucial role in the prevention of disease progression.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/inmunología , Inmunidad Celular/inmunología , Virus JC/inmunología , Leucoencefalopatía Multifocal Progresiva/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/mortalidad , Infecciones Oportunistas Relacionadas con el SIDA/virología , Síndrome de Inmunodeficiencia Adquirida/mortalidad , Síndrome de Inmunodeficiencia Adquirida/virología , Humanos , Leucoencefalopatía Multifocal Progresiva/mortalidad , Leucoencefalopatía Multifocal Progresiva/virología , Pronóstico , Tasa de Supervivencia , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/virologíaRESUMEN
Immune containment of persistent viral infections has long been a focus of interest for investigators. However, the technologies needed to evaluate the role of CD8+ cytotoxic T lymphocytes (CTLs) in this process have only recently become available. Recent studies performed using tetramer, ELISPOT and cytokine-production assays have evaluated the role of CD8+ CTLs in controlling lentivirus and herpesvirus infections in humans and nonhuman primates. These studies demonstrate dramatic expansions of virus-specific CTLs in primary infection and the maintenance of unexpectedly high levels of virus-specific CTLs in chronic infection. These findings underscore the importance of CD8+ CTLs in the immune control of persistent viral infections.
Asunto(s)
Herpesviridae/inmunología , Lentivirus/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Citomegalovirus/inmunología , VIH-1/inmunología , Herpesvirus Humano 4/inmunología , Humanos , Virus de la Inmunodeficiencia de los Simios/inmunología , Virosis/inmunologíaRESUMEN
The T cell-stimulatory cytokine interleukin 2 (IL-2) is being evaluated as a therapeutic in the clinical settings of HIV infection and cancer. However, the clinical utility of IL-2 may be mitigated by its short in vivo half-life, toxic effects, and high production costs. We show here that an IL-2/Ig fusion protein possesses IL-2 immunostimulatory activity in vitro and a long in vivo half-life. IL-2/Ig treatment of healthy rhesus monkeys induced significant increases in CD4(+) T lymphocyte counts and expression of CD25 by these cells. Short courses of IL-2/Ig treatment of simian immunodeficiency virus (SIV)-infected rhesus monkeys in conjunction with antiretroviral drugs resulted in increased CD25 expression on T lymphocytes, and transient increases in CD4(+) T lymphocyte counts. Plasma viremia did not increase in these treated animals. Treatment of healthy or SIV-infected rhesus monkeys with a plasmid encoding the IL-2/Ig protein did not affect CD4(+) T lymphocytes. These results demonstrate that IL-2/Ig has potential utility as an immunostimulatory therapeutic.
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Linfocitos T CD4-Positivos/inmunología , Inmunoglobulina G/uso terapéutico , Interleucina-2/uso terapéutico , Proteínas Recombinantes de Fusión , Proteínas Recombinantes de Fusión/farmacología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Animales , Fármacos Anti-VIH/administración & dosificación , Citometría de Flujo , Inmunoglobulina G/genética , Interleucina-2/genética , Recuento de Linfocitos , Macaca mulatta , Plásmidos/administración & dosificación , Plásmidos/inmunología , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/farmacocinética , Transfección , Carga ViralRESUMEN
The mechanism of the progressive loss of CD4+ T lymphocytes, which underlies the development of AIDS in human immunodeficiency virus (HIV-1)-infected individuals, is unknown. Animal models, such as the infection of Old World monkeys by simian-human immunodeficiency virus (SHIV) chimerae, can assist studies of HIV-1 pathogenesis. Serial in vivo passage of the nonpathogenic SHIV-89.6 generated a virus, SHIV-89.6P, that causes rapid depletion of CD4+ T lymphocytes and AIDS-like illness in monkeys. SHIV-KB9, a molecularly cloned virus derived from SHIV-89.6P, also caused CD4+ T-cell decline and AIDS in inoculated monkeys. It has been demonstrated that changes in the envelope glycoproteins of SHIV-89.6 and SHIV-KB9 determine the degree of CD4+ T-cell loss that accompanies a given level of virus replication in the host animals (G. B. Karlsson et. al., J. Exp. Med. 188:1159-1171, 1998). The envelope glycoproteins of the pathogenic SHIV mediated membrane fusion more efficiently than those of the parental, nonpathogenic virus. Here we show that the minimal envelope glycoprotein region that specifies this increase in membrane-fusing capacity is sufficient to convert SHIV-89.6 into a virus that causes profound CD4+ T-lymphocyte depletion in monkeys. We also studied two single amino acid changes that decrease the membrane-fusing ability of the SHIV-KB9 envelope glycoproteins by different mechanisms. Each of these changes attenuated the CD4+ T-cell destruction that accompanied a given level of virus replication in SHIV-infected monkeys. Thus, the ability of the HIV-1 envelope glycoproteins to fuse membranes, which has been implicated in the induction of viral cytopathic effects in vitro, contributes to the capacity of the pathogenic SHIV to deplete CD4+ T lymphocytes in vivo.
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Linfocitos T CD4-Positivos/inmunología , Proteína gp120 de Envoltorio del VIH/metabolismo , Proteína gp41 de Envoltorio del VIH/metabolismo , VIH-1/patogenicidad , Depleción Linfocítica , Virus de la Inmunodeficiencia de los Simios/patogenicidad , Animales , Proteína gp120 de Envoltorio del VIH/genética , Proteína gp41 de Envoltorio del VIH/genética , Infecciones por VIH/inmunología , VIH-1/fisiología , Humanos , Ganglios Linfáticos/citología , Ganglios Linfáticos/inmunología , Macaca , Fusión de Membrana , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/fisiologíaRESUMEN
JC virus (JCV), the causative agent of progressive multifocal leukoencephalopathy (PML), has a hypervariable regulatory region (JCV RR). A conserved archetype form is found in the urines of healthy and immunocompromised individuals, whereas forms with tandem repeats and deletions are found in the brains of PML patients. Type I JCV RR, seen in MAD-1, the first sequenced strain of JCV, contains two 98-bp tandem repeats each containing a TATA box. Type II JCV RR has additional 23-bp and 66-bp inserts or fragments thereof and only one TATA box. We cloned and sequenced JCV RR from different anatomic compartments of PML patients and controls and correlated our findings with the patients' clinical outcome. Twenty-three different sequences were defined in 198 clones obtained from 16 patients. All 104 clones with tandem repeats were type II JCV RR. Patients with poor clinical outcome had high proportions of JCV RR clones with both tandem repeats in plasma (54%) and brain or cerebrospinal fluid (85%). In those who became survivors of PML, archetype sequences predominated in these anatomic compartments (75 and 100%, respectively). In patients with advanced human immunodeficiency virus infection without PML, only 8% of JCV RR clones obtained in the plasma contained tandem repeats. These data suggest that the presence of tandem repeats in plasma and CNS JCV RR clones is associated with poor clinical outcome in patients with PML.