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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Current evidence suggests that a strong induced CD8 human immunodeficiency virus type 1 (HIV-1)-specific cell mediated immune response may be an important aspect of an HIV vaccine. The response rates and the magnitude of the CTL responses induced by current DNA vaccines in humans need to be improved and cellular immune responses to DNA vaccines can be enhanced in mice by co-delivering DNA plasmids expressing immune modulators. Two reported to work well in the mouse systems are interleukin (IL)-12 and CD40L. We sought to compare these molecular adjuvants in a primate model system. The cDNA for macaque IL-12 and CD40L were cloned into DNA vectors. Groups of cynomolgus macaques were immunized with 2 mg of plasmid expressing SIVgag alone or in combination with either IL-12 or CD40L. CD40L did not appear to enhance the cellular immune response to SIVgag antigen. However, more robust results were observed in animals co-injected with the IL-12 molecular adjuvant. The IL-12 expanded antigen-specific IFN-gamma positive effector cells as well as granzyme B production. The vaccine immune responses contained both a CD8 component as well a CD4 component. The adjuvanted DNA vaccines illustrate that IL-12 enhances a CD8 vaccine immune response, however, different cellular profiles.
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PMID:SIV DNA vaccine co-administered with IL-12 expression plasmid enhances CD8 SIV cellular immune responses in cynomolgus macaques. 1612 21

The impaired functional activity of cytotoxic T lymphocytes and natural killer cells during HIV-1 infection has recently been attributed to decreased intracellular levels of perforin and granzyme B. In sera from individuals chronically infected with HIV-1 we report increased levels of extracellular perforin compared with uninfected individuals. Increased perforin was also observed during experimental SIV/SHIV infection. The combination of reduced intracellular perforin levels and an increased serum level indicates that HIV infection induces aberrant perforin secretion.
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PMID:Elevated levels of serum perforin in chronic HIV-1 and acute SIV/SHIV infection. 1632 31

We investigated the circulating cytotoxic CD160+ CD8(high) subset in correlation to antiviral immunity and response to highly active antiretroviral therapy (HAART) in HIV+ subjects. The study included 45 treatment-naive patients receiving HAART for 18 months, retrospectively defined as good (n=29) and transient (n=16) responders. HIV-specific CD8 T lymphocyte levels were measured by IFNgamma production in response to p17 Gag, in the presence of immobilized anti-CD160 mAb. We report a significantly increased baseline level of CD160+ CD8(high) subset in good therapy responders. CD160+ CD8(high) subset correlates with CD4+ T cell count, immune activation, and viral load. CD160+ CD8(high) lymphocytes contain a high amount of Granzyme B and include virus-specific T lymphocytes in HIV-1+ subjects. Co-stimulation through CD160 molecules enhances IFNgamma production in response to p17 Gag. Therefore, the CD160+ CD8(high) subset may be useful for monitoring of virus-specific cellular immunity and predicting response to antiretroviral therapy in chronic HIV-1 infection.
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PMID:The CD160+ CD8high cytotoxic T cell subset correlates with response to HAART in HIV-1+ patients. 1633 31

HIV-1 infection generates maturational responses in overall CD4 and CD8 T cell populations in adults, with elevated expression of lytic effector molecules perforin and granzyme B, and reduced expression of CCR7 and CD45RA. Here, we have found that these marked effects were significantly less pronounced in children, both in terms of the skewed CCR7/CD45RA expression profile as well as the increased perforin expression. Similar to adults, HIV-specific CD8 cells in children were largely CD27+ CD45RA- and lacked perforin. However, one pediatric subject with late-stage infection displayed robust expansion of Gag 77-85-specific CD8 T cells which were perforin+ and lytic, but lacked expression of CD27 and IFNgamma. Our data indicate that the T cell effector maturation induced by HIV-1 infection is markedly weaker in children as compared to adults. The data also suggest, however, that the perforin-deficient state of HIV-specific CD8 T cells in children may be reversible.
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PMID:CD8 T cell effector maturation in HIV-1-infected children. 1640 47

Functional impairment of virus-specific memory CD8(+) T lymphocytes has been associated with clinical disease progression following HIV, SIV, and simian human immunodeficiency virus infection. These lymphocytes have a reduced capacity to produce antiviral cytokines and mediators involved in the lysis of virally infected cells. In the present study, we used polychromatic flow cytometry to assess the frequency and functional capacity of central memory (CD28(+)CD95(+)) and effector memory (CD28(-)CD95(+)) subpopulations of Gag-specific CD8(+) T cells in SIV/simian human immunodeficiency virus-infected rhesus monkeys. The aim of this study was to determine whether Ag-specific, memory CD8(+) T cell function could be preserved in infected monkeys that had been immunized before infection with a vaccine regimen consisting of a plasmid DNA prime followed by a recombinant viral vector boost. We observed that vaccination was associated with the preservation of Gag-specific central memory CD8(+) T cells that were functionally capable of producing IFN-gamma, and effector memory CD8(+) T cells that were capable of producing granzyme B following viral Ag exposure.
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PMID:Preservation of functional virus-specific memory CD8+ T lymphocytes in vaccinated, simian human immunodeficiency virus-infected rhesus monkeys. 1662 1

A 17-year-old girl previously in good health presented with a 2-month history of recurrent, high-grade fever; general fatigue; anorexia; a 10-kg weight loss; and multiple, painful, reddish skin lesions on the lower abdomen. Some lesions were ulcerated, with an oily yellowish brown discharge. A systemic review was unremarkable other than bleeding from the nose. Her medical and family histories were unremarkable. On examination, the patient was pale, jaundiced, and febrile (temperature of 39 degrees C). She had enlarged lymph nodes in the axillary and inguinal areas. There was moderate hepatosplenomegaly. Local skin examination revealed multiple erythematous, tender, and firm subcutaneous nodules of variable size (1-2 cm) on the lower abdomen. Some nodules were ulcerated, with oily yellowish brown discharge and overlying ecchymosis (Figures 1 and 2). Mucous membranes were free of lesions. Laboratory investigations showed pancytopenia, an elevated erythrocyte sedimentation rate (>80 mm/h), normal renal function tests, abnormal hepatic function tests (alanine aminotransferase 172 U/L, aspartate aminotransferase 229 U/L, alkaline phosphatase 725 U/L, and total bilirubin 100 mmol/L [normal range 0-18 mmol/L]), conjugated bilirubin 45 mmol/L (normal range 0-5 mmol/L), and high triglycerides 855 mg/dL (normal range 20-200 mg/dL). Prolonged prothrombin time, 26 seconds (normal range 13-16 seconds); prolonged activated partial thromboplastin time, 61 seconds (normal range 26-38 seconds); positive disseminated intravascular coagulation studies evidenced by low fibrinogen, 74 mg/dL (normal range 160-350 mg/dL); and positive fibrinogen degradation products were also noted. Throat, midstream urine, and blood culture results were negative. Serologic tests for syphilis, HIV, and hepatitis B and C viruses were negative. Epstein-Barr virus and cytomegalovirus serologic values revealed evidence of past infection. Tuberculin and Coombs tests were negative. The alpha1-antitrypsin level was normal. Antinuclear and anti-smith antibodies, rheumatoid factor, and cryoglobulins were negative. CT showed enlarged lymph nodes in the axillary and inguinal areas, bilateral small pleural effusion, moderate hepatosplenomegaly, severe fatty infiltration of the liver, and thickening of lower abdominal subcutaneous tissue. A liver biopsy showed steatohepatitis. Bone marrow aspirate and trephine were normal. A deep punch biopsy of a nodule from the right lower abdomen revealed lobular panniculitis with atypical lymphocytes and large macrophages with cytophagocytosis ("beanbag" cells) (Figures 3 and 4). Immunohistochemistry showed that these atypical cells were positive for CD3, CD8, granzyme B, and perforin, and negative for CD56. T-cell gene rearrangement studies on skin lesions revealed a monoclonal T-cell receptor (gamma-chain) gene rearrangement, supporting the diagnosis of subcutaneous panniculitis-like T-cell lymphoma. On presentation, the initial treatment included 6 U of fresh frozen plasma, 2 U of packed red blood cells, and 2 g IV fibrinogen for 3 consecutive days. The patient was started on prednisolone 60 mg orally once daily and cyclosporine A 5 mg/kg/d orally in two divided doses. The fever and other systemic symptoms and skin lesions resolved within 2 weeks after the treatment. The prednisolone dose was tapered gradually, and a maintenance dose of cyclosporine A was continued. The patient's condition remained in remission at 12-month follow-up; there was no evidence of clinical relapse.
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PMID:Subcutaneous panniculitis-like T-cell lymphoma with hemophagocytic syndrome successfully treated with cyclosporin A. 1685 14

CD8+ T cells infiltrate brains with human immunodeficiency virus type-1 (HIV-1) encephalitis (HIVE) and related animal models; their perineuronal localization suggests cytotoxic T cell (CTL)-mediated neuronal killing. Because CTLs have not been identified in acquired immunodeficiency syndrome (AIDS) brains, the authors identified their cytotoxic granules in autopsy AIDS brains with HIVE and without HIVE (HIVnE) plus controls (7 to 13 cases/group) and determined gene expression profiles of CTL-associated genes in a separate series of cases. CD3+ and CD8+ T cells were significantly increased (P < .01) in perivascular spaces and inflammatory nodules in HIVE but were rare or absent in brain parenchyma in HIVnE and control brains. Eight HIVE brains contained granzyme B+ T cells and five contained perforin+ T cells. Their T-cell origin was confirmed by colocalization of CD8 and granzyme B in the same cell and the absence of CD56+ natural killer cells. The CTLs directly contacted with neurons, as the authors showed previously for CD3+ and CD8+ T cells. CTLs were rare or absent in HIV nonencephalitis (HIVnE) and controls. Granzyme B and H precursor gene expression was up-regulated and interleukin (IL)-12A precursor, a maturation factor for natural killer cells and CTLs, was down-regulated in HIVE versus HIVnE brain. This study demonstrates, for the first time, CTLs in HIVE and shows that parenchymal T cells and CTLs are sensitive biomarkers for HIVE. Consequently, CD8+ T cells and CTLs could mediate brain injury in HIVE and may represent an important biomarker for productive brain infection by HIV-1.
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PMID:Brain CD8+ and cytotoxic T lymphocytes are associated with, and may be specific for, human immunodeficiency virus type 1 encephalitis in patients with acquired immunodeficiency syndrome. 1696 18

HIV DNA vaccines are potent inducers of cell-mediated immune (CMI) response in mice but elicit poor HIV-specific IFN-gamma-producing T cells in monkeys and humans. In this study, we performed kinetic analyses on splenocytes of BALB/c mice that were immunized by a single injection with a unique DNA vaccine. Using IFN-gamma-ELISPOT and multiparametric FACS analysis, we characterized the induced CMI response. We found that the response was detectable for at least 63 wk. ELISPOT detection of IFN-gamma-producing T cells showed a profile with two waves separated by a long period of minimal response. Multiparametric FACS analysis showed two populations of CD3(+)CD8(+) T cells that were specific for all HIV Ags. These cells had similar robust proliferation abilities and contained granzyme B. However, only a few produced IFN-gamma. Both IFN-gamma-producing and non-IFN-gamma-producing HIV-specific CD8(+) T cells were detected in the early stage (week (W)1 and W2 postimmunization (PI)), in the prolonged intermediate period of minimal response (W4-W26 PI), and in the final late phase of increased response (W30-W63 PI). Our longitudinal characterization showed that both subsets of cells underwent expansion, contraction, and memory generation/maintenance phases throughout the lifespan of the animal. Altogether, these findings bring insight to the heterogeneity of the immune T cell response induced by a single immunization with this DNA and strengthen the concept that used of the IFN-gamma-ELISPOT assay alone may be insufficient to detect critical T cell responses to candidate HIV vaccines.
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PMID:Phenotypic and functional analysis of immune CD8+ T cell responses induced by a single injection of a HIV DNA vaccine in mice. 1727 37

The quality of virus-specific CD8(+) CTL immune responses generated by mucosal and systemic poxvirus prime-boost vaccines were evaluated in terms of T cell avidity and single-cell analysis of effector gene expression. Intranasal (I.N.) immunization regimes generated higher avidity CTL responses specific for HIV K(d)Gag(197-205) (amino acid sequence AMQMLKETI; H-2K(d) binding) compared with i.m. immunization regime. Single-cell RT-PCR of K(d)Gag(197-205)-specific mucosal and systemic CTL revealed that the cytokine and granzyme B expression profiles were dependent on both the route and time after immunization. The I.N./i.m.-immunized group elicited elevated number of CTL-expressing granzyme B mRNA from the genitomucosal sites compared with the i.m./i.m. regime. Interestingly, CTL generated after both I.N. or i.m. immunization demonstrated expression of Th2 cytokine IL-4 mRNA that was constitutively expressed over time, although lower numbers were observed after I.N./I.N. immunization. Results suggest that after immunization, Ag-specific CTL expression of IL-4 may be an inherent property of the highly evolved poxvirus vectors. Current observations indicate that the quality of CTL immunity generated after immunization can be influenced by the inherent property of vaccine vectors and route of vaccine delivery. A greater understanding of these factors will be crucial for the development of effective vaccines in the future.
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PMID:Mucosal HIV-1 pox virus prime-boost immunization induces high-avidity CD8+ T cells with regime-dependent cytokine/granzyme B profiles. 1727 43

Repeated exposure to human immunodeficiency virus (HIV) does not always result in HIV infection, and several cohorts of HIV-exposed but uninfected (EU) individuals have been described. We studied T-helper and granule-dependent cytotoxic T-lymphocyte (CTL) activities in a group of 30 EU partners of HIV type 1 (HIV-1)-infected individuals. HIV-1-specific helper-T-cell activity was studied by measuring the levels of interleukin 2 (IL-2) produced by peripheral blood mononuclear cells (PBMCs) and the granule-dependent CTL activity by measuring the intracellular levels of perforin and granzyme B expression in CD8+ T cells after stimulation with gag p24 antigen. Elevated IL-2 production by PBMCs after p24 stimulation occurred in EU individuals. The levels of perforin and granzyme B expression in CD8+ T cells were also higher among EU individuals than among healthy controls. HIV-specific helper-T-cell and granule-dependent CTL activities inversely correlated with the time since the last unprotected sexual exposure in these individuals. In our cohort, activation of T-helper and granule-dependent CTL activities against HIV might be due to unprotected sexual contact. These results indicate that HIV-1-specific T-cell responses could play a role in protection against acquiring infection in this cohort of EU individuals.
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PMID:Human immunodeficiency virus (HIV) gag antigen-specific T-helper and granule-dependent CD8 T-cell activities in exposed but uninfected heterosexual partners of HIV type 1-infected individuals in North India. 1782 71


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