Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 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 recently proposed Piqueras classification of common variable immunodeficiency (CVID) patients is based on flow cytometric quantification of IgD class-switched and CD27 membrane-expressing mature blood B cells. But, many patients also have circulating T cells with immunophenotypic abnormalities, often associated with clinical complications, such as splenomegaly, autoimmune disease, lymphoid proliferation and/or granulomatosis. In 50 unselected CIVD patients, classified according to CD27 and IgD B-cell expression, we analyzed T-lymphocyte subsets according to their expression of HLA-DR and intracellular perforin and/or granzyme B in CD8+ T lymphocytes, CCR7 and CD45RA. CD3+DR+ T-lymphocyte percentages, predominantly CD8+DR+, were significantly higher in patients with clinical complications. MB0 classified patients, characterized by fewer CD27+ B cells, had higher percentages of CD8+DR+ T lymphocytes expressing perforin and/or granzyme with a differentiated effector (CCR7- and CD45RA+) phenotype. In contrast, MB2 patients (with normal CD27+ and IgD- B cells) were free of clinical complications and showed no signs of T-cell activation. MB1 patients (normal CD27+ numbers but fewer IgD- B cells) were either clinically normal or had complications. Combining the set of markers described herein might better define homogeneous groups of patients for etiological studies and clearly segregate patients with clinical complications.
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PMID:CD8+HLA-DR+ T lymphocytes are increased in common variable immunodeficiency patients with impaired memory B-cell differentiation. 1641 28

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

Circulating CD4+ CD8+ T lymphocytes have been described in the peripheral blood of humans and several animal species. However, the origin and functional properties of these cells remain poorly understood. In the present study, we evaluated the frequency, phenotype and function of peripheral CD4+ CD8+ T cells in rhesus macaques. Two distinct populations of CD4+ CD8+ T cells were identified: the dominant one was CD4hi CD8lo and expressed the CD8alphaalpha homodimer, while the minor population was CD4lo CD8hi and expressed the CD8alphabeta heterodimer. The majority of CD4hi CD8alphalo T cells exhibited an activated effector/memory phenotype (CCR5lo CD7- CD28- HLA-DR+) and expressed relatively high levels of granzyme B. Intracellular cytokine staining assays demonstrated that the frequency of cytomegalovirus-specific T cells was enriched five-fold in CD4hi CD8alphalo T cells compared to single-positive CD4+ T cells, whereas no consistent enrichment was observed for simian immunodeficiency virus (SIV)-specific T cells. Cross-sectional studies of SIV-infected animals demonstrated that the frequency of CD4hi CD8alphalo T cells was lower in wild-type SIV-infected animals compared to uninfected controls, although prospective studies of SIV-infected animals demonstrated depletion of CD4hi CD8alphalo lymphocytes only in a subset of animals. Taken together, these data suggest that CD4+ T cells expressing CD8alpha represent an effector/memory subset of CD4+ T cells and that this cell population can be depleted during the course of SIV infection.
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PMID:Expression of CD8alpha identifies a distinct subset of effector memory CD4+ T lymphocytes. 1731 53

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

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

Antibody-dependent cellular cytotoxicity (ADCC) is a potentially effective adaptive immune response to human immunodeficiency virus (HIV) infection. The study of ADCC responses has been hampered by the lack of simple methods to quantify these responses and map effective epitopes. We serendipitously observed that standard intracellular cytokine assays on fresh whole blood from a cohort of 26 HIV-infected subjects identified non-T lymphocytes expressing gamma interferon (IFN-gamma) in response to overlapping linear peptides spanning HIV-1 proteins. The effector cells were CD3(-) CD4(-) CD8(-) CD14(-) CD2(+) CD56(+/-) NK lymphocytes and degranulated granzyme B and perforin in response to antigen stimulation. Serum transfer assays demonstrated that the specific response was mediated by immunoglobulin G. Fresh blood samples from half of the HIV-infected cohort demonstrated robust HIV peptide-specific IFN-gamma expression by NK cells, predominately to Env, Pol, and Vpu HIV-1 proteins. Responses were readily mapped to define minimal epitopes utilizing this assay. Antibody-dependent, HIV-specific NK cell recognition, involving components of both innate and adaptive immune systems, represents a potentially effective immune response to induce by vaccination.
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PMID:Robust NK cell-mediated human immunodeficiency virus (HIV)-specific antibody-dependent responses in HIV-infected subjects. 1835 57

African green monkeys (AGM) do not develop overt signs of disease following simian immunodeficiency virus (SIV) infection. While it is still unknown how natural hosts like AGM can cope with this lentivirus infection, a large number of investigations have shown that CD8(+) T-cell responses are critical for the containment of AIDS viruses in humans and Asian nonhuman primates. Here we have compared the phenotypes of T-cell subsets and magnitudes of SIV-specific CD8(+) T-cell responses in vervet AGM chronically infected with SIVagm and rhesus monkeys (RM) infected with SIVmac. In comparison to RM, vervet AGM exhibited weaker signs of immune activation and associated proliferation of CD8(+) T cells as detected by granzyme B, Ki-67, and programmed death 1 staining. By gamma interferon enzyme-linked immunospot assay and intracellular cytokine staining, SIV Gag- and Env-specific immune responses were detectable at variable but lower levels in vervet AGM than in RM. These observations demonstrate that natural hosts like SIV-infected vervet AGM develop SIV-specific T-cell responses, but the disease-free course of infection does not depend on the generation of robust CD8(+) T-cell responses.
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PMID:Simian immunodeficiency virus (SIV)-specific CD8+ T-cell responses in vervet African green monkeys chronically infected with SIVagm. 1882 48

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections impair plasmacytoid dendritic cell (PDC) and natural killer (NK) cell subset numbers and functions, though little is known about PDC-NK cell interactions during these infections. We evaluated PDC-dependent NK cell killing and gamma interferon (IFN-gamma) and granzyme B production, using peripheral blood mononuclear cell (PBMC)-based and purified cell assays of samples from HCV- and HIV-infected subjects. CpG-enhanced PBMC killing and IFN-gamma and granzyme B activity (dependent on PDC and NK cells) were impaired in viremic HIV infection. In purified PDC-NK cell culture experiments, CpG-enhanced, PDC-dependent NK cell activity was cell contact and IFN-alpha dependent, and this activity was impaired in viremic HIV infection but not in HCV infection. In heterologous PDC-NK cell assays, impaired PDC-NK cell killing activity was largely attributable to an NK cell defect, while impaired PDC-NK cell IFN-gamma-producing activity was attributable to both PDC and NK cell defects. Additionally, the response of NK cells to direct IFN-alpha stimulation was defective in viremic HIV infection, and this defect was not attributable to diminished IFN-alpha receptor expression, though IFN-alpha receptor and NKP30 expression was closely associated with killer activity in viremic HIV infection but not in healthy controls. These data indicate that during uncontrolled HIV infection, PDC-dependent NK cell function is impaired, which is in large part attributable to defective IFN-alpha-induced NK cell activity and not to altered IFN-alpha receptor, NKP30, NKP44, NKP46, or NKG2D expression.
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PMID:Impaired plasmacytoid dendritic cell (PDC)-NK cell activity in viremic human immunodeficiency virus infection attributable to impairments in both PDC and NK cell function. 1969 59

Regulatory CD4(+) T cells (Treg) are important modulators of the immune response. Different types of Treg have been identified based on whether they are thymically derived (natural Treg) or induced in the periphery (adaptive Treg). We recently reported on an adaptive Treg phenotype that can be induced by the concomitant stimulation of human CD4(+) T cells through CD3 and the membrane complement regulator CD46. These complement (CD46)-induced regulatory T cells (cTreg) potently inhibit bystander T-cell proliferation through high-level secretion of IL-10. In addition, cTreg express granzyme B and exhibit cytotoxic effects toward activated effector T cells. Here, we analyzed the effect of cTreg on B-cell functions in a co-culture system. We found that cTreg enhance B-cell Ab production. This B-cell support is dependent on cell/cell contact as well as cTreg-derived IL-10. In addition, we show that T cells from a CD46-deficient patient are not capable of promoting B-cell responses, whereas CD46-deficient B cells have no intrinsic defect in Ig production. This finding may relate to a subset of CD46-deficient patients, who present with common variable immunodeficiency. Thus, the lack of cTreg function in optimizing B-cell responses could explain why some CD46-deficient patients develop common variable immunodeficiency.
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PMID:CD46-induced human Treg enhance B-cell responses. 1978 49


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