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Productive human immunodeficiency virus type 1 infection in peripheral blood predominantly takes place in CD4/CD8 double-negative T lymphocytes.

ABSTRACT: Human immunodeficiency virus type 1 (HIV-1) transcription is subject to substantial fluctuation during the viral life cycle. Due to the low frequencies of HIV-1-infected cells, and because latently and productively infected cells collocate in vivo, little quantitative knowledge has been attained about the range of in vivo HIV-1 transcription in peripheral blood mononuclear cells (PBMC). By combining cell sorting, terminal dilution of intact cells, and highly sensitive, patient-specific PCR assays, we divided PBMC obtained from HIV-1-infected patients according to their degree of viral transcription activity and their cellular phenotype. Regardless of a patient's treatment status, the bulk of infected cells exhibited a CD4+ phenotype but transcribed HIV-1 provirus at low levels, presumably insufficient for virion production. Furthermore, the expression of activation markers on the surface of these CD4+ T lymphocytes showed little or no association with enhancement of viral transcription. In contrast, HIV-infected T lymphocytes of a CD4-/CD8- phenotype, occurring exclusively in untreated patients, exhibited elevated viral transcription rates. This cell type harbored a substantial proportion of all HIV RNA+ cells and intracellular viral RNAs and the majority of cell-associated virus particles. In conjunction with the observation that the HIV quasispecies in CD4+ and CD4-)/CD8- T cells were phylogenetically closely related, these findings provide evidence that CD4 expression is downmodulated during the transition to productive infection in vivo. The abundance of viral RNA in CD4-/CD8- T cells from viremic patients and the almost complete absence of viral DNA and RNA in this cell type during antiretroviral treatment identify HIV+ CD4-/CD8 T cells as the major cell type harboring productive infection in peripheral blood.

SUBMITTER: Kaiser P

PROVIDER: S-EPMC2045436 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature

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Productive human immunodeficiency virus type 1 infection in peripheral blood predominantly takes place in CD4/CD8 double-negative T lymphocytes.

Kaiser Philipp P Joos Beda B Niederöst Barbara B Weber Rainer R Günthard Huldrych F HF Fischer Marek M

Journal of virology 20070703 18

Human immunodeficiency virus type 1 (HIV-1) transcription is subject to substantial fluctuation during the viral life cycle. Due to the low frequencies of HIV-1-infected cells, and because latently and productively infected cells collocate in vivo, little quantitative knowledge has been attained about the range of in vivo HIV-1 transcription in peripheral blood mononuclear cells (PBMC). By combining cell sorting, terminal dilution of intact cells, and highly sensitive, patient-specific PCR assay ...[more]

PMID: 17609262

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Project description:Human immunodeficiency virus type 1 (HIV-1) infection is characterized by progressive depletion of CD4+ T lymphocytes and dysfunction of the immune system. The numbers of CD4+ T lymphocytes in the human body are maintained constantly by homeostatic mechanisms that failed during HIV-1 infection, resulting in progressive loss of CD4+ T cells mainly via apoptosis. Recently, a non-apoptotic form of necrotic programmed cell death, named necroptosis, has been investigated in many biological and pathological processes. We then determine whether HIV-1-infected cells also undergo necroptosis. In this report, we demonstrate that HIV-1 not only induces apoptosis, but also mediates necroptosis in the infected primary CD4+ T lymphocytes and CD4+ T-cell lines. Necroptosis-dependent cytopathic effects are significantly increased in HIV-1-infected Jurkat cells that is lack of Fas-associated protein-containing death domain (FADD), indicating that necroptosis occurs as an alternative cell death mechanism in the absence of apoptosis. Unlike apoptosis, necroptosis mainly occurs in HIV-infected cells and spares bystander damage. Treatment with necrostatin-1(Nec-1), a RIP1 inhibitor that specifically blocks the necroptosis pathway, potently restrains HIV-1-induced cytopathic effect and interestingly, inhibits the formation of HIV-induced syncytia in CD4+ T-cell lines. This suggests that syncytia formation is mediated, at least partially, by necroptosis-related processes. Furthermore, we also found that the HIV-1 infection-augmented tumor necrosis factor-alpha (TNF-?) plays a key role in inducing necroptosis and HIV-1 Envelope and Tat proteins function as its co-factors. Taken together,necroptosis can function as an alternative cell death pathway in lieu of apoptosis during HIV-1 infection, thereby also contributing to HIV-1-induced cytopathic effects. Our results reveal that in addition to apoptosis, necroptosis also plays an important role in HIV-1-induced pathogenesis.

Project description:To investigate the mechanism and functional significance of infection of CD8+ lymphocytes by human immunodeficiency virus type 1 (HIV-1) in vivo, we determined frequencies of infection, proviral conformation, and genetic relationships between HIV-1 variants infecting naive (CD45RA+) and memory (CD45RO+) peripheral blood CD4+ and CD8+ lymphocytes. Infection of CD3+ CD8+ CD45RA+ cells was detected in 9 of 16 study subjects at frequencies ranging from 30 to 1,400 proviral copies/10(6) cells, more frequently than CD3+ CD8+ lymphocytes expressing the RO isoform of CD45 (n = 2, 70 and 260 copies /10(6) cells). In agreement with previous studies, there was no evidence for a similar preferential infection of CD4+ naive lymphocytes. Proviral sequences in both CD4+ and CD8+ lymphocyte subsets were complete, as assessed by quantitation using primers from the long terminal repeat region spanning the tRNA primer binding site. In six of the seven study subjects investigated, variants infecting CD8+ lymphocytes were partially or completely genetically distinct in the V3 region from those recovered from CD4+ lymphocytes and showed a greater degree of compartmentalization than observed between naive and memory subsets of CD4+ lymphocytes. In two study subjects, arginine substitutions at position 306, associated with use of the chemokine coreceptor CXCR4, were preferentially found in CD4 lymphocytes. These population differences may have originated through different times of infection rather than necessarily indicating a difference in their biological properties. The preferential distribution of HIV-1 in naive CD8+ lymphocytes indeed suggests that infection occurred early in T-lymphocyte ontogeny, such as during maturation in the thymus. Destruction of cells destined to become CD8+ lymphocytes may be a major factor in the decline in CD8+ lymphocyte frequencies and function on disease progression and may contribute directly to the observed immunodeficiency in AIDS.

Project description:BACKGROUND:High-affinity tumor antigen-specific T-cell receptor (TCR) gene is required to engineer potent T cells for therapeutic treatment of cancer patients. However, discovery of suitable therapeutic TCR genes is hampered by the fact that naturally occurring tumor antigen-specific TCRs are generally of low-affinity, and artificial modification of TCRs can mediate cross-reactivity to other antigens expressed in normal tissues. Here, we discovered a naturally occurring T-cell clone which expressed high-affinity HLA-A*02:01 (A*02)-restricted TCR against NY-ESO-1 from a patient who had NY-ESO-1-expressing ovarian tumor. METHODS:A*02-restricted NY-ESO-1-specific T-cell clones were established from peripheral blood of patients who had NY-ESO-1-expressing ovarian tumors. TCR ? and ? chain genes were retrovirally transduced into polyclonally activated T cells. Phenotype and function of the parental and TCR-transduced T cells were analyzed by flow cytometry, ELISA and cytotoxicity assay. In vivo therapeutic efficacy was investigated in a xenograft model using NOD/SCID/IL-2R?-deficient (NSG) mice. RESULTS:A rare population of NY-ESO-1-specific T cells, which we named 19305DP, expressed cell surface CD4, CD8?, and CD8? but not CD56 and recognized A*02+NY-ESO-1+ cancer cell lines in a CD4- and CD8-independent manner. 19305DP showed a gene expression profile that is consistent with a mixed profile of CD4+ and CD8+ single-positive T cells. Both CD4+ and CD8+ T cells that were retrovirally transduced with 19305DP-derived TCR gene (19305DP-TCR) showed strong reactivity against A*02+NY-ESO-1+ cancer cells, whereas TCR genes from the conventional A*02-restricted NY-ESO-1-specific CD8+ single-positive T-cell clones functioned only in CD8+ T cells. Both 19305DP-TCR gene-engineered CD4+ and CD8+ T cells eliminated A*02+NY-ESO-1+ tumor xenografts in NSG mice. Finally, based on reactivity against a series of alanine-substituted peptides and a panel of normal human tissue-derived primary cells, 19305DP-TCR was predicted to have no cross-reactivity against any human non-NY-ESO-1 proteins. CONCLUSION:Together, our results indicate that the naturally occurring 19305DP-TCR derived from CD4+CD8+ double-positive ?? T cells, is a promising therapeutic TCR gene for effective and safe adoptive T-cell therapy in A*02+ patients with NY-ESO-1-expressing tumor.

Project description:BACKGROUND: CD4+/CD8+ double positive (DP) T cells have been described in healthy individuals as well as in patients with autoimmune and chronic infectious diseases. In chronic viral infections, this cell subset has effector memory phenotype and displays antigen specificity. No previous studies of double positive T cells in parasite infections have been carried out. METHODOLOGY/PRINCIPAL FINDINGS: Seventeen chronic chagasic patients (7 asymptomatic and 10 symptomatic) and 24 non-infected donors, including 12 healthy and 12 with non-chagasic cardiomyopathy donors were analyzed. Peripheral blood was stained for CD3, CD4, CD8, HLA-DR and CD38, and lymphocytes for intracellular perforin. Antigen specificity was assessed using HLA*A2 tetramers loaded with T. cruzi K1 or influenza virus epitopes. Surface expression of CD107 and intracellular IFN-? production were determined in K1-specific DP T cells from 11 chagasic donors. Heart tissue from a chronic chagasic patient was stained for both CD8 and CD4 by immunochemistry. Chagasic patients showed higher frequencies of DP T cells (2.1% ± 0.9) compared with healthy (1.1% ± 0.5) and non-chagasic cardiomyopathy (1.2% ± 0.4) donors. DP T cells from Chagasic patients also expressed more HLA-DR, CD38 and perforin and had higher frequencies of T. cruzi K1-specific cells. IFN-? production in K1-specific cells was higher in asymptomatic patients after polyclonal stimulation, while these cells tended to degranulate more in symptomatic donors. Immunochemistry revealed that double positive T cells infiltrate the cardiac tissue of a chagasic donor. CONCLUSIONS: Chagasic patients have higher percentages of circulating double positive T cells expressing activation markers, potential effector molecules and greater class I antigenic specificity against T. cruzi. Although K1 tetramer positive DP T cell produced little IFN-?, they displayed degranulation activity that was increased in symptomatic patients. Moreover, K1-specific DP T cells can migrate to the heart tissue.

Dataset Information

Productive human immunodeficiency virus type 1 infection in peripheral blood predominantly takes place in CD4/CD8 double-negative T lymphocytes.

Publications

Productive human immunodeficiency virus type 1 infection in peripheral blood predominantly takes place in CD4/CD8 double-negative T lymphocytes.

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