scholarly journals Human Immunodeficiency Virus Type 1 Envelope gp120-Induced Partial T-Cell Receptor Signaling Creates an F-Actin-Depleted Zone in the Virological Synapse

2009 ◽  
Vol 83 (21) ◽  
pp. 11341-11355 ◽  
Author(s):  
Gaia Vasiliver-Shamis ◽  
Michael W. Cho ◽  
Catarina E. Hioe ◽  
Michael L. Dustin
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Infected Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Cd4 T Cell ◽  
Virological Synapse ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Cell-to-cell transmission of human immunodeficiency virus type 1 (HIV-1) occurs via a virological synapse (VS), a tight cell-cell junction formed between HIV-infected cells and target cells in which the HIV-1-infected cell polarizes and releases virions toward the noninfected target cell in a gp120- and intercellular adhesion molecule 1 (ICAM-1)-dependent process. The response of the target cell has been less studied. We utilized supported planar bilayers presenting gp120 and ICAM-1 as a reductionist model for the infected-cell membrane and investigated its effect on the target CD4 T cell. This study shows that HIV-1 gp120 interaction with its receptors is initially organized into microclusters that undergo F-actin-dependent consolidation into a central supramolecular activation complex (cSMAC). Src kinases are active in both gp120 microclusters and in the VS cSMAC. The early T-cell receptor (TCR) signaling machinery is partially activated at the VS, and signaling does not propagate to trigger Ca2+ elevation or increase CD69 expression. However, these partial TCR signals act locally to create an F-actin-depleted zone. We propose a model in which the F-actin-depleted zone formed within the target CD4 T cell enhances the reception of virions by releasing the physical barrier for HIV-1 entry and facilitating postentry events.

scholarly journals T-Cell Receptor-Mediated Anergy of a Human Immunodeficiency Virus (HIV) gp120-Specific CD4+ Cytotoxic T-Cell Clone, Induced by a Natural HIV Type 1 Variant Peptide

2000 ◽  
Vol 74 (5) ◽  
pp. 2121-2130 ◽  
Author(s):  
Latifa Bouhdoud ◽  
Patricia Villain ◽  
Abderrazzak Merzouki ◽  
Maximilian Arella ◽  
Clément Couture
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Cytotoxic T Cell ◽  
Ctl Response ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection triggers a cytotoxic T-lymphocyte (CTL) response mediated by CD8+ and perhaps CD4+ CTLs. The mechanisms by which HIV-1 escapes from this CTL response are only beginning to be understood. However, it is already clear that the extreme genetic variability of the virus is a major contributing factor. Because of the well-known ability of altered peptide ligands (APL) to induce a T-cell receptor (TCR)-mediated anergic state in CD4+ helper T cells, we investigated the effects of HIV-1 sequence variations on the proliferation and cytotoxic activation of a human CD4+ CTL clone (Een217) specific for an epitope composed of amino acids 410 to 429 of HIV-1 gp120. We report that a natural variant of this epitope induced a functional anergic state rendering the T cells unable to respond to their antigenic ligand and preventing the proliferation and cytotoxic activation normally induced by the original antigenic peptide. Furthermore, the stimulation of Een217 cells with this APL generated altered TCR-proximal signaling events that have been associated with the induction of T-cell anergy in CD4+ T cells. Importantly, the APL-induced anergic state of the Een217 T cells could be prevented by the addition of interleukin 2, which restored their ability to respond to their nominal antigen. Our data therefore suggest that HIV-1 variants can induce a state of anergy in HIV-specific CD4+ CTLs. Such a mechanism may allow a viral variant to not only escape the CTL response but also facilitate the persistence of other viral strains that may otherwise be recognized and eliminated by HIV-specific CTLs.

scholarly journals Random T-Cell Receptor Recruitment in Human Immunodeficiency Virus Type 1 (HIV-1)-Specific CD8+ T Cells from Genetically Identical Twins Infected with the Same HIV-1 Strain

2007 ◽  
Vol 81 (22) ◽  
pp. 12666-12669 ◽  
Author(s):  
Xu G. Yu ◽  
Mathias Lichterfeld ◽  
Katie L. Williams ◽  
Javier Martinez-Picado ◽  
Bruce D. Walker
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cell Receptor ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) cytotoxic T-lymphocyte escape mutations represent both a major reason for loss of HIV immune control and a considerable challenge for HIV-1 vaccine design. Previous data suggest that initial HIV-1-specific CD8+ T-cell responses are determined largely by viral and host genetics, but the mechanisms influencing the subsequent viral evolution are unclear. Here, we show a random recruitment of T-cell receptor (TCR) alpha and beta clonotypes of the initial HIV-1-specific CD8+ T cells during primary infection in two genetically identical twins infected simultaneously with the same virus, suggesting that stochastic TCR recruitment of HIV-1-specific CD8+ T cells contributes to the diverse and unpredictable HIV-1 sequence evolution.

scholarly journals Progression of Human Immunodeficiency Virus Disease Is Associated with Increasing Disruptions within the CD4+T Cell Receptor Repertoire

1998 ◽  
Vol 177 (3) ◽  
pp. 579-585 ◽  
Author(s):  
Juan C. Gea‐Banacloche ◽  
Emma E. Weiskopf ◽  
Claire Hallahan ◽  
Juan Carlos López Bernaldo de Quirós ◽  
Mark Flanigan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
T Cell Receptor ◽  
Virus Disease ◽  
Cell Receptor ◽  
Cd4 T Cell ◽  
Receptor Repertoire ◽  
Immunodeficiency Virus ◽  
T Cell Receptor Repertoire ◽  
Cell Receptor Repertoire

scholarly journals Entry and Transcription as Key Determinants of Differences in CD4 T-Cell Permissiveness to Human Immunodeficiency Virus Type 1 Infection

2004 ◽  
Vol 78 (19) ◽  
pp. 10747-10754 ◽  
Author(s):  
Angela Ciuffi ◽  
Gabriela Bleiber ◽  
Miguel Muñoz ◽  
Raquel Martinez ◽  
Corinne Loeuillet ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Virus Production ◽  
Cd4 T Cell ◽  
Total Variance ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Isolated primary human cells from different donors vary in their permissiveness—the ability of cells to be infected and sustain the replication of human immunodeficiency virus type 1 (HIV-1). We used replicating HIV-1 and single-cycle lentivirus vectors in a population approach to identify polymorphic steps during viral replication. We found that phytohemagglutinin-stimulated CD4+ CD45RO+ CD57− T cells from healthy blood donors (n = 128) exhibited a 5.2-log-unit range in virus production. For 20 selected donors representing the spectrum of CD4 T-cell permissiveness, we could attribute up to 42% of the total variance in virus production to entry factors and 48% to postentry steps. Efficacy at key intracellular steps of the replicative cycle (reverse transcription, integration, transcription and splicing, translation, and budding and release) varied from 0.71 to 1.45 log units among donors. However, interindividual differences in transcription efficiency alone accounted for 64 to 83% of the total variance in virus production that was attributable to postentry factors. While vesicular stomatitis virus G protein-mediated fusion was more efficacious than CCR5/CD4 entry, the latter resulted in greater transcriptional activity per proviral copy. The phenotype of provirus transcription was stable over time, indicating that it represents a genetic trait.

scholarly journals Zeta Chain of the T-Cell Receptor Interacts with nef of Simian Immunodeficiency Virus and Human Immunodeficiency Virus Type 2

1998 ◽  
Vol 72 (12) ◽  
pp. 9827-9834 ◽  
Author(s):  
Anita Y. M. Howe ◽  
Jae U. Jung ◽  
Ronald C. Desrosiers
Keyword(s):  
Amino Acids ◽  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Tyrosine Kinase ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Jurkat Cells ◽  
Zeta Chain ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT A truncated version of the nef gene of simian immunodeficiency virus SIVmac239 capable of encoding amino acids 98 to 263 was used as bait to screen a cDNA library from activated lymphocytes in a yeast two-hybrid system. The zeta chain of the T-cell receptor (TCRζ) was found to interact specifically not only with truncated SIV nef in yeast cells but also with full-length glutathione S-transferase (GST)-SIVnef fusion protein in vitro. Coimmunoprecipitation of TCRζ with full-length SIV nef was demonstrated in transfected Jurkat cells and in Cos 18 cells which express the cytoplasmic domain of TCRζ fused to the external domain of CD8 via the CD8 transmembrane domain. Using a series of nef deletion mutants, we have mapped the binding site within the central core domain of nef (amino acids 98 to 235). Binding of TCRζ was specific for nef isolated from SIVmac239, SIVsmH4, and human immunodeficiency virus (HIV)-2ST and was not detected with nef from five different HIV-1 isolates. An active tyrosine kinase was coprecipitated with nef-TCRζcomplexes from Jurkat cells but not from J.CAM1.6 cells which lack a functional Lck tyrosine kinase. These results demonstrate a specific association of SIV and HIV-2 nef, but not HIV-1 nef, with TCRζ.

scholarly journals The Heptad Repeat 2 Domain Is a Major Determinant for Enhanced Human Immunodeficiency Virus Type 1 (HIV-1) Fusion and Pathogenicity of a Highly Pathogenic HIV-1 Env

2009 ◽  
Vol 83 (22) ◽  
pp. 11715-11725 ◽  
Author(s):  
Vijay Sivaraman ◽  
Liguo Zhang ◽  
Eric G. Meissner ◽  
Jerry L. Jeffrey ◽  
Lishan Su
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Cd4 T Cell ◽  
Heptad Repeat ◽  
Fusion Activity ◽  
Highly Pathogenic ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-mediated depletion of CD4+ lymphocytes in an infected individual is the hallmark of progression to AIDS. However, the mechanism for this depletion remains unclear. To identify mechanisms of HIV-1-mediated CD4 T-cell death, two similar viral isolates obtained from a rapid progressor patient with significantly different pathogenic phenotypes were studied. One isolate (R3A) demonstrates enhanced pathogenesis in both in vivo models and relevant ex vivo lymphoid organ model systems compared to another isolate, R3B. The pathogenic determinants were previously mapped to the V5-gp41 envelope region, correlating functionally with enhanced fusion activity and elevated CXCR4 binding affinity. To further elucidate specific differences between R3A and R3B within the V5-gp41 domains that enhance CD4 depletion, R3A-R3B chimeras to study the V5-gp41 region were developed. Our data demonstrate that six residues in the ectodomain of R3A provide the major determinant for both enhanced Env-cell fusion and pathogenicity. Furthermore, three amino acid differences in the heptad repeat 2 (HR-2) domain of R3A determined its fusion activity and significantly elevated its pathogenic activity. The chimeric viruses with enhanced fusion activity, but not elevated CXCR4 affinity, correlated with high pathogenicity in the thymus organ. We conclude that the functional domain of a highly pathogenic HIV-1 Env is determined by mutations in the HR-2 region that contribute to enhanced fusion and CD4 T-cell depletion.

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