CD4

Résumé

CD4 (cluster de différenciation 4) est une glycoprotéine exprimée à la surface des lymphocytes T CD4+, des cellules régulatrices T, des monocytes, des macrophages et de certaines cellules dendritiques. Historique CD4 fut découvert à la fin des années 1970. Cette protéine fut d'abord appelée Leu-3 et T4 (l'anticorps monoclonal OKT4 réagissant avec cette protéine) avant d'être rebaptisée CD4 en 1984. Caractéristiques & structure CD4 est une glycoprotéine de dont le poids moléculaire est de chez l'homme. Cette protéine est codée par le gène CD4. Ce gène de est constitué de et se situe sur le (locus 12p13.31). Comme de nombreux marqueurs/récepteurs de surface, CD4 fait partie de la Superfamille des immunoglobulines. CD4 contient immunoglobuline dans sa partie extracellulaire.

Les domaines D1 et D3 ressemblent aux domaines variables des immunoglobulines (IgV).
Les domaines D2 et D4 ressemblent aux domaines constants des immunoglobulines (IgC).

CD4 p

Source officielle

https://fr.wikipedia.org/wiki/CD4

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Publications associées (41)

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Concepts associés (41)

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Cours associés (5)

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Séances de cours associées (9)

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APOBEC3G-depleted resting CD4+ T cells remain refractory to HIV1 infection

Francesca Santoni de Sio, Didier Trono

BACKGROUND: CD4+ T lymphocytes are the primary targets of HIV1 but cannot be infected when fully quiescent, due to a post-entry block preventing the completion of reverse transcription. Chiu et al. recently proposed that this restriction reflects the action of APOBEC3G (A3G). They further suggested that T cell activation abrogates the A3G-mediated block by directing this protein to a high molecular mass complex. METHODOLOGY/PRINCIPAL FINDINGS: In the present work, we sought to explore further this model. However, we found that effective suppression of A3G by combined RNA interference and expression of HIV1 Vif does not relieve the restrictive phenotype of post-activation resting T cells. We also failed to find a correlation between HIV resistance and the presence of A3G in a low molecular complex in primary T cells. CONCLUSIONS/SIGNIFICANCE: We conclude that A3G is unlikely to play a role in the HIV restrictive phenotype of quiescent T lymphocytes.

2009

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Background: Kaposi's sarcoma, the most common AIDS-related cancer, represents a major public concern in resource-limited countries. Single nucleotide polymorphisms within the Interferon lambda 3/4 region (IFNL3/4) determine the expression, function of IFNL4, and influence the clinical course of an increasing number of viral infections. Objectives: To analyze whether IFNL3/4 variants are associated with susceptibility to AIDS-related Kaposi's sarcoma among MSM enrolled in the Swiss HIV Cohort Study (SHCS). Methods: The risk of developing Kaposi's sarcoma according to the carriage of IFNL3/4 SNPs rs8099917 and rs12980275 and their haplotypic combinations was assessed by using cumulative incidence curves and Cox regression models, accounting for relevant covariables. Results: Kaposi's sarcoma was diagnosed in 221 of 2558 MSM Caucasian SHCS participants. Both rs12980275 and rs8099917 were associated with an increased risk of Kaposi's sarcoma (cumulative incidence 15 versus 10%, P=0.01 and 16 versus 10%, P=0.009, respectively). Diplotypes predicted to produce the active P70 form (cumulative incidence 16 versus 10%, P=0.01) but not the less active S70 (cumulative incidence 11 versus 10%, P=0.7) form of IFNL4 were associated with an increased risk of Kaposi's sarcoma, compared with those predicted not to produce IFNL4. The associations remained significant in a multivariate Cox regression model after adjustment for age at infection, combination anti retrovi ral therapy, median CD4(+) T-cel I count nadir and CD4(+) slopes (hazard ratio 1.42, 95% confidence interval 1.06-1.89, P=0.02 for IFLN P70 versus no IFNL4). Conclusion: This study reports for the first time an association between IFNL3/4 polymorphisms and susceptibility to AIDS-related Kaposi's sarcoma. Copyright (C) 2018 Wolters Kluwer Health, Inc. All rights reserved.

LIPPINCOTT WILLIAMS & WILKINS2018

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ARF1 regulates Nef-induced CD4 degradation

Didier Trono

BACKGROUND: The HIV Nef protein downregulates CD4 through sequential connection with clathrin-coated pits and the COP1 coatomer, resulting in accelerated endocytosis and lysosomal targeting. RESULTS: Here we report that the small GTPase ARF1 controls the Nef-induced, COP-mediated late-endosomal targeting of CD4. We find that Nef binds ARF1 directly and can recruit the GTPase onto endosomal membranes. Furthermore, a complex comprising Nef, ARF1, and betaCOP can be immunoprecipitated from cells expressing the viral protein. Residues in a C-terminal loop of the viral protein facilitate both these interactions and the targeting of Nef and CD4 to acidic late endosomes, whereas other residues primarily involved in mediating CD4 endocytosis are dispensable for this process. Finally, a dominant-negative ARF1 mutant blocks the migration of the Nef-CD4 complex to lysosomes. CONCLUSIONS: Our results support a model in which ARF1 is the immediate downstream partner of Nef for CD4 lysosomal targeting.

2004

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