MilliporeSigma
  • Home
  • Search Results
  • HIV-1 Nef and Vpu Interfere with L-Selectin (CD62L) Cell Surface Expression To Inhibit Adhesion and Signaling in Infected CD4+ T Lymphocytes.

HIV-1 Nef and Vpu Interfere with L-Selectin (CD62L) Cell Surface Expression To Inhibit Adhesion and Signaling in Infected CD4+ T Lymphocytes.

Journal of virology (2015-03-31)
Lia Vassena, Erica Giuliani, Herwig Koppensteiner, Sebastian Bolduan, Michael Schindler, Margherita Doria
ABSTRACT

Leukocyte recirculation between blood and lymphoid tissues is required for the generation and maintenance of immune responses against pathogens and is crucially controlled by the L-selectin (CD62L) leukocyte homing receptor. CD62L has adhesion and signaling functions and initiates the capture and rolling on the vascular endothelium of cells entering peripheral lymph nodes. This study reveals that CD62L is strongly downregulated on primary CD4(+) T lymphocytes upon infection with human immunodeficiency virus type 1 (HIV-1). Reduced cell surface CD62L expression was attributable to the Nef and Vpu viral proteins and not due to increased shedding via matrix metalloproteases. Both Nef and Vpu associated with and sequestered CD62L in perinuclear compartments, thereby impeding CD62L transport to the plasma membrane. In addition, Nef decreased total CD62L protein levels. Importantly, infection with wild-type, but not Nef- and Vpu-deficient, HIV-1 inhibited the capacity of primary CD4(+) T lymphocytes to adhere to immobilized fibronectin in response to CD62L ligation. Moreover, HIV-1 infection impaired the signaling pathways and costimulatory signals triggered in primary CD4(+) T cells by CD62L ligation. We propose that HIV-1 dysregulates CD62L expression to interfere with the trafficking and activation of infected T cells. Altogether, this novel HIV-1 function could contribute to virus dissemination and evasion of host immune responses. L-selectin (CD62L) is an adhesion molecule that mediates the first steps of leukocyte homing to peripheral lymph nodes, thus crucially controlling the initiation and maintenance of immune responses to pathogens. Here, we report that CD62L is downmodulated on the surfaces of HIV-1-infected T cells through the activities of two viral proteins, Nef and Vpu, that prevent newly synthesized CD62L molecules from reaching the plasma membrane. We provide evidence that CD62L downregulation on HIV-1-infected primary T cells results in impaired adhesion and signaling functions upon CD62L triggering. Removal of cell surface CD62L may predictably keep HIV-1-infected cells away from lymph nodes, the privileged sites of both viral replication and immune response activation, with important consequences, such as systemic viral spread and evasion of host immune surveillance. Altogether, we propose that Nef- and Vpu-mediated subversion of CD62L function could represent a novel determinant of HIV-1 pathogenesis.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Dimethyl sulfoxide, ACS reagent, ≥99.9%
Sigma-Aldrich
Dimethyl sulfoxide, puriss. p.a., dried, ≤0.02% water
Sigma-Aldrich
Dimethyl sulfoxide, puriss. p.a., ACS reagent, ≥99.9% (GC)
Sigma-Aldrich
Dimethyl sulfoxide, suitable for HPLC, ≥99.7%
Sigma-Aldrich
Dimethyl sulfoxide, ReagentPlus®, ≥99.5%
Sigma-Aldrich
L-Glutamine, BioUltra, ≥99.5% (NT)
Sigma-Aldrich
Dimethyl sulfoxide solution, 50 wt. % in H2O
Sigma-Aldrich
Interleukin-2 human, IL-2, recombinant, expressed in HEK 293 cells, suitable for cell culture, endotoxin tested
SAFC
L-Glutamine
Sigma-Aldrich
L-Glutamine
Supelco
Dimethyl sulfoxide, analytical standard
Sigma-Aldrich
Fluorescein 5(6)-isothiocyanate, BioReagent, suitable for fluorescence, mixture of 2 components, ≥90% (HPLC)
Supelco
L-Glutamine, certified reference material, TraceCERT®
Supelco
L-Glutamine, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
IL-2 human, Animal-component free, recombinant, expressed in E. coli, ≥98% (SDS-PAGE), ≥98% (HPLC), suitable for cell culture
Sigma-Aldrich
Interleukin-2 human, IL-2, recombinant, expressed in E. coli, lyophilized powder, suitable for cell culture
Sigma-Aldrich
Cycloheximide solution, Ready-Made Solution, microbial, 100 mg/mL in DMSO, Suitable for cell culture
Sigma-Aldrich
Interleukin-2 human, recombinant, expressed in Pichia pastoris, suitable for cell culture
Sigma-Aldrich
Anti-Integrin β1 Antibody, clone 6S6, clone 6S6, Chemicon®, from mouse
Sigma-Aldrich
Dimethyl sulfoxide, PCR Reagent
Sigma-Aldrich
Dimethyl sulfoxide, meets EP testing specifications, meets USP testing specifications
Sigma-Aldrich
Anti-Glyceraldehyde-3-Phosphate Dehydrogenase Antibody, clone 6C5, clone 6C5, Chemicon®, from mouse
Sigma-Aldrich
L-Glutamine, meets USP testing specifications, suitable for cell culture, 99.0-101.0%, from non-animal source
Sigma-Aldrich
L-Glutamine, ReagentPlus®, ≥99% (HPLC)
Sigma-Aldrich
Dimethyl sulfoxide, ≥99.5% (GC), suitable for plant cell culture
Sigma-Aldrich
Dimethyl sulfoxide, Hybri-Max, sterile-filtered, BioReagent, suitable for hybridoma, ≥99.7%
Sigma-Aldrich
Dimethyl sulfoxide, for molecular biology
Sigma-Aldrich
Fluorescein 5(6)-isothiocyanate, ≥90% (HPLC)
Sigma-Aldrich
L-Glutamine, γ-irradiated, BioXtra, suitable for cell culture
Sigma-Aldrich
Dimethyl sulfoxide, anhydrous, ≥99.9%