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Updated: Jul 7, 2026

Imaging of HIV-1 Envelope-induced Virological Synapse and Signaling on Synthetic Lipid Bilayers
Published on: March 8, 2012
HIV-1 envelope protein binds to and signals through integrin alpha4beta7, the gut mucosal homing receptor for
James Arthos1, Claudia Cicala, Elena Martinelli
1Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. jarthos@niaid.nih.gov
Abstract:
Infection with human immunodeficiency virus 1 (HIV-1) results in the dissemination of virus to gut-associated lymphoid tissue. Subsequently, HIV-1 mediates massive depletion of gut CD4+ T cells, which contributes to HIV-1-induced immune dysfunction. The migration of lymphocytes to gut-associated lymphoid tissue is mediated by integrin alpha4beta7. We demonstrate here that the HIV-1 envelope protein gp120 bound to an activated form of alpha4beta7. This interaction was mediated by a tripeptide in the V2 loop of gp120, a peptide motif that mimics structures presented by the natural ligands of alpha4beta7. On CD4+ T cells, engagement of alpha4beta7 by gp120 resulted in rapid activation of LFA-1, the central integrin involved in the establishment of virological synapses, which facilitate efficient cell-to-cell spreading of HIV-1.
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