Could CD4 Capture byCD8+T Cells Play a Role in HIV Spreading?

Abstract

CD8+T cells have been shown to capture plasma membrane fragments from target cells expressing their cognate antigen, a process termed “trogocytosis”. Here, we report that human CD4, the Human Immunodeficiency Virus (HIV) receptor, can be found among the proteins transferred by trogocytosis. CD4 is expressed in a correct orientation after its capture byCD8+T cells as shown by its detection using conformational antibodies and its ability to allow HIV binding on recipientCD8+T cells. Although we could not find direct evidence for infection ofCD8+T cells having captured CD4 by HIV, CD4 was virologically functional on these cells as it conferred on them the ability to undergo syncytia formation induced by HIV-infected MOLT-4 cells. Our results show that acquisition of CD4 byCD8+T cells via trogocytosis could play a previously unappreciated role forCD8+T cells in HIV spreading possibly without leading to their infection.