Could CD4 capture by CD8⁺ T cells play a role in hiv spreading?

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 by CD8+ T cells as shown by its detection using conformational antibodies and its ability to allow HIV binding on recipient CD8+ T cells. Although we could not find direct evidence for infection of CD8+ 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 by CD8+ T cells via trogocytosis could play a previously unappreciated role for CD8+ T cells in HIV spreading possibly without leading to their infection.