Enhanced Susceptibility to Human Immunodeficiency Virus Infection in CD4 + T Lymphocytes Genetically Deficient in CD43

CD43 is a cell surface sialoglycoprotein expressed by most cells of hematopoietic origin, including all T lymphocytes. Elimination of CD43 expression by gene targeting in the CEM T cell line results in its increased homotypic adhesion and binding to HIV-1 gp120. Here we report that the CD43-negative CEM cells show increased susceptibility to HIV-1 infection and increased viral replication compared with the parental CD43⁺ CEM cell line. Increased HIV-1 replication also was observed in CEM cells with diminished CD43 expression secondary to functional inactivation of a single CD43 allele. The CD43^- CEM cells were more susceptible to HIV-1-induced cytopathicity than their CD43⁺ counterparts. HIV-1 replication also was increased in the CD43^- CEM cells after transfection with the infectious HIV molecular clone pNL4-3. These data suggest that factors that diminish CD43 expression on T lymphocytes may enhance their susceptibility to HIV-1 infection.