CD4 and infection: During our early chemokine studies, the group of Paolo Lusso reported in 1995 that the CC chemokines CCL5/RANTES, CCL3/MIP-1α, and CCL4/Mip-1β, isolated from an immortalized CD8+ T lymphocyte clone, blocked infection of a CD4+ T cell line susceptible to primary HIV-1 isolates and some HIV-2 and SIV isolates (1).