CD4 and HIV infectious disease: To evaluate the potential impact of β-chemokine production on HIV susceptibility of vector-specific CD4 T cells in our system, in vitro HIV infection (CCR5-tropic; US-1) was conducted in the presence of neutralizing antibodies against these β-chemokines (CCL3/MIP-1α, CCL4/MIP-1β, and CCL5/RANTES).