CD4 and HIV-1 infection: 3B). This was consistent with the hypothesis that the inhibition of HIV-1 infection in PHA-activated CD4 T cells from subjects W278 and B195 involved chemokines produced upon cell activation. However, quantification of β-chemokines produced by PHA-activated CD4 T cells at the time of HIV-1 infection (three days after PHA stimulation) showed no significant increase in β-chemokine secretion in W278 and B195 cell cultures compared to controls (Table 2).