RT-PCR analysis of the expression of the messages for IL-15 and mean fluorescence intensity values of IL-15, CD80, and CD86 histograms shown by AM recovered from two patients with HIV infection. Specifically, case #6 was a symptomatic patient with AIDS-related complex whereas case #8 had full-blown AIDS (P. cariniipneumonia). The percentages of lymphocytes detected in the BAL are indicated on the right side of the fig. There was a strict association between the expression of IL-15, the MFI of IL-15, and B7 family members and the degree of T-cell infiltration, determined on the basis of BAL lymphocytes percentage. MFI 1: mean fluorescence intensity of control histogram; MFI 2: mean fluorescence intensity of CD80 histogram; MFI 3: mean fluorescence intensity of CD86 histogram.