Heterogeneity of the CD8 lymphocytes in healthy and HIV 1 infected subjects

CD8 lymphocytes have been subdivided on the basis of Leu2 antigen cell surface density and coexpression of Leu4 and Leu11 antigens in two categories: Leu2bright and Leu2dim. Some CD8 lymphocyte phenotypes present in small percentages in some subjects do not come under these subsets. Flow cytometry analysis moreover shows that the distribution of fluorescence intensity tends to aggregate in most subjects in three distinct spots, here called Leu2HD, ID, and LD. The first, defined by fluorescence levels higher than 450, corresponds to the area of the Leu2+ Leu4+ lymphocytes that express the Leu7 antigen. These cells are all Leu11- and reach remarkably higher percentages in subjects with HIV 1 infection. They are totally included in the area of the Leu2bright cells, but their lowest level of fluorescence is higher. Our data seem to indicate a greater phenotypic homogeneity for these cells. The Leu2LD lymphocytes included in fluorescence levels lower than 175 are all Leu4-Leu11+ and 30% coexpress the Leu7 antigen. They are included in the fluorescence area of the Leud2dim cells, but reach medially lower fluorescence levels. The subset named LeuID has a mean fluorescence ranging between 175 and 450 and includes cells of the Leu4+ 11- and Leu4-11+ phenotypes. Moreover, HIV positive subjects exhibit very low percentages of Leu4+ 11+ and Leu4-11- cells. It is interesting to note that the Leu7 antigen density on the CD8 cell surface is highest for the Leu2HD lymphocytes and diminishes proportionally to the Leu2 antigen density in the Leu2ID and Leu2LD lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)