EXPRESSION OF CD26 DOES NOT CORRELATE WITH THE REPLICATION OF MACROPHAGE-TROPIC STRAINS OF HIV-1 IN T-CELL LINES

Strains of human immunodeficiency virus type 1 (HIV-1) differ signific antly in both genetic content and biological properties. One of the ea rliest discovered differences between HIV-1 strains was divergence in the relative ability of different strains to replicate in either T-cel l lines or monocytes/macrophages. This observation has led to the sugg estion that molecules present on the surface of HIV-susceptible cells other than CD4 may interact with gp120 in facilitating the entry of HI V-1 into host cell populations. Several reports have suggested that CD 26, a cell surface protease expressed on many cells of the immune syst em including some CD4(+) T-cells and macrophage, may be an accessory m olecule for HIV-1 entry. Recently, it has also been reported that the expression of high levels of CD26 correlates with the entry and replic ation of macrophage-tropic strains of HIV-1 in a T-cell line. In this report, we demonstrate that replication of macrophage-tropic strains o f HIV-1 in T-cell lines is independent of CD26 expression, From this o bservation, we conclude that CD26 plays no role in the entry of HIV-1 into these cells. (C) 1996 Academic Press, Inc.