RT Journal Article SR Electronic(1) A1 Hohdatsu, Tsutomu A1 Okubo, Miki A1 Koyama, HiroyukiYR 1998 T1 Feline CD8+ T cell non-cytolytic anti-feline immunodeficiency virus activity mediated by a soluble factor(s) JF Journal of General Virology, VO 79 IS 11 SP 2729 OP 2735 DO https://doi.org/10.1099/0022-1317-79-11-2729 PB Microbiology Society, SN 1465-2099, AB Feline immunodeficiency virus (FIV) is more readily isolated from CD8 T cell-depleted peripheral blood mononuclear cells (PBMC) of FIV-infected cats than from unfractionated PBMC cultures. However, it is not known whether feline CD8 T cells down- regulate FIV expression by direct interaction with FIV-infected cells or via a soluble mediator. Furthermore, it is not known whether this anti-FIV activity involves a lytic or non-lytic mechanism. In the present study, we demonstrated that autologous and allogeneic CD8 T cells from asympto-matic FIV-infected cats inhibited the replication of FIV in CD8 T cell-depleted PBMC cultures in a dose-dependent manner. The inhibitory effect was mediated by a non-lytic mechanism, and was not dependent on direct cell-to-cell contact: an inhibitory effect was exerted by CD8 T cells across a semi-permeable membrane, and an inhibitory activity was also present in cell-free supernatants from CD8 T cells. These results suggest that this suppressive effect is mediated, at least in part, by soluble factors produced by CD8 T cells., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-79-11-2729