Involvement of cytolytic and non-cytolytic T cells in the control of feline immunodeficiency virus infection

Vet Immunol Immunopathol. 2002 Mar;85(3-4):159-70. doi: 10.1016/s0165-2427(01)00425-1.


The appearance of non-cytolytic T cells that suppressed feline immunodeficiency virus (FIV) replication in vitro, and FIV-specific cytotoxic T cell (CTL) responses was compared in a group of seven, specific pathogen free (SPF) domestic cats following primary infection with the Glasgow(8) isolate of FIV (FIV(GL-8)). FIV proviral burdens were quantified in the blood and lymphoid tissues by real-time PCR. Non-cytolytic T cell suppression of FIV replication was measured by co-cultivating lymphoblasts prepared from the cats at different time-points during infection with FIV-infected MYA-1 cells in vitro. Non-cytolytic suppressor activity was detected as early as 1 week after infection, and was evident in all the lymphoid tissues examined. Further, this activity was present in subpopulations of T cells in the blood with normal (CD8(hi)) or reduced (CD8(lo)) expression of the CD8 molecule, and temporal modulations in non-cytolytic suppressor activity were unrelated to the circulating CD8(+) T cell numbers. Virus-specific CTL responses, measured by (51)Cr release assays, were not detected until 4 weeks after infection, with the emergence of FIV-specific effector CTLs in the blood. Throughout infection the response was predominantly directed towards FIV Gag-expressing target cells, and by 47 weeks after infection CTL responses had become localised in the lymph nodes and spleen. The results suggest that both non-cytolytic T cell suppression of FIV replication and FIV-specific CTL responses are important cellular immune mechanisms in the control of FIV replication in infected asymptomatic cats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • Cat Diseases / blood
  • Cat Diseases / immunology*
  • Cat Diseases / virology
  • Cats
  • DNA, Viral / chemistry
  • DNA, Viral / isolation & purification
  • Flow Cytometry / veterinary
  • Immunodeficiency Virus, Feline / genetics
  • Immunodeficiency Virus, Feline / growth & development
  • Immunodeficiency Virus, Feline / immunology*
  • Lentivirus Infections / blood
  • Lentivirus Infections / immunology
  • Lentivirus Infections / veterinary*
  • Lentivirus Infections / virology
  • Longitudinal Studies
  • Polymerase Chain Reaction / veterinary
  • Specific Pathogen-Free Organisms
  • T-Lymphocytes, Cytotoxic / immunology*
  • Viral Load / veterinary


  • DNA, Viral