Related Experiment Video
Updated: Aug 8, 2026
Phenotypic and Functional Analysis of Activated Regulatory T Cells Isolated from Chronic Lymphocytic Choriomeningitis Virus-infected Mice
Published on: June 22, 2016
Phenotypic changes in CD8+ peripheral blood lymphocytes in cats infected with feline immunodeficiency virus
Masayuki Shimojima1, Yorihiro Nishimura, Takayuki Miyazawa
1Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Insights
Feline immunodeficiency virus (FIV) alters CD8+ T cells, creating diverse subpopulations with distinct activation markers. CD4+ T cells showed fewer changes in FIV-infected cats.
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- T lymphocyte cell surface molecules change with immune activation.
- Feline immunodeficiency virus (FIV) infection reduces CD8beta chain expression in cats' peripheral blood lymphocytes (PBLs).
Purpose of the Study:
- To investigate phenotypic changes in CD4+ PBLs alongside CD8+ PBLs in FIV-infected cats.
- To analyze activation-associated cell surface molecules and light scatters in feline PBLs post-FIV infection.
Main Methods:
- Three-color flow-cytometric analysis was used.
- Examined activation markers (CD2, CD11a, CD45RA-like, MHC II) and light scatters (size, complexity).
- Studied PBLs from five FIV-infected cats and one uninfected control.
Main Results:
- CD8+ PBLs, not CD4+ PBLs, showed subpopulations with increased CD11a, reduced CD8beta, and more intracellular granules.
- CD8+ PBLs expressed CD45RA-like antigen diversely, unlike CD4+ PBLs.
- Higher MHC II expression in CD8+ PBLs correlated with CD8beta reduction; CD4+ PBLs showed no such correlation.
Conclusions:
- FIV infection induces phenotypically heterogeneous CD8+ PBL subpopulations, including activated phenotypes.
- CD4+ PBLs exhibit fewer FIV-induced phenotypic changes compared to CD8+ PBLs.
Abstract:
It is well documented that several cell surface molecules of T lymphocytes are altered by immune activation. We previously reported that feline immunodeficiency virus (FIV) infection induces a reduction in CD8beta chain expression of peripheral blood lymphocytes (PBLs) in cats. In this study, we performed three-color flow-cytometric analysis for activation-associated cell surface molecules (CD2, CD11a, CD45RA-like and major histocompatibility complex antigen class II (MHC II)) and light scatters (cellular size and complexity) to examine whether phenotypic changes also occurred in CD4(+) PBLs in addition to CD8(+) PBLs, of five FIV-infected cats and one uninfected cat. It was shown that (i) CD8alpha(+) PBLs, but not CD4(+) PBLs, had a distinct subpopulation with increased CD11a expression accompanying a reduced CD8beta chain and increased intracellular granules (ii) CD8alpha(+) PBLs, but not CD4(+) PBLs, expressed CD45RA-like antigen with diverse expression levels and (iii) MHC II expression was greater in CD8alpha(+) PBLs than CD4(+) PBLs, and the CD8beta chain reduction was correlated with the MHC II decrease within CD8alpha(+) PBLs. These results suggest that FIV infection induces phenotypically heterogeneous subpopulations in CD8(+) PBLs, including activated phenotypes, rather than in CD4(+) PBLs.
