Canine CD4+CD8+ double positive T cells in peripheral blood have features of activated T cells.
In dogs a CD4(+)CD8(+) double positive T cell subpopulation exists that has not been phenotypically defined yet. We demonstrate that canine CD4(+)CD8(+) T cells are mature CD1a(-) and TCRαβ(+) T cells. To analyse the activation potential of CD4(+)CD8(+) T cells, PBMC from dogs vaccinated against canine distemper virus (CDV) were re-stimulated with CDV. Upon antigen-specific stimulation, the CD4(+)CD8(+) T cell fraction increases and consists nearly exclusively of proliferated cells. Similarly, other features of activated effector/memory T cells such as up-regulation of CD25 and MHC-II as well as down-regulation of CD62L (L-selectin) were observed in CD4(+)CD8(+) T cells after stimulation. Canine CD4(+)CD8(+) T cells are less abundant, but more heterogeneous than porcine ones, comprising a small proportion expressing the β chain of CD8 in addition to the CD8α chain, like human CD4(+)CD8(+) T cells. In summary, this analysis provides the basis for functional characterisation of the in vivo relevance of CD4(+)CD8(+) T cells in T-cell mediated immunity.
Institute of Immunology, College of Veterinary Medicine, University of Leipzig, An den Tierkliniken 11, 04103 Leipzig, Germany. Doris.Bismarck@vetmed.uni-leipzig.de
Doris
D
Bismarck
Nicole
N
Schütze
Peter
P
Moore
Mathias
M
Büttner
Gottfried
G
Alber
Heiner v
Hv
Buttlar
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D004217:Distemper Virus, Canine / Q000276:immunology; D004285:Dogs / Q000097:blood / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D000949:Histocompatibility Antigens Class II / Q000097:blood; D016130:Immunophenotyping / Q000662:veterinary; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood; D019041:L-Selectin / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male
D000949:Histocompatibility Antigens Class II; D053645:Interleukin-2 Receptor alpha Subunit; D019041:L-Selectin