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Phenotypic analysis of peripheral CD4 + CD8 + T cells in the rat
Author(s) -
Kenny E.,
Mason D.,
Pombo A.,
Ramírez F.
Publication year - 2000
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1046/j.1365-2567.2000.00071.x
Subject(s) - double negative , cd8 , biology , cytotoxic t cell , priming (agriculture) , microbiology and biotechnology , immunophenotyping , phenotype , flow cytometry , t cell , in vitro , immunology , immune system , biochemistry , gene , botany , germination
Summary Among peripheral T cells, the expression of CD4 and CD8 is almost mutually exclusive. However, here we show, using flow cytometric analysis, that ex vivo approximately 6% of rat T cells stained for both CD4 and CD8. These double positive cells were also detected by confocal microscopy. Only around 50% of double positive cells expressed the CD8β chain, the remaining cells expressed the CD8α chain alone. Double positive cells were blast‐like with a phenotype, distinct from that of either CD4 or CD8 single positive cells, suggestive of an activated state. Previous reports of double positive T cells have also suggested that coexpression of CD4 and CD8 is linked to the activation state of the cell. There was an indication that priming animals with a hapten‐carrier complex increased the ratio of CD8αα : αβ expressing double positive T cells, although we did not detect an increase in the frequency of double positive T cells following priming. We also show that the frequency of double positive cells was reduced following thymectomy and with age. In conclusion, these studies show that peripheral T cells expressing both CD4 and CD8 can be detected in the rat and that they are phenotypically distinct from CD4 and CD8 single positive T cells.