TY - JOUR
T1 - Expression of CD8α identifies a distinct subset of effector memory CD4+ T lymphocytes
AU - Macchia, Iole
AU - Gauduin, Marie Claire
AU - Kaur, Amitinder
AU - Johnson, R. Paul
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/10
Y1 - 2006/10
N2 - Circulating CD4+ CD8+ T lymphocytes have been described in the peripheral blood of humans and several animal species. However, the origin and functional properties of these cells remain poorly understood. In the present study, we evaluated the frequency, phenotype and function of peripheral CD4+ CD8+ T cells in rhesus macaques. Two distinct populations of CD4+ CD8+ T cells were identified: the dominant one was CD4hi CD8lo and expressed the CD8αα homodimer, while the minor population was CD4lo CD8hi and expressed the CD8αβ heterodimer. The majority of CD4hi CD8αlo T cells exhibited an activated effector/memory phenotype (CCR5lo CD7- CD28- HLA-DR+) and expressed relatively high levels of granzyme B. Intracellular cytokine staining assays demonstrated that the frequency of cytomegalovirus-specific T cells was enriched five-fold in CD4hi CD8αlo T cells compared to single-positive CD4+ T cells, whereas no consistent enrichment was observed for simian immunodeficiency virus (SIV)-specific T cells. Cross-sectional studies of SIV-infected animals demonstrated that the frequency of CD4hi CD8αlo T cells was lower in wild-type SIV-infected animals compared to uninfected controls, although prospective studies of SIV-infected animals demonstrated depletion of CD4hi CD8αlo lymphocytes only in a subset of animals. Taken together, these data suggest that CD4+ T cells expressing CD8α represent an effector/memory subset of CD4 + T cells and that this cell population can be depleted during the course of SIV infection.
AB - Circulating CD4+ CD8+ T lymphocytes have been described in the peripheral blood of humans and several animal species. However, the origin and functional properties of these cells remain poorly understood. In the present study, we evaluated the frequency, phenotype and function of peripheral CD4+ CD8+ T cells in rhesus macaques. Two distinct populations of CD4+ CD8+ T cells were identified: the dominant one was CD4hi CD8lo and expressed the CD8αα homodimer, while the minor population was CD4lo CD8hi and expressed the CD8αβ heterodimer. The majority of CD4hi CD8αlo T cells exhibited an activated effector/memory phenotype (CCR5lo CD7- CD28- HLA-DR+) and expressed relatively high levels of granzyme B. Intracellular cytokine staining assays demonstrated that the frequency of cytomegalovirus-specific T cells was enriched five-fold in CD4hi CD8αlo T cells compared to single-positive CD4+ T cells, whereas no consistent enrichment was observed for simian immunodeficiency virus (SIV)-specific T cells. Cross-sectional studies of SIV-infected animals demonstrated that the frequency of CD4hi CD8αlo T cells was lower in wild-type SIV-infected animals compared to uninfected controls, although prospective studies of SIV-infected animals demonstrated depletion of CD4hi CD8αlo lymphocytes only in a subset of animals. Taken together, these data suggest that CD4+ T cells expressing CD8α represent an effector/memory subset of CD4 + T cells and that this cell population can be depleted during the course of SIV infection.
KW - Animal models/studies: primates
KW - Helper T cells (Th cells, Th0, Th1, Th2, Th3)
KW - Memory cells
KW - Simian immunodeficiency virus
UR - http://www.scopus.com/inward/record.url?scp=33748740886&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33748740886&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2567.2006.02428.x
DO - 10.1111/j.1365-2567.2006.02428.x
M3 - Article
C2 - 16836648
AN - SCOPUS:33748740886
VL - 119
SP - 232
EP - 242
JO - Immunology
JF - Immunology
SN - 0019-2805
IS - 2
ER -