TY - JOUR
T1 - Clonotypic structure of the human CD4+ memory T cell response to cytomegalovirus
AU - Bitmansour, A. D.
AU - Waldrop, S. L.
AU - Pitcher, C. J.
AU - Khatamzas, E.
AU - Kern, F.
AU - Maino, V. C.
AU - Picker, L. J.
PY - 2001/8/1
Y1 - 2001/8/1
N2 - High steady-state frequencies of CMV-specific CD4+ memory T cells are maintained in CMV-exposed subjects, and these cells are thought to play a key role in the immunologic control of this permanent infection. However, the essential components of this response are poorly defined. Here, we report the use of a step-wise application of flow cytometric and molecular techniques to determine the number and size of the TCR Vβ-defined clonotypes within freshly obtained CMV-specific CD4+ memory T cell populations of four healthy, CMV-exposed human subjects. This analysis revealed a stable clonotypic hierarchy in which 1-3 dominant clonotypes are maintained in concert with more numerous subdominant and minor clonotypes. These dominant clonotypes accounted for 10-50% of the overall CMV response, and comprised from 0.3 to 4.0% of peripheral blood CD4+ T cells. Two subjects displayed immunodominant responses to single epitopes within the CMV matrix phosphoprotein pp65; these single epitope responses were mediated by a single dominant clonotype in one subject, and by multiple subdominant and minor clonotypes in the other. Thus, the CMV-specific CD4+ T cell memory repertoire in normal subjects is characterized by striking clonotypic dominance and the potential for epitope focusing, suggesting that primary responsibility for immunosurveillance against CMV reactivation rests with a handful of clones recognizing a limited array of CMV determinants. These data have important implications for the understanding of mechanisms by which a genetically stable chronic viral pathogen such as CMV is controlled, and offer possible insight into the failure of such control for a genetically flexible pathogen like HIV-1.
AB - High steady-state frequencies of CMV-specific CD4+ memory T cells are maintained in CMV-exposed subjects, and these cells are thought to play a key role in the immunologic control of this permanent infection. However, the essential components of this response are poorly defined. Here, we report the use of a step-wise application of flow cytometric and molecular techniques to determine the number and size of the TCR Vβ-defined clonotypes within freshly obtained CMV-specific CD4+ memory T cell populations of four healthy, CMV-exposed human subjects. This analysis revealed a stable clonotypic hierarchy in which 1-3 dominant clonotypes are maintained in concert with more numerous subdominant and minor clonotypes. These dominant clonotypes accounted for 10-50% of the overall CMV response, and comprised from 0.3 to 4.0% of peripheral blood CD4+ T cells. Two subjects displayed immunodominant responses to single epitopes within the CMV matrix phosphoprotein pp65; these single epitope responses were mediated by a single dominant clonotype in one subject, and by multiple subdominant and minor clonotypes in the other. Thus, the CMV-specific CD4+ T cell memory repertoire in normal subjects is characterized by striking clonotypic dominance and the potential for epitope focusing, suggesting that primary responsibility for immunosurveillance against CMV reactivation rests with a handful of clones recognizing a limited array of CMV determinants. These data have important implications for the understanding of mechanisms by which a genetically stable chronic viral pathogen such as CMV is controlled, and offer possible insight into the failure of such control for a genetically flexible pathogen like HIV-1.
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U2 - 10.4049/jimmunol.167.3.1151
DO - 10.4049/jimmunol.167.3.1151
M3 - Article
C2 - 11466329
AN - SCOPUS:0035423369
SN - 0022-1767
VL - 167
SP - 1151
EP - 1163
JO - Journal of Immunology
JF - Journal of Immunology
IS - 3
ER -