title: Sustained high frequencies of specific CD4 T cells restricted to a single persistent virus.
abstract: Replication of cytomegalovirus (CMV) is largely controlled by the cellular arm of the immune response. In this study the CMV-specific CD4 T-cell response was characterized in a cohort of apparently healthy individuals. In 11% of all individuals, extremely high frequencies, between 10 and 40%, were found. High-level frequencies of CMV-specific CD4 T cells persisted over several months and were not the result of an acute infection. Specific T cells were oligoclonal and were phenotypically and functionally characterized as mature effector cells, with both cytokine-secreting and proliferative potential. These high-level frequencies do not seem to compromise the immune response towards heterologous infections, and no signs of immunopathology were observed. Whereas a large temporary expansion of virus-specific T cells is well known to occur during acute infection, we now show that extremely high frequencies of virus-specific T cells may continuously exist in chronic CMV infection without overtly compromising the remaining protective immunity.
authors.affiliation: Medical Department IV, Institute of Medical Microbiology and Hygiene, University of the Saarland, D-66421 Homburg, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Sester
authors.forename: Urban
authors.initials: U
authors.lastname: Sester
authors.forename: Barbara
authors.initials: B
authors.lastname: Gärtner
authors.forename: Boris
authors.initials: B
authors.lastname: Kubuschok
authors.forename: Matthias
authors.initials: M
authors.lastname: Girndt
authors.forename: Andreas
authors.initials: A
authors.lastname: Meyerhans
authors.forename: Hans
authors.initials: H
authors.lastname: Köhler
mesh_terms: D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002908:Chronic Disease; D003587:Cytomegalovirus / Q000276:immunology* / Q000502:physiology; D003586:Cytomegalovirus Infections / Q000276:immunology* / Q000821:virology; D005434:Flow Cytometry; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008213:Lymphocyte Activation; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D019562:Viral Load
chemical_list: D000914:Antibodies, Viral