title: Functional heterogeneity of memory CD4 T cell responses in different conditions of antigen exposure and persistence.
abstract: Memory CD4 T cell responses are functionally and phenotypically heterogeneous. In the present study, memory CD4 T cell responses were analyzed in different models of Ag-specific immune responses differing on Ag exposure and/or persistence. Ag-specific CD4 T cell responses for tetanus toxoid, HSV, EBV, CMV, and HIV-1 were compared. Three distinct patterns of T cell response were observed. A dominant single IL-2 CD4 T cell response was associated with the model in which the Ag can be cleared. Polyfunctional (single IL-2 plus IL-2/IFN-gamma plus single IFN-gamma) CD4 T cell responses were associated with Ag persistence and low Ag levels. A dominant single IFN-gamma CD4 T cell response was associated with the model of Ag persistence and high Ag levels. The results obtained supported the hypothesis that the different patterns observed were substantially influenced by different conditions of Ag exposure and persistence.
authors.affiliation: Laboratory of AIDS Immunopathogenesis, Division of Immunology and Allergy, Department of Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Harari
authors.forename: Florence
authors.initials: F
authors.lastname: Vallelian
authors.forename: Pascal R
authors.initials: PR
authors.lastname: Meylan
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pantaleo
mesh_terms: D000941:Antigens / Q000008:administration & dosage / Q000276:immunology*; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D002908:Chronic Disease; D003587:Cytomegalovirus / Q000276:immunology; D003586:Cytomegalovirus Infections / Q000276:immunology; D018450:Disease Progression; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology; D015497:HIV-1 / Q000276:immunology; D004854:Herpesvirus 4, Human / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000378:metabolism; D018139:Simplexvirus / Q000276:immunology; D013745:Tetanus Toxoid / Q000008:administration & dosage / Q000276:immunology; D017735:Virus Latency / Q000276:immunology
chemical_list: D000941:Antigens; D000942:Antigens, Bacterial; D000956:Antigens, Viral; D018984:Epitopes, T-Lymphocyte; D007376:Interleukin-2; D013745:Tetanus Toxoid