Divergent Generation of Heterogeneous Memory CD4 T Cells

• Published in: Journal of Immunology 2006-07, Vol.177 (2), p.869-876
• Main Authors: Moulton, Vaishali R, Bushar, Nicholas D, Leeser, David B, Patke, Deepa S, Farber, Donna L
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; CD4-Positive T-Lymphocytes - cytology; CD4-Positive T-Lymphocytes - immunology; Cell Differentiation - immunology; Cells, Cultured; Epitopes, T-Lymphocyte - immunology; Hemagglutinin Glycoproteins, Influenza Virus - immunology; Immunologic Memory; Lymphocyte Activation - immunology; Mice; Mice, Inbred BALB C; Mice, Transgenic; Molecular Sequence Data; Ovalbumin - immunology; Stem Cells - cytology; Stem Cells - immunology; Time Factors
• ISSN: 0022-1767; 1550-6606; 1365-2567
• DOI: 10.4049/jimmunol.177.2.869

Mechanisms for the generation of memory CD4 T cells and their delineation into diverse subsets remain largely unknown. In this study, we demonstrate in two Ag systems, divergent generation of heterogeneous memory CD4 T cells from activated precursors in distinct differentiation stages. Specifically, we show that influenza hemagglutinin- and OVA-specific CD4 T cells activated for 1, 2, and 3 days, respectively, exhibit gradations of differentiation by cell surface phenotype, IFN-gamma production, and proliferation, yet all serve as direct precursors for functional memory CD4 T cells when transferred in vivo into Ag-free mouse hosts. Using a conversion assay to track the immediate fate of activated precursors in vivo, we show that day 1- to 3-activated cells all rapidly convert from an activated phenotype (CD25(high)IL-7R(low)CD44(high)) to a resting memory phenotype (IL-7R(high)CD25(low)CD44(high)) 1 day after antigenic withdrawal. Paradoxically, stable memory subset delineation from undifferentiated (day 1- to 2-activated) precursors was predominantly an effector memory (CD62L(low)) profile, with an increased proportion of central memory (CD62L(high)) T cells arising from more differentiated (day 3-activated) precursors. Our findings support a divergent model for generation of memory CD4 T cells directly from activated precursors in multiple differentiation states, with subset heterogeneity maximized by increased activation and differentiation during priming.