title: Gene expression in antigen-specific CD8+ T cells during viral infection.
abstract: Following infection with intracellular pathogens, Ag-specific CD8(+) T cells become activated and begin to proliferate. As these cells become activated, they elaborate effector functions including cytokine production and cytolysis. After the infection has been cleared, the immune system returns to homeostasis through apoptosis of the majority of the Ag-specific effector cells. The surviving memory cells can persist for extended periods and provide protection against reinfection. Little is known about the changes in gene expression as Ag-specific cells progress through these stages of development, i.e., naive to effector to memory. Using recombinant MHC class I tetramers, we isolated Ag-specific CD8(+) T cells from mice infected with lymphocytic choriomeningitis virus at various time points and performed semiquantitative RT-PCR. We examined expression of: 1) genes involved in cell cycle control, 2) effector and regulatory functions, and 3) susceptibility to apoptosis. We found that Ag-specific CD8(+) memory T cells contain high steady-state levels of Bcl-2, BAX:, IFN-gamma, and lung Kruppel-like factor (LKLF), and decreased levels of p21 and p27 mRNA. Moreover, the pattern of gene expression between naive and memory cells is distinct and suggests that these two cell types control susceptibility to apoptosis through different mechanisms.
authors.affiliation: Emory Vaccine Center and Department of Microbiology and Immunology, Emory University, Atlanta, GA 30332, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Grayson
authors.forename: K
authors.initials: K
authors.lastname: Murali-Krishna
authors.forename: J D
authors.initials: JD
authors.lastname: Altman
authors.forename: R
authors.initials: R
authors.lastname: Ahmed
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D002469:Cell Separation; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D053222:Fas Ligand Protein; D005260:Female; D015967:Gene Expression Regulation, Viral / Q000276:immunology*; D007399:Interphase / Q000235:genetics / Q000276:immunology; D051741:Kruppel-Like Transcription Factors; D008213:Lymphocyte Activation / Q000235:genetics; D008216:Lymphocytic Choriomeningitis / Q000235:genetics / Q000276:immunology*; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000821:virology; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics
chemical_list: D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; C498314:Klf2 protein, mouse; D051741:Kruppel-Like Transcription Factors; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D015534:Trans-Activators