title: Differential effects of cytolytic T cell subsets on intracellular infection.
abstract: In analyzing mechanisms of protection against intracellular infections, a series of human CD1-restricted T cell lines of two distinct phenotypes were derived. Both CD4(-)CD8(-) (double-negative) T cells and CD8(+) T cells efficiently lysed macrophages infected with Mycobacterium tuberculosis. The cytotoxicity of CD4(-)CD8(-) T cells was mediated by Fas-FasL interaction and had no effect on the viability of the mycobacteria. The CD8(+) T cells lysed infected macrophages by a Fas-independent, granule-dependent mechanism that resulted in killing of bacteria. These data indicate that two phenotypically distinct subsets of human cytolytic T lymphocytes use different mechanisms to kill infected cells and contribute in different ways to host defense against intracellular infection.
authors.affiliation: Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, Los Angeles, CA 90095, USA.
authors.forename: S
authors.initials: S
authors.lastname: Stenger
authors.forename: R J
authors.initials: RJ
authors.lastname: Mazzaccaro
authors.forename: K
authors.initials: K
authors.lastname: Uyemura
authors.forename: S
authors.initials: S
authors.lastname: Cho
authors.forename: P F
authors.initials: PF
authors.lastname: Barnes
authors.forename: J P
authors.initials: JP
authors.lastname: Rosat
authors.forename: A
authors.initials: A
authors.lastname: Sette
authors.forename: M B
authors.initials: MB
authors.lastname: Brenner
authors.forename: S A
authors.initials: SA
authors.lastname: Porcelli
authors.forename: B R
authors.initials: BR
authors.lastname: Bloom
authors.forename: R L
authors.initials: RL
authors.lastname: Modlin
mesh_terms: D018949:Antigens, CD1 / Q000276:immunology*; D002460:Cell Line; D018920:Coculture Techniques; D015169:Colony Count, Microbial; D003594:Cytoplasmic Granules / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D053222:Fas Ligand Protein; D053804:Granzymes; D006801:Humans; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000254:growth & development / Q000276:immunology*; D054353:Perforin; D010641:Phenotype; D052899:Pore Forming Cytotoxic Proteins; D012697:Serine Endopeptidases / Q000378:metabolism; D013324:Strontium / Q000494:pharmacology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019014:fas Receptor / Q000276:immunology / Q000378:metabolism
chemical_list: D018949:Antigens, CD1; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D019014:fas Receptor; D054353:Perforin; D053804:Granzymes; D012697:Serine Endopeptidases; C509212:GZMA protein, human; D013324:Strontium