Differential effects of cytolytic T cell subsets on intracellular infection.
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.
Stenger
S
S
Department of Microbiology and Immunology, University of California Los Angeles School of Medicine, Los Angeles, CA 90095, USA.
Mazzaccaro
R J
RJ
Uyemura
K
K
Cho
S
S
Barnes
P F
PF
Rosat
J P
JP
Sette
A
A
Brenner
M B
MB
Porcelli
S A
SA
Bloom
B R
BR
Modlin
R L
RL
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
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