Cloned L3T4+ T lymphocytes protect mice against Listeria monocytogenes by secreting IFN-gamma.
Murine T lymphocyte clones sensitized to Listeria monocytogenes were developed to investigate specific mechanisms of T cell-mediated immunity. The clones were of the Thy-1.2+, L3T4+, Lyt-2- phenotype and proliferated in a dose response fashion to heat-killed Listeria. Cloned T lymphocytes injected intravenously protected nonimmune mice against L. monocytogenes challenge as determined by spleen and liver bacterial numbers. Supernatants, produced by stimulating clones with heat-killed Listeria for 48 h, also afforded protection against L. monocytogenes. The clonal supernatants contained significant quantities of IFN-gamma and CSF. IFN-gamma production was Ag specific and occurred within 24 h of stimulation. CSF production by clones was increased four- to sixfold over baseline as determined by a bone marrow colony-forming assay and was Ag specific. When the IFN-gamma in supernatants was neutralized with a specific mAb, protection afforded by the supernatants was lost. These data indicate that one mechanism for Ag-specific, T lymphocyte-mediated protection against L. monocytogenes is the release of IFN-gamma.
Magee
D M
DM
Department of Medicine, University of Pittsburgh, School of Medicine, PA 15213.
Wing
E J
EJ
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D002474:Cell-Free System; D002999:Clone Cells / Q000145:classification / Q000378:metabolism / Q000637:transplantation; D003115:Colony-Stimulating Factors / Q000378:metabolism; D000939:Epitopes / Q000276:immunology; D005260:Female; D007116:Immunization, Passive; D007371:Interferon-gamma / Q000096:biosynthesis*; D008088:Listeriosis / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control*; D051379:Mice; D008810:Mice, Inbred C57BL; D009500:Neutralization Tests; D010641:Phenotype; D013601:T-Lymphocytes / Q000145:classification / Q000378:metabolism / Q000637:transplantation*
D000942:Antigens, Bacterial; D000945:Antigens, Differentiation, T-Lymphocyte; D003115:Colony-Stimulating Factors; D000939:Epitopes; D007371:Interferon-gamma