title: CD4(+) T-cell subsets that mediate immunological memory to Mycobacterium tuberculosis infection in mice.
abstract: We have studied CD4(+) T cells that mediate immunological memory to an intravenous infection with Mycobacterium tuberculosis. The studies were conducted with a mouse model of memory immunity in which mice are rendered immune by a primary infection followed by antibiotic treatment and rest. Shortly after reinfection, tuberculosis-specific memory cells were recruited from the recirculating pool, leading to rapidly increasing precursor frequencies in the liver and a simultaneous decrease in the blood. A small subset of the infiltrating T cells was rapidly activated (<20 h) and expressed high levels of intracellular gamma interferon and the T-cell activation markers CD69 and CD25. These memory effector T cells expressed intermediate levels of CD45RB and were heterogeneous with regard to the L-selectin and CD44 markers. By adoptive transfer into nude mice, the highest level of resistance to a challenge with M. tuberculosis was mediated by CD45RB(high), L-selectin(high), CD44(low) cells. Taken together, these two lines of evidence support an important role for memory cells which have reverted to a naive phenotype in the long-term protection against M. tuberculosis.
authors.affiliation: Department of TB Immunology, Statens Serum Institut, Copenhagen, Denmark. pa@ssi.dk
authors.forename: P
authors.initials: P
authors.lastname: Andersen
authors.forename: B
authors.initials: B
authors.lastname: Smedegaard
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D018960:Hyaluronan Receptors / Q000032:analysis; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis; D017493:Leukocyte Common Antigens / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D014376:Tuberculosis / Q000276:immunology*
chemical_list: D018960:Hyaluronan Receptors; D007371:Interferon-gamma; D017493:Leukocyte Common Antigens