Open AccessInterleukin-7 or Interleukin-15 Enhances Survival ofMycobacterium tuberculosis-Infected Mice
Author(s) -
Markus Maeurer,
P. K. E. Trinder,
Gerhard Hommel,
Wolfgang Walter,
Kirsten Freitag,
Derek Atkins,
Stefan Störkel
Publication year - 2000
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.68.5.2962-2970.2000
Subject(s) - biology , spleen , immune system , cytokine , immunology , mycobacterium tuberculosis , antigen , interferon gamma , tuberculosis , tumor necrosis factor alpha , interleukin 12 , interleukin 2 , interleukin , interleukin 4 , microbiology and biotechnology , cytotoxic t cell , medicine , pathology , in vitro , biochemistry
Both antigen-presenting cells and immune effector cells are required to effectively eradicate or containMycobacterium tuberculosis -infected cells. A variety of cytokines are involved to ensure productive “cross talk” between macrophages and T lymphocytes. For instance, infection of macrophages with mycobacteria leads to effective interleukin-7 (IL-7) and IL-15 secretion, and both cytokines are able to maintain strong cellular immune responses of α/β and γ/δ T cells. Here we show that either cytokine is able to enhance survival ofM. tuberculosis -infected BALB/c mice significantly compared to application of IL-2, IL-4, or phosphate-buffered saline (as a control). Enhanced survival could be achieved only when IL-7 or IL-15 was delivered as a treatment (i.e., 3 weeks postinfection), not when it was administered at the time of infection. Increased survival ofM. tuberculosis -infected animals was observed following passive transfer of spleen cells harvested fromM. tuberculosis -infected, IL-7- or IL-15-treated animals, but not after transfer of spleen cells obtained from mice which received either cytokine alone. Histological examination revealed that IL-7 and IL-15 failed to significantly impact on the number and composition of granulomas formed or the bacterial load. Our data indicated that administration of IL-7 or IL-15 toM. tuberculosis -treated animals resulted in a qualitatively different cellular immune response in spleen cells as reflected by increased tumor necrosis factor alpha and decreased gamma interferon secretion in response toM. tuberculosis -infected antigen-presenting cells.