Interleukin-15 induces antimicrobial activity after release by Cryptococcus neoformans-stimulated monocytes.
A newly described cytokine, interleukin (IL)-15, shares many activities with IL-2; however, little is known about the stimuli for release of IL-15, and its role in antimicrobial host defense has not previously been demonstrated. This study found that Cryptococcus neoformans is a potent stimulus for the release of biologically active IL-15 from monocytes. Both IL-15 and IL-2 made significant contributions to lymphocyte proliferation and lymphocyte-mediated anticryptococcal activity to encapsulated and acapsular C. neoformans. IL-15 restored lymphocyte proliferation and anticryptococcal activity that had been abrogated by blocking IL-2. IL-15 also enhanced the anticryptococcal activity of lymphocytes but did not enhance the activity of monocytes. This suggests that IL-15 and IL-2 cooperate for lymphocyte activation and proliferation in vitro and demonstrates that IL-15 can induce antimicrobial activity. Taken together, these data suggest that microbes, and in particular C. neoformans, are an important stimulus for IL-15 and that IL-15 may have an important role in induction of antimicrobial effector mechanisms.
Mody
C H
CH
Department of Internal Medicine, University of Calgary, Alberta, Canada. cmody@acs.ucalgary.ca
Spurrell
J C
JC
Wood
C J
CJ
D000911:Antibodies, Monoclonal / Q000378:metabolism; D002448:Cell Adhesion; D002455:Cell Division; D003455:Cryptococcus neoformans / Q000276:immunology*; D019409:Interleukin-15 / Q000276:immunology* / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D015375:Receptors, Interleukin-2 / Q000378:metabolism
D000911:Antibodies, Monoclonal; D019409:Interleukin-15; D007376:Interleukin-2; D015375:Receptors, Interleukin-2