Effects of Biological Response Modifiers On Lung Natural Killer Activity

Abstract

Natural killer (NK) activity plays an important role in host defense against tumors, especially once augmented by immunomodulators. It is likely that the modulation of NK cells is a reflection of the environment in which they reside. the current study was undertaken to characterize the response profile of lung interstitial lymphocyte natural killer (LLNK) activity to various biological response modifiers (BRM) in vitro after short term incubation (18h). the presented data show that treatment of lung lymphocytes with human recombinant interleukin 2 (rlL-2), purified rat interferon alpha/beta (IFN-α/ß), or murine recombinant tumor necrosis factor alpha (rTNF-α) resulted in a dose-dependent increase in LLNK activity. the maximum stimulation was similar for rlL-2 and IFN-α/ß, although a much higher concentration of IFN-α/ß was required to reach this level of stimulation. the maximum response to rTNF-α treatment was about half that seen with rlL-2 or IFN-α/ß and it, too, required a high concentration. By contrast, rat recombinant interferon gamma (rlFN-γ) or murine recombinant interleukin 1 (rlL-1) failed to alter LLNK activity significantly when used alone. Furthermore, doses of IFN-α/ß and rTNF-α that had little enhancing effect were able to synergize with a suboptimal dose of rlL-2, whereas rlL-1 and rlFN-γ failed to do so. These data demonstrate the response of lung NK activity to BRM treatment, which is important for the responsible and effective use of BRM. However the spectrum of lung NK cell response to BRM is smaller than that previously reported for NK cells from other anatomic compartments.