Proliferative responses of circulating human NK cells: delineation of a unique pathway involving both direct and helper signals

摘要: The present studies were performed to investigate mechanisms of human natural killer (NK) cell activation. NK-active cells purified out heterogeneous large granular lymphocytes (LGL)-enriched suspensions using a "pan NK"-specific monoclonal antibody termed anti-NKH1A. It was found that treatment NKH1A+-sorted by T lymphocyte mitogens such as phytohemagglutinin (PHA) or anti-T11(2) plus anti-T11(3) did not induce proliferative responses. In fact, there no measurable interleukin 2 (IL2) secretion and significant increase in IL2 susceptibility following incubation with either PHA anti-T11(3). However, opposed small resting lymphocytes, NKH1A+ moderately proliferated the presence IL2. This IL2-dependent proliferation dramatically increased after interaction between certain hematopoietic lines K562 EBV-transformed lymphoblastoid lines. These indicate unique activation can be identified when NK are LGL-enriched fractions. pathway delineated here appears essentially distinct from those described for lymphocytes. Indeed nature cell/inducing is unknown triggering cannot related, example, conventional allogeneic effect mediated through membrane exposure class I II major histocompatibility complex gene products. Moreover, these interactions do lead development autocrine Together results support view direct signals preactivate but sufficient trigger which must therefore regulated helper populations.