Expression of a laminin-like substance on the surface of murine natural killer (NK) lymphocytes and its role in NK recognition of tumor target cells.
We have identified a structure on the surface of murine NK cells that is immunochemically cross-reactive with laminin. Treatment of normal CBA/J spleen cells with monospecific anti-laminin serum plus complement completely eliminated NK cytolytic activity against YAC-1 or RL male 1 target cells. In the absence of added complement, spleen cells preincubated with anti-laminin serum were also reduced in their cytolytic activity due to a reduced capacity to bind to the target cells. Treatment with anti-asialo GM1 serum plus complement also eliminated NK activity, but pretreatment of NK cells with anti-asialo GM1 in the absence of complement did not reduce cytolytic activity. Thus, anti-laminin and anti-asialo GM1 bind to structures on the surface of NK cells that distinguish functional (laminin) from nonfunctional (asialo GM1) sites. Flow cytometric analysis revealed that approximately 15% of normal nonadherent splenic lymphocytes expressed laminin-like structures, whereas 16% expressed asialo GM1 and 19% expressed the NK alloantigen NK 2.1. Treatment of alloimmune cytotoxic T lymphocytes (CTL) with anti-laminin plus complement did not affect CTL activity. Thus, anti-laminin serum appears to detect a cell surface structure present on the NK subset of lymphocytes.
D000818:Animals; D002460:Cell Line; D003165:Complement System Proteins / Q000502:physiology; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry; D007106:Immune Sera / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D007797:Laminin / Q000276:immunology / Q000378:metabolism* / Q000502:physiology; D008223:Lymphoma / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D013154:Spleen / Q000166:cytology
D007106:Immune Sera; D007166:Immunosuppressive Agents; D007797:Laminin; D003165:Complement System Proteins