Document 0645
 DOCN  M95A0645
 TI    Specific activation of natural killer (NK) cells. American Pediatric
       Society 104th annual meeting and Society for Pediatric Research 63rd
       annual meeting; 1994 May 2-5; Seattle.
 DT    9510
 AU    Reichlin A; Karlhofer FM; Yokoyama WM; Mount Sinai Medical Center,
       Department of Pediatrics, New York,; NY, USA.
 SO    Pediatr AIDS HIV Infect. 1994 Oct;5(5):314 (unnumbered abstract). Unique
       Identifier : AIDSLINE AIDS/95330399
 AB    NK cells are the third largest population of lymphocytes and provide
       significant host responses to intracellular challenges, including
       viruses, Listeria, and Toxoplasma, by lysing infected cells and by
       producing cytokines. However, the molecular basis of recognition and
       activation is still not fully understood. Monoclonal antibodies (mAbs)
       have been useful in defining both functionally important cell surface
       molecules and activation pathways. The mAb PK136 is specific for the
       NK1.1 antigen, the most specific serologic marker on murine NK cells.
       Previous investigations have demonstrated that this mAb can specifically
       stimulate NK cell cytolytic activity. In this study, we used
       3H-thymidine incorporation assays to determine that mAb PK136 was
       capable of activating C57BL/10-derived splenic NK cells to proliferate.
       This effect required low concentrations of IL-2 and immobilization of
       mAb PK136 to plastic tissue culture wells, implying a need for the mAb
       to crosslink its ligand. An isotype-matched control mAb, AF68853
       (anti-Kb), failed to stimulate proliferation even though this mAb binds
       to the cells at equivalent levels, demonstrating the specificity of the
       anti-NK1.1 stimulation. Moreover, four days after activation, we
       analyzed the responding cells by flow cytometry. Nearly all of the
       stimulated cells expressed the NK1.1 and Fc gamma RII/III molecules but
       were CD3-, indicating that the stimulated cells bore the phenotype of NK
       cells and not T cells. Thus, NK cells can be activated to proliferate
       and respond to IL-2 through the NK1.1 molecule. Further studies of NK1.1
       stimulation should provide significant insight into specific NK cell
       activation.
 DE    Animal  Antibodies, Monoclonal  Antigens/ANALYSIS/IMMUNOLOGY  Cells,
       Cultured  Interleukin-2/PHARMACOLOGY  Killer Cells, Natural/*IMMUNOLOGY
       *Lymphocyte Transformation  Mice  Mice, Inbred C57BL
       Proteins/ANALYSIS/IMMUNOLOGY  MEETING ABSTRACT  JOURNAL ARTICLE

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