REGULATION OF NK REACTIVITY BY SUPPRESSOR CELLS

Publisher Summary This chapter discusses the results of the study analyzing regulation of natural killer (NK) reactivity by suppressor cells. CBA/H mice and DA and BD X rats entered the experiments at the age of 6–8 (mice) and 8–12 (rats) weeks, respectively. YAC (A/Sn lymphoma) and G-l (W/Fu lymphoma) in NK assays, Con-A blasts for T-killer cells, and chicken red blood cells (CRBC) coated with rabbit anti-CRBC hyperimmune serum in the antibody-dependent cellular cytotoxicity (ADCC) system were used. Thymus, lymph nodes (LN), spleen, bone marrow (BM), peripheral blood lymphocytes (PBL), and peritoneal cells (PC) were prepared like usual and fractionated by discontinuous Percoll gradient centrifugation. When analyzing NK activity in various Percoll density fractions, it was observed that some fractions contained higher NK activity per unit cell number than the original population. Significant NK activity could be recovered also from organs that were normally almost or completely devoid of NK activity before fractionation such as the thymus. The peak activity of NK function was not same in the various lymphoid organs, being skewed to the lighter density fractions in the low NK organs.