Human natural killer cells do not inhibit growth of Cryptococcus neoformans in the absence of antibody.

摘要: The interaction between human natural killer (NK) cells and yeast of Cryptococcus neoformans was investigated because experiments in mice indicated that NK inhibited the growth C. neoformans. Strains serotype A differed both resistance to alveolar macrophages size composition their capsules were evaluated. Human cells, which isolated from normal peripheral blood, activated by preincubation with interleukin-2 alpha interferon generate lymphokine-activated (LAK) cells. Yeast incubated effector (NK or LAK cells); inhibition cell measured at 4, 8, 24 h comparing quantitative plate counts controls consisting yeasts absence cytolytic activity against target confirmed release radiolabel 51Cr-labeled K-562 tumor Neither nor 13 strains ratios as high 500:1. Monocytes, same populations leukocytes two 100:1 (92 46% inhibition), 50:1 (87 17%), 1:1 (49 0%). could inhibit an antibody-dependent cellular cytotoxicity mechanism presence rabbit anticryptococcal antiserum dilutions up 1:4,000. Purified capsular polysaccharide had no effect on viability tumoricidal These data suggest are not impaired neoformans, antibody, is rarely detectable patients, they afford much less protection than monocytes do.