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Cytoplasmic Components of Natural Killer Cells Limit the Growth of Cryptococcus neoformans
Author(s) -
Hidore Michelle R.,
Nabavi Nasrin,
Reynolds Craig W.,
Henkart Pierre A.,
Murphy Juneann W.
Publication year - 1990
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.48.1.15
Subject(s) - percoll , biology , cytolysin , granule (geology) , cryptococcus neoformans , cytolysis , cell fractionation , cytoplasm , lysis , differential centrifugation , natural killer cell , microbiology and biotechnology , cytotoxic t cell , centrifugation , in vitro , biochemistry , enzyme , paleontology , virulence , gene
Murine natural killer (NK) cell‐mediated inhibition of growth of a yeast‐like target cell, Cryptococcus neoformans , was completely abrogated by blocking the effector cell secretory process with monensin. Therefore, further studies were performed to determine the ability of various cytoplasmic fractions of NK cells to mediate inhibition of cryptococcal growth. Percoll‐fractionated homogenates of rat LGL tumor cells demonstrated that the granule‐containing fractions plus three additional sets of less dense cytoplasmic fractions displayed anti‐cryptococcal activity; whereas only the cytoplasmic granule‐containing fractions had cytotoxic activity against YAC‐1 tumor cell and sheep erythrocyte targets. Maximal cryptococcal growth inhibition induced by LGL granules occurred after a 1 h incubation, required the presence of Ca 2+ (1.0 mM) or Mg 2+ (0.5 mM or 5.0 mM), and was completely abrogated in the presence of rabbit anti‐LGL granule IgG. Cytolysin, the granule component which mediates tumor cell and sheep erythrocyte lysis, effectively limited the growth of cryptococci. Since Percoll gradient fractionation of the LGL homogenates demonstrated three separate peaks of anti‐cryptococcal activity other than the granule peak, it is possible that the cytolysin‐containing granules are not the only subcellular component of NK cells playing a role in inhibition of C. neoformans growth.