Macrophage cell lines P388D1 and IC-21 stimulated with gamma interferon fail to inhibit the intracellular growth of Histoplasma capsulatum

Abstract

Histoplasma capsulatum, a facultative intracellular parasite of macrophages, grows within mononuclear cells of the P388D1 and IC-21 cell lines with a generation time comparable to that with which it grows in normal resident peritoneal macrophages (10 +/- 2 h). Recombinant murine gamma interferon (rMuIFN-gamma) activates P388D1 cells to express la antigens but not to inhibit the intracellular growth of H. capsulatum, alone or in combination with lipopolysaccharide. IC-21 cells also could not be activated to fungistasis with rMuIFN-gamma. Explanted resident peritoneal macrophages of the C57BL/6 (from which the IC-21 cell line derives), C3H/HeJ, DBA/2 (from which the P388D1 cell line derives), A/J, and SJL/J strains of mice were all stimulated by rMuIFN-gamma to inhibit the fungus.

Expression of inducible nitric oxide synthase by stimulated macrophages correlates with their antihistoplasma activity

“…Treatment of RAW 264.7 cells with rMuIFN--y results in the production of NO which correlates with the antihistoplasma activity of the cells (10). However, P388D, macrophages do not restrict the intracellular growth of H. capsulatum following treatment with rMuIFN-,y alone or in combination with LPS (13). The goal of this study was to measure iNOS expression in rMuIFN--y-treated RAW 264.7 and P388D, cells in an attempt to (i) explain the differences between the cell lines in the release NO and (ii) correlate the expression of iNOS with antihistoplasma activity.…”

Intracellular growth inhibition of Histoplasma capsulatum induced in murine macrophages by recombinant gamma interferon is not due to a limitation of the supply of methionine or cysteine to the fungus

“…The percent reductions recorded in rows 8, 9, 10, and 11 were made with results from MEM(-Met/Cys) supplemented with Cys as indicated. d This portion of the protocol (rows 1, 2, and 3) has been repeated a very large number of times with very similar results in the context of other experiments (23)(24)(25)(26)28). e The experiment recorded in this row was repeated one additional time with 0.4 mM cysteine.…”

“…rMuIFN--y was supplied by Genentech, Inc., South San Francisco, Calif. The assay for intracellular growth was similar to that previously reported on a number of occasions (24,25,28).…”

“…The growth of Histoplasma capsulatum within mouse peritoneal macrophages is inhibited by recombinant murine gamma interferon (rMuIFN--y) (23)(24)(25). The intracellular yeasts are not killed by the interaction (28), but their growth is often completely suppressed (26,28).…”

“…Resident peritoneal macrophages harvested from C57BL/6 mice were washed and suspended in complete or deficient Earle's minimal essential medium (MEM) devoid of the amino acid(s) in question. The macrophages were set up in cell culture as described previously (24,25). The media devoid of certain amino acids were prepared from Earle's MEM Select-Amine Kit (GIBCO Laboratories, Grand Island, N.Y.).…”