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Phagosome‐Lysosome Fusion in P388D1 Macrophages Infected With Histoplasma capsulatum
Author(s) -
Eissenberg Linda Groppe,
Schlesinger Paul H.,
Goldman William E.
Publication year - 1988
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.43.6.483
Subject(s) - biology , histoplasma capsulatum , histoplasma , lysosome , phagosome , phagocytosis , microbiology and biotechnology , histoplasmosis , immunology , virology , biochemistry , enzyme
The issue of whether or not phagocytized Histoplasma capsulatum yeasts evade phagosome‐lysosome fusion (P‐LF) has been debated by several investigators. To resolve this problem, yet avoid drawbacks associated with the conventional assays of P‐LF (electron microscopy and the acridine orange assay), we used fluorescein isothiocyanate‐labeled dextran (FITC‐dextran) to monitor P‐LF in the macrophage‐like cell line P388D1.D2. Controls indicated that FITC‐dextran could be used to distinguish between evasion of P‐LF by Toxoplasma gondii and phagolysosome formation following ingestion of Saccharomyces cerevisiae. Phagosomes containing H. capsulatum clearly fused with FITC‐dextran‐labeled lysosomes at a rate comparable to that observed for S. cerevisiae. This was true for several strains of H. capsulatum including two avirulent strains derived in this laboratory. Varying the dose of H. capsulatum did not alter the percentage of phagolysosomes formed. Our results indicate that H. capsulatum is one of a small number of organisms which is able to survive in phagolysosomes.