Inhibition of germ tube development of Aspergillus fumigatus in cell-free transudate produced in subcutaneous chambers in rabbits.
The interaction of Aspergillus fumigatus conidia with host factors produced in rabbits was studied by means of subcutaneous, perforated plastic chambers. Transudate fluid from spore-free chambers, sampled 30 days after implantation, supported germ tube development and rapid hyphal growth of A. fumigatus in an assay in vitro. Inoculation of spores into chambers implanted 30 days previously produced a rapid infiltration of leukocytes, predominately neutrophils, into the chamber fluid. Cell-free supernatants, prepared from transudates collected 5-6 days after inoculation, inhibited germ tube development in vitro. This inhibition was also demonstrated using lysates derived from 3.6 X 10(6) leukocytes obtained from chambers 5 days after inoculation with 1 X 10(7) spores. However, lysates derived from greater than 10(7) leukocytes obtained from pre-inoculated chambers as well as peritoneal exudate cells did not inhibit germ tube development in vitro. The inhibitory activity of cell free supernatants was not altered by heating at 56 degrees C for 30 min but was destroyed by pronase treatment as well as boiling. These results provide evidence for a host defense mechanism against rapid hyphal extension mediated by the extracellular release of inhibitory factors by leukocytes.
Larocco
M T
MT
Buckley
H R
HR
Mandle
R J
RJ
D000818:Animals; D001228:Aspergillosis / Q000276:immunology*; D001232:Aspergillus fumigatus / Q000254:growth & development* / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D008297:Male; D010586:Phagocytes / Q000276:immunology*; D011817:Rabbits; D013172:Spores, Fungal / Q000276:immunology