GALLIUM-ARSENIDE DIFFERENTIALLY AFFECTS PROCESSING OF PHAGOLYSOSOMAL TARGETED ANTIGEN BY MACROPHAGES

Gallium arsenide, a semiconductor utilized in the electronics industry , causes immunosuppression in animals, The chemical's effect on macrop hages to process antigen for activating pigeon cytochrome-specific hel per T cell hybridoma was investigated, Mice were administered 200 mg/k g gallium arsenide or vehicle intraperitoneally, Five-day exposure sup pressed processing by splenic macrophages but augmented processing by thioglycollate-elicited and resident peritoneal macrophages, Cytochrom e coupled to latex beads was targeted to phagolysosomes to examine pro cessing in lysosomes, Cytochrome beads required phagocytosis for proce ssing and were located in phagolysosomes, Gallium arsenide did not alt er the phagocytic ability of macrophages, Peritoneal macrophages norma lly processed the targeted antigen, indicating that gallium arsenide i nfluenced compartment(s) preceding lysosomes, However, the processing efficiency of exposed splenic macrophages depended on the size of part iculate cytochrome, suggesting that processing varied in phagolysosome s of different sizes, Gallium arsenide impacted different intracellula r compartments in these macrophages, perhaps contributing to systemic immunotoxicity and local inflammation caused by exposure.