Hyporesponsiveness of canine bronchoalveolar lymphocytes to mitogens: II. Analysis of macromolecular synthesis, T-cell antigen, and mitogen-binding.
Canine bronchoalveolar lymphocytes (BAL) and peripheral blood lymphocytes (PBL) were prepared by filtration over nylon wool columns and were studied for their ability to: (a) synthesize protein, RNA, and DNA after mitogen stimulation; (b) express T-cell antigen; and (c) bind radiolabeled mitogen. Bronchoalveolar lymphocytes were shown to be markedly hyporesponsive to mitogen stimulation as assessed by DNA synthesis after 72 hr of culture or by protein and RNA synthesis after 24 hr of culture. The hyporesponsiveness of BAL was not due to a decrease in the number of T-cells; results of an indirect immunofluorescent assay employing a rabbit antiserum indicated similar percentages of T-cells in BAL (78%) and PBL (79%). The hyporesponsiveness was not due to abnormalities in mitogen binding by BAL; results of a radiolabeled mitogen-binding assay indicated essentially no difference in mitogen receptor number or affinity between BAL and PBL. Thus, the initial interaction bronchoalveolar T lymphocytes and mitogen appears to be normal. This normal interaction with mitogen, however, fails to trigger an appropriate level of macromolecular synthesis by BAL. This suggests that the hyporesponsiveness of BAL is due to an abnormality in one of the early metabolic processes induced by the interaction of a mitogen with the cell membrane.
D000818:Animals; D000941:Antigens / Q000276:immunology; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004285:Dogs; D005455:Fluorescent Antibody Technique; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D008934:Mitogens / Q000276:immunology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000276:immunology*; D012313:RNA / Q000096:biosynthesis; D011817:Rabbits; D013601:T-Lymphocytes / Q000276:immunology*
D000941:Antigens; D008934:Mitogens; D010835:Phytohemagglutinins; D012313:RNA; D004247:DNA