A Crude Preparation of Lymphocyte Chalone and Its Suppressive Effect on Immune Function in Mice

A crude preparation of lymphocyte chalone was extracted from calf Spleen using coldaoctone and distilled water.Its inhibitory cffect on mouse lymphocyte proliferation was demonstratedby 3H-TdR incorporation method in vitro.This extract shoed no inhibitory effect on the3H-TdR uptake of K562 cells and displayed no cytotoxicity to mouse lymphocyte,suggesting thatthere existed the activity of lymphocytc chalone in the extract.The crude chalone inhibited 3H-TdRuptake of mouse lymphocyte stimulated with concanavalin A（Con A）and mixed lymphocytc re-sponse（MLR）,and the degree of the inhibition was greater as the doses of the extract in culturesbecame higher,indicating it had inhibitory effect on T lymphocytes Its influence on the numbers ofrosette-forming cells（RFC）and plaque-forming cells（PFC）in the spleen of mice revealed that ithad inhibitory effocts on some stages of immunization,including the actions on T and B lymphocytes