Study on suppressive factor of lymphocyte blastogenesis in human liver cell surface extract.

Relationship between general or specific immunoreactivity and prognosis in postoperative patients with hepatocellular carcinoma

“…This indicated that the crude extracts suppressed lymphocyte blastogenesis. Our previous experiment [26] confirmed that such suppression was due to depletion of the limited amount of arginine present in the culture m e d i u m by arginase in the liver extract, and also confirmed that arginine itself did not have any activity to stimulate lymphocytes. All tests were therefore performed using culture m e d i u m containing 2 .…”

“…However, to our knowledge, there has been no study of HCC-specific immunity using this test, and instead alternative techniques, such as the leucocyte migration inhibition test [6] or leucocyte adherence inhibition test [3,13], using allogeneic HCC extract, have been employed. As we [26] and other investigators [1] have already reported, liver extract prepared using 3 M KC1 contains variable degrees of arginase activity. This arginase inhibits the in vitro proliferation of PBL by depleting the limited amount of arginine present in conventional culture medium [ 1].…”

“…This is a potential hazard to the successful detection of HCC-specific immunity using an in vitro system. The interference of arginase in the in vitro proliferation of PBL can be prevented completely by the addition of extra arginine to the medium [26]. Our preliminary experiments have indicated that the effects of other inhibitors possibly present in liver extract can be excluded from consideration.…”

“…When crude extracts were used, the culture was perforrned in medium containing 2.5, 5, 10 or 20 mM arginine to avoid any depletion by arginase in the extracts [26]. Therefore, at least 12 kinds of culture were performed for each test.…”