CHRONIC ALLOGRAFT REJECTION IN LUMBRICUS TERRESTRIS

To determine the capacity of earthworms to reject tissue transplants, first‐set orthotopic allografts of body wall were exchanged between 280 adult Lumbricus terrestris. In addition, 30 worms were autografted as controls. Both auto‐ and allogeneic tissue transplants healed in promptly; autografts survived permanently while allografts showed varying degrees of incompatibility. Intrapopulation allografts in worms from Canada showed 22% permanently surviving transplants while 95% were not destroyed in the Oregon group; the remaining allografts in both groups were completely destroyed after prolonged chronic periods or showed incomplete rejection after observations during eight and one‐half months. No intrapopulation Oregon transplants were rejected completely while only 1% were in the Canadian group. About 5.5% of interpopulation allografts were destroyed on Oregon hosts and 15.3% on Canadian recipients between 38 and 153 days after grafting. Therefore, recognition and rejection of tissue allo‐antigens are characteristic of the primitive immune response of annelid worms. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company