Effects of antilymphocyte serum on hyperacute renal rejection in goats

An experiment is described whereby the suppressive action of antilymphocyte serum on the suspected immunological response in exteriorized goat kidneys, produced by specifically sensitized thoracic duct cells, was tesIed. The results suggest Ihat in this system, the specific lymphocytic reaction mechanism is inhibited by antilymphocyte serum and is more in accord with the 'blindfolding' theory than any other

ACUTE DESTRUCTION BY HUMORAL ANTIBODY OF RAT SKIN GRAFTED TO MICE : THE ROLE OF COMPLEMENT AND POLYMORPHONUCLEAR LEUKOCYTES

A study has been made of the roles played by complement and polymorphonuclear leukocytes (PMN) in the acute destruction of xenografts of rat skin that follows injection of their hosts with antisera specifically reactive with graft antigens. The rat skin was grafted onto mice whose immune responses were suppressed by removal of the thymus and a brief course of treatment with rabbit antimouse lymphocyte serum. At about 2 wk after grafting the mice were injected intravenously or intraperitoneally with mouse antirat serum (MARS). This time interval was chosen because it avoided the complications that might be associated with either the process of healing in or with incipient rejection. Signs of graft damage were evident as early as 10 min after the injection of MARS, and in most animals so injected the grafts were completely destroyed within 24–48 h. The role of complement (C) in this acute destructive process is indicated by the results of three lines of experimentation. (a) Non-C-fixing antibodies or antibody fragments failed to cause damage to the grafts. Indeed, both chicken antirat serum and F(ab')2 fragments from rabbit antirat serum completely protected the grafts against the effects of MARS that was administered 24 h later. (b) When mice were depleted of hemolytic C by treatment with cobra venom factor or heat-aggregated gamma globulin, the damage caused by MARS was greatly reduced or completely inhibited. (c) In mice with a genetically determined absence of C5 much greater quantities of MARS were required to cause graft damage; the tempo of the destructive process was consistently slower; and a greater number of grafts recovered from the initial inflammatory process than was the case for animals with an intact complement system. The participation of PMN in serum-mediated destruction of grafts was initially suggested by the results of microscope examination of fixed tissues. The essential role of these cells in the process is indicated by the failure of MARS to cause tissue damage in mice whose circulating PMN have been reduced to very low levels by treatment with nitrogen mustard or more specifically with an anti-PMN serum. The absence of tissue damage when circulating PMN are reduced but C levels are normal suggests that C-mediated cytolysis is unimportant in graft destruction and that the role of C lies in its ability to generate chemotactic factors. The latter may then attract the PMN that provide mediators of tissue damage

Notes on the preparatio and assay of anti-lymphocyte serum for use in mice

The `activity' of rabbit anti-mouse ALS was measured in terms of its power to prolong the life of A-strain homografts on CBA mice. Antisera raised by lymphocytes from mice of other strains were active in CBA mice, and conversely antisera raised by CBA lymphocytes were active in mice of other strains. All active sera were cytotoxic to mouse lymphocytes in the presence of mouse complement, but not all cytotoxic sera were active. ALS raised in species (chicken, duck) of which the sera do not bind with mouse complement were inactive in mice. Neither cytotoxicity nor the power to circumvent graft-versus-host reactions give adequate measures of the activity of impure antisera. Good antiserum (`two-pulse' ALS) for use in mice could be raised in New Zealand White rabbits by the intravenous injection of 10(9) mouse thymocytes on two occasions 14 days apart, followed by bleeding out 7 days after the second injection. Further injections of antigen increased the titre of undesirable contaminants in ALS (e.g. red cell agglutinins) but usually did not increase (and sometimes lowered) activity. ALS raised with adjuvants, though powerful, was highly toxic and required extensive absorption