A study has been made of the roles played by complement and @entity6415 ( @entity6415 ) in the acute destruction of xenografts of @entity35 skin that follows injection of their hosts with antisera specifically reactive with graft antigens. The @entity35 skin was grafted onto @entity19 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 @entity19 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 @entity19 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 @entity19 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 @entity6415 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 @entity19 whose circulating @entity6415 have been reduced to very low levels by treatment with @entity1568 mustard or more specifically with an anti- @entity6415 serum. The absence of tissue damage when circulating @entity6415 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 @entity6415 that provide mediators of tissue damage.

Acute destruction by humoral antibody of XXXX skin grafted to @entity19 .

@entity6415 :: ('MESH:C566014', 'Disease') :: ['polymorphonuclear leukocytes', 'PMN'] @entity1568 :: ('MESH:D009584', 'Chemical') :: ['nitrogen'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity35 :: ('10116', 'Species') :: ['rat']
@entity35 :: (10116,Species) :: ['rat']
