Search

A specific anti-macrophage serum (AMS) has been obtained by immunizing rabbits with mouse peritoneal exudate cells and after repeated absorption with mouse erythrocytes, thymocytes and splenic lymphocytes. A comparative study of the cytotoxic activities of this serum on macrophages, thymocytes and lymph node cells, before and after absorption, showed that macrophage posses antigens which are common to both thymic and lymph node lymphocytes, and other antigens which are in common with lymph node lymphocytes but absent on thymocytes, as well as antigens being particular to macrophages. The absorbed sera had a definite cytotoxic effect on macrophages in vitro. This effect was observed when complement was added immediately or 4 hours after incubation with serum. It was lost after 24 hours. An inhibitory effects of AMS on phagocytosis in vivo has also been observed, which disappeared after one day. Antibody production in vivo was only moderately affected by a pretreatment with AMS. However, addition of AMS to spleen cell cultures stimulated with sheep red blood cells inhibited the appearance of hemolytic plaque forming cells.

The effect of Corynebacterium parvum (C. parvuum) on the immune response of the guinea pig to ovalbumin varies with the protocol of immunization. The marked effect of C. parvum on the anamnestic response in the rabbit has been confirmed in the guinea pig when immunization is carried out intradermally with a mixture of C. parvum and ovalbumin. When C. parvum is given intravenously or subcutaneously or intradermally but separately from the antigen, this effect is not observed. Whatever the route of injection guinea pigs treated with C. parvum show skin reactions of delayed type hypersensitivity at the site of an intradermal booster when the latter is given at least 27 days after primary immunization.

The effect of the irritant chosen to provoke the peritoneal exudate in donors of cells for the in vitro migration inhibition test was studied. Guinea-pigs with delayed hypersensitivity to tubercle bacilli were used. Irritants studied included starch, Bayol and thioglycollate medium. The exudates obtained with thioglycollate were found to show greater inhibition than those obtained with the other irritants in the in vitro response to PPD, Inhibition of migration was seen when 1 microgram/ml of PPD was added to the culture medium; with this dose the inhibition of migration was 53%. The state of activation of macrophages caused by the irritant thus appears to have some importance for their responsiveness to factors liberated by specifically sensitized lymphocytes.

Cytotoxic and cytostatic properties of peritoneal exudate cells from BALB/c mice either normal or pretreated with Corynebacterium parvum normal were studied using as target cells two lines of BALB/c fibroblasts one normal (BALB) and one transformed by Kirsten virus (K.BALB).. C. parvum activated cells displayed higher cytotoxic as measured by 51Cr or 3H-thymidine release and cytostatic, as measured by 3H-thymidine incorporation, activities against these lines of syngeneic cells. Cytotoxic effect of normal peritoneal cells was evident when 51Cr or 3H-thymidine release was used whereas no such effect was found when cytolytic plaque formation test was used. Sensitivity of both BALB and K.BALB target cell lines was found to be equal to cytotoxic and cytostatic activities of C. parvum activated or normal syngeneic peritoneal cells.

After intradermal immunization with a mixture of Corynebacterium parvum (C. parvum) and ovalbumin guinea pigs show a markedly increased anamnestic response to an intradermal booster of ovalbumin as compared to controls treated with ovalbumin only. At the same time a reaction of delayed type hypersensitivity is observed in the treated animals, but not in controls. The enhanced anamnestic response as well as the posivitive skin reaction were transferred to strain 2 histocompatible guinea pigs by peripheral blood leukocytes as well as by peritoneal exudate cells. Passive transfer was not obtained after prior irradiation of donor animals.