Suppressive action of Candida albicans on the immune response in guinea pigs

The influence of Candida albicans on the immune response in guinea pigs was studied. Several groups of animals were inoculated with red blood cells (RBC) from different species, either human (HRC), sheep (ShRC) or chick (ChRC), together with complete Freund's adjuvant (CFA). Their immune responses were compared to those of guinea pigs inoculated with the same kind of RBC and with the addition of a live C. albicans suspension. A comparison was made of the weights of the spleens and regional lymph nodes as well as the values obtained from the direct rosette formation (DRF), indirect rosette formation (IRF) and haemagglutination (HA) tests. In animals inoculated with RBC together with CFA and C. albicans, the weight of the spleens and lymph nodes were low compared to those of animals inoculated with RBC and CFA alone. According to the DRF and IRF tests, the animals inoculated with RBC together with CFA and C. albicans produced less cytophilic antibodies than those injected with RBC and CFA alone. The difference was most evident on the 7th day after inoculation and decreased on the 14th, 21st and 28th days. No difference was observed in HA titres. In guinea pigs inoculated with C. albicans either 3 or 7 days prior to the injection of RBC and CFA, the partial suppression of the immune response was more marked and more persistent than that obtained by simultaneous inoculations of RBC, CFA and C. albicans. In addition, HA titres were also lower in these animals than in controls. Considering the low weight index of spleen and lymph nodes, as well as the impaired antibody production in guinea pigs inoculated with RBC, CFA and C. albicans, compared to those injected with RBC and CFA alone, it is possible to assume that C. albicans might have a suppressive effect on the immune system of guinea pigs.