[Use of the immune tolerance induction in the production of an antilymphocyte serum (ALS) free of antibodies against serum proteins].

The possibility has been investigated of a direct gain of ALS free of undesirable antibodies against serum proteins by inducing immunologic tolerance in productive animals (pigs). Preliminary experiments made with tolerogenic amounts of 10 and 50 ml of sera and with immunization by the serum alone proved applicability of this method. Electrophoresis showed antibodies against 6 to 7 and 2 to 3 fractions in animals tolerated with 10 and 50 ml respectively, compared to 18 to 20 fractions in the control group, which was not tolerated. This has been confirmed when preparing ALS in practice, where the toleration was carried out with 25 ml of serum or with the same amount of serum with the addition of hemoglobin and immunization by lymphocytes isolated from peripheral blood. Final ALS of untolerated animals contained antibodies against 7 to 8 fractions, whereas that of experimental group tolerated with serum and Hb was free of antibodies against serum protein, hemoglobin included. ALS of the group tolerated with normal serum contained only antibodies against hemoglobin. In vitro tests (i.e. lymphoagglutination t., lymphocytotoxicity t., rosette inhibition t.) proved that by inducing tolerance towards serum protein the activity of ALS was in no was affected. According to the results this method can be employed not only for the preparation of ALS, but also for other purposes, such as preparation of monovalent antisera for immunoelectrophoresis.