An Experimental Study on the Immuno-Suppressive Mechanisms of the Anti-Dog Lymphocyte Rabbit Serum

Kim, Si Whang

Abstract

The purpose of the following experiments was to determine the in vivo properties on immunologic specificity and duration of action of anti-dog lymphocyte rabbit serum (ADLRS) prepared against dog lymphocyte. Twenty adult mongrel dogs having average body weight of 10kg. were used in this experiments, being divided into control (10 dogs) and experimental group (10 dogs) for the comparison of the results Experimental group: O.7 cc/kg. of ADLRS was injected into the both gluteal region with intervals of 6 hours, 12 hours, 24 hours, 48 hours and 72 hours. Control group: 10 cc of normal rabbit serum(NRS) was injected into the both gluteal region with same intervals as experimental group. Peripheral blood findings and bone marrow pictures were compared with the results of pre. and post-injection of ADLRS and NRS, and histopathological studies were investigated The following results were obtained. 1. The total REC and WBC counts remained within normal limits; however, the mean decrease percentages of the peripheral lymphocyte in the experimental group were 32.9%, 45.8N, 51.3%, 48.4% and 32.8% respectively. On the other hand, the decrease of the lymphocyte in the control group was quite meager. 2. No significant changes in bone marrow pictures were noted in both groups. 3. Histopathologically, the specific alterations of lymphoid tissues accompanying delayed-type immune depression consisted of an early selective depletion of small lymphocytes from the thymus-dependent areas of spleen follicles, lymph nodes, thymus and other lymphoid tissues. 4. The small lymphocyte depleted-areas were partially replaced by large pyroninophilic cells. 5. Plasmacytoid hyperplasia and germinal center development occurring afterwards, always outside thymus-dependent areas, were also observed in control dogs treated with normal rabbit serum. These results confirmed that the target cell of the ALS is thymus-dependent areas and supported the hypothesis.that two different population of lymphocyte exist within the lymphoid organs. 6. The thymus, which showed only occasionally and cellulartity, seemed to be also affected by ALS in later period. 7. ADLRS prepared by the author reached its peak of action during the period of 24 to 48 assumed that the immunosuppressive response will return to normal possibly in 7~10 days after injection.