Abstracts 109

B 9.1.205 CELL-FREE ASSAY PREDICTS PROLIFERATIVE SUPPRESSION BY CYCLOSPORINE AND RAPAMYCIN. PM Kimball, RH Kerman, and BD Kahan, Univeristy of Texas Medical School, Houston, Texas.

We report that Cyclosporine (CsA) and Rapamycin (RAPA) inhibit protein kinase C[PKC]-triggering of the intracellular activation signal ADR (Activator of DNA Replication) in a cell-free assay. Furthermore, ADR induction is dose- dependent and correlates with proliferative suppression by CsA or RAPA. Peripheral blood lymphocyte cytosol was isolated and endogenous PKC triggered with 50 nM phorbol myristate acetate (PMA). ADR was subsequently measured by uptake of tritiated thymidine. PKC activation induced ADR (890+ 120 cpm v~ 3910+345, p<0.001). In contrast, PKC inhibition by H-7 blocked ADR generation (100+50 cpm vs 3910+345, p<0.001). ADR was not found following cell cultivation with PHA and 50 nM CsA (910+40 cpm with CsA vs 6410+830 cpm without CsA, p<0.001) nor was it induced by PKC (750+80 cpm). Pretreatment of unstimulated cells with CsA or RAPA blocked ADR induction by PKC. CsA doses of 10, 50 or 100 ng/ml inhibited ADR induction 10%, 59% or 73% and T-cell mitogenesis by 15%, 63% or 79%, respectively. RAPA pretreatment of resting cells resulted in similar correlations between ADR inducability versus proliferation suppression. In summary, cytosolic ADR was generated following PKC activation. Cell-free quantitation of ADR mimiced proliferative inhibition by CsA and RAPA. Thus, cell-free assay of ADR may permit monitoring of clinical immunosuppression as well as dissection of phosphorylated intermediates necessary for intracellular communication.

B 9.1.206 HLA-A,B AND C FREQUENCIES IN LEBANESE. May Abdelnoor and Alexander M. Abdelnoor, Notre Dame Des Secours Hospital an~--~merlcan ~n-i-~ersity of Beirut,Lebanon.

HLA-A,B and C frequencies were determined in 416 lebanese.These included 237 moslems and 179 christians. Among the moslems there were 149 chiites and 88 sunnites. Among the christians there were 129 maronites,27 orthodox and 23 catholics. The method used for HLA determinations was the complement dependent microcytotoxicity assay. The

frequencies of the various HLA-A,B and C determined in leb- anese christians and moslems were compared to each other and to those of reported frequencies for europeans.

The results indicated that; i- A2,B7 and B27 occurred more frequently in moslems than in christians. 2- A9,B35 and Cw4 occurred more frequently in christians than in moslems. 3- A9,B5,B35,B21 and Cw4 occurred more frequently in leb- anese (christian and moslem) than in europeans. 4- B27 and Cw3 occurred more frequently in europeans than in lebanese. 5- There were other minor differences in HLA frequencies among the groups compared.

In conclusion, these results may be useful in disease association and anthropological studies in lebanese.