Population Studies of HLA-linked SB Antigens and Their Relative Importance in Primary MLC Typing Analysis of HLA-D Homozygous Typing Cells and Normal Heterozygous Populations G. Pawelec, S. Shaw, M. Schneider, M. Blaurock, M. Frauer, D. Brackertz, and P. Wernet ABSTRACT: SB phenotyping was undertaken on 96 HLA-D homozygons typing cells *HTCs) and 129 normal unselected heterozygous donors in the German population, n~ing Interte~,ki~- propagated primed lymphocyte typing (PLT~ reagents. The results shou'ed that the SB a,,tigen5 in the normal population behave as a system of alleles at a single locus in Hardy-~'einberg equilibrium (p ~- 0.20). Estimated genefrequencies in the German population appoared to be significantly different (p < 0.002)fr0m the North American Caucasian population: the principat differences were increased frequencies of the specificities SB I and SB4. and decreased frequencie~ of blanks. Of HLA heterozygous donors 41% typed for two distinct SB specificities: 5 7 ~ t)ped for one; and 2% were blank. In the HTC group. 20% typed for tu'o specificities: 68~ tyi~d for one: and 12% were blank. Thus, a significant proportion of HLA-D homezygeus t,~t ceils were, nonetheless, heterozygousfor HLA-linked SB antigens. Performanceof c h e e k ~ r d mixed leukocyte cultures (MLCs) between 16 SB typed HLA-Dw3 HTCs. hewez'er, did not indicate that the observedmutual or one-way responseswere influenced in any simple way by SB an,'igens: neither heterozygosity nor assumed homozygosity for SB antigens appeared to influence t~% fre- quency of MLC typing responses of HLA-Dw3-positive donors on these HTCs. These ,mutts add further confirmation of the genetic and functional independence of the SB gone#mduct¢s* and the HLA-D/DR goneproduct(s). ABBREVIATIONS DNV double normalized value PBMC peripheral blood mom~nuc~em- HTC (HLA-D) homozygous typing leukocytes cell PLT(L) primed lymphocyte typing IL2 Interleukin 2 (line) MLC mixed leukocyte culture SB secondary B cell (speckficity: SRR stabilized relative response From the ImmunologyLaboratory. MediziniscbeKlinik. Tiibingen. WestGerman)'eG.P.. M.S.. M.B.. M.F.. P.W.); the lmmunolo~ Branch. National CancerInstitute. NIH. Bethesda.Ma~/and qS.$.~:a~d the St, Vinzenz and Elisabeth Hospital. Mainz. WestGermany eD.B.J. Address requests for reprints to G. Pau.elec. ImmunologyL~.b.MedizinischeKlinik. D-7400 T ~ ' ~ . West Germany. Rueived May 3. 1982"accepted July 6. 1982. Human Immunology 5, 215-223 (1982), © El~ier SciencePublishing Co., inc,, 1982 215 52 Vanderbjlt Ave., New York,NY 10017 0198"885~ ~82j070215~-7~