Abstracts S24 Poster Group 7 - Immune Regulation 94 HUMORAL AND CELLULAR IMMUNE RESPONSE 93 MECHANISMS DIRECTED AGAINST THE FETUS SUPERIOR T CELL SUPPRESSION BY RAPAMYCIN+FK506, CONTRIBUTE TO PLACENTAL ABRUPTION. OVER RAPAMYCIN+CSA, DUE TO ABROGATED CTL INDUCTION, IMPAIRED MEMORY RESPONSES AND Andrea Steinborn, Cyrus Sayehli, Christoph Sohn, Erhard Seifried, PERSISTENT APOPTOSIS Edgar Schmitt, Manfred Kaufmann, Christian Seidl. Department of Obstetrics and Gynecology, University of Frankfurt; Hans JPM Koenen, Etienne CHJ Michielsen, Jochem Verstappen, Institute of Immunology, University of Mainz; Department of Esther Fasse and Irma Joosten. Department for Blood Transfusion Transplantation Immunology, RCBDS, Germany and Transplantation Immunology, University Medical Center Placental abruption is an unpredictable severe complication in Nijmegen, The Netherlands. pregnancy. In order to investigate the possibility that the activation Immunosuppressive therapy is best achieved with a combination of agents of the fetal non-adaptive immune system may be involved in the targeting multiple activation steps of T-cells. In transplantation, Cyclosporin-A pathogenesis of this disease, IL-6 release from cord blood (CsA) or Tacrolimus (FK506) are successfully combined with Rapamycin monocytes was examined by intracellular cytokine staining and (Rap). Rap and CsA were first considered for combination therapy because flow cytometric analysis. Our results demonstrate that preterm FK506 and Rap target the same intracellular protein and thus may act in an antagonistic way. However, in clinical studies FK506+Rap proved to be placental abruption (n=15) in contrast to uncontrollable preterm effective. To date, there is no in vitro data supporting these in vivo findings and labour (n=33) is associated with significantly (p<0.001) increased it is unclear whether the observed effects are T cell mediated. In a human release of IL-6 from the fetal monocytes. The same holds true for polyclonal allogeneic in vitro model, we found that although combined drug Rhesus disease that is characterized by a maternal production of treatment markedly reduced expansion of naive T cells, T cell activation antibodies against the rhesus-D antigen expressed by the fetal occurred irrespective of the drug combination used. The induction of cytotoxic effector T cells was reduced by CsA+Rap, but completely abolished by erythrocytes. This suggests that in the course of Rhesus disease IL- FK506+Rap. Importantly, combined immunosuppression allowed generation of 6 release of monocytes is induced by antibody-mediated cross- memory CD4+ and CD8+ T cells and hence did not result in T cell anergy. linking of these cells to the erythrocytes in the fetal circulation. To However, FK506+Rap treatment resulted in a reduced number of allospecific elucidate this potential mechanism, the presence of anti-HLA- memory T cells showing a decreased cell cycle turnover and cytokine antibodies was assessed in the maternal circulation of patients with production. In contrast, CsA+Rap treatment led to increased memory T cell numbers responding with elevated kinetics. The ability of Rap to promote placental abruption (n=17) and patients with uncontrollable apoptosis, which contributes to T cell suppression, remained unaffected upon preterm labour (n=29). The percentage of women producing anti- combination with FK506 or CsA. These data support the combined use of paternal HLA-antibodies was significantly (p< 0.01) increased in FK506+Rap over CsA+Rap for immunosuppressive therapy the group of women with preterm placental abruption (47%) in comparison to women with uncontrollable preterm labour (14%). Our results suggest that an increased humoral immune response of the mother against the fetus is involved in the pathogenesis of placental abruption. Poster Group 8 - Population Genetics and Anthropology 95 96 THE ORIGIN OF MAYANS ACCORDING TO HLA GENES AND SNP SCREENING OF A KOREAN POPULATION USING THE UNIQUENESS OF AMERINDIANS. ALKALINE-MEDIATED DIFFERENTIAL INTERACTION (AMDI) Eduardo Gómez-Casado, Jorge Martínez-Laso, Juan Moscoso, Jorge Zamora, Patricia Lucas Gramajo#, Carlos Silvera-Redondo, Ernesto Lowy, and Antonio Susan. Tonks, Jin C. Kim and Walter.F. Bodmer Arnaiz-Villena. Cancer Research UK Department of Immunology and Molecular Biology, Hosp. 12 de Octubre, Universidad Complutense, 28040 Madrid, Spain. E-mail: The polymerase chain reaction (PCR) and the identification of SNPs (single nucleotide polymorphisms) throughout the genome have had a major impact on [email protected]. #Department of Laboratory, Hospital Regional the study of human population genetics at the DNA level. It is important, de Xela (Quetzaltenango, Guatemala). however, not to rely on a single set of markers to elucidate the demographic and The HLA allele frequency distribution of the Mayans from Guatemala has been migrational history of a given population, but to use a range of markers, studied and compared with those of other First American Natives and encompassing the non-recombinant portion of the Y chromosome, the worldwide populations (a total of 12,364 chromosomes and 6,182 individuals mitochondrial genome and autosomal markers, which may or may not be under from 60 different populations). The main conclusions are: 1)The closest selective pressure. Amerindian group to Mayans is the Arhuacs, who were the first recorded PCR has greatly enhanced the ability to type for SNPs. Until recently, Caribbean Islands inhabitants. 2)Mayans are not so close to Mesoamerican however, many detection methods have relied on the use of gels or specially Zapotec, Mixe and Mixtec Amerindians, who genetically cluster together. Mixe labelled probes. AMDI (Alkaline Mediated Differential Interaction) is a had been related to Mayans only on linguistic bases. 3)DRB1*0407 and detection system devised in our laboratory which avoids the use of gels, lends DRB1*0802 alleles are found in 50% of Mayans; these alleles are also found in itself to automation and high throughput screening, and is simple and other Amerindians ,but the Mayans high frequencies may be showing a founder inexpensive. effect for this Mesoamerican-Caribbean population. 4)Extended Mayan specific We now describe the typing of a Korean population for a number of markers, HLA haplotypes are described for the first time. 5)Language and genes do not including HLA, KIR and SNPs in the non-recombining region of the Y completely correlate in microgoegraphical studies. 6)Peopling of the Americas chromosome using AMDI. The results obtained are direct fluorescence readings was probably more complex than postulated by Greenberg and others (three from a fluorimeter, from which DNA types can be automatically assigned. peopling waves). Significant genetic input from outside is not noticed in Meso These results have been compared with those using a gel-based detection system and South American Amerindians according to the genetic analyses; while all and show good concordance in signal and the presence or absence of a band. world populations (including Africans, Europeans, Asians, Australians, Polynesians, North American Na-Dene Indians and Eskimos) are genetically related. Meso and South American Amerindians tend to remain isolated in the neighbour joining, correspondence and plane genetic distances analyses. Genes and Immunity Abstracts S25 97 98 GENE[VA] PROJECT: CHECKING AND TESTING HLA DATA WHAT IS A FREQUENT HLA HAPLOTYPE? Johan Renquin, David Roessli, Alicia Sanchez-Mazas Pierre-Antoine Gourraud1, Henk Van Der Zanden2, Colette Laboratory of Genetics and Biometry, Department of Anthropology Raffoux3, Jean-François Eliaou4, Anne Cambon-Thomsen1 on behalf and Ecology, University of Geneva, Switzerland of the MADO consortium www.euromado.org 1- INSERM U558 Investigating HLA genetic diversity in human populations requires to follow Toulouse, France 2- Europdonor Leiden, The Netherlands 3-FGM several important steps in data analysis, among which checking for Hardy- Paris, France 4-CHU Saint Eloi Monptellier, France Weinberg equilibrium, or testing linkage disequilibrium and associations with diseases. Although a number of computer programs are currently available for In 2001, around 14 out of 100 HLA A B DR split phenotypes of the new population genetics analyses, they do not always apply to HLA data which haematopoietic stem cell (HSC) potential donors were not already present in the exhibit both numerous loci and high numbers of alleles per locus, including a file of Bone Marrow Donor Worldwide: four times less than ten years ago. The possible blank recessive. recruitment of unrelated HSC donor needs to be optimised, trying to avoid One of the GeneVA (« Gene Visual Access ») project’s aim is to help frequent HLA types. To go on increasing the probability to find a donor for a immunogeneticists in differents steps of investigation after their laboratory patient, here we aim at defining which HLA are frequent in Europe. work. How to format and handle HLA data, and how to choose statistical Methods: We adopted the haplotype frequency estimation viewpoint as it methods for specific research purposes are often not straightforward, leading to gives an estimation of the HLA distribution in the population from where the very heterogeneous data sets. We propose here some interactive tools to donors came. Haplotype estimations were obtained by Maximum likelihood standardise HLA data formats for their use in different computer programs, and method implemented within an Expectation Maximisation algorithm.