COMPLEXITY OF THE BOVINE MHC CLASS-II SPECIFICITY DW3 AS DEFINED BY ALLOANTISERA

Alloantisera related to the bovine major histocompatibility complex (MHC) class-II specificity Dw3 were investigated by cross-absorption experiments and by application of the monoclonal antibody-specific immobilization of lymphocyte antigen assay (MAILA). The absorption study revealed antibodies specific for an antigenic determinant shared by all Ds03 (Dw3)-positive animals, and several other antibody populations recognizing the locally defined specificites Ds10, Ds11 and Ds15, that are closely associated with Ds03. The results of the MAILA-assay indicate that the Ds03 specificity is probably encoded by DQ, whereas specificities Ds10 and Ds11 are more closely associated with DR molecules. The data presented here provide the first evidence that bovine DR and DQ specificities can be identified separately by serological methods using alloimmune antisera.     

The HLA dictionary 2001: a summary of HLA-A, -B, -C, -DRB1/3/4/5, -DQB1 alleles and their association with serologically defined HLA-A, -B, -C, -DR, and -DQ antigens

This report presents the serologic equivalents of 123 HLA-A, 272 HLA-B, and 155 HLA-DRB1 alleles. The equivalents cover over 64 percent of the presently identified HLA-A, -B, and -DRB1 alleles. The dictionary is an update of the one published in 1999 (Schreuder GMTh, Hurley CK, Marsh SGE, Lau M, Maiers M, Kollman C, Noreen H. The HLA dictionary 1999: a summary of HLA-A, -B, -C, -DRB1/3/4/5, -DQB1 alleles and their association with serologically defined HLA-A, -B, -C, -DR and -DQ antigens. Tissue Antigens 54:407, 1999) and also includes equivalents for HLA-C, DRB3, DRB4, DRB5, and DQB1 alleles. The data summarize information obtained by the WHO Nomenclature Committee for Factors of the HLA System, the International Cell Exchange (UCLA), the National Marrow Donor Program (NMDP), and individual laboratories. In addition, a listing is provided of alleles which are expressed as antigens with serologic reaction patterns that differ from the well-established HLA specificities. The equivalents provided will be useful in guiding searches for unrelated hematopoietic stem cell donors in which patients and/or potential donors are typed by either serology or DNA-based methods. These equivalents will also serve typing and matching procedures for organ transplant programs where HLA typings from donors and from recipients on waiting lists represent mixtures of serologic and molecular typings. The tables with HLA equivalents and a questionnaire for submission of serologic reaction patterns for poorly identified allelic products will also be available on the WMDA web page: www.worldmarrow.org.     

Competition-based cellular peptide binding assays for 13 prevalent HLA class I alleles using fluorescein-labeled synthetic peptides

We report the development, validation, and application of competition-based peptide binding assays for 13 prevalent human leukocyte antigen (HLA) class I alleles. The assays are based on peptide binding to HLA molecules on living cells carrying the particular allele. Competition for binding between the test peptide of interest and a fluorescein-labeled HLA class I binding peptide is used as read out. The use of cell membrane-bound HLA class I molecules circumvents the need for laborious biochemical purification of these molecules in soluble form. Previously, we have applied this principle for HLA-A2 and HLA-A3. We now describe the assays for HLA-A1, HLA-A11, HLA-A24, HLA-A68, HLA-B7, HLA-B8, HLA-B14, HLA-B35, HLA-B60, HLA-B61, and HLA-B62. Together with HLA-A2 and HLA-A3, these alleles cover more than 95% of the Caucasian population. Several allele-specific parameters were determined for each assay. Using these assays, we identified novel HLA class I high-affinity binding peptides from HIVpol, p53, PRAME, and minor histocompatibility antigen HA-1. Thus these convenient and accurate peptide-binding assays will be useful for the identification of putative cytotoxic T lymphocyte epitopes presented on a diverse array of HLA class I molecules.     

Five newly identified HLA alleles: A*0310, A*2907, B*4435, Cw*0206, Cw*0506, and confirmation of A*3106, B*3924, Cw*0314, DRB1*0322, and DRB1*1433 alleles

A number of HLA alleles have been newly identified. This concerns HLA-A*0310, A*2907, B*4435, Cw*0206, Cw*0506, of which Cw*0206 was found in three unrelated individuals, all B*4002 positive. Some other alleles are also presented but confirm earlier detected sequences: A*3106, Cw*0314, DRB1*0322, and DRB1*1433. Moreover, we identified B*3924 in a bone marrow transplant recipient and in five of six unrelated stem cell donors, selected for this patient. In all cases, B*3924 was found on a haplotype combining A*0201, B*3924, Cw*0701, and DRB1*1303. The observation of this extended haplotype is of importance for the selection for stem cell transplantation. Cells expressing B*3924 and B*4435 were typed by serology as B39 and B44, respectively. Cells expressing HLA-A*0310 do not express A3 but type as A-Blank.     

Ninth International Histocompatibility pre-workshop testing of Dw6 HTCs. Two subtypes of Dw6

In the scope of the cellular part of the 9th International Histocompatibility Workshop, the offered homozygous typing cells (HTCs) of several specificities have been screened in a pre-Workshop. In Leiden and Seattle all HTCs typing for "HLA-Dw6" have been tested. This implied that in both laboratories mixed lymphocyte culture (MLC) matrices were performed between the Dw6 HTCs and that all HTCs were tested as stimulator cells against a panel of heterozygous responder cells. The results clearly demonstrated that "HLA-Dw6" as defined by the different participating laboratories can be split into two major groups, Dw6.a and Dw6.b. This observation confirms and extends previous reports. None of the 9th Workshop B-cell sera could discriminate between the two presently described subgroups of HLA-Dw6.     

Transcription Factor PU.1 Promotes Conventional Dendritic Cell Identity and Function via Induction of Transcriptional Regulator DC-SCRIPT

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Cryosurgery in long bones; an experimental study of necrosis and revitalization in rabbits

Cryosurgery is an established adjuvant treatment of bone tumors which reduces the local recurrence rate. In this study, cryosurgical experiments were carried out in rabbits to study the temperature field, the extent of necrosis, and the revitalization process in order to optimize treatment. Intramedullary freezing of long bones with a closed liquid nitrogen cryoprobe and three consecutive sessions induces osteonecrosis down to the -10 degrees C isotherm without compromising the soft tissues. The application of a tourniquet does not influence the thermodynamics. The revitalization process is distinguished into an osteogenic and a remodelling phase. In rabbits, there is an obvious periosteal osteogenesis starting from 1 week after operation and overlapping the remodelling phase, which starts between 3 and 5 weeks after operation. Two out of eight rabbits sustained a pathologic fracture within 3 weeks of cryosurgery. No pathologic fractures were encountered during the remodelling phase, probably because of the profuse periosteal bone apposition that added mechanical strength. In clinical practice, no profound periosteal bone apposition and a high risk for pathologic fractures during the remodelling phase were noted. Future research should focus on bone strength during the remodelling phase of cryosurgically treated long bones, to decide on the role of preventive osteosynthesis or postoperative restrictions. This animal model is not advised for these biomechanical experiments because of its profuse periosteal bone apposition.     

Prognostic indices to predict survival of first and second renal allografts

In order to predict kidney graft survival, the influence of independent prognostic factors can be examined multivariately and the factors combined into a prognostic index. Data on 7121 patients receiving an unrelated first and 1033 patients receiving an unrelated second transplant from nonliving donors, between 1 January 1984 and 31 December 1987, were analyzed to ascertain the most important prognostic variables up to 4.5 years posttransplantation. Factors found to be significant for graft survival were donor and recipient age and sex, recipient blood group, whether the recipient was diabetic, cold ischemic period, number of HLA-B and - DR mismatches, highest percent panel-reactive antibody, transplant center, and--for second transplants--duration of first graft. A risk score for graft failure, based on the prognostic factors, was developed using these factors and five risk groups (from excellent to very poor prognosis) were identified. This index was tested on an independent data set and showed a good fit when compared with the observed Kaplan-Meier graft survival: patients allocated by the risk score into the "excellent prognosis" group had an observed one-year graft survival of 90.4%, compared with a predicted value of 90.3% for first transplants. Corresponding results for second transplants were 86.2% (observed) and 86.0% (predicted). For the "very poor" prognosis group, the results were 73.4% (observed) and 74.4% (predicted), for first transplants, and 60.9% (observed) and 60.1% (predicted), for second transplants. A prognostic index can therefore identify patients likely to have a high or low graft survival, leading to improved decision-making and aiding the choice of patient management once a recipient has been transplanted.