Sequence of a new HLA-DR11 allele with a DR4-specific first hypervariable region.
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Alleles↗
Biomedical subjects
J M Tiercy
Publications and source records attributed to J M Tiercy.
Transfusion-associated graft-versus-host disease in a patient treated with Cladribine (2-chlorodeoxyadenosine): demonstration of exogenous DNA in various tissue extracts by PCR analysis.
Transfusion-associated graft-versus-host disease can occur in both immunocompetent and immunocompromised hosts. Cladribine is a synthetic analogue of adenine used in the treatment of lymphoid malignancies, commonly associated with a decrease in T lymphocytes. Cladribine was given for a low-grade non-Hodgkin's lymphoma with thrombocytopenia as the main side-effect. Six units of pooled non-irradiated platelets were transfused from six unrelated donors; 10 d later a clinical picture typical of graft-versus-host disease resulted. Polymerase chain reaction of the highly polymorphic DNA minisatellites and HLA-DR oligotyping were used to demonstrate the exogenous DNA. In the patient's blood and tissues, only the pattern of donor 5 was found. The patient (DRB1*0301/1101; DRB3*0101/02) and this donor (DRB1*0301/1104; DRB3*02) by chance shared a partial common haplotype. This complication highlights the sensitivity of DNA minisatellite analysis. It further raises the question of transfusion and of prophylactic irradiation of all blood products in immunosuppressed patients and those treated with cladribine. This case represents a previously unreported situation where an immunosuppressed patient was able to eliminate cells from five totally HLA-DR dissimilar donors but not from one heterozygous donor with strong HLA-DR similarity.
Aged↗
Histoincompatibilities in ABDR-matched unrelated donor recipient combinations.
To get an insight into the degree of major histocompatibility mismatches in donor/recipient (D/R) combinations who were 'ABDR-matched' by serology for class I and by oligotyping for DR1-14 (low resolution typing), we performed additional HLA testing using a combination of molecular, biochemical and cellular techniques. For class II we used extended oligotyping, discriminating all the common DRB1/B3/B5-subtypes. For class I (-subtypes) we used oligotyping (HLA-A2,-A3,-B35,-B41,-B44), sequencing (HLA-B35,-B41,-Cw16), isoelectrofocusing (IEF), primary cytotoxic T lymphocyte (CTL) assays and class I-subtype specific T cell clones. In addition, all combinations were serologically typed for HLA-C. This high resolution typing by the combination of techniques revealed numerous histoincompatibilities. Fifty-three per cent of all 'ABDR-matched' combinations tested (n = 198) appeared to be DR incompatible. Moreover, independent of the presence of a class II mismatch, 47% of the donors tested (n = 131) displayed pretransplant cytotoxic activity against the patient. This activity was found to be rigorously correlated with the presence of class I incompatibilities, predominantly HLA-A,-B subtypes and HLA-C. Thus, although the D/R pairs had been originally matched for AB including serological splits and by generic class II typing, only 28% of the pairs were in fact ABCDR identical. As many as 38% of the D/R pairs were mismatched for one, 14% for two, 13% for three and 6% for four A, B, C or DRB1 antigens. We conclude that the presence of such a high number of histoincompatibilities in a group of relatively well matched D/R pairs will severely hinder the analysis of the role of HLA in marrow transplantation and that conclusions from studies in which D/R pairs are matched by conventional typing must be interpreted with extreme caution.
Bone Marrow Transplantation↗
An HLA-DRB alpha-helix motif shared by DR11 and DR8 alleles is implicated in the pluriallelic restriction of peptide-specific T-cell lines.
The T-cell recognition of HLA-DR-peptide complexes is generally restricted by the polymorphism of the DRB molecules but pluriallelic restriction has been described. The molecular basis of restriction and promiscuity of such peptide-specific responses is poorly understood. We isolated a panel of T-cell lines specific for the tetanus toxin peptide p2 (TT830-843) exhibiting pluriallelic restriction by DR11 and DR8 alleles. Fine restriction specificity of the T-cell lines was examined in functional assays against DR oligotyped APCs expressing different variants of DR11 and DR8 alleles. Our results show that (a) polymorphisms between serologically related alleles are relevant in terms of restriction of the peptide-specific T-cell response; in some instances, a single amino acid substitution can determine the restriction of a T-cell line; (b) different patterns of restriction are not the result of specific differences in DR-p2 binding as p2 peptide binds to all DR11 and DR8 alleles tested (DRB1* 1101, -1102, -1103, -1104, 110X, -0801, -0802, -0803, and -0806); and (c) pluriallelic restriction of the peptide-specific T-cell response correlates with the presence of a DRB1 alpha-helix motif (67-71-86) shared by some DR11 and DR8 alleles. Possible implications of pluriallelic restriction of peptide-specific T-cell response in autoimmune disorders associated with DR11 and DR8 are discussed.
Alleles↗
Oligotyping of HLA-A2, -A3, and -B44 subtypes. Detection of subtype incompatibilities between patients and their serologically matched unrelated bone marrow donors.
We have set up a simple PCR-SSO oligotyping procedure that is able to discriminate ten HLA-A2 (2 PCR/11 probes), two HLA-A3 (1 PCR/1 probe), and two HLA-B44 subtypes (1 PCR/2 probes). The frequency of these subtypes has been determined in a large panel of local blood donors and leukemic patients in combination with their unrelated potential donors. A*0201 and A*0301 were the predominant subtypes (> 95%) for A2 and A3, respectively. B*4402 occurred twice as frequently as B*4403. A2 and B44 subtype mismatches were analyzed in a group of 30 patients and their 116 unrelated potential donors who were matched serologically (low-stringency matching: AB without splits, DR1-10). For seven patients (23%) at least one A2- or B44-subtype-mismatched donor was found. For two of these patients (7%), the subtype-mismatched donor would have been considered as compatible on the basis of high stringency matching (AB splits, DRB1 subtypes, DRB3/B5). For one patient of Mediterranean origin, all five donors recruited from a north European registry (matched with high stringency) appeared to be subtype incompatible (A*0201/A*0205). The rather low percentage of A2- and B4-subtype mismatches in DRB1/B3/B5 matched combinations confirms the significance of linkage disequilibria of HLA antigens. Because unrelated donor selection is done through international registries, however, class I subtyping might be necessary when individuals originate from different geographic areas.
Base Sequence↗
HLA-B35-subtype mismatches in ABDR serologically matched unrelated donor-recipient pairs.
We have characterized HLA incompatibilities in a group of 17 B35-positive patients who were ABDR matched (AB serology and oligotyping for DR1-14) with their 28 (unrelated) potential bone marrow donors. High-resolution oligotyping for DR subtypes disclosed that nine combinations were in fact DR mismatched. Cytotoxic T-lymphocyte (CTL) activity was detected in nine combinations (32%). In the group matched for DR subtypes, three (16%) of 19 combinations were CTL positive. Patient-specific cytotoxic activity appeared to be directed against HLA C (two cases) or against a subtype of B35. In the group of DR-subtype-mismatched combinations, CTL activity was found in six (67%) of nine pairs. In all four cases that were studied in detail, however, CTL reactivity appeared to be directed against a variant subtype of B35. We have studied the B35 incompatibilities recognized in five different combinations by specificity analysis of the B35-specific CTLs and by partially sequencing of relevant segments of B35 exon 3. Preliminary data show that, within this relatively small Caucasoid group, at least five B35-variant subtypes could be distinguished. This would make B35 an antigen that will be frequently subtype mismatched, in particular when DR matching is done with low resolution (DR1-14) only.
HLA-A Antigens↗
HLA-DRB1 matched kidneys are preferentially HLA-A and -B compatible and survive longer.
HLA-DR matching was analysed in 111 cadaveric donors and 156 patients who underwent kidney transplantation. We compared the results of conventional DR serology with sequence specific oligonucleotide typing performed on PCR-amplified DRB1 exon 2 DNA. We found discrepancies between serology and DNA typing in 10.1% when the broad antigen specificities DR1-10 were considered. The graft survival probability at 2.5 years between HLA-DR matched versus mismatched transplants was not different (0.87 vs 0.83) when matching was based on serology. However, a significant graft survival difference (0.95 vs 0.82) was found when matching was based on oligotyping for DRB1 (including all subtypes). Furthermore, a better matching for HLA-A and -B was found in the DRB1 matched group. Therefore, precise matching at one particular locus (as shown here for the DRB1 locus) significantly increases the chance to be matched at further MHC loci. The further development of high-resolution typing techniques for most or all HLA-A, -B, -C, -DR, -DQ, -DP antigens may in the future allow more precise definitions of clinically important mismatches helping to develop rational matching strategies.
Graft Survival↗
Processing and presentation of tetanus toxin by antigen-presenting cells from patients with chronic granulomatous disease (CGD) to human specific T cell clones are not impaired.
The capacity of peripheral blood lymphocytes (PBL) or Epstein-Barr virus (EBV)-transformed B cell lines from CGD patients to process and present tetanus toxin (tt)-specific epitopes was assessed using various tt preparations and human tt-specific T cell clones. PBL from all of the donors were able to process and present either native tt and/or denatured tt to human T cell clones specific for various tt epitopes. Furthermore, no difference was found in the antigen requirement when normal or CGD EBV-B cell lines were used as antigen-presenting cells (APC). These results suggest that the deficiency in oxygen metabolism in CGD cells does not affect tt processing and presentation.
Amino Acid Sequence↗
Sequencing of a novel functional HLA-B44 subtype differing in two residues in the alpha 2 domain.
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Amino Acid Sequence↗
HLA-DPB1 DNA polymorphism in the Swiss population: linkage disequilibrium with other HLA loci and population genetic affinities.
Allelic diversity at the HLA-DPB1 locus was determined by PCR-oligotyping in a sample of 125 healthy Swiss individuals. A total of 17 alleles were detected among which four main alleles (DPB1*0401, *0201, *0301, *0402) reached a cumulative frequency of 74.8%. HLA-A and -B (by serology) and HLA-DRB1 (by oligotyping) allelic polymorphisms were analysed also. HLA-B and HLA-DRB1 loci were highly polymorphic with 25 and 28 alleles respectively and similar heterozygosity levels of 0.93 and 0.92. These two loci were found to be more polymorphic than expected under neutrality, while lower heterozygosity levels were found for HLA-A (0.87) and DPB1 (0.81) loci. This paper presents also a global comparison of DPB1 allelic frequencies among 15 populations from four continents. As opposed to the DRB1 locus, overall DPB1 is shown to have a lower level of polymorphism and may be considered as neutral in all tested populations. DPB1 genetic diversity is correlated significantly with geography also, as found previously for DRB1. Two- and four-locus haplotype frequencies were determined and the significance of their linkage disequilibrium tested by an original non-parametric method. A significant positive linkage disequilibrium was found for 11 A-B, 16 B-DRB1, 7 DRB1-DPB1 and 3 A-B-DRB1-DPB1 haplotypes. The overall linkage disequilibrium between DRB1 and DPB1 was much lower than expected from the physical distance and lower than for A-B and B-DRB1 pairs. The implications of these results for bone marrow transplantation and for the evolution of HLA loci are discussed.
Alleles↗
Relation between the resolution of HLA-typing and the chance of finding an unrelated bone marrow donor.
The chance of finding an unrelated bone marrow donor depends on the size of the donor registry, the frequency of the patient's HLA phenotype and the degree of histoincompatibility considered acceptable. We have studied 60 unrelated bone marrow donor searches and the probability of finding a donor when increasing HLA-compatibility requirements were applied. For 21 (35%) of the patients no donor could be identified who was (serologically) matched for all six ABDR antigens. For the remaining 39 (65%), a median of two (range 1-20) blood samples from serologically-matched potential donors was obtained for further analysis. Eighteen (30%) patients appeared to be mismatched with all the pre-selected donors because of DR (sub-)type mismatches detected by oligotyping. A further 7 (12%) patients did not have an MLC and/or cytotoxic T lymphocyte precursor (CTLp) negative donor. Thus, a 'perfectly matched' donor was found for 11 (18%) patients. To find a suitable donor for more patients we propose that many or all the potential donors identified in the various registries for a particular patient are simultaneously evaluated as many of the serologically ABDR-matched donors will appear to be incompatible after high resolution HLA-typing. This strategy will not only allow selection of the best matched donor more rapidly but the consequent use of high resolution typing might also lead to the definition of a certain number of acceptable mismatches.
Bone Marrow Transplantation↗
[Pretransplant activity of cytotoxic T-lymphocytes in non-related bone marrow donor/recipient combinations with a perfect HLA match].
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Bone Marrow Transplantation↗
[A new method of HLA-DR typing using molecular biology: 1-year experience in bone marrow transplantation].
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Bone Marrow Transplantation↗
High-resolution histocompatibility testing of a group of sixteen B44-positive, ABDR serologically matched unrelated donor-recipient pairs. Analysis of serologically undisclosed incompatibilities by cellular techniques, isoelectrofocusing, and HLA oligotyping.
We have characterized HLA incompatibilities in a group of 16 B44-positive patients who were serologically ABDR matched with their 23 (unrelated) potential bone marrow donors. After analysis with a combination of cellular techniques, IEF for HLA-A/B and oligotyping for class II and HLA-B44, 44% of the patients revealed one or more HLA incompatibility with at least one of their potential donors. CTL activity was detected in 12 of the 22 combinations tested. CTL incompatibility occurred more frequently in DR subtype-mismatched combinations, but CTL reactivity was always directed against class I. To characterize these incompatibilities between matched unrelated individuals, we analyzed the specificity of T-cell clones from seven primary CTL cultures. In three combinations, CTL reactivity was directed against a subtype of B44. In two combinations, the CTL reactivity was directed against a non-B44 class I subtype. In two of seven combinations, the CTLs recognized an antigen that, though unconditionally associated with B4403, was expressed by 60% of the B4403+ cells only. Because all 12 of these B4403+ targets recognized could be typed for one HLA-C allele only (Cwl-Cw8), we believe that this alloreactivity might be directed against a serologically undefined Cw antigen.
Base Sequence↗
The frequency of pretransplant donor cytotoxic T cell precursors with anti-host specificity predicts survival of patients transplanted with bone marrow from donors other than HLA-identical siblings.
Transplantation with bone marrow from other than genotypically HLA-identical donors is associated with an increased incidence and severity of graft-versus-host disease (GvHD). The precise influence of HLA incompatibilities is not easy to analyze as even perfectly matched, HLA-identical unrelated donors might still express HLA differences that remain undetected by conventional typing. To measure T cell activity against serologically detectable and nondetectable HLA antigens, we analyzed the frequencies of CTL precursors (CTLp) between 11 unrelated HLA-matched and five related haploidentical donor/recipient pairs in graft-versus-host direction. Our results show that whenever HLA class I disparities could be identified by serology, high precursor frequencies (1/28,000-1/94,000) were measured. In contrast, in donor/recipient pairs that differed for class II only, no precursors were detected. CTLp were elevated in two out of eight fully matched donor/recipient combinations. These combinations displayed activities as high (1/21,000; 1/52,000) as the combinations that were serologically HLA class I disparate. The incompatibilities detected by the cellular assay were highly significant for the clinical results after transplantation. High CTLp frequencies before transplantation correlated with unfavorable clinical results independent of the incidence of detected HLA differences. Five out of the six patients with high (> 1/100,000) CTLp frequencies died within 120 days after transplantation. GvHD IV was the cause of death for all (3/5) patients who had received an unmanipulated bone marrow. In the group with intermediate or undetectable CTLp frequencies, eight out of 10 patients are alive, seven (CTLp frequency undetectable) without GvHD more severe than grade II, while one patient (CTLp frequency = 1/180,000) suffered from GvHD grade III. One patient rejected the graft and was rescued by an autologous BMT.
Adolescent↗
Replacement of HLA class II serology by the HLA-DR microtitre plate oligotyping assay: a one-year experience in unrelated bone marrow donor selection.
Because the selection of unrelated bone marrow donors requires a more accurate HLA-typing technique than is used for sibling donors, we have replaced class II serology by a rapid and highly discriminative HLA-DR DNA oligotyping assay on microtitre plates. We present here our 1-year experience with class II typing for 112 potential donors identified for 33 consecutive leukaemic patients. Although the donors were selected to be HLA-A, -B, -DR serologically identical, the microtitre plate oligotyping assay detected DR incompatibilities in 52.7% of the patient/donor pairs. One third was due to incorrect or incomplete typing of DR11 to DR16, the others to mismatches for the serologically indistinguishable subtypes of DR1, 11, 13 and 15, known to be relevant for T cell recognition.
Bone Marrow Transplantation↗
A new HLA-DR4 allele with a DR11 alpha-helix sequence.
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Alleles↗
Functional dissection of the serological DR LYGUE and genotypic DRB1*1303 specificities using a tetanus toxin-specific T-cell clone.
The DRB1 sequence of the homozygous cell line HAG (DR13-DwHAG-DQ7) represents a new DRB allele assigned DRB1*1103, whereas its DRB3 sequence corresponds to the previously described DRB3*0101 (DR52a) allele. The DRB1*1303 gene product is undetectable by current sera used in routine serology typing. We report here direct evidence that the MHC molecule encoded by the DRB1*1303 gene is functional in antigen presentation and in T-cell restriction. We describe a T-cell clone specific for tetanus toxin whose restriction pattern strictly follows the DRB1*1303 allele, as defined by oligonucleotide typing. It also follows the serologic reactivity with the serum LYGUE and also the DwHAG MLC-defined specificity pattern, with one exception. The potential functional sites for the DRB1*1303 gene product involved in T-cell restriction were deduced from sequence comparisons between DRB1*1303 and closely related DRB1 alleles. The relevant as substitutions were located within close proximity to each other on the HLA class II structural model. Our results demonstrate that 1) DRB1*1303 is functional in antigen presentation and T-cell restriction 2) the functional region involved in antigen presentation and T-cell restriction by DRB1*1303 can be defined structurally.
Alleles↗