Next-generation sequencing (NGS) is increasingly used in transplantation settings, but also as a method of choice for in-depth analysis of population-specific HLA genetic architecture and its linkage to various diseases. With respect to complex ethnic admixture characteristic for East Croatian population, we aimed to investigate class-I (HLA-A, -B, -C) and class-II (HLA-DRB1, -DQA1, -DQB1) HLA diversity at the highest, 4-field resolution level in 120 healthy, unrelated, blood donor volunteers. Genomic DNA was extracted and HLA genotypes of class I and DQA1 genes were defined in full-length, -DQB1 from intron 1 to 3' UTR, and -DRB1 from intron 1 to intron 4 (Illumina MiSeq platform, Omixon Twin algorithms, IMGT/HLA release 3.30.0_5). Linkage disequilibrium statistics, Hardy-Weinberg departures, and haplotype frequencies were inferred by exact tests and iterative Expectation-Maximization algorithm using PyPop 0.7.0 and Arlequin v3.5.2.2 software. Our data provide first description of 4-field allele and haplotype frequencies in Croatian population, revealing 192 class-I and class-II alleles and extended haplotypic combinations not apparent from the existing 2-field HLA reports from Croatia. This established reference database complements current knowledge of HLA diversity and should prove useful in future population studies, transplantation settings, and disease-associated HLA screening.
- MeSH
- běloši genetika MeSH
- dárci krve MeSH
- dospělí MeSH
- frekvence genu MeSH
- haplotypy MeSH
- HLA-A antigeny genetika MeSH
- HLA-B antigeny genetika MeSH
- HLA-C antigeny genetika MeSH
- HLA-DQ alfa řetězec genetika MeSH
- HLA-DQ beta řetězec genetika MeSH
- HLA-DRB1 řetězec genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- sekvenční analýza DNA MeSH
- vazebná nerovnováha MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Chorvatsko MeSH
We detected a somatic mutation in the HLA-B gene in a Czech hematooncological patient. We followed the development of this somatic mutation during the transition from severe aplastic anaemia through to myelodysplastic syndrome to acute myeloid leukaemia until haploidentical related transplantation. The somatic mutation differs from HLA-B*14:02 in exon 3 resulting in an exchange from cysteine to serine at position 101 of the mature protein. Homology modelling of mutated S101 in HLA-B*14 indicated possible conformational changes, which might also result in an aberrant expression. The assumption is that somatic mutation arose as a possible result of a selection mediated by a protective immune response against leukaemia.
- MeSH
- akutní myeloidní leukemie genetika patologie MeSH
- aplastická anemie genetika patologie MeSH
- dospělí MeSH
- HLA-B antigeny genetika MeSH
- lidé MeSH
- mutace * MeSH
- myelodysplastické syndromy genetika patologie MeSH
- nádorová transformace buněk genetika MeSH
- progrese nemoci MeSH
- stupeň závažnosti nemoci MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
Human leukocyte antigen (HLA) genes play a key role in the immune response to infectious diseases, some of which are highly prevalent in specific environments, like malaria in sub-Saharan Africa. Former case-control studies showed that one particular HLA-B allele, B*53, was associated with malaria protection in Gambia, but this hypothesis was not tested so far within a population genetics framework. In this study, our objective was to assess whether pathogen-driven selection associated with malaria contributed to shape the HLA-B genetic landscape of Africa. To that aim, we first typed the HLA-A and -B loci in 484 individuals from 11 populations living in different environments across the Sahel, and we analysed these data together with those available for 29 other populations using several approaches including linear modelling on various genetic, geographic and environmental parameters. In addition to relevant signatures of populations' demography and migrations history in the genetic differentiation patterns of both HLA-A and -B loci, we found that the frequencies of three HLA alleles, B*53, B*78 and A*74, were significantly associated with Plasmodium falciparum malaria prevalence, suggesting their increase through pathogen-driven selection in malaria-endemic environments. The two HLA-B alleles were further identified, by high-throughput sequencing, as B*53:01:01 (in putative linkage disequilibrium with one HLA-C allele, C*04:01:01:01) and B*78:01 in all but one individuals tested, making them appropriate candidates to malaria protection. These results highlight the role of environmental factors in the evolution of the HLA polymorphism and open key perspectives for functional studies focusing on HLA peptide-binding properties.
- MeSH
- alely MeSH
- HLA-B antigeny genetika MeSH
- lidé MeSH
- odolnost vůči nemocem genetika MeSH
- populační genetika * MeSH
- tropická malárie genetika MeSH
- vazebná nerovnováha MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- subsaharská Afrika MeSH
The identification of a novel HLA-B*35:279 allele in a Czech patient is described. This allele is identical to the B*35:03:01 variant except the G/A nucleotide exchange at position 652 of the HLA-B gene that corresponds to the amino acid substitution from valine to isoleucine in alpha 3 domain of the HLA-B antigen.
- MeSH
- alely * MeSH
- HLA-B antigeny genetika imunologie izolace a purifikace MeSH
- lidé MeSH
- sekvence nukleotidů MeSH
- substituce aminokyselin MeSH
- testování histokompatibility MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Terapeutický efekt nepříbuzenské transplantace krvetvorných buněk (TKB) je nejvíce určován genetickou – HLA – neshodou mezi příjemcem a dárcem. Ta umožňuje jak u malignit žádoucí reakci štěpu proti leukemii (GVL – graft versus leukemia effect) snižující riziko relapsu, tak reakci štěpu proti hostiteli (GVHD-graft versus host disease) zvyšující mortalitu. Práce se snaží shrnout současný pohled na celkový význam HLA shody a interpretovat kvalitativní a kvantitativní efekt neshod v individuálních HLA genech na výsledek TKB od dospělého nepříbuzného dárce a to především u maligních onemocnění. Standardem je v současnosti snaha nalézt dárce alelicky shodného minimálně v HLA-A,-B,-C a–DRB1, protože izolovaná neshoda v každém z těchto genů zvyšuje mortalitu o přibližně 10 % a vícečetné neshody mají dokonce synergický negativní vliv. Efekt neshody je však významně ovlivněn stadiem základního onemocnění, protože u vysoce rizikových nemocných je v důsledku akcentované GVL reakce mnohem méně významný či dokonce zanedbatelný. S možnou výjimkou HLA-C lokusu u transplantace periferními krvetvornými buňkami jsou neshody na alelické i antigenní úrovni zřejmě srovnatelně tolerované. Je-li nutné akceptovat neshodného dárce, pak u kostní dřeně je lépe vyhnout se neshodám v HLA-A či DRB1, u periferních krvetvorných buněk je nejhůře tolerovanou „antigenní“ neshoda v HLA-C. Mimo HLA shodu existuje celá řada faktorů na straně dárce, které ovlivňují výsledek TKB a zde nutno zdůraznit především včasnost provedení transplantace, protože rychlost nalezení nepříbuzného dárce a neprodlené provedení TKB je takřka stejně důležité jako stupeň shody.
The therapeutic effect of unrelated donor stem cell transplantation (SCT) is predominantly determined by genetic non-identity – HLA-mismatch – between recipient and donor. This facilitates both the desirable graft versus leukaemia (GVL) effect, which reduces the risk of relapse in malignancies as well as the graft-versus-host disease (GVHD), which increases mortality. This paper attempts to summarize the current view on the overall significance of HLA match and to interpret the qualitative and quantitative effect of mismatches in individual HLA genes on the outcome of SCT from an unrelated adult donor, particularly in malignant diseases. The current standard involves an effort to find an allele-level matched donor at least in HLA-A,-B,-C,-DRB1, because isolated mismatch in each of these genes increases mortality by approximately 10% and multiple mismatches actually have a negative synergistic effect. However, the consequences of incompatibility are significantly influenced by disease stage, as in high-risk patients these are much less significant or even negligible because of the accentuated GVL response. With the possible exception of the HLA-C locus, mismatches either on allelic or antigenic level seem to be comparably tolerated in peripheral blood stem cell transplantation. If it is necessary to accept a mismatched donor, then in the case of bone marrow it is best to avoid mismatches in HLA-A and DRB1, while in the case of peripheral blood stem cells the worst tolerated “antigenic” mismatch involves HLA-C. Apart from HLA match, there are many factors on the donor side that affect SCT outcome. These especially include timely transplantation, as the speed of finding an unrelated donor and SCT within the shortest possible time are almost as important as the degree of HLA-compatibility.
- Klíčová slova
- krvetvorné buňky,
- MeSH
- časové faktory MeSH
- dárci krve MeSH
- dospělí MeSH
- HLA antigeny genetika imunologie MeSH
- HLA-A antigeny genetika imunologie MeSH
- HLA-B antigeny genetika imunologie MeSH
- HLA-C antigeny genetika imunologie MeSH
- HLA-DRB1 řetězec genetika imunologie MeSH
- homologní transplantace MeSH
- krevní a lymfatické nemoci terapie MeSH
- lidé MeSH
- nepříbuzný dárce * MeSH
- reakce štěpu proti hostiteli genetika imunologie MeSH
- reakce štěpu proti leukémii imunologie MeSH
- rizikové faktory MeSH
- testování histokompatibility * metody MeSH
- transplantace kmenových buněk * MeSH
- výběr dárců MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
Human leucocyte antigen (HLA) modifications observed in blast cells in haematologic malignancies can play an important role in disease progression and its therapy. Here we describe an insertion/deletion mutation in the second exon of HLA-B*39:01 that occurred in the blast cells of a patient with B-ALL. This mutation was not present in the nonleukemic cells, in which HLA-B*39:01 was normally expressed.
A novel HLA-B (human leukocyte antigen-B) allele, HLA-B*4442, was identified both in a Czech patient with leukaemia and in his mother. The presence of a novel allele was initially suspected because conflicting results were obtained by serological and DNA typing techniques. The HLA typing using the polymerase chain reaction-sequence-specific primers (PCR-SSP) at the two-digit level indicated an allele belonging to the HLA-B*44 group, whereas serological typing indicated HLA-B21. Typing with PCR-sequence-specific oligonucleotides (PCR-SSO) resulted in a unique reaction pattern that could not be assigned to a known allele, PCR-SSP typing at the four-digit level did not match any known B*44 allele, either. The sequencing-based typing of the HLA-B locus then revealed the novel B*4442 allele that is identical with B*4405 except a single C-->G nucleotide exchange at position 572. This exchange results in an amino acid substitution from serine to tryptophan at position 167 of the expressed HLA-B protein. The B21 serological reactivity of the novel B*4442 allele product was confirmed by employing an additional serological panel of typing sera. Our findings support previous reports claiming that serine at the position 167 in the alpha-2 domain of the HLA-B protein is a major determinant of the HLA-B44(12) serological epitope.
- MeSH
- alely MeSH
- bodová mutace imunologie MeSH
- financování organizované MeSH
- HLA-B antigeny genetika imunologie MeSH
- leukemie genetika imunologie MeSH
- lidé MeSH
- molekulární sekvence - údaje MeSH
- regulace genové exprese u leukemie genetika imunologie MeSH
- rodokmen MeSH
- sekvence nukleotidů MeSH
- substituce aminokyselin účinky léků MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- alely MeSH
- frekvence genu MeSH
- HLA-A antigeny genetika MeSH
- HLA-B antigeny genetika MeSH
- HLA-C antigeny genetika MeSH
- lidé MeSH
- polymorfismus genetický MeSH
- transplantace kostní dřeně normy MeSH
- Check Tag
- lidé MeSH
- Geografické názvy
- Slovenská republika MeSH
