RESUMEN
PURPOSE OF REVIEW: Patients with Lynch syndrome have a high probability of developing colorectal and other carcinomas. This review provides a comprehensive assessment of the immunologic aspects of Lynch syndrome pathogenesis and provides an overview of potential immune interventions for patients with Lynch syndrome polyps and Lynch syndrome-associated carcinomas. RECENT FINDINGS: Immunogenic properties of the majority of Lynch syndrome polyps and associated cancers include microsatellite instability leading to a high mutational burden and the development of novel frameshift peptides, i.e., neoantigens. In addition, patients with Lynch syndrome develop T cell responses in the periphery and in the tumor microenvironment (TME) to tumor-associated antigens, and a proinflammatory cytokine TME has also been identified. However, Lynch syndrome lesions also possess immunosuppressive entities such as alterations in MHC class I antigen presentation, TGFß receptor mutations, regulatory T cells, and upregulation of PD-L1 on tumor-associated lymphocytes. The rich immune microenvironment of Lynch syndrome polyps and associated carcinomas provides an opportunity to employ the spectrum of immune-mediating agents now available to induce and enhance host immune responses and/or to also reduce immunosuppressive entities. These agents can be employed in the so-called prevention trials for the treatment of patients with Lynch syndrome polyps and for trials in patients with Lynch syndrome-associated cancers.
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Anticuerpos/inmunología , Neoplasias Colorrectales Hereditarias sin Poliposis/inmunología , Repeticiones de Microsatélite/inmunología , Microambiente Tumoral , Humanos , Inestabilidad de MicrosatélitesRESUMEN
BACKGROUND: Identifying stage II patients with colorectal cancer (CRC) at higher risk of progression is a clinical priority in order to optimize the advantages of adjuvant chemotherapy while avoiding unnecessary toxicity. Recently, the intensity and the quality of the host immune response in the tumor microenvironment have been reported to have an important role in tumorigenesis and an inverse association with tumor progression. This association is well established in microsatellite instable CRC. In this work, we aim to assess the usefulness of measures of T-cell infiltration as prognostic biomarkers in 640 stage II, CRC tumors, 582 of them confirmed microsatellite stable. METHODS AND FINDINGS: We measured both the quantity and clonality index of T cells by means of T-cell receptor (TCR) immunosequencing in a discovery dataset (95 patients with colon cancer diagnosed at stage II and microsatellite stable, median age 67, 30% women) and replicated the results in 3 additional series of stage II patients from 2 countries. Series 1 and 2 were recruited in Barcelona, Spain and included 112 fresh frozen (FF, median age 69, 44% women) and 163 formalin-fixed paraffin-embedded (FFPE, median age 67, 39% women) samples, respectively. Series 3 included 270 FFPE samples from patients recruited in Haifa, Northern Israel, as part of a large case-control study of CRC (median age 73, 46% women). Median follow-up time was 81.1 months. Cox regression models were fitted to evaluate the prognostic value of T-cell abundance and Simpson clonality of TCR variants adjusting by sex, age, tumor location, and stage (IIA and IIB). In the discovery dataset, higher TCR abundance was associated with better prognosis (hazard ratio [HR] for ≥Q1 = 0.25, 95% CI 0.10-0.63, P = 0.003). A functional analysis of gene expression on these tumors revealed enrichment in pathways related to immune response. Higher values of clonality index (lower diversity) were not associated with worse disease-free survival, though the HR for ≥Q3 was 2.32 (95% CI 0.90-5.97, P = 0.08). These results were replicated in an independent FF dataset (TCR abundance: HR = 0.30, 95% CI 0.12-0.72, P = 0.007; clonality: HR = 3.32, 95% CI 1.38-7.94, P = 0.007). Also, the association with prognosis was tested in 2 independent FFPE datasets. The same association was observed with TCR abundance (HR = 0.41, 95% CI 0.18-0.93, P = 0.03 and HR = 0.56, 95% CI 0.31-1, P = 0.042, respectively, for each FFPE dataset). However, the clonality index was associated with prognosis only in the FFPE dataset from Israel (HR = 2.45, 95% CI 1.39-4.32, P = 0.002). Finally, a combined analysis combining all microsatellite stable (MSS) samples demonstrated a clear prognosis value both for TCR abundance (HR = 0.39, 95% CI 0.26-0.57, P = 1.3e-06) and the clonality index (HR = 2.13, 95% CI 1.44-3.15, P = 0.0002). These associations were also observed when variables were considered continuous in the models (HR per log2 of TCR abundance = 0.85, 95% CI 0.78-0.93, P = 0.0002; HR per log2 or clonality index = 1.16, 95% CI 1.03-1.31, P = 0.016). LIMITATIONS: This is a retrospective study, and samples had been preserved with different methods. Validation series lack complete information about microsatellite instability (MSI) status and pathology assessment. The Molecular Epidemiology of Colorectal Cancer (MECC) study had information about overall survival instead of progression-free survival. CONCLUSION: Results from this study demonstrate that tumor lymphocytes, assessed by TCR repertoire quantification based on a sequencing method, are an independent prognostic factor in microsatellite stable stage II CRC.
Asunto(s)
Neoplasias Colorrectales/genética , Neoplasias Colorrectales/inmunología , Repeticiones de Microsatélite/genética , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Estudios de Casos y Controles , Quimioterapia Adyuvante , Neoplasias Colorrectales/metabolismo , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Humanos , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Masculino , Inestabilidad de Microsatélites , Repeticiones de Microsatélite/inmunología , Persona de Mediana Edad , Mutación , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , España , Microambiente Tumoral/genética , Microambiente Tumoral/inmunologíaRESUMEN
The failure of the maternal immune system to recognize fetal antigens and vice versa due to MHC similarity between the foal and its dam might result in the lack of placental separation during parturition in mares. The aim of the study was to investigate the influence of MHC similarity between a mare and a foal on the incidence of retained fetal membranes (RFM) in post-partum mares. DNA was sampled from 43 draft mares and their foals. Mares which failed to expel fetal membranes within three hours after foal expulsion were considered the RFM group (n = 14) and mares that expelled fetal membranes during the above period were the control group (n = 29). Nine MHC microsatellites of MHC I and MHC II were amplified for all mares and foals. MHC compatibility and MHC genetic similarity between mares and their foals was determined based on MHC microsatellites. The inbreeding coefficient was also calculated for all horses. The incidence of RFM in the studied population was 33%. Compatibility in MHC I and MHC II did not increase the risk of RFM in the studied population of draft mares (P>0.05). Differences in MHC similarity at the genetic level were not observed between mare-foal pairs in RFM and control group (P>0.05). We suspect that RFM in draft mares may not be associated with MHC similarity between a foal and its dam. Despite the above, draft horses could be genetically predisposed to the disease.
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Enfermedades de los Caballos/inmunología , Caballos/inmunología , Endogamia , Complejo Mayor de Histocompatibilidad/inmunología , Retención de la Placenta/veterinaria , Animales , Estudios Transversales , Femenino , Técnicas de Genotipaje , Enfermedades de los Caballos/epidemiología , Caballos/genética , Incidencia , Complejo Mayor de Histocompatibilidad/genética , Repeticiones de Microsatélite/genética , Repeticiones de Microsatélite/inmunología , Retención de la Placenta/epidemiología , Retención de la Placenta/inmunología , Periodo Posparto , EmbarazoRESUMEN
Although immune checkpoint blockade therapies have demonstrated clinical efficacy in cancer treatment, harnessing this strategy is largely encumbered by resistance in multiple cancer settings. Here, we show that tumor-infiltrating T cells are severely exhausted in the microsatellite stable (MSS) colorectal cancer (CRC), a representative example of PD-1 blockade-resistant tumors. In MSS CRC, we found wound healing signature to be up-regulated and that T cell exhaustion is driven by vascular endothelial growth factor-A (VEGF-A). We report that VEGF-A induces the expression of transcription factor TOX in T cells to drive exhaustion-specific transcription program in T cells. Using a combination of in vitro, ex vivo, and in vivo mouse studies, we demonstrate that combined blockade of PD-1 and VEGF-A restores the antitumor functions of T cells, resulting in better control of MSS CRC tumors.
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Neoplasias Colorrectales/inmunología , Proteínas del Grupo de Alta Movilidad/inmunología , Proteínas de Homeodominio/inmunología , Receptor de Muerte Celular Programada 1/inmunología , Linfocitos T/inmunología , Factor A de Crecimiento Endotelial Vascular/inmunología , Animales , Células CACO-2 , Neoplasias Colorrectales/patología , Humanos , Ratones , Ratones Endogámicos C57BL , Repeticiones de Microsatélite/inmunologíaRESUMEN
BACKGROUND: A major molecular pathway of genetic instability in cancer is DNA mismatch repair deficiency. High-level microsatellite instability (MSI-H) is currently the best predictor of responsiveness towards immune checkpoint blockade. Data about the prevalence of high-level microsatellite instability in cholangiocarcinoma (CCA) has been conflicting. METHODS: We employed a cohort comprising 308 Western-world, non-liver fluke-associated CCAs (159 intrahepatic, 106 perihilar, and 43 distal). We analysed the mononucleotide microsatellite instability marker panel consisting of BAT25, BAT26, and CAT25 and detected MSI-H in 4/308 CCAs (1.3%). RESULTS: Patients affected by MSI-H CCA had mostly an atypical histomorphology (p = 0.004), showed a longer overall survival, although having a high tumour stage, and were of younger age. Correlation analysis of microsatellite instability status with tumour-infiltrating immune cells, MHC I, and PD-L1 expression in the same cholangiocarcinoma cohort showed higher numbers of CD8 + T cells, FOXP3 + regulatory T cells, CD20 + B cells and high or at least moderate MHC I expression levels in MSI-H CCAs. CONCLUSIONS: Even though the overall number of MSI-H CCAs is low, the dismal prognosis of the disease and the therapeutic option of immune checkpoint blockade in the respective patients justify MSI testing of cholangiocarcinoma, particularly in younger patients showing an atypical histomorphology.
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Neoplasias Encefálicas/genética , Colangiocarcinoma/genética , Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN/genética , Síndromes Neoplásicos Hereditarios/genética , Pronóstico , Adulto , Anciano , Antígenos CD20/inmunología , Antígeno B7-H1/genética , Antígeno B7-H1/inmunología , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/terapia , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/patología , Colangiocarcinoma/complicaciones , Colangiocarcinoma/patología , Colangiocarcinoma/terapia , Neoplasias Colorrectales/complicaciones , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/terapia , Femenino , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/inmunología , Humanos , Hígado/metabolismo , Hígado/patología , Masculino , Inestabilidad de Microsatélites , Repeticiones de Microsatélite/genética , Repeticiones de Microsatélite/inmunología , Persona de Mediana Edad , Estadificación de Neoplasias , Síndromes Neoplásicos Hereditarios/complicaciones , Síndromes Neoplásicos Hereditarios/patología , Síndromes Neoplásicos Hereditarios/terapiaRESUMEN
Devil Facial Tumour Disease (DFTD), a highly contagious cancer, has decimated Tasmanian devil (Sarcophilus harrisii) numbers in the wild. To ensure its long-term survival, a captive breeding program was implemented but has not been as successful as envisaged at its launch in 2005. We therefore investigated the reproductive success of 65 captive devil pair combinations, of which 35 produced offspring (successful pairs) whereas the remaining 30 pairs, despite being observed mating, produced no offspring (unsuccessful pairs). The devils were screened at six MHC Class I-linked microsatellite loci. Our analyses revealed that younger females had a higher probability of being successful than older females. In the successful pairs we also observed a higher difference in total number of heterozygous loci, i.e. when one devil had a high total number of heterozygous loci, its partner had low numbers. Our results therefore suggest that devil reproductive success is subject to disruptive MHC selection, which to our knowledge has never been recorded in any vertebrate. In order to enhance the success of the captive breeding program the results from the present study show the importance of using young (2-year old) females as well as subjecting the devils to MHC genotyping.
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Enfermedades de los Animales , Especies en Peligro de Extinción , Genes MHC Clase I/inmunología , Marsupiales , Repeticiones de Microsatélite/inmunología , Neoplasias , Envejecimiento/genética , Envejecimiento/inmunología , Enfermedades de los Animales/genética , Enfermedades de los Animales/inmunología , Animales , Australia , Femenino , Marsupiales/genética , Marsupiales/inmunología , Neoplasias/genética , Neoplasias/inmunologíaRESUMEN
Resistance to soybean rust (SBR), caused by Phakopsora pachyrhizi Syd. & Syd., has been identified in many soybean germplasm accessions and is conferred by either dominant or recessive genes that have been mapped to six independent loci (Rpp1 -Rpp6), but No U.S. cultivars are resistant to SBR. The cultivar DT 2000 (PI 635999) has resistance to P. pachyrhizi isolates and field populations from the United States as well as Vietnam. A F6:7 recombinant inbred line (RIL) population derived from Williams 82 × DT 2000 was used to identify genomic regions associated with resistance to SBR in the field in Ha Noi, Vietnam, and in Quincy, Florida, in 2008. Bulked segregant analysis (BSA) was conducted using the soybean single nucleotide polymorphism (SNP) USLP 1.0 panel along with simple sequence repeat (SSR) markers to detect regions of the genome associated with resistance. BSA identified four BARC_SNP markers near the Rpp3 locus on chromosome (Chr.) 6. Genetic analysis identified an additional genomic region around the Rpp4 locus on Chr. 18 that was significantly associated with variation in the area under disease progress curve (AUDPC) values and sporulation in Vietnam. Molecular markers tightly linked to the DT 2000 resistance alleles on Chrs. 6 and 18 will be useful for marker-assisted selection and backcrossing in order to pyramid these genes with other available SBR resistance genes to develop new varieties with enhanced and durable resistance to SBR.
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Cromosomas de las Plantas/química , Genoma de Planta , Glycine max/genética , Phakopsora pachyrhizi/fisiología , Enfermedades de las Plantas/genética , Esporas Fúngicas/fisiología , Alelos , Mapeo Cromosómico , Resistencia a la Enfermedad/genética , Sitios Genéticos , Marcadores Genéticos/inmunología , Genotipo , Repeticiones de Microsatélite/inmunología , Phakopsora pachyrhizi/patogenicidad , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Polimorfismo de Nucleótido Simple , Glycine max/inmunología , Glycine max/microbiología , Esporas Fúngicas/patogenicidadRESUMEN
Collectins and ficolins are multimeric proteins present in various tissues and are actively involved in innate immune responses. In chickens, six different collagenous lectins have been characterized so far: mannose-binding lectin (MBL), surfactant protein A (SP-A), collectin 10 (COLEC10), collectin 11 (COLEC11), collectin 12 (COLEC12), lung lectin (LL) and one ficolin (FCN). However, the structural and functional features of the chicken collectins and ficolin are still not fully understood. Therefore, the aims of this study were: (i) to make an overview of the genetic structure and function of chicken collectins and the ficolin, (ii) to investigate the variation in the chicken collectins and the ficolin gene in different chicken populations, and (iii) to assess the presence of MBL gene variants in different chicken populations. We performed comparative genomic analysis using publically available data. The obtained results showed that collectins and ficolins have conserved protein sequences and gene structure across all vertebrate groups and this is especially notable for COLEC10, COLEC11 and COLEC12. For the purpose of studying the genetic variation, 179 animals from 14 populations were genotyped using 31 SNPs covering five genomic regions. The obtained results revealed low level of heterozygosity in the collagenous lectins except for the COLEC12 gene and the LL-SPA-MBL region compared to heterozygosity at neutral microsatellite markers. In addition, the MBL gene variants were assessed in different chicken populations based on the polymorphisms in the promoter region. We observed 10 previously identified MBL variants with A2/A8 and A4 as the most frequent alleles.
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Proteínas Aviares/genética , Pollos/genética , Colectinas/genética , Bases de Datos de Ácidos Nucleicos , Anotación de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Alelos , Animales , Proteínas Aviares/inmunología , Pollos/inmunología , Colectinas/inmunología , Frecuencia de los Genes/inmunología , Heterocigoto , Repeticiones de Microsatélite/inmunologíaRESUMEN
The major histocompatibility complex is one of the best studied systems in vertebrates providing evidence for the long-term action of selection. Here, we examined the intra- and inter-population genetic diversity of the MHC class II DRB locus in European brown hare (Lepus europaeus) and correlated the results with genetic variability already estimated from the MHC DQA locus and from maternally (mitochondrial DNA (mtDNA)) and biparentally (allozymes, microsatellites) inherited loci. L. europaeus showed remarkable genetic polymorphism in both DQA and DRB1 loci. The Anatolian populations exhibited the highest genetic polymorphism for both loci. Balancing selection has established increased variability in the European populations despite the founder effects after the last glaciation. Different evolutionary rates were traced for DRB1 and DQA loci, as evidenced by the higher number of common DRB1 than DQA alleles and the greater differences between DRB1 alleles with common origin in comparison with DQA alleles. The high number of rare alleles with low frequencies detected implies that frequency-dependent selection drives MHC evolution in the brown hare through the advantage of rare alleles. Both loci were under the influence of positive selection within the peptide-binding region. The functional polymorphism, recorded as amino acid substitutions within the binding pockets, fell also within distinct geographic patterns, yet it was much narrower than the genetic polymorphism. We hypothesize that certain structural and functional characteristics of the binding pockets set limitations to the actual shape of genetic polymorphism in MHC.
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Variación Genética/inmunología , Cadenas alfa de HLA-DQ/genética , Cadenas HLA-DRB1/genética , Liebres/genética , Filogenia , Alelos , Animales , ADN Mitocondrial/genética , ADN Mitocondrial/inmunología , Europa (Continente) , Evolución Molecular , Frecuencia de los Genes , Cadenas alfa de HLA-DQ/clasificación , Cadenas alfa de HLA-DQ/inmunología , Cadenas HLA-DRB1/clasificación , Cadenas HLA-DRB1/inmunología , Liebres/inmunología , Patrón de Herencia , Repeticiones de Microsatélite/inmunología , FilogeografíaRESUMEN
African green monkeys (AGM) are among the most widely used nonhuman primate models used in various fields of medical research. One species of AGM that originated from West Africa, Chlorocebus sabaeus, was introduced three centuries ago in the Caribbean islands. We present here a systematic study of the major histocompatibility complex (MHC) polymorphism of Caribbean AGM which is currently frequently used as an animal model. We studied 54 animals originated from Barbados (N=25) or Saint Kitts (N=29). The MHC polymorphism was characterized by means of 17 MHC microsatellites spread across MHC and DRB genotyping by DGGE sequencing. We defined nine frequent MHC haplotypes of which two were found in the two insular populations suggesting either past exchanges between the two populations or a common origin of the founders of the two populations. By the analysis of a previously described EST library, we characterized 38 MHC cDNA sequences (17 class I and 21 class II). In conclusion, we characterized for the first time the MHC polymorphism of Barbados and Saint Kitts AGM. We found a restricted polymorphism due to a founding effect, which is responsible for a strong bottleneck. The poorness of MHC polymorphism observed in the Caribbean AGM populations is similar to that observed in the Mauritian cynomolgus macaque population.
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Chlorocebus aethiops/genética , Efecto Fundador , Complejo Mayor de Histocompatibilidad/genética , Polimorfismo Genético , Animales , Región del Caribe , Chlorocebus aethiops/inmunología , Etiquetas de Secuencia Expresada , Femenino , Técnicas de Genotipaje , Haplotipos , Islas , Complejo Mayor de Histocompatibilidad/inmunología , Masculino , Repeticiones de Microsatélite/inmunología , Análisis de Secuencia de ADNRESUMEN
PROBLEM: Previous studies support a role for MHC on mating preference, yet it remains unsettled as to whether mating occurs preferentially between individuals sharing human leukocyte antigen (HLA) determinants or not. Investigating sex-mate preferences in the contemporary Israeli population is of further curiosity being a population with distinct genetic characteristics, where multifaceted cultural considerations influence mate selection. METHOD OF STUDY: Pairs of male-female sex partners were evaluated in three groups. Two groups represented unmarried (n = 1002) or married (n = 308) couples and a control group of fictitious male-female couples. HLA and short-tandem-repeat (STR) genetic identification markers were assessed for the frequency of shared antigens and alleles. RESULTS: Human leukocyte antigen results showed that Class I and/ or Class II single antigen as well as double antigen sharing was more common in sex partners than in control group couples (P < 0.001). Married versus unmarried pairs were not distinguishable. In contrast, STR-DNA markers failed to differentiate between sex-mates and controls (P = 0.78). CONCLUSION: Sex partnerships shared HLA determinants more frequently than randomly constituted male-female pairs. The observed phenomenon does not reflect a syngenetic background between sex-mates as STR markers were not selectively shared. Thus, sex-mate selection in man may contravene the evolutionary pressure for genetic diversity in regard to HLA.
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Antígenos HLA/genética , Matrimonio/psicología , Repeticiones de Microsatélite/inmunología , Conducta Sexual/psicología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Femenino , Frecuencia de los Genes , Marcadores Genéticos , Variación Genética , Antígenos HLA/inmunología , Haplotipos , Humanos , Israel/etnología , Masculino , Matrimonio/etnología , Persona de Mediana Edad , Selección Genética , Conducta Sexual/etnología , Parejas Sexuales/psicologíaRESUMEN
The major histocompatibility complex (MHC) plays an important role in the immune response and may thus crucially affect an individual's fitness, relevant also for studies on evolutionary ecology and wildlife conservation. Detailed knowledge on the genomic organization, polymorphism and diversity of the MHC has a narrow taxonomic focus though and among macaques is only available for rhesus and long-tailed macaques-the species most commonly kept for biomedical research. The lack of data on wild populations is largely due to the difficulty of obtaining blood or tissue samples necessary for genotyping approaches. Here, we aimed at analyzing MHC-DRB from non-invasively collected fecal samples in wild Assamese macaques (Macaca assamensis), utilizing the MHC-DRB-STR (D6S2878) microsatellite marker. Due to the fecal DNA source incomplete genotypes occurred, which may be improved in the future by method refinement. We detected 28 distinct DRB-STR lengths in 43 individuals with individual genotypes containing 1-9 MHC-DRB-STRs and defined four haplotypes segregating between families in Mendelian fashion. Our results indicate that variability and diversity of MHC-DRB in Assamese macaques is comparable to that of other macaque species and importantly, that fecal samples can be used for non-invasive analysis of MHC genes after refinement of the applied methods, opening a number of opportunities for MHC research on natural populations.
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Heces/química , Genotipo , Cadenas beta de HLA-DR/genética , Macaca/genética , Complejo Mayor de Histocompatibilidad/genética , Animales , ADN/análisis , Haplotipos/genética , Macaca/inmunología , Repeticiones de Microsatélite/genética , Repeticiones de Microsatélite/inmunologíaRESUMEN
BACKGROUND: A detailed genetic study of the pre-Columbian population inhabiting the Tompullo 2 archaeological site (department Arequipa, Peru) was undertaken to resolve the kin relationships between individuals buried in six different chullpas. Kin relationships were an important factor shaping the social organization in the pre-Columbian Andean communities, centering on the ayllu, a group of relatives that shared a common land and responsibilities. The aim of this study was to evaluate whether this Andean model of a social organization had an influence on mortuary practices, in particular to determine whether chullpas served as family graves. RESULTS: The remains of forty-one individuals were analyzed with both uniparental (mtDNA, Y-chromosome) and biparental (autosomal microsatellites) markers. Reproducible HVRI sequences, autosomal and Y chromosomal STR profiles were obtained for 24, 16 and 11 individuals, respectively. Mitochondrial DNA diversity was comparable to that of ancient and contemporary Andean populations. The Tompullo 2 population exhibited the closest relationship with the modern population from the same region. A kinship analysis revealed complex pattern of relations within and between the graves. However mean relatedness coefficients regarding the pairs of individuals buried in the same grave were significantly higher than those regarding pairs buried in different graves. The Y chromosome profiles of 11 males suggest that only members of one male line were buried in the same grave. CONCLUSIONS: Genetic investigation of the population that inhabited Tompullo 2 site shows continuity between pre-Columbian and modern Native Amerindian populations inhabiting the Arequipa region. This suggests that no major demographic processes have influenced the mitochondrial DNA diversity of these populations during the past five hundred years. The kinship analysis involving uni- and biparental markers suggests that the community that inhabited the Tompullo 2 site was organized into extended family groups that were buried in different graves. This finding is in congruence with known models of social organization of Andean communities.
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Arqueología , ADN/análisis , Familia , Indígenas Sudamericanos/genética , Entierro , ADN Mitocondrial/análisis , Genética de Población , Humanos , Masculino , Repeticiones de Microsatélite/inmunología , PerúRESUMEN
BACKGROUND: In malaria endemic areas, host genetics influence whether a Plasmodium falciparum-infected child develops uncomplicated or severe malaria. TLR2 has been identified as a receptor for P. falciparum-derived glycosylphosphatidylinositol (GPI), and polymorphisms within the TLR2 gene may affect disease pathogenesis. There are two common polymorphisms in the 5' un-translated region (UTR) of TLR2, a 22 base pair deletion in the first unstranslated exon (Δ22), and a GT dinucleotide repeat in the second intron (GTn). METHODS: These polymorphisms were examined in a Ugandan case control study on children with either cerebral malaria or uncomplicated malaria. Serum cytokine levels were analysed by ELISA, according to genotype and disease status. In vitro TLR2 expression was measured according to genotype. RESULTS: Both Δ22 and GTn polymorphisms were highly frequent, but only Δ22 heterozygosity was associated with protection from cerebral malaria (OR 0.34, 95% confidence intervals 0.16, 0.73). In vitro, heterozygosity for Δ22 was associated with reduced pam3cys inducible TLR2 expression in human monocyte derived macrophages. In uncomplicated malaria patients, Δ22 homozygosity was associated with elevated serum IL-6 (p = 0.04), and long GT repeat alleles were associated with elevated TNF (p = 0.007). CONCLUSION: Reduced inducible TLR2 expression may lead to attenuated pro-inflammatory responses, a potential mechanism of protection from cerebral malaria present in individuals heterozygous for the TLR2 Δ22 polymorphism.
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Resistencia a la Enfermedad/genética , Malaria Cerebral/genética , Polimorfismo Genético/inmunología , Eliminación de Secuencia , Receptor Toll-Like 2/genética , Alelos , Estudios de Casos y Controles , Niño , Preescolar , Resistencia a la Enfermedad/inmunología , Exones , Femenino , Genotipo , Heterocigoto , Homocigoto , Humanos , Lactante , Interleucina-6/sangre , Interleucina-6/inmunología , Intrones , Malaria Cerebral/inmunología , Malaria Cerebral/parasitología , Masculino , Repeticiones de Microsatélite/genética , Repeticiones de Microsatélite/inmunología , Plasmodium falciparum/fisiología , Receptor Toll-Like 2/inmunología , UgandaRESUMEN
Maedi-Visna (MV) and ovine pulmonary adenocarcinoma (OPA) are two retroviral diseases occurring worldwide that affect adult sheep. Differences in incidence, which may be related to sheep-rearing and housing choices, as well as to genetics, and disease progression have been reported for both diseases. In this work four microsatellites located in immune-relevant regions, the major histocompatibility complex (MHC) region, interferon-γ and interleukin-12p35, were genotyped to determine their association with disease progression. The analysed sample included Latxa sheep with and without OPA and MV-characteristic lesions in their lungs. The microsatellites in the MHC were the most diverse, while the ones located in the cytokines were the less polymorphic. In the case of IFN-γ the results suggested the presence of null alleles. Significant results were detected for several microsatellite alleles in the association analysis carried out by logistic regression. All statistical analyses included a flock effect adjustment to avoid false positives due to genetic structuration. MHC Class I microsatellite alleles OMHC1*205 and OMHC1*193 were associated with disease progression for Maedi and OPA, respectively. Moreover, MHC Class II microsatellite allele DRB2*275 was associated with presence of lesions in Maedi. Furthermore, the MHC microsatellites were combined for a bioinformatic haplotype inference with the PHASE software. In total, 73 haplotypes were detected, 18 of them in more than 6 animals. After standard and weighted logistic regression analysis, two of them were significantly associated with susceptibility: OMHC1*205-DRB2*271 for Maedi and OMHC1*193-DRB2*271 for OPA, both with the Class I microsatellite alleles associated in the marker by marker study. Although more extensive analyses are needed to disentangle the relationship between host genetics and disease, as far as we know this is the first study demonstrating a significant association between sheep MHC Class I microsatellite alleles and susceptibility to Maedi-Visna and OPA viral diseases.
Asunto(s)
Complejo Mayor de Histocompatibilidad/genética , Repeticiones de Microsatélite/genética , Neumonía Intersticial Progresiva de los Ovinos/genética , Adenomatosis Pulmonar Ovina/genética , Virus Visna-Maedi , Alelos , Animales , Frecuencia de los Genes/genética , Genes MHC Clase I/genética , Genes MHC Clase I/inmunología , Genes MHC Clase II/genética , Genes MHC Clase II/inmunología , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad/genética , Genotipo , Haplotipos/genética , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-12/genética , Interleucina-12/inmunología , Complejo Mayor de Histocompatibilidad/inmunología , Repeticiones de Microsatélite/inmunología , Neumonía Intersticial Progresiva de los Ovinos/inmunología , Adenomatosis Pulmonar Ovina/inmunología , Ovinos/genética , Ovinos/inmunologíaRESUMEN
Hematopoietic stem cell transplantation (HSCT) with HLA-A, -B, -C, -DRB1, -DQB1 allele matched (10 of 10) unrelated donors is still associated with a significant rate of posttransplantation complications. In order to disclose additional immunogenetic factors, we analyzed the impact of HLA-DPB1 disparities and major histocompatibility complex (MHC)-resident microsatellite polymorphisms in 246 HLA 10 of 10 matched HSCT patients. First we showed that patients with more frequent/conserved HLA haplotypes had a higher 5-year survival (55% ± 18% versus 39% ± 18%, P = .021). In addition, DPB1 incompatibilities and 3 microsatellite alleles were associated with outcome. In a Cox regression model adjusting for European Blood and Marrow Transplant (EBMT) risk score, T cell depletion, and year of treatment, HSCT with a tumor necrosis factor d (TNFd) 4/d5-positive donor was associated with increased mortality (hazard ratio [HR] = 2.03; confidence interval [CI] 1.25-3.31; P = .004), whereas the D6S510-184 allele was protective (HR = 0.44; CI 0.22-0.87; P = .018). The 2 MHC-linked genetic donor factors, DPB1 mismatch (MM), and TNFd4/d5-positivity, acted in synergy with the EBMT risk score with an always lower survival (HR = 2.97; CI 1.27-6.92; P = .012). These data show that multiple MHC-linked genetic donor factors impact on outcome after unrelated donor HSCT. Their additive and potentially divergent effects could explain previous discrepant results, particularly with respect to the role of HLA-DPB1 disparities. We conclude that HLA-DPB1 typing combined with a simple TNFd microsatellite genotyping assay may significantly help in pretransplantation risk assessment for graft-versus-host disease and mortality, particularly for patients with several potential 10 of 10 matched donors.
Asunto(s)
Enfermedad Injerto contra Huésped/prevención & control , Cadenas beta de HLA-DP/inmunología , Trasplante de Células Madre Hematopoyéticas , Trastornos Linfoproliferativos/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Adulto , Anciano , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Enfermedad Injerto contra Huésped/inmunología , Cadenas beta de HLA-DP/genética , Haplotipos/genética , Haplotipos/inmunología , Prueba de Histocompatibilidad , Humanos , Lactante , Trastornos Linfoproliferativos/mortalidad , Trastornos Linfoproliferativos/terapia , Complejo Mayor de Histocompatibilidad/genética , Complejo Mayor de Histocompatibilidad/inmunología , Masculino , Repeticiones de Microsatélite/genética , Repeticiones de Microsatélite/inmunología , Persona de Mediana Edad , Polimorfismo Genético , Estudios Retrospectivos , Riesgo , Factor de Necrosis Tumoral alfa/genética , Donante no Emparentado , Adulto JovenRESUMEN
We investigated the association of equine arteritis virus (EAV) infection and three short tandem repeat (STR) polymorphisms located within or in close proximity to equine lymphocyte antigen (ELA) region. We used a case-control design as a first approach before proceeding to select candidate genes. One hundred and sixty-five Silla Argentino horses were taken in 2002 from positive serological detections of EAV in Argentina, to determine whether STR genotypes were correlated to genetic susceptibility to EVA. Allele frequency distribution did not show significant differences between both groups (P = 0.0781). However, in particular alleles, Fisher exact test and odds ratio calculations showed significant values >1 for TKY08 and LEX52, and <1 for UM011, TKY08, LEX52 and VHL20. Interestingly, TKY08 STR is located in ELA class I region.
Asunto(s)
Infecciones por Arterivirus/genética , Equartevirus , Antígenos de Histocompatibilidad Clase I/genética , Enfermedades de los Caballos/genética , Repeticiones de Microsatélite/genética , Polimorfismo Genético , Alelos , Animales , Argentina , Infecciones por Arterivirus/inmunología , Frecuencia de los Genes/genética , Frecuencia de los Genes/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Enfermedades de los Caballos/inmunología , Enfermedades de los Caballos/virología , Caballos , Repeticiones de Microsatélite/inmunologíaRESUMEN
Polymorphisms of short tandem repeats of <10 nucleotides, or microsatellites (Msat), are largely used for post-transplant chimerism analyses in clinical hematopoietic stem cell transplantation (HSCT). Compared to single nucleotide polymorphisms (SNP), they have the advantage of a higher degree of allelic polymorphism and thus a potentially larger degree of informativity. Msat markers contribute to approximately 3% of the human genome and have been highly informative in disease association studies, population genetics, forensic medicine and organ and HSC transplantation. They allowed to expand our knowledge of the haplotypic structure of the HLA complex, including the noncoding sequences in the MHC, and to reach a better characterization of immunological phenotypes. Among the different immunogenetic studies in HSCT patients reviewed here, four Msat loci linked to cytokine genes have been analysed by a number of laboratories as potential candidates markers for HSCT outcome: IFNG, TNFd, IL-10(-1064) and IL-1RN. The low patient numbers and high diversity of clinical parameters account for some heterogeneity of the results. Among the trends starting to emerge from these studies, specific TNFd Msat alleles seem to be associated with acute graft-versus-host disease and mortality. Patient/donor Msat incompatibilities have also been used as surrogate markers to map biologically relevant polymorphisms, with a main focus on MHC-resident genetic variation. High throughput SNP typing and next-generation sequencing technologies will allow acquisition of large-scale genomic data and should allow refined analyses of clinically relevant genotypes in the transplantation settting, although the heterogeneity of the study cohorts will remain an issue. The analysis of Msat polymorphisms may still have a place in functional studies on the impact of Msat diversity in the control of immune response gene expression.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Fenómenos Inmunogenéticos , Repeticiones de Microsatélite/genética , Repeticiones de Microsatélite/inmunología , Polimorfismo de Nucleótido Simple , Citocinas/genética , Humanos , Complejo Mayor de Histocompatibilidad/genéticaRESUMEN
Colorectal cancers (CRC) develop through 2 major pathways of genetic instability. In contrast to the majority of CRCs, which are characterized by chromosomal instability, high-level microsatellite unstable (MSI-H) CRCs arise as a consequence of the loss of DNA mismatch repair (MMR) functions and show accumulation of insertion and deletion mutations particularly in microsatellite sequences. MSI-H occurs in about 15% of CRCs, and virtually all CRCs occurring in the context of the hereditary cancer-predisposing Lynch syndrome. These tumors are characterized by a comparably good prognosis and a low frequency of distant metastases. Because of the expression of a defined set of tumor-specific antigens, MSI-H CRCs elicit a strong local and systemic antitumoral immune response of the host and therefore use different strategies to evade the control of the immune system. In this review, we will summarize novel molecular mechanisms that at the same time drive pathogenesis, immunogenicity and immune evasion during the development and progression of MSI-H CRCs. We will focus on the current knowledge about alterations in human leukocyte antigen (HLA) antigen presentation and discuss how immune evasion-while offering protection against local antitumoral immune responses-paradoxically might interfere with the ability of the tumor to form distant organ metastases.
Asunto(s)
Neoplasias Colorrectales/inmunología , Repeticiones de Microsatélite/inmunología , Escape del Tumor , HumanosRESUMEN
A human microsatellite DNA-mimicking ODN (MS ODN) composed of CCT repeats, designated as SAT05f, has been studied for its capacity of negatively regulating innate immunity induced by TLR7/TLR9 agonists in vitro and in mice. The result showed that SAT05f could down-regulate TLR7/9-dependent IFN-alpha production in cultured human PBMC stimulated by inactivated Flu virus PR8 or HSV-1 or CpG ODN or imiquimod, protect d-GalN-treated mice from lethal shock induced by TLR9 agonist, not by TLR3/4 agonist. In addition, SAT05f significantly inhibit IFN-alpha production from purified human plasmacytoid cells (pDCs) stimulated by CpG ODN. Interestingly, SAT05f could up-regulate CD80, CD86, and HLA-DR on the pDCs in vitro, implying that SAT05f-mediated inhibition on IFN-alpha production could be related to the activation of pDCs. The data suggest that SAT05f could be developed as a candidate medicament for the treatment of TLR7/9 activation-associated diseases by inhibiting TLR7/9 signaling pathways.