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5.
PLoS One ; 7(9): e44707, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22970293

RESUMEN

NY-ESO-1 has been a major target of many immunotherapy trials because it is expressed by various cancers and is highly immunogenic. In this study, we have identified a novel HLA-B*1801-restricted CD8(+) T cell epitope, NY-ESO-1(88-96) (LEFYLAMPF) and compared its direct- and cross-presentation to that of the reported NY-ESO-1(157-165) epitope restricted to HLA-A*0201. Although both epitopes were readily cross-presented by DCs exposed to various forms of full-length NY-ESO-1 antigen, remarkably NY-ESO-1(88-96) is much more efficiently cross-presented from the soluble form, than NY-ESO-1(157-165). On the other hand, NY-ESO-1(157-165) is efficiently presented by NY-ESO-1-expressing tumor cells and its presentation was not enhanced by IFN-γ treatment, which induced immunoproteasome as demonstrated by Western blots and functionally a decreased presentation of Melan A(26-35); whereas NY-ESO-1(88-96) was very inefficiently presented by the same tumor cell lines, except for one that expressed high level of immunoproteasome. It was only presented when the tumor cells were first IFN-γ treated, followed by infection with recombinant vaccinia virus encoding NY-ESO-1, which dramatically increased NY-ESO-1 expression. These data indicate that the presentation of NY-ESO-1(88-96) is immunoproteasome dependent. Furthermore, a survey was conducted on multiple samples collected from HLA-B18(+) melanoma patients. Surprisingly, all the detectable responses to NY-ESO-1(88-96) from patients, including those who received NY-ESO-1 ISCOMATRIX™ vaccine were induced spontaneously. Taken together, these results imply that some epitopes can be inefficiently presented by tumor cells although the corresponding CD8(+) T cell responses are efficiently primed in vivo by DCs cross-presenting these epitopes. The potential implications for cancer vaccine strategies are further discussed.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Células Dendríticas/inmunología , Epítopos/inmunología , Antígeno HLA-B18/inmunología , Western Blotting , Línea Celular Tumoral , Humanos , Melanoma/inmunología , Melanoma/patología
7.
J Neurovirol ; 16(1): 41-7, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20105104

RESUMEN

Because human leukocyte antigen (HLA) associations with various infectious diseases have recently been reported, we examined the role of HLA class I alleles in the development of progressive multifocal leukoencephalopathy (PML) or its outcome in 152 patients, including 123 Caucasians and 29 African Americans. Compared to a human immunodeficiency virus positive (HIV+) control population, we observed decreased frequency of HLA-A3 (P = 0.03) in the Caucasian PML group, whereas B18 (P = 0.02), was more frequent. No such difference was found among African American PML patients. We then sought to characterize differences in HLA between PML progressors, whose survival doesn't exceed 1 year, and survivors. Caucasian survivors were less likely to harbor A68 (P = 0.01), whereas African American survivors less frequently displayed Cw4 (P = .01). However, none of these differences reached statistical significance after Bonferroni correction for multiple testing. Further investigations are needed to assess the role of genetics in the incidence of PML or its outcome. Physicians may exercise caution in the use of immunomodulatory medications in patients whose genetic background is associated with an increased risk of PML.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/genética , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/inmunología , Leucoencefalopatía Multifocal Progresiva/genética , Leucoencefalopatía Multifocal Progresiva/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/patología , Negro o Afroamericano , Progresión de la Enfermedad , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , VIH , Antígenos HLA-A/clasificación , Antígenos HLA-A/genética , Antígeno HLA-A3/clasificación , Antígeno HLA-A3/genética , Antígenos HLA-B/clasificación , Antígenos HLA-B/genética , Antígeno HLA-B18 , Antígenos HLA-C/clasificación , Antígenos HLA-C/genética , Humanos , Virus JC , Leucoencefalopatía Multifocal Progresiva/patología , Serotipificación , Población Blanca
8.
Parasitol Res ; 106(4): 795-800, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20111876

RESUMEN

Hydatid disease (HD) is a parasitosis caused by Echinococcus granulosus, which is still an important health problem worldwide, and our country is an endemic region for HD. There is little information regarding the role of human leucocyte antigen (HLA) in genetic susceptibility or resistance to HD. In this study, we aimed to investigate the HLA profile of Turkish children with HD and to compare them with healthy individuals. We also planned to investigate whether HLAs have a potential role in the predisposition to or prevention of the occurrence of HD and to study the relationship between the clinical features of HD and the HLA profile of the patients. The study included 81 children (25 boys, 56 girls) with HD aged between 3 and 18 years. All the patients' and control subjects' HLA class I and II antigens were examined, antigen allele frequencies were calculated, and clinical characteristics were also evaluated. The frequency of HLA-B18, -DR1, and -DR15 alleles were significantly different between the patients and healthy groups; HLA-DR15 antigen might be associated with HD occurrence, and the presence of HLA-B18 and HLA-DR1 antigens might be associated with HD resistance. Compared with the healthy group, patients with lung HD had a significant increase in HLA-B44 frequency, and liver HD patients had a significant increase in HLA-DR15 antigen frequency. Furthermore, presence of HLA-DR11 was found to be a significant factor associated with cure of the disease. We concluded that HLA types have significant impact on the development of HD and clinical course of disease.


Asunto(s)
Equinococosis/genética , Equinococosis/patología , Predisposición Genética a la Enfermedad , Antígenos HLA-B/genética , Antígenos HLA-DR/genética , Antígeno HLA-DR1/genética , Inmunidad Innata , Adolescente , Niño , Preescolar , Equinococosis/inmunología , Femenino , Frecuencia de los Genes , Antígeno HLA-B18 , Subtipos Serológicos HLA-DR , Humanos , Masculino , Polimorfismo Genético , Pronóstico , Turquía
9.
Genomics ; 94(4): 228-32, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19591919

RESUMEN

Previous studies have suggested that the ancestral haplotype 18.2 (AH18.2) carries additional susceptibility gene to Type 1 Diabetes (T1D) on the Major Histocompatibility Complex (MHC). We analyzed 10 DR3/TNFa1b5 homozygous subjects in order to establish the conservation of the AH18.2 and then compared this conserved region with other DR3 haplotype, the AH8.1. The Illumina's HumanHap550 Bead chip was used to perform an extensive genotyping of the MHC region. The AH18.2 was highly conserved between DDR1 and HLA-DQA1 genes; therefore most probably the second susceptibility gene is located within this region. We can exclude the region centromeric to HLA-DRA gene and telomeric to DDR1 gene. A comparison between the AH18.2 and AH8.1 haplotypes showed that 233 SNPs were different in the aforementioned conserved region. These data suggest that the 1.65 Mb MHC region between DDR1 and HLA-DRA genes is likely to carry additional susceptibility alleles for T1D on the AH18.2 haplotype.


Asunto(s)
Mapeo Cromosómico , Diabetes Mellitus Tipo 1/genética , Predisposición Genética a la Enfermedad , Haplotipos , Polimorfismo de Nucleótido Simple , Edad de Inicio , Alelos , Estudios de Casos y Controles , Cromosomas Humanos , Diabetes Mellitus Tipo 1/inmunología , Femenino , Marcadores Genéticos , Genotipo , Antígenos HLA-B , Antígeno HLA-B18 , Homocigoto , Humanos , Masculino , Repeticiones de Microsatélite , Miembro 25 de Receptores de Factores de Necrosis Tumoral/genética , España
10.
Tissue Antigens ; 67(1): 66-9, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16451205

RESUMEN

Strategies to resolve B*18 alleles which carry a deletion in intron 1 close to the 5' end of exon 2 relative to other HLA-B alleles or a null allele mutation in exon 1 and to resolve ambiguities among allele combinations including B*18 are described. B*18 allele frequencies from volunteer donors recruited for two hematopoietic stem cell registries show the presence of two alleles, B*180101 and B*1802, in a population from Singapore and only B*180101 in African-Americans.


Asunto(s)
Alelos , Negro o Afroamericano , Frecuencia de los Genes , Antígenos HLA-B/genética , Prueba de Histocompatibilidad , Análisis de Secuencia de ADN/métodos , Secuencia de Bases , China/etnología , Cartilla de ADN , Variación Genética , Genética de Población , Antígeno HLA-B18 , Humanos , India/etnología , Malasia/etnología , Datos de Secuencia Molecular , Sistema de Registros , Alineación de Secuencia , Singapur/epidemiología
11.
Pancreas ; 29(1): 41-4, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15211110

RESUMEN

PURPOSE: In this study we investigated the relationship between specific HLA antigens and sporadic pancreatic cancer in Greek population. METHODS: The allele frequencies of serologically and molecular defined class I and II HLA antigens were studied in 60 unrelated patients with pancreatic cancer histologically confirmed. The results obtained for HLA frequencies were compared with those of 105 healthy control subjects (control group). RESULTS: Increased frequencies of HLA-A30 (16.7 vs. 3.8%; P < 0.01; OR = 5.05), A31 (9.5 vs. 1.9%; P < 0.05; OR = 5.72), B18 (31.7 vs. 14.3%; P < 0.05; OR = 2.78) and Cw7 (53.3 vs. 21.9%; P < 0.01; OR = 4.07) were observed in patients with pancreatic cancer in comparison to the control subjects. CONCLUSIONS: This study demonstrates the association between specific HLA antigens and pancreatic cancer development in whites and suggests a genetic susceptibility factor for the disease.


Asunto(s)
Antígenos de Neoplasias/análisis , Antígenos HLA/análisis , Neoplasias Pancreáticas/genética , Anciano , Anciano de 80 o más Años , Alcoholismo/epidemiología , Antígenos de Neoplasias/genética , Comorbilidad , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Frecuencia de los Genes , Genes MHC Clase I , Genes MHC Clase II , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Genotipo , Grecia/epidemiología , Antígenos HLA/genética , Antígenos HLA-A/análisis , Antígenos HLA-A/genética , Antígenos HLA-B/análisis , Antígenos HLA-B/genética , Antígeno HLA-B18 , Antígenos HLA-C/análisis , Antígenos HLA-C/genética , Prueba de Histocompatibilidad , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/epidemiología , Neoplasias Pancreáticas/inmunología , Población Blanca/genética
12.
Tissue Antigens ; 63(6): 592-4, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15140039

RESUMEN

In this brief communication, we describe a novel human leukocyte antigen-B (HLA-B) allele (HLA-B*1819). This allele, found in an Italian Caucasian individual, differs from HLA-B*180101 by three nucleotide changes in exon 3. These mutations are located at positions 527, 538, and 539 where a T, a C, and a T are substituted respectively, by an A, a T, and a G, leading to three aminoacidic substitutions at codon 152 from Valine to Glutamic Acid (GTG-->GAG), at codon 155 from Histidine to Glutamine (CAC-->CAG), and at codon 156 from Cysteine to Tryptophan (TGT-->TGG).


Asunto(s)
Antígenos HLA-B/genética , Secuencia de Bases , Antígeno HLA-B18 , Humanos , Datos de Secuencia Molecular
13.
J Immunol ; 172(5): 2944-52, 2004 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-14978097

RESUMEN

MHC class I molecules present host- and pathogen-derived peptides for immune surveillance. Much attention is given to the search for viral and tumor nonself peptide epitopes, yet the question remains, "What is self?" Analyses of Edman motifs and of small sets of individual peptides suggest that the class I self repertoire consists of thousands of different peptides. However, there exists no systematic characterization of this self-peptide backdrop, causing the definition of class I-presented self to remain largely hypothetical. To better understand the breadth and nature of self proteins sampled by class I HLA, we sequenced >200 endogenously loaded HLA-B*1801 peptides from a human B cell line. Peptide-source proteins, ranging from actin-related protein 6 to zinc finger protein 147, possessed an assortment of biological and molecular functions. Major categories included binding proteins, catalytic proteins, and proteins involved in cell metabolism, growth, and maintenance. Genetically, peptides encoded by all chromosomes were presented. Statistical comparison of proteins presented by class I vs the human proteome provides empiric evidence that the range of proteins sampled by class I is relatively unbiased, with the exception of RNA-binding proteins that are over-represented in the class I peptide repertoire. These data show that, in this cell line, class I-presented self peptides represent a comprehensive and balanced summary of the proteomic content of the cell. Importantly, virus- and tumor-induced changes in virtually any cellular compartment or to any chromosome can be expected to be presented by class I molecules for immune recognition.


Asunto(s)
Presentación de Antígeno , Autoantígenos/inmunología , Autoantígenos/metabolismo , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Oligopéptidos/inmunología , Oligopéptidos/metabolismo , Proteómica , Línea Celular Transformada , Membrana Celular/inmunología , Membrana Celular/metabolismo , Núcleo Celular/inmunología , Núcleo Celular/metabolismo , Proteínas Cromosómicas no Histona/inmunología , Proteínas Cromosómicas no Histona/metabolismo , Citoplasma/inmunología , Citoplasma/metabolismo , Antígenos HLA/inmunología , Antígenos HLA-B/inmunología , Antígenos HLA-B/metabolismo , Antígeno HLA-B18 , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Ligandos , Proteómica/métodos , Proteínas de Unión al ARN/inmunología , Proteínas de Unión al ARN/metabolismo , Análisis de Secuencia de Proteína , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
14.
Tissue Antigens ; 60(1): 16-24, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12366779

RESUMEN

Antigens encoded by MAGE genes are of particular interest for cancer immunotherapy because of their tumoral specificity and because they are shared by many tumors. Antigenic peptide MEVDPIGHLY, which is encoded by MAGE-3 and is known to be presented by human leukocyte antigen (HLA)-B44, is currently being used in therapeutic vaccination trials. We report here that a cytolytic T lymphocyte (CTL) clone, which is restricted by HLA-B*1801, recognizes the same peptide and, importantly, lyzes HLA-B18 tumor cells expressing MAGE-3. These results imply that the use of peptide MEVDPIGHLY can now be extended to HLA-B18 patients. We also provide evidence that, under limiting amounts of protein MAGE-3, HLA B*1801 and B*4403 compete for binding to the peptide.


Asunto(s)
Presentación de Antígeno/fisiología , Antígenos de Neoplasias/metabolismo , Linfocitos T CD8-positivos/metabolismo , Antígenos HLA-B/metabolismo , Proteínas de Neoplasias/metabolismo , Antígenos de Neoplasias/aislamiento & purificación , Linfocitos B/metabolismo , Linfocitos B/virología , Linfocitos T CD8-positivos/virología , Transformación Celular Viral , Células Clonales/química , Células Clonales/inmunología , Células Clonales/virología , Células Dendríticas/metabolismo , Células Dendríticas/virología , Antígeno HLA-B18 , Antígeno HLA-B44 , Herpesvirus Humano 4/metabolismo , Humanos , Activación de Linfocitos , Proteínas de Neoplasias/aislamiento & purificación , Células Tumorales Cultivadas
15.
Leuk Lymphoma ; 43(5): 1013-9, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12148880

RESUMEN

The etiology of chronic lymphocytic leukemia (CLL) appears to be influenced by genetic factors which may contribute to its differential, gender- and age-specific incidence. The presented study is the first, which investigated the frequencies of DNA-typed alleles of all relevant human leukocyte antigens (HLA) loci in CLL patients with regard to gender and age at disease onset. The most remarkable result was the higher frequency of homozygosity for MHC class II loci in female patients. Particularly, an increased frequency of overall homozygosity for the DRB3/4/5 loci was observed in female patients compared to gender matched controls (RR = 2.8) and male patients. The previously demonstrated association of DQB1 homozygosity with CLL in general was found to be specific for female patients (RR = 4.4). Considering the lack of an a priori hypothesis which made it virtually impossible to obtain statistical significance it was not unexpected that none of the observed differences remained significant after correction for multiple comparisons. However, these results suggest a recessive, gender-specific susceptibility factor for CLL within or in vicinity of the human MHC class II region and should serve as an a priori hypothesis for future studies focusing on these gene loci. Furthermore, an increased frequency for HLA-Cw*06 was seen in patients with an early onset age (RR = 2.7) but lost significance after correction for multiple comparisons. The previously reported association of HLA-DRB4*0103 with CLL in general was observed in all groups irrespective of gender and age. Conclusively, our study supports the concept, that CLL represents a disease with a complex etiology and genetic susceptibility which appears to be influenced by the human MHC.


Asunto(s)
Frecuencia de los Genes , Genes MHC Clase II , Leucemia Linfocítica Crónica de Células B/genética , Adulto , Factores de Edad , Anciano , Femenino , Antígenos HLA-B/genética , Antígeno HLA-B18 , Antígenos HLA-C/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Cadenas HLA-DRB4 , Homocigoto , Humanos , Leucemia Linfocítica Crónica de Células B/inmunología , Masculino , Persona de Mediana Edad , Factores Sexuales
16.
Clin Lab Haematol ; 24(4): 215-9, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12181024

RESUMEN

While the exact aetiology of myeloma is unknown, genetic factors feature among the potential risk factors. The HLA phenotypes in African blacks with myeloma (the commonest haematopoietic malignancy in this group) have not been characterized. The purpose of this study was to determine the HLA class I and class II phenotypes of patients with multiple myeloma and to compare the findings to an ethnically matched control group of 100 individuals. Analysis of the HLA class I and class II phenotypes in 62 myeloma patients revealed: (i) a corresponding statistically significant association with HLA B18 [odds ratio (OR) 6.3; 95% confidence interval (CI) 1.013-39.727; P < 0.005]; (ii) no statistically significant association with HLA B13, Cw2, Cw6 or the DR and DQ antigens; and (iii) a statistically significant negative (protective) association with HLA Cw7 (OR 0.4; 95% CI 0.21-0.87; P < 0.005). This study suggests that although genetic factors may play a role in the multifactorial aetiology of multiple myeloma, with the exception of HLA B18, there is no specific association between HLA types and multiple myeloma in South African blacks.


Asunto(s)
Antígenos de Histocompatibilidad Clase II/análisis , Antígenos de Histocompatibilidad Clase I/análisis , Mieloma Múltiple/inmunología , Adulto , África Austral/epidemiología , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad , Antígenos HLA-B , Antígeno HLA-B18 , Antígenos HLA-C , Humanos , Inmunofenotipificación , Masculino , Persona de Mediana Edad , Mieloma Múltiple/epidemiología , Mieloma Múltiple/etiología , Oportunidad Relativa , Factores de Riesgo
17.
J Neurooncol ; 52(3): 253-61, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11519856

RESUMEN

Expression of human leukocyte antigens (HLA) is important for the immune response against infectious agents and malignant cells. Association of single HLA antigens or HLA haplotypes with disease has been investigated previously, and positive correlations between HLA and some cancers, such as cervical or nasopharyngeal carcinomas have been reported. In the present study, HLA antigen frequencies of 65 adult Caucasian patients with low-grade, anaplastic, or malignant astrocytic glioma (WHO grades II-IV) were compared with 157 racially similar, asymptomatic control individuals. Both standard serologic and PCR techniques for HLA typing were employed for all patients and controls. Our results suggest a positive association between single HLA antigens and presence of symptomatic cerebral glioma. Compared with the control population, patients positive for HLA-A*25 had a 3.0-fold increased risk of glioma (p = 0.04), patients positive for HLA-B*27, a 2.7-fold risk (p = 0.03), and patients positive for HLA-DRB1*15, a 2.2-fold risk (p = 0.03), whereas HLA-DRB1*07 was associated with a 0.4-fold decreased risk of glioma (p = 0.02). Occurrence rate of some HLA antigen combinations and estimated haplotypes was also different in glioma patients. Thus, HLA-DRB1*15:DRB5*(51) occurrence in combination with HLA-DRB1*11 was associated with a 13.4-fold increased risk of glioma (p = 0.001), and the incidence of HLA-Cw*6:DRB1*07 with a 0.2-fold decreased risk of glioma (p = 0.03). In conclusion, single HLA antigens and their combinations and estimated haplotypes are possibly significantly more or less frequent in persons developing symptomatic cerebral glioma during their adult life, compared with asymptomatic individuals.


Asunto(s)
Astrocitoma/genética , Neoplasias Encefálicas/genética , Glioblastoma/genética , Antígenos HLA/análisis , Adulto , Astrocitoma/inmunología , Neoplasias Encefálicas/inmunología , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Glioblastoma/inmunología , Antígenos HLA/genética , Antígenos HLA/inmunología , Antígenos HLA-A/análisis , Antígenos HLA-B/análisis , Antígeno HLA-B18 , Antígeno HLA-B27/análisis , Antígenos HLA-DR/análisis , Cadenas HLA-DRB1 , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/genética
18.
Eur J Immunol ; 30(8): 2281-9, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10940919

RESUMEN

Human papilloma virus type 16 (HPV-16) is the HPV most frequently associated with cervical carcinoma in humans. For the prevention or treatment of cervical carcinoma, the E6 and E7 oncoproteins appear to be good targets for vaccine-induced cytotoxic T lymphocytes (CTL). Lipopeptide vaccination is an efficient way of stimulating cellular responses. However, to synthesize effective lipopeptides, it is necessary to define which epitopes are immunogenic. In this study we first determined that peptide 80 - 88 of the E6 protein was recognized by CTL from a healthy donor in association with the HLA-B18 molecule. We then defined the HLA-B18 anchoring peptide motif by testing the binding of various short peptides with the HLA-B18 molecule and showed that it was related to the HLA-A1-specific peptide motif. Furthermore, in analyzing the potential E7 epitopes susceptible to associating with HLA-B18, we demonstrated that peptide E7 44 - 52 gave the strongest binding. It could also be recognized by CTL from peripheral blood mononuclear cells (PBMC) of the same healthy donor. Finally, with PBMC from a patient with a cervical intraepithelial neoplasia grade 3, we found CTL which recognized the E6 80 - 88 epitope. We have hence identified two peptides encoded by the E6 and E7 proteins which are presented by the HLA-B18 molecule and could be included in a vaccine against HPV-16.


Asunto(s)
Antígenos HLA-B/metabolismo , Proteínas Oncogénicas Virales/inmunología , Proteínas Represoras , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Sitios de Unión , Antígeno HLA-B18 , Humanos , Datos de Secuencia Molecular , Proteínas E7 de Papillomavirus , Fragmentos de Péptidos/inmunología
19.
Dis Colon Rectum ; 42(1): 66-70, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10211522

RESUMEN

PURPOSE: Similar to findings obtained for most carcinomas, the pathogenesis of colorectal cancer is considered to be multifactorial. There is strong evidence for an inherited, genetic predisposition to disease in patients with familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer. There is still debate, however, about the contribution of genetic factors to the pathogenesis of sporadic colorectal cancer. The present study was undertaken to search for human leukocyte antigen associations in a group of patients with colorectal cancer and to correlate the findings with both the histology of the disease and family history. SUBJECTS AND METHODS: The allele frequencies of serologically defined human leukocyte antigen class I and II antigens were studied in 101 patients with a recent, histologically confirmed diagnosis of colorectal cancer. All individuals in this study were unrelated to each other. After surgical treatment, all patients were grouped according to the stage (Dukes Stages A, B, C, and D), differentiation (Grades 1, 2, and 3), and the site of the tumor. Patients were also classified with regard to family history for colorectal cancer. The results obtained for human leukocyte antigen frequencies were compared with those of 105 healthy control subjects (control group). RESULTS: An increased frequency of human leukocyte antigen-B18 (27.72 vs. 14.28 percent; P < 0.025; odds ratio = 2.3) and of human leukocyte antigen-DQ5 (43.56 vs. 22.5 percent; P < 0.01; odds ratio = 2.65) was observed for patients with colorectal cancer vs. control subjects, respectively. In addition, human leukocyte antigen-B18 was present with increased frequency (30.76 percent; P < 0.05; odds ratio = 2.66; and 26.67 percent; P < 0.05; odds ratio = 2.18) among patients with rectal and colon carcinoma, respectively. A higher frequency of human leukocyte antigen-DQ5 (45.33 percent; P < 0.01; odds ratio = 2.84) was observed among patients with colon carcinoma. Remarkably, human leukocyte antigen-DQ5 (50 vs. 22.5 percent; P < 0.05; odds ratio = 3.43) and human leukocyte antigen-A1 (41.66 vs. 12.38 percent; P < 0.01; odds ratio = 5.05) were found to be strongly associated with a family history of colorectal cancer. CONCLUSION: The observation of specific human leukocyte antigen associations with particular subsets of colorectal cancer strongly suggests that genetic susceptibility for the development of colorectal cancer exists. Although the multifactorial pathogenesis of colorectal cancer must be considered, human leukocyte antigens may have useful predictive and diagnostic value.


Asunto(s)
Neoplasias Colorrectales/genética , Marcadores Genéticos , Antígenos HLA/análisis , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Susceptibilidad a Enfermedades , Antígenos HLA-A/análisis , Antígenos HLA-B/análisis , Antígeno HLA-B18 , Antígenos HLA-C/análisis , Antígenos HLA-DQ/análisis , Antígenos HLA-DR/análisis , Humanos , Masculino , Persona de Mediana Edad
20.
J Clin Invest ; 102(9): 1758-65, 1998 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-9802890

RESUMEN

Many people who remain persistently seronegative despite frequent HIV exposure have HIV-specific immune responses. The study of these may provide information about mechanisms of natural protective immunity to HIV-1. We describe the specificity of cytotoxic T lymphocyte responses to HIV in seronegative prostitutes in Nairobi who are apparently resistant to HIV infection. These women have had frequent exposure to a range of African HIV-1 variants, primarily clades A, C, and D, for up to 12 yr without becoming infected. Nearly half of them have CTL directed towards epitopes previously defined for B clade virus, which are largely conserved in the A and D clade sequences. Stronger responses are frequently elicited using the A or D clade version of an epitope to stimulate CTL, suggesting that they were originally primed by exposure to these virus strains. CTL responses have been defined to novel epitopes presented by HLA class I molecules associated with resistance to infection in the cohort, HLA-A*6802 and HLA-B18. Estimates using a modified interferon-gamma Elispot assay indicate a circulating frequency of CTL to individual epitopes of between 1:3,200 and 1:50,000. Thus, HIV-specific immune responses-particularly cross-clade CTL activity- may be responsible for protection against persistent HIV infection in these African women.


Asunto(s)
Epítopos de Linfocito T/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Estudios de Cohortes , Secuencia Conservada , Epítopos de Linfocito T/química , Femenino , Productos del Gen gag/inmunología , Proteasa del VIH/inmunología , Transcriptasa Inversa del VIH/inmunología , Antígenos HLA-A/inmunología , Antígenos HLA-B/inmunología , Antígeno HLA-B18 , Humanos , Inmunidad Innata , Kenia , Péptidos , Análisis de Secuencia , Trabajo Sexual , Linfocitos T Citotóxicos/virología
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