HLA-alleles class I and II associated with genetic susceptibility to neuromyelitis optica in Brazilian patients / Alelos HLA classes I e II associados à suscetibilidade genética a neuromielite óptica em pacientes brasileiros

ABSTRACT Objective: To study the genetic susceptibility to neuromyelitis optica (NMO) as well as the relationship between HLA genotypes and susceptibility to the disease in the southern Brazilian population. Methods: We analyzed patients with NMO, who met criteria for Wingerchuk's diagnosis of NMO, with detected serum anti-AQP4-IgG antibody. The HLA genotyping was performed by high-resolution techniques (Sanger sequencing) in patients and controls. The HLA genotypes were statistically compared with a paired control population. Results: The HLA genotyping revealed the diversity of the southern Brazilian population whose HLA profile resembled European and Asian populations. Some alleles had statistical correlations with a positive association (increased susceptibility) with NMO, particularly the HLA-DRB1*04:05 and *16:02. Conclusions: In our study, the HLA genotype was different to that previously reported for other Brazilian populations. Although our study had a small cohort, HLA genotypes were associated with increased susceptibility to NMO for HLA-DRB1*04:05 and *16:02. The alleles of HLA class I HLA-A*02:08 and *30:09, HLA-B*08:04 and *35:04 showed an association before the Bonferroni correction.

RESUMO Objetivo: Estudar a suscetibilidade genética a neuromielite óptica (NMO) assim como sua relação com o genótipo HLA na população do sul do Brasil. Métodos: Nós analisamos pacientes com NMO que preenchiam os critérios diagnósticos de Wingerchuk para NMO, com presença do anticorpo anti-AQP4-IgG no soro. O genótipo HLA foi realizado usando técnicas de alta resolução (sequenciamento de Sanger) em pacientes e controles. Genótipos HLA foram estatisticamente comparados com uma população controle pareada. Resultados: Genotipagem HLA revelou a diversidade da população sul brasileira cujo perfil HLA lembra as populações europeia e asiática. Alguns alelos tiveram correlação estatística com associação positiva (suscetibilidade aumentada) com NMO, particularmente o HLA-DRB1*04:05 e *16:02. Conclusões: Em nosso estudo, o genótipo HLA foi diferente do previamente relatado em outras populações brasileiras. Embora o número de pacientes tenha sido pequeno, HLA específicos foram associados com suscetibilidade aumentada a NMO para HLA-DRB1*04:05, *16:02. Os alelos HLA classe I HLA*02:08 e *30:09, HLA-B*08:04 e *35:04 tiveram associação antes da correção de Bonferroni.

PPARγ induces growth inhibition and apoptosis through upregulation of insulin-like growth factor-binding protein-3 in gastric cancer cells

Peroxisome proliferator activator receptor-gamma (PPARγ) is a ligand-activated transcriptional factor involved in the carcinogenesis of various cancers. Insulin-like growth factor-binding protein-3 (IGFBP-3) is a tumor suppressor gene that has anti-apoptotic activity. The purpose of this study was to investigate the anticancer mechanism of PPARγ with respect to IGFBP-3. PPARγ was overexpressed in SNU-668 gastric cancer cells using an adenovirus gene transfer system. The cells in which PPARγ was overexpressed exhibited growth inhibition, induction of apoptosis, and a significant increase in IGFBP-3 expression. We investigated the underlying molecular mechanisms of PPARγ in SNU-668 cells using an IGFBP-3 promoter/luciferase reporter system. Luciferase activity was increased up to 15-fold in PPARγ transfected cells, suggesting that PPARγ may directly interact with IGFBP-3 promoter to induce its expression. Deletion analysis of the IGFBP-3 promoter showed that luciferase activity was markedly reduced in cells without putative p53-binding sites (-Δ1755, -Δ1795). This suggests that the critical PPARγ-response region is located within the p53-binding region of the IGFBP-3 promoter. We further demonstrated an increase in PPARγ-induced luciferase activity even in cells treated with siRNA to silence p53 expression. Taken together, these data suggest that PPARγ exhibits its anticancer effect by increasing IGFBP-3 expression, and that IGFBP-3 is a significant tumor suppressor.

Exon 2 Ovar-DRB1 gene polymorphism in the Iranian Sangsari sheep

The major histocompatibility complex [MHC] plays a central role in the control of disease resistance and immune response. Extensive genetic diversity in MHC genes provides a valuable source for genetic improvement, via selection, in many domestic animals. Exon 2 of the class II MHC, termed Ovar-DRBl in domestic sheep [Ovis aries] has been suggested as important disease resistance and immune response gene. We characterized Ovar-DRBl in DNA samples from 138 individuals of a population of the Iranian Sangsari sheep breed using PCR-RFLP. Eight DRB1 alleles were identified among Iranian Sangsari sheep, including one previously unrecognized allele. Eight homozygous genotypes were observed: a, b, c, d, f, g, h andN. Genotype bb was the most common pattern [46 of 138]. Heterozygous genotypes [ag, cb, cd, bf, and bN] were also observed. The observed homozygosity and heterozygosity values were 0.6377 and 0.3623, respectively, vs expected values of 0.220 and 0.779. Iranian Sangsari population deviate significantly from the theoretical proportions [FIS = 0.5283; p = 0.0005]. In conclusion, PCR-RFLP analysis allows rapid identification of Ovar-DRBl types and discrimination of homozygous and heterozygous genotypes. This study indicates that the exon 2 region of the Ovar-DRBl gene is highly polymorphic in the Iranian Sangsari sheep breed

Estudo de HLA classes I e II em trinta pacientes equatorianos com artrite reumatoide em comparação com alelos de indivíduos sadios e afetados com outras doenças reumáticas / Study of class I and II HLA alleles in 30 ecuadorian patients with rheumatoid arthritis compared with alleles from healthy and affected subjects with other rheumatic diseases

INTRODUÇÃO: A artrite reumatoide (AR) é uma doença inflamatória crônica sistêmica autoimune que provém de uma desordem incapacitante. Até hoje, a etiologia da AR é desconhecida. No entanto, já se cogitou a existência de indivíduos geneticamente passíveis de tê-la. Muitos estudos já foram realizados em todo o mundo, como, por exemplo, na Polônia, Argentina, Chile, México, Brasil, Colômbia, entre outros países, com relação à influência entre os alelos HLA-DR e a doença, mas não no Equador. OBJETIVO: O principal objetivo deste estudo foi determinar a participação dos alelos de HLA classes I e II em pacientes com AR. PACIENTES E MÉTODOS: Esta pesquisa foi desenvolvida em 30 pacientes adultos com AR, previamente diagnosticados de acordo com os critérios de classificação do Colégio Norte-Americano de Reumatologia (ACR, 1987) e 28 controles. Para a tipificação de HLA classes I e II, adotou-se a técnica PCR-SSP, e as significâncias estatísticas foram avaliadas pelo teste de Qui-Quadrado. RESULTADOS: O HLA-DR4 está presente em 76,7 por cento dos pacientes, com uma frequência alélica de 45 por cento, enquanto apenas 21 por cento dos sujeitos controle o apresentaram. O teste de Qui-Quadrado confirma que as variáveis HLA-DR4 e RA estão altamente vinculadas (X² = 11,38, P = 0,00074). CONCLUSÃO: Há frequência maior de HLA-DR4 e HLA-DR14. Os resultados encontrados são similares aos encontrados em outros estudos. Porém, seria desejável aumentar o tamanho da amostra para encontrar um maior número de perfis genéticos e de alelos envolvidos.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic systemic inflammatory autoimmune disease that originates from a disabling disorder. To date, the etiology of RA is unknown. However, the existence of genetically susceptible individuals was considered. Many studies have been performed worldwide, for example, in Poland, Argentina, Chile, Mexico, Brazil, and Colombia, among others, regarding the influence between HLA-DR alleles and disease, but not in Ecuador. OBJECTIVE: The aim of this study was to determine the involvement of Class I and II HLA alleles in patients with RA. PATIENTS AND METHODS: This study was conducted in 30 adult patients with RA previously diagnosed, according to the classification criteria of the American College of Rheumatology (ACR, 1987) and 28 controls. For Class I and II HLA typing, we adopted the PCR-SSP, and statistical significances were evaluated by Chi-Square. RESULTS: HLA-DR4 is present in 76.7 percent of patients, with an allele frequency of 45 percent, while only 21 percent of control subjects presented it. The chi-square confirms that HLA-DR4 and RA variables are highly bound (X2 = 11.38, P = 0.00074). CONCLUSION: There is increased frequency of HLA-DR4 and HLA-DR14. The results are similar to those found in other studies. But it would be desirable to increase the sample size in order to find a greater number of genetic profiles and alleles involved.

Evaluation of immune response against hepatitis A and typhoid vaccines and their combination

The immunogenicity of both Typhoid Vi polysaccharide and inactivated Hepatitis A vaccines were tested and the immunogenic reflection of each vaccine on the other one in combination was detected. Groups of balb/C mice were immunized with different formulations containing different concentrations of typhoid Vi polysaccharide and hepatitis A vaccines, Four experiments were done a fellows:-Exp. I group I [mice was injected with alum 1mg/ ml], group 2, 3, 4 were immunized with three concentration [25, 12.5.6.25 micro g / ml typhoid [Ty] vaccine respectively. Exp. II groups 5, 6, 7 were immunized with hepatitis A [HA] vaccine with three concentration [400, 200, 100 IU/ ml respectively. Exp. III group 3A was immunized with [25 micro g / ml Ty vaccine], groups 33, 3C, 3D were immunized with combination of typhoid and hepatitis A vaccines [25 micro g / ml Ty +400, 200, 100 IU /ml HA respectively]. Exp. IV group 4A was immunized with [400 IU /ml HA vaccine], groups 43, 4C were immunized with combination of hepatitis A and typhoid vaccines. The results revealed that hepatitis A vaccine has a synergistic effect on the immunogenicity of typhoid Vi vaccine. On the other hand, the immune response against hepatitis A was higher when combined with different concentrations of typhoid vaccine

Antinuclear antibodies and HLA class II alleles in Jamaican patients with systemic lupus erythematosus / Anticuerpos antinucleares y aleles HLA de clase II en pacientes Jamaicanos con lupus eritematoso sistémico

OBJECTIVE: The relationship between human leukocyte antigens class II (HLA) and antinuclear antibodies was investigated in Jamaican patients with Systemic Lupus Erythematosus (SLE). METHODS: Samples of blood of 82 patients with SLE and 75 healthy controls were tested for antinuclear antibodies using the fluorescent antinuclear antibody (FANA) test, counterimmunoelectrophoresis (CIEP) and the Crithidia luciliae immunofluorescence test (CL-IFT). A DNA-based HLA typing method was used to determine the frequencies of alleles of HLA-DRB1, DRB3, DRB4 and DRB5 in patients and healthy controls. RESULTS: The FANA test was positive in all of the sera from patients with SLE. Anti-dsDNA antibodies were present in 49% (40/82), anti-Sm/RNP 44% (36/82) and anti-Ro/La 43% (35/82) of the sera from SLE patients. The frequency of HLA-DR4 was significantly lower in SLE patients than in healthy controls (2/82, 2% vs 15/75, 20%; RR = 0.12; p = 0.0004; CP = 0.005) but no other HLA-DRB1 SLE associations were found. A positive HLA-DR3 anti-Ro/La antibody association was found in the patients with SLE (9/21, 43% vs 5/55, 9%; odds ratio (OR) = 7.5; CP = 0.01). In contrast, possession of HLA-DR6 was negatively associated with the absence of anti-dsDNA antibodies (9/32, 28% vs 27/44, 61%; OR = 0.2; CP = 0.05). CONCLUSION: The HLA-DR6 allele is associated with the absence of antinuclear antibodies and HLA-DR3 with the presence of anti-Ro/La antibodies in Jamaican patients with SLE. However, these results and those of previous studies of Jamaican patients suggest that the HLA-DR3 association with the development of SLE reported in other populations might in fact reflect the association of HLA-DR3 with anti-Ro/La antibodies. Further investigations are needed to determine whether HLA-DRB antinuclear antibody associations define clinical subsets of SLE in Jamaican patients.

OBJETIVO Se investigó la relación entre los antígenos de leucocito humano (human leukocyte antigens o HLAs). Clase II y los anticuerpos antinucleares en pacientes jamaicanos con lupus eritematoso sistémico (LES). MÉTODOS: Se examinaron muestras de sangre de 82 pacientes con LES y 75 controles saludables para determinar la presencia de anticuerpos antinucleares, usando la prueba del anticuerpo antinuclear fluorescente (FANA), la contrainmunoelectroforesis (CIEP) y el test de inmunofluorescencia con Crithidia luciliae (CL-IFT). Un método de tipificación HLA basado en el ADN fue usado para determinar las frecuencias de aleles de HLA-DRB1, DRB3, DRB4 y DRB5 tanto en los pacientes como en los controles saludables. RESULTADOS: La prueba FANA fue positiva en todos los sueros de pacientes con LES. Anticuerpos anti-dsADN se hallaban presentes en 49% (40/82), anti-Sm/RNP en 44% (36/82) y anti-Ro/La en 43% (35/82) de los sueros de los pacientes de LES. La frecuencia de HLA-DR4 fue significativamente más baja en los pacientes con LES que en los controles saludables (2/82, 2% vs 15/75, 20%; RR = 0.12; p = 0.0004; CP = 0.005) pero no se hallaron otras asociaciones de LES con HLA-DRB1. Se halló una asociación positiva de anticuerpos HLA-DR3 anti-Ro/La en los pacientes con LES (9/21, 43% vs 5/55, 9%; odds ratio (OR) = 7.5; CP = 0.01). En contraste con ello, la posesión de HLA-DR6m estuvo asociada negativamente con la ausencia de anticuerpos anti-dsADN (9/32, 28% vs 27/44, 61%; OR = 0.2; CP = 0.05). CONCLUSIÓN: El alele HLA-DR6 está asociado con la ausencia de anticuerpos antinucleares y el de HLA-DR3 con la presencia de anticuerpos anti-Ro/La en pacientes jamaicanos con LES. Sin embargo, estos resultados al igual que los de los previos estudios de pacientes jamaicanos, sugieren que la asociación HLA-DR3 con el desarrollo de LES reportado en otras poblaciones podría de hecho reflejar la asociación de HLA-DR3 con anticuerpos anti-Ro/La. Se requieren investigaciones ulteriores a fin de determinar si las asociaciones de anticuerpo antinuclear HLA-DRB definen subconjuntos de LES en pacientes jamaicanos.

Delayed allograft rejection by the suppression of class II transactivator

We examined the effect of class II transactivator (CIITA) down-modulation on allograft rejection. To inhibit the function of CIITA, we constructed a series of CIITA mutants and found one exhibiting the dominant-negative effect on the regulation of major histocompatibility complex (MHC) class II expression. To test whether the CIITA dominant-negative mutant reduces immunogenecity, CIITA-transfected melanoma cells were injected into allogeneic host and assessed for immune evading activity against host immune cells. We demonstrated that the CIITA dominant-negative mutant allowed tumor nodules to develop earlier in the lung than control by this tumor challenge study. Furthermore, skin grafts deficient for CIITA also survived longer than wild-type in allogeneic hosts. Both the tumor challenge and skin graft studies suggest the inhibition of CIITA molecules in donor tissue would be beneficial to the control of allo-response.

Molecular Analysis of HLA Class ll-Associated Susceptibility to Neuroinflammatory Diseases in Korean Children

The work was done to study immunogenetic peculiarities of neuroinflammatory diseases among Korean children. A total of 13 children with neuroinflammatory diseases (8 males and 5 females; mean age 4.6+/-2.6 yr) were consecutively recruited. Genomic typing was performed on their HLA DRB/HLA DQB genes using PCR-SSOP/ SSP techniques with gel immunoelectrophoresis. The frequencies of HLA-DR1* 15 in children with acute disseminated encephalomyelitis (ADEM) (31%) and DQB1* 06 in other neuroinflammatory diseases (38%) were significantly increased compared with control subjects. The frequencies of HLA-DRB3*0202 (100%), HLA-DRB1*1302 (67%), HLA-DRB3*0301 (67%), and HLA-DQB1*0301 (67%) were significantly increased in children with multiple sclerosis and the frequencies of HLA-DRB1*1501 (40%) and HLA-DRB5*0101 (40%) were significantly increased in children with ADEM. HLA-DRB1*1401, HLA- DRB3*0202, and HLA-DQB1*0502 were found in children with acute necrotizing encephalopathy. In conclusion, HLA-DR1*15 and DQB1*06 may be involved in susceptibility to inflammation in Korean children. The frequencies of HLA-DRB1*1501, HLA-DRB5*0101, HLA-DRB3*0301, and HLADQB1* 0602 were not as high in Korean children with multiple sclerosis as in western children. However, HLA-DRB3*0202 was seen in all children with multiple sclerosis. Our data may provide further evidence that the immunogenetic background of neuroinflammatory diseases in Korean is distinctly different from the ones in western countries. Further studies are necessary to confirm this finding.

Complejo de histocompatibilidad / Histocompatibility complex

El compleho principal de histocompatibilidda (MHC) es un complejo génico altamente polimórfico que controla la expresión de moléculas que desempeñan un rol fundamental en las interacciones celulares que se producen durante la respuesta inmune y en el procesamiento y presentación de antígenos a los linfocitos T. Los genes de clase I del MHC controlan la expresión de los clásicos antígenos de histocompatibilidad y que en realidad funcionan como moléculas de presentación de fragmentos antigénicos a los linfocitos TCD8+ (linfocitos T citotóxicos). Los genes de clase II corresponden a los antiguos genes de respuesta inmune (genes Ir) y codifican la expresión de moléculas de presentación de fragmentos peptídicos a linfocitos TCD4+ (linfocitos T helper). Los genes de clase II codifican la expresión de los factores de complemento C4, Bf y C2. El complejo incluye, además, genes que codifican la expresión de subunidades del proteasoma (LMP2 y LMP7), transportadores peptídicos (TAP1 y TAP2), factor de necrosis tumoral (TNFa y TBFb) y proteínas de shock térmico (hsp70)

Los mecanismos moleculares de susceptibilidad y de protección dependientes del MHC en la diabetes tipo I en mexicanos / Molecular susceptibility and protection mechanisms dependent of MHC in type I diabetes in Mexicans

Los genes clase II del MHC juegan un papel central en la destrucción autoinmune de las células b del páncreas, en la DMDI. Se investigó el patrón genético de la DMDI en mexicanos. Los hallazgos serológicos del HLA mostraron una asociación muy significativa con los antígenos DR3, DR4, DQ2 y DQ8 y un efecto protector de DR11, DR15, DQ5, DQ6 y DQ7. Con estos datos, se analizaron los alelos DRB1, B3, B4, DQA1, DQB1,DPA1 y DPB1 a nivel del DNA por PCR, hibridando con sondas alelo-específicas. El 92.7 por ciento de los pacientes portan alelos DQA1 que tienen ARG en la posición 52 de la cadena DQa y el 78,2 por ciento son ASP57- en la cadena DQ~. El RR para los homocigotos es de 32.8 y 5.6 respectivamente. El haplotipo principalmente involucrado es DRB1*0405, DQA1*0301, DQB1*0302. Se concluye que las cadenas DQa y DQ forman un sitio relevante para el reconocimiento del péptido "diabetogénico" que induce la respuesta autoinmune destructiva. Las posiciones 57 y 74 del gen DRB1 contribuyen importantemente a la expresión y a la severidad de la DMDI en mestizos y en otros grupos étnicos, pero no en caucasoides o negros