Killer cell immunoglobulin-like receptor (KIR) genes and their HLA ligands in a Brazilian population.

Killer cell immunoglobulin-like receptors (KIR) exhibit extensive diversity, giving rise to different KIR profiles in populations worldwide. This study aimed to investigate the distribution of KIR genes and HLA ligands in a population from Campinas, southeastern Brazil (n = 292), and to compare their results with other populations. A comprehensive analysis of population-specific genes, genotype, and haplotype frequencies of KIR may facilitate a better understanding of their evolution and role in immunity. The genotyping of 16 KIR genes and HLA class I alleles was performed by the reverse sequence-specific oligonucleotide methodology using the Luminex platform (One Lambda, Inc., Canoga Park, CA). The framework genes were present in all individuals, with the most common non-framework KIR genes detected being KIR2DP1(96.6%), KIR2DL1(95.5%), KIR3DL1(94.5%), KIR2DS4(93.8%) and KIR2DL3(87.3%). KIR2DS1, KIR2DS3, KIR2DS5, and KIR3DS1 presented frequencies below 40%. KIR2DL2, KIR2DL5, and KIR2DS2 showed intermediate frequencies (between53% and 58%). The activating gene KIR2DS5 was the least common in this population (30.8%). Forty-five KIR profiles were found with the commonest being the homozygous A haplotype (27.4%). The distribution of KIR genes in the Brazilian population is similar to Caucasian European and Euro-descendant populations.

Impact of SNPs/Haplotypes of IL10 and IFNG on the Development of Diffuse Large B-Cell Lymphoma.

The purpose of this study was to assess the influence of single-nucleotide polymorphisms (SNPs) on cytokine genes in the development of diffuse large B-cell lymphoma (DLBCL). One hundred and twelve patients and 221 controls were investigated. Among them, 97 patients treated with R-CHOP were subdivided into two groups: (i) complete remission of the disease and (ii) patients who progressed to death, relapsed, or had disease progression. The SNPs investigated by PCR-SSP were TNF -308G>A (rs1800629), IFNG +874A>T (rs2430561), IL6 -174G>C (rs1800795), IL10 -1082A>G (rs1800896), IL10 -819C>T (rs1800871), IL10 -592C>A (rs1800872), and TGFB1 codon10T>C (rs1982073) and codon25G>C (rs1800471). In general, the genotypes that have been associated in the literature with lower production or intermediate production of IL-10 and higher production of IFN-γ were associated with the protection of the development of the disease, possibly favoring the Th1 immune response and diminishing the capacity of cell proliferation. However, patients receiving R-CHOP treatment presented unfavorable prognoses in the presence of genotypes related to the intermediate production of IL-10 and high production of TGF-ß1, indicating that cytokines may be related to the response to treatment and action mechanisms of Rituximab.

Synergistic effect of KIR ligands missing and cytomegalovirus reactivation in improving outcomes of haematopoietic stem cell transplantation from HLA-matched sibling donor for treatment of myeloid malignancies.

The goal of this study was to evaluate the influence of KIR-HLA genotypes on the outcome of patients undergoing treatment for haematological malignancies by non-T-depleted lymphocyte haematopoietic stem cell transplantation (HSCT) from HLA-matched sibling donors. The prospective study was conducted at the Center of Hematology, University of Campinas, and 50 patients and their donors were followed up from 2008 to 2014. KIR and HLA class I genes were genotyped and patients grouped based on the presence of KIR ligands combined with KIR genotype of their respective donors. Patients with all KIR ligands present (n=13) had a significantly higher (p=0.04) incidence of acute graft-versus-host-disease (GVHD) than patients with one or more KIR ligands missing (n=37). The overall survival following transplantation of patients with myeloid malignancies (n=27) was significantly higher (p=0.035) in the group with one or more KIR ligands missing (n=18) than in the group with all ligands present (n=9). Presence of KIR2DS2 was associated with a worsening of HSCT outcome while reactivation of cytomegalovirus (CMV) infection improved the outcome of patients with one or more KIR ligands missing. Our results indicate that KIR-HLA interactions affect the outcome of the HLA-matched transplantation, particularly in patients with myeloid malignancies.

Investigation of deletion of 22pb in KIR2DS4 gene in a population of southern Brazil.

BACKGROUND: The aim of this study was to investigate the distribution of full-length and deleted variants of KIR2DS4 in a population of southern Brazil and compare the results with other populations, as well as comparing two techniques, PCR-SSP and PCR-SSO, for typing of variants. METHODS: 258 individuals from southern Brazil were analysed by PCR-SSO ("polymerase chain reaction-sequence specific oligonucleotides", One Lambda, Inc., Canoga Park, CA), of which 161 were also analysed by PCR-SSP. RESULTS: The study population showed similarities with other Caucasian populations; 46.5% of individuals had only KIR2DS4 variants, 21.3% had the full-length form and 25.1% had both forms. CONCLUSION: The frequencies found in both groups (genotyped by PCR-SSP and PCR-SSO) were 100% concordant.

The association of the immune response genes to human papillomavirus-related cervical disease in a Brazilian population.

The genetic variability of the host contributes to the risk of human papillomavirus (HPV)-related cervical disease. Immune response genes to HPV must be investigated to define patients with the highest risk of developing malignant disease. The aim of this study was to investigate the association of polymorphic immune response genes, namely KIR, HLA class I and II, and single-nucleotide polymorphisms (SNPs) of cytokines with HPV-related cervical disease. We selected 79 non-related, admixed Brazilian women from the state of Paraná, southern region of Brazil, who were infected with high carcinogenic risk HPV and present cervical intraepithelial neoplasia grade 3 (CIN3), and 150 HPV-negative women from the same region matched for ethnicity. KIR genes were genotyped using an in-house PCR-SSP. HLA alleles were typed using a reverse sequence-specific oligonucleotide technique. SNPs of TNF -308G>A, IL6 -174G>C, IFNG +874T>A, TGFB1 +869T>C +915G>C, and IL10 -592C>A -819C>T -1082G>A were evaluated using PCR-SSP. The KIR genes were not associated with HPV, although some pairs of i(inhibitory)KIR-ligands occurred more frequently in patients, supporting a role for NK in detrimental chronic inflammatory and carcinogenesis. Some HLA haplotypes were associated with HPV. The associations of INFG and IL10 SNPs potentially reflect impaired or invalid responses in advanced lesions.

KIR genes and their human leukocyte antigen ligands in the progression to cirrhosis in patients with chronic hepatitis C.

Natural killer (NK) cells play pivotal roles in immune responses against infection with viruses, such as hepatitis C virus (HCV), and killer cell immunoglobulin-like receptors (KIRs) are related to the activation and inhibition of NK cells. The aim of this study was to investigate the possibility that KIR genes and their human leukocyte antigen (HLA) ligands influence progression to cirrhosis in patients infected with genotype 1 of HCV. A total of 145 Brazilian patients with confirmed chronic hepatitis C grouped from F0 to F4 according to fibrosis progression to cirrhosis were evaluated. Genotyping of KIR and HLA genes was performed by polymerase chain reaction with sequence-specific oligonucleotide probes. The HLA-C2 KIR ligand was more frequent in patients than in healthy controls (74.5% vs 64.3%, p = 0.04, odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.03-2.52). Moreover, the HLA-C1C2 genotype was more frequent in patients with advanced fibrosis or cirrhosis (F3-F4 group) than in patients in the F0-F2 group (61.6% vs 44.7%, p = 0.06) and in the F4 group compared with the F0-F3 group (65.7% vs 46.7%, p = 0.05, OR = 2.19, 95% CI = 1.01-4.73). NK and KIR ligands may contribute to the development of liver damage in patients chronically infected by HCV.

Otimização de metodologia para o estudo de genes KIR / Methodology optimization for KIR genotyping

Receptores killer cell immunoglobulin-like (KIRs) são moléculas localizadas na superfície de células natural killer (NK) e em subpopulações de linfócitos T codificadas por genes do cromossomo 19q13.4. A interação entre receptores KIR e moléculas antígeno leucocitário humano (HLA) de classe I determina se células NK exercerão ou não sua função citotóxica e/ou secretora de citocinas ou se esta será inibida. Este trabalho teve por finalidade otimizar a metodologia para a genotipagem KIR, baseando-se nas condições descritas por Martin (2004). A técnica utilizada foi a reação em cadeia da polimerase com primers de sequência específica (PCR-SSP) com iniciadores sintetizados pela Invitrogen® e visualização do produto amplificado em gel de agarose a 2 por cento com brometo de etídio. Adaptações foram realizadas e a concentração de alguns reagentes foi alterada, como a do controle interno de 100 nM para 150 nM, iniciadores específicos senso e antissenso de KIR12.5/12.3, KIR13.5/13.3, KIR14.5/14.3, KIR22.5/22.3 e KIR36.5/36.3 de 500 nM para 750 nM e da solução de MgCl2 de 1,5 mM para 2 mM. As concentrações dos demais reagentes e temperaturas de amplificação foram mantidas. Nessas condições, o uso da Taq DNA polimerase recombinante (Invitrogen®) foi satisfatório. Os resultados das genotipagens de 70 indivíduos foram confirmados por rSSO-Luminex® (One Lambda, Canoga Park, CA, EUA). A tipagem de genes KIR por essa técnica apresentou sensibilidade, especificidade, reprodutibilidade e baixo custo.

The killer cell immunoglobulin-like receptors (KIRs) are molecules expressed on natural killer (NK) cells surface and in T-cell subsets encoded by genes located in chromosome 19q13.4. The interaction between KIR receptors and HLA class I molecules determines if the NK cells will fulfill their cytotoxic function and/or cytokine secretion or if this function will be inhibited. The objective of this work was to optimize KIR genotyping method described by Martin (2004). It was used PCR-SSP (polymerase chain reaction-sequence-specific primers) with primers synthesized by Invitrogen® and visualization of the amplified products on 2 percent agarose gel electrophoresis, containing ethidium bromide. Some adaptations were made and the reagents had their concentrations increased: the internal control from 100 nM to 150 nM, forward and reverse specific primers KIR12.5/12.3, KIR13.5/13.3, KIR14.5/14.3, KIR22.5/22.3 and KIR36.5/36.3 from 500 nM to 750 nM, and MgCl2 solution from 1.5 mM to 2 mM. Other reagent concentrations and amplification temperatures were maintained. Satisfactory results were obtained with Taq DNA Polymerase Recombinant (Invitrogen®). The results of seventy samples were confirmed by rSSO-Luminex® (One Lambda, Canoga Park, CA, USA). This KIR typing method proved to be accurate, specific, reproducible and cost effective.

Killer cell immunoglobulin-like receptor gene diversity in a Southern Brazilian population from the state of Paraná.

Killer cell immunoglobulin-like receptors (KIR) are encoded by polymorphic genes and have as binding human leukocyte antigen (HLA) class I molecules. The aim of this study was to investigate the distribution of KIR genes and inhibitory KIR/HLA pairs in a population from Southern Brazil, in the state of Paraná, and to compare the results with results from other populations. The genotyping of 16 KIR genes and HLA class I alleles of 289 unrelated individuals was accomplished by reverse sequence-specific oligonucleotide Luminex (One Lambda, Inc., Canoga Park, CA). This Brazilian population demonstrated several similarities to Caucasian populations with regard to the frequency of KIR genes. Thirty-eight genotypes were defined in which the most frequent was the homozygous haplotype A (33.2%). Therefore, it was possible to define two new genotypes. Most of the individuals demonstrated at least one inhibitory KIR/HLA pair. Two pairs were the most frequent (40.4%), followed by three pairs (38.2%), one pair (14.6%), and four pairs (6.4%). The KIR2DL2/3 + HLA-C1 pair was the most frequent (79.9%) and the least frequent pair was KIR3DL2 + HLA-A3/11 (25.0%). This study demonstrated the diversity of KIR genes in a population of Paraná, as well as the characteristic pattern of Caucasians with racial admixture, which enabled the definition of two new genotypes and the identification of one individual without the inhibitory KIR/HLA pair.

Receptores Kir de células Natural Killer / Kir receptors of natural killer cells

As células NK (natural killer) são uma subpopulação de linfócitos que desempenham função essencial na resposta imune inata. As moléculas KIR (killer immunoglobulin-like receptor) são receptores expressos na superfície dessas células com função inibitória ou ativatória e contribuem para a regulação da função dascélulas NK. Os genes KIR fazem parte do Complexo de Receptores Leucocitários, localizado no cromossomo 19q13 e apresentam alto polimorfismo. Os ligantes de KIR são moléculas HLA de classe I, e a regulação dascélulas NK está relacionada à variação da expressão dessas moléculas na superfície das células-alvo, principalmente células infectadas, tumorais e alogênicas. O objetivo desse trabalho foi proceder a uma revisão bibliográfica sobre os receptores KIR. O levantamento foi realizado nos sites Pubmed/medline e ScienceDirect,e foram utilizadas como palavras-chave receptor, NK e KIR. A estrutura molecular desses receptores, a nomenclatura e classificação de KIR, a variabilidade gênica, alélica e haplotípica e os ligantes foram apresentados. Ênfase foi dada à regulação da expressão dos genes KIR e sua relação com a função das célulasNK.

NKC (natural killer cells) are a population of lymphocytes that play an essential role in innate immunity. KIR molecules are receptors expressed on the surface of these cells with an inhibitory or activating function that contributes to the regulation of NK cells. The KIR genes are located on chromosome 19q13 at the Leukocyte Receptor Complex, and exhibit high polymorphism. The KIR ligands are HLA class I molecules. NK cell functionsare related to the variation of the expression of these molecules on the surface of the target cells – especially infected, allogeneic and tumor cells. The aim of this work was to make a review about KIR receptors. The Pubmed/medline and ScienceDirect online databases were accessed, using receptor, NK and KIR as keywords. KIR molecular structure, nomenclature and classification, gene diversity, allelic and haplotypic variability and itsligands were described. Regulation of KIR genes expression and NK cell function were also presented.

Las células NK (natural killer) son una subpoblación de linfocitos que desempeñan una función esencial en la respuesta inmune innata. Las moléculas KIR (killer immunoglobulin-like receptor) son receptores expresos en la superficie de esas células con función inhibidora o activadora y contribuyen para la regulación de la función delas células NK. Los genes KIR hacen parte del Complejo de Receptores Leucocitarios, localizado en el cromosoma 19q13 y presentan alto polimorfismo. Los ligantes de KIR son moléculas HLA de clase I, y laregulación de las células NK está relacionada a la variación de la expresión de esas moléculas en la superficiede las células blanco, principalmente células infectadas, tumorosos y alogénicas. El objetivo de ese trabajo fue proceder una revisión bibliográfica sobre los receptores KIR. La pesquisa fue realizada en los sites Pubmed/medline y ScienceDirect, y fueron utilizadas como palabras clave receptor, NK y KIR. La estructura molecular de esos receptores, la nomenclatura y clasificación de KIR, la variabilidad génica, alélica y haplotípicay los ligantes fueron presentados. Énfasis fue dada a la regulación de la expresión de los genes KIR y surelación con la función de las células NK.