Performance of the tetra-primer PCR technique compared to PCR-RFLP in the search for rs12979860 (C/T) and rs8099917 (T/G) single nucleotide polymorphisms (SNPs) in the IFNL4 gene / Desempenho da técnica tetra-primer PCR em relação a PCR-RFLP na pesquisa de polimorfismos de nucleotídeos únicos (SNPs) rs12979860 (C/T) e rs8099917 (T/G) no gene IFNL4

Single nucleotide polymorphisms (SNPs, rs12979860 e rs8099917) in the Interferon Lambda 4 gene (IFNL4, formerly IFNL3and/or IL28B) has been associated with failure in the innate immune response, sustained virological response in hepatitis C, and HTLV-1-associated myelopathy (HAM) development. To search for these polymorphisms several methodologies can be employed, such as sequencing, real-time or quantitative polymerase chain reaction (qPCR), restriction fragment length polymorphism analysis in PCR products (PCR-RFLP), and tetra-primer PCR. The present study compared the performance of the tetra-primer PCR in relation to the PCR-RFLP, both optimized in the Research HTLV Laboratory of the Center of Immunology of Instituto Adolfo Lutz in São Paulo. One hundred DNA samples obtained from patients of STD/Aids Reference Centre in São Paulo, previously analyzed for IL28B SNPs by PCR-RFLP were selected for analysis, after confirming that they represent all IL28B SNPs patterns described in the literature. The results obtained showed concordance between the PCR-RFLP and the tetra-primer PCR SNPs results, and because of the low cost, easy to perform, and minor employment of biological specimen and reagents, the tetra-primer PCR is of choice to be used in routine. (AU)

Polimorfismos de nucleotídeos únicos (single nucleotide polymorphisms, SNPs rs12979860 e rs8099917) no gene que codifica o Interferon Lambda 4 (IFNL4, antigamente IFNL3 e/ou IL28B) têm sido associados às falhas na resposta imune inata e resposta virológica sustentada na hepatite C, e a mielopatia associada ao HTLV-1 (HTLV-1-associated myelopathy, HAM). A pesquisa destes polimorfismos pode empregar diversas metodologias: sequenciamento, reação em cadeia da polimerase em tempo real ou quantitativa (quantitative polymerase chain reaction, qPCR), análise de fragmentos de restrição enzimática em produtos de PCR (restriction fragment length polymorphism in PCR products, PCR-RFLP) e a tetra-primer PCR. Este estudo comparou o desempenho da tetra-primer PCR em relação a PCR-RFLP, ambas otimizadas no Laboratório de Pesquisa em HTLV do Centro de Imunologia do Instituto Adolfo Lutz de São Paulo. Foram selecionadas 100 amostras de DNA obtidas de pacientes do Centro de Referência e Treinamento em DST/Aids de São Paulo cujos SNPs na IL28B foram anteriormente determinados por PCR-RFLP e representaram todos os perfis descritos em literatura. Os resultados obtidos mostraram concordância entre elas, e pelo fato da tetra-primer PCR ter menor custo, ser de fácil execução, empregar menos tempo, insumos e material biológico, é a técnica de escolha para uso em rotina. (AU)

Infection by bovine alphaherpesvirus types 1 and 5 induces IFN-λ3 expression in neuronal-type cells and bovine neural tissues.

Type III interferons (IFNs) are components of the innate immunity, with IFN lambda- (λ)3 having the most potent bioactivity in humans. IFN-λ has a predominant role in epithelial cells. However, antiviral function in certain infections of the central nervous system has also been demonstrated. IFN-λ3 expression in neural tissues of cattle has not been investigated. Thus, the aim of this study was to analyze whether an antiviral IFN-λ3 response is mounted after infection with bovine alphaherpesviruses (BoHV-1 and BoHV-5) in vitro, in neuronal-type cells, and in neural tissues from experimentally-infected calves. This study demonstrated that there is a strong IFN-λ3 response early after BoHV-1infection of undifferentiated neuroblastoma cells. During acute BoHV-1 and BoHV-5 infection of calves, low levels of IFN-λ3 expression were detected in the brain, which would favor virus spread within this tissue. Striking differences in the transcriptional levels of IFN-λ3 were observed in trigeminal ganglion, particularly in BoHV-1-acutely- and latently-infected calves. During reactivation, IFN-λ3 expression was down-regulated, which may be a requirement for virus replication and spread. Overall, different patterns of IFN-λ3 expression were detected during BoHV-1 and BoHV-5 infection, particularly during latency.

Interferon-lambda 3 and 4 Polymorphisms Increase Sustained Virological Responses and Regulate Innate Immunity in Antiviral Therapy With Pegylated Interferon-Alpha.

Sustained virologic response (SVR) in chronic hepatitis C (CHC) treatment denotes that the host genetics controls the immune response and unequivocally contribute to viral clearance or disease severity. In this context, single nucleotide polymorphisms (SNPs) in the locus of interferon lambda 3 and 4 genes (IFNL3/4) have been important genetic markers of responsiveness to CHC as prognostic markers for the pegylated-Interferon-alpha/ribavirin (Peg-IFN-α/RBV). Here, we analyzed 12 SNPs at the IFNL3/4 region in 740 treatment-naïve patients with CHC infected with hepatitis C virus (HCV) genotypes 1, 2, or 3 treated with Peg-IFN-α/RBV. Individually, rs12979860-CC, rs8109886-CC, or rs8099917-TT were predictive markers of SVR, while rs12979860-CC demonstrated the stronger effect. Besides, the genotypic combination of these three predictors' genotypes, CC/CC/TT, increased the rate of SVR. Serum levels of cytokines and gene expression analysis on the genes IFNL3, IFNL4, IFNA1, and some of the IFN-stimulated genes (ISGs) were measured in a subgroup of 24 treated patients and 24 healthy volunteers. An antagonist effect was highlighted between the expression of IFNL3/4 and IFNA1 mRNA among patients. Besides, a prominent production of the pro-inflammatory chemokines CCL4 and CXCL10 was observed at a 12-week treatment follow-up. Lower serum levels of these chemokines were detected in patients with an rs12979860-CC genotype associated with the better treatment outcome. Also, lower expression levels of the IFI6, IFI16, IRF9 genes were observed among rs12979860-CC individuals. In conclusion, a combination of the genotypes at the IFNL3/4 locus can act as a better marker for the prognosis for virological responses in an admixed Brazilian population presenting the modulating effect over innate immunity and inflammation that are controlling the outcome of the viral infection, but also other infectious diseases. This study is registered on the ClinicalTrials.gov platform (accession number NCT01889849 and NCT01623336).

Association of interferon lambda-4 rs12979860 polymorphism with hepatocellular carcinoma in patients with chronic hepatitis C infection.

BACKGROUND: Hepatitis C virus (HCV) infection is a public health concern worldwide. Several factors, including genetic polymorphisms, may be evolved in the progression of HCV infection to liver diseases. Interferon lambdas (IFNLs) modulate the immune response during viral infections. IFNLs induce antiviral activity, interfering in the viral replication by promoting the expression of several genes that regulate immunological functions. The interferon lambda-4 (IFNL4) rs12979860 polymorphism, which is characterized by a C to T transition in intron 1, is associated with spontaneous and treatment-induced clearance of HCV infection and may play a role in the development of HCV-associated liver diseases, including hepatocellular carcinoma (HCC). AIM: To investigate the association of IFNL4 rs12979860 polymorphism with fibrosis, cirrhosis, and HCC in patients with chronic HCV infection. METHODS: This study was comprised of 305 chronic HCV-infected patients (53 fibrosis, 154 cirrhosis, and 98 HCC cases). The control group was comprised of 260 HCV-negative healthy individuals. The IFNL4 rs12979860 polymorphism was genotyped using the TaqMan assay. Fibrosis was diagnosed based on liver biopsy findings, while cirrhosis was diagnosed through clinical, laboratory, anatomopathological, and/or imaging data. HCC was diagnosed through imaging tests, tumor, and/or anatomopathological markers. RESULTS: The T allele was observed in the three groups of patients (fibrosis, cirrhosis, and HCC) at a significantly higher frequency when compared with the control group (P = 0.047, P < 0.001, and P = 0.01, respectively). Also, genotype frequencies presented significant differences between the control group and cirrhosis patients (P < 0.001) as well as HCC patients (P = 0.002). The risk analysis was performed using the codominant and dominant T allele models. In the codominant model, it was observed that the CT genotype showed an increased risk of developing cirrhosis in comparison with the CC genotype [odds ratio (OR) = 2.53; 95% confidence interval (CI): 1.55-4.15; P < 0.001] as well as with HCC (OR = 2.54; 95%CI: 1.44-4.56; P = 0.001). A similar result was observed in the comparison of the TT vs CC genotype between the control group and cirrhosis group (OR = 2.88; 95%CI: 1.44-5.77; P = 0.001) but not for HCC patients. In the dominant T allele model, the CT + TT genotypes were associated with an increased risk for progression to cirrhosis (OR = 2.60; 95%CI: 1.63-4.19; P < 0.001) and HCC (OR = 2.45; 95%CI: 1.42-4.31; P = 0.001). CONCLUSION: These findings suggest that the T allele of IFNL4 rs12979860 polymorphism is associated with the development of cirrhosis and HCC in chronic HCV-infected patients.

The influence of gene-chronic hepatitis C virus infection on hepatic fibrosis and steatosis.

Host single nucleotide polymorphisms (SNPs) in different genes can play a role in chronic hepatitis C virus (HCV) infection and influence the presence of hepatic fibrosis and comorbidities such as hepatic steatosis. We assessed the combined effect of SNPs in the PNPLA3, MTTP, TM6SF2, and IFNL3/IFNL4 genes in 288 Brazilian patients who were chronically infected with HCV. Hepatic fibrosis was observed in 246 (85.4%) patients and hepatic steatosis in 141 (49.0%) patients. PNPLA3 rs738409 (CG/GG) (P = 0.044) and TM6SF2 rs58542926 (CT) (P = 0.004) were alone associated with fibrosis, and PNPLA3 rs738409 (P < 0.05, in distinct genetic models) was associated with steatosis. Multiple logistic regression of each SNP combined with HCV genotype 3 infection showed that MTTP rs1800591 (GT/TT) combined with HCV genotype 3 was associated with a 6.72-fold increased chance of hepatic steatosis (P = 0.013). In the analysis of SNPs combined 2 by 2, no influence on hepatic fibrosis or steatosis was observed.

Host and viral mechanisms of congenital Zika syndrome.

In 2015-2016, in the Americas, and especially in northeast Brazil, a significant number of cases of microcephaly and other congenital brain abnormalities were linked with an outbreak of Zika virus (ZIKV) infection in pregnant women. While maternal symptoms of ZIKV are generally mild and self-limiting, clinical presentation in fetuses and newborns infected is extensive and includes microcephaly, decreased cortical development, atrophy and hypoplasia of the cerebellum and cerebellar vermis, arthrogryposis, and polyhydramnios. The term congenital ZIKV syndrome (CZS) was introduced to describe the range of findings associated with maternal-fetal ZIKV transmission. ZIKV is primarily transmitted by Aedes aegypti mosquitoes, however non-vector-dependent routes are also possible. Mechanisms of maternal-fetal transmission remain unknown, and the trans-placental route has been extensively studied in animal models and in human samples. The aim of this review was to summarize recent studies that helped to elucidate the mechanism of CZS in animal models and observational studies. There are still challenges in the diagnosis and prevention of CZS in humans, due to the large gap that remains in translating ZIKV research to clinical practice. Translational research linking governments, local health workers, scientists and industry is fundamental to improve care for mothers and children.

Interferons and systemic sclerosis: correlation between interferon gamma and interferon-lambda 1 (IL-29).

BACKGROUND: Interferon (IFN)-λ1 is a newly described cytokine, member of type III interferons family, which is known for its antiviral, anti-proliferative and antitumor activity. Recent studies indicated that this cytokine has also immune-regulatory function, but its role in the pathogenesis of autoimmune diseases is not established yet. We evaluated serum levels of IFN-λ1 in systemic sclerosis (SSc) patients and healthy controls and its association with IFN-γ and clinical manifestations. METHODS: IFN-λ1 and IFN-γ serum levels were measured by ELISA from 52 patients with SSc and 53 healthy controls. Association of cytokines serum levels was sought with clinical parameters. RESULTS: IFN-λ1 and IFN-γ levels in SSc patients were significantly higher than those in healthy individuals (24.82 ± 8.78 and 11.04 ± 3.04 pg/ml, p < 0.0001; 34.11 ± 8.11 and 10.73 ± 2.77 pg/ml, p < 0.0001, respectively). We found a positive correlation between IFN-λ1 and IFN-γ levels in SSc patients (p = 0.0103, r = 0.3526). IFN-γ levels were associated with muscle involvement (p = 0.0483). CONCLUSION: We first showed raised IFN-λ1 levels in SSc patients. Furthermore, we found a correlation between IFN-λ1 and IFN-γ levels and an association between IFN-γ and myositis. Additional in vitro and in vivo studies are needed to understand IFN-λ1 role in SSc.