cGAS/STING signaling pathways induces the secretion of type Ⅰ interferon in porcine alveolar macrophages infected with porcine circovirus type 2 / 生物工程学报

In order to study the signal pathway secreting type Ⅰ interferon in porcine alveolar macrophages (PAMs) infected with porcine circovirus type 2 (PCV2), the protein and the mRNA expression levels of cGAS/STING pathways were analyzed by ELISA, Western blotting and quantitative reverse transcriptase PCR in PAMs infected with PCV2. In addition, the roles of cGAS, STING, TBK1 and NF-κB/P65 in the generation of type I interferon (IFN-I) from PAMs were analyzed by using the cGAS and STING specific siRNA, inhibitors BX795 and BAY 11-7082. The results showed that the expression levels of IFN-I increased significantly at 48 h after infection with PCV2 (P<0.05), the mRNA expression levels of cGAS increased significantly at 48 h and 72 h after infection (P<0.01), the mRNA expression levels of STING increased significantly at 72 h after infection (P<0.01), and the mRNA expression levels of TBK1 and IRF3 increased at 48 h after infection (P<0.01). The protein expression levels of STING, TBK1 and IRF3 in PAMs infected with PCV2 were increased, the content of NF-κB/p65 was decreased, and the nuclear entry of NF-κB/p65 and IRF3 was promoted. After knocking down cGAS or STING expression by siRNA, the expression level of IFN-I was significantly decreased after PCV2 infection for 48 h (P<0.01). BX795 and BAY 11-7082 inhibitors were used to inhibit the expression of IRF3 and NF-κB, the concentration of IFN-I in BX795-treated group was significantly reduced than that of the PCV2 group (P<0.01), while no significant difference was observed between the BAY 11-7028 group and the PCV2 group. The results showed that PAMs infected with PCV2 induced IFN-I secretion through the cGAS/STING/TBK1/IRF3 signaling pathway.

Análisis molecular del cáncer de colon esporádico / Molecular analysis of sporadic colon cancer

Background: In Chile, colorectal cancer (CRC) is often diagnosed in late stages. Thus, surgical treatment must be complemented with chemotherapy. KRAS mutations and microsatellite instability have been detected in these tumors. However, the response to treatment in patients without KRAS mutations varies and requires a better understanding. Aim: To determine the frequency and distribution of somatic point mutations in KRAS, BRAF and PIK3CA genes and microsatellite instability status (MSI) in patients with colon cancer (CC). Material and Methods: A prospective observational study of patients undergoing surgery for colon cancer. Tumor-derived DNA was analyzed by polymerase chain reaction (PCR) for the most frequent mutations of KRAS, BRAF and PIK3CA. PCR was also used to analyze MSI. Results: Fifty-eight patients with sporadic CC were analyzed, 16 showed KRAS mutations (G12R, G12D, G12V, G13D) and out of the 42 patients that did not show any mutation, 10 had mutations in BRAF (V600E) and PIK3CA (E542K, E545D, E545K, Q546E, H1047R). BRAF mutations alone or in combination with PIK3CA mutations were observed in 27% of high MSI tumors and in 2% of tumors without instability (p < 0.049). A higher percentage of high MSI tumors were located in the right colon (p < 0.001), and showed BRAF mutation (p < 0.020). Conclusions: The highest percentage of high MSI and BRAF mutations was observed in the right colon. Therefore, this study suggests the presence of different molecular features between right and left colon tumors that should be considered when defining the therapeutic management.

In acute lymphoblastic leukemia deletion of the tumor suppressor gene P16 is associated with abnormal interferon genes

The putative tumor-suppressor gene p16 was mapped to human chromosome 9p21, close to the interferon alpha cluster. The frequency and association of gene alterations of p16, interferon alpha and interferon beta were investigated in a total of 39 Acute Lymphoblastic Leukemia (ALL) patients. Of these, 10 patients (25.6 per cent) presented abnormalities of at least one of the three genes studied. In 32 ALL cases studies of the three genes could be accomplished. In 23 out of 32 ALL cases the 3 genes studied were normally preserved. In the remaining 9 ALL, p16 was affected in 8 cases by homozygous deletions. In 2 patients, p16 deletion was associated with homozygous deletions for interferon alpha and interferon beta genes and in 1 case with total deletion of interferon beta 1 gene and partial deletion of interferon alpha. In the remaining 5 cases, p16 was the only gene deleted with no alteration of type interferon genes. These data indicate that p16 gene is deleted in a higher frequency than type I interferon genes in ALL. Moreover, within the ALL group with p16 gene deletion, 37.5 per cent are associated with interferon deletions and in general, ALL with alpha and/or beta interferon gene deletions are associated with p16 deletions. Therefore, p16 gene deletion with preserved type I interferon genes in some ALL suggests that the absence of this cdk inhibitor may disturb the normal cell cycle and favor blast transformation.

Altos niveles de expresión del gen del interferón *-2 humano bajo el control del promotor derecho del fago Lambda en E. coli / High expression levels of human *-2 interferón gene under the control of Lambda right promoter in E. coli

El gen del interferón *-2 humano (IFN-2) fue expresado en E. coli bajo el control del promotor derecho del bacteriófago Lambda (PR). La expresión de la actividad de IFN-2 en células que contenían este plásmido fue termoinducible. Se lograron niveles de expresión de hasta 5 x 108 UI/I

The effect of interferon on Japanese encephalitis virus in vitro.

The studies on the effect of the Recombinant Leukocyte A Interferon (r IFN-alpha A) on 4 local strains of JE virus in Thailand were performed in vitro in our laboratories in Bangkok during August - October 1984. The procedures consisted of the plaque reduction assay and the Rhesus monkey kidney cell line, LLC-MK2 cells. These 4 strains namely Vip, KE-093, KE-094 and KE-095 were isolated from the JE patients in Thailand during 1983-1984. The results revealed that all of the JE virus strains tested were sensitive to the r IFN-alpha A with its minimal effective doses ranging from 30 I.U./ml to 1,500 I.U./ml. The studies on the effects of r IFN-alpha A on JE virus replicating in the cell culture for 0 hour, 1 hour and 6 hours indicated that if the virus had more hours to replicate in the cell culture, higher concentration of the IFN was needed in order to combat the replication of the virus in the cell culture. r IFN-alpha A at higher concentrations showed more efficacy in combating the replication of the JE virus in vitro.