A Broadly Cross-protective Vaccine Presenting the Neighboring Epitopes within the VP1 GH Loop and VP2 EF Loop of Enterovirus 71.

Human enterovirus 71 (EV71) and coxsackievirus A16 (CA16) are the major etiological agents of hand, foot and mouth disease (HFMD) and are often associated with neurological complications. Currently, several vaccine types are being developed for EV71 and CA16. In this study, we constructed a bivalent chimeric virus-like particle (VLP) presenting the VP1 (aa208-222) and VP2 (aa141-155) epitopes of EV71 using hepatitis B virus core protein (HBc) as a carrier, designated HBc-E1/2. Immunization with the chimeric VLPs HBc-E1/2 induced higher IgG titers and neutralization titers against EV71 and CA16 in vitro than immunization with only one epitope incorporated into HBc. Importantly, passive immunization with the recombinant HBc-E2 particles protected neonatal mice against lethal EV71 and CA16 infections. We demonstrate that anti-VP2 (aa141-155) sera bound authentic CA16 viral particles, whereas anti-VP1 (aa208-222) sera could not. Moreover, the anti-VP2 (aa141-155) antibodies inhibited the binding of human serum to virions, which demonstrated that the VP2 epitope is immunodominant between EV71 and CA16. These results illustrated that the chimeric VLP HBc-E1/2 is a promising candidate for a broad-spectrum HFMD vaccine, and also reveals mechanisms of protection by the neighboring linear epitopes of the VP1 GH and VP2 EF loops.

Metastasis of human gastric adenocarcinoma partly depends on phosphoinositide-specific phospholipase γ1 expression.

It is known that phosphoinositide-specific phospholipases γ1(PLCγ1) can trigger several signalling pathways to regulate cell proliferation, differentiation, and metastasis. However, whether this kinase is highly expressive and active in human gastric adenocarcinomas, and whether it can play an important role in the development of the cancer, have not yet been investigated. The aim of the study was to investigate the expression of PLCγ1 in human gastric adenocarcinoma, while the question of whether PLCγ1 can be activated through protein kinase B (Akt) signalling pathways to regulate cell migration was further explored using human gastric adenocarcinoma BGC-823 cell line. The expression of PLCγ1 in human adenocarcinoma was detected using immunohistochemical staining. The BGC-823 cells were cultured and treated with inhibitors or transfected with plasmid construction. The cell migration of BGC-823 cells was measured with wound healing assay, cell migration assay, and the ruffling assay. The expression levels of PLCγ1 and its related signal molecules in BGC-823 cells were assessed using Western blot analysis or gelatine zymography assay. PLCγ1 was highly expressed in humangastric adenocarcinomas, especially in the region with lymph node metastasis. It was shown that migration of BGC-823 cells in vitro depends on PLCγ1 activation. This activation is mediated through Akt, an upstream of PLCγ1 that triggers the PLCγ1/extracellular signal-regulated kinase (ERK)/matrix metalloproteinase (MMP) pathway in BGC-823 cells. PLCγ1 activities play an important role in the metastasis of gastric adenocarcinoma, and may serve as a potential therapeutic target in this type of cancer.

ORF7 of varicella-zoster virus is a neurotropic factor.

Varicella-zoster virus (VZV) is the causative agent of chickenpox and herpes zoster (shingles). After the primary infection, the virus remains latent in sensory ganglia and reactivates upon weakening of the cellular immune system due to various conditions, erupting from sensory neurons and infecting the corresponding skin tissue. The current varicella vaccine is highly attenuated in the skin and yet retains its neurovirulence and may reactivate and damage sensory neurons. The factors involved in neuronal invasion and establishment of latency are still elusive. Previously, we constructed a library of whole-gene deletion mutants carrying a bacterial artificial chromosome sequence and a luciferase marker in order to perform a comprehensive VZV genome functional analysis. Here, screening of dispensable gene deletion mutants in differentiated neuronal cells led to the identification of ORF7 as the first known, likely a main, VZV neurotropic factor. ORF7 is a virion component localized to the Golgi compartment in infected cells, whose deletion causes loss of polykaryon formation in epithelial cell culture. Interestingly, ORF7 deletion completely abolishes viral spread in human nervous tissue ex vivo and in an in vivo mouse model. This finding adds to our previous report that ORF7 is also a skin-tropic factor. The results of our investigation will not only lead to a better understanding of VZV neurotropism but could also contribute to the development of a neuroattenuated vaccine candidate against shingles or a vector for delivery of other antigens.

The diversity expression of p62 in digestive system cancers.

The expression of p62 autoantigen and the frequency of p62 autoantibody have been reported in hepatocellular carcinoma (HCC) and many types of malignant tumors, respectively, but information regarding to the expression of p62 in other cancer tissues and the association of autoantibody to p62 with tumor behaviors is not available. In the current study, the expression of p62 in tissues and the appearance of p62 autoantibody in sera were detected by immunohistochemical staining and ELISA in four clinical types of digestive system cancers including gastric cancer, esophageal cancer, large intestine cancer and HCC, respectively. Interestingly, the immunohistochemistry staining of p62 has been shown in all of digestive canal tissues (stomach, esophagus, large intestine) including tissues with cancers, beside cancers and from non-malignant patients, whereas the frequencies were 62.5% and 0% in tissues with cancer and beside cancer in patients with HCC, respectively. Importantly, we found that the p62 expression and the frequency of autoantibody to p62 were associated to cell differentiation and tumor metastasis, respectively. These results suggest that the expression of p62 in tissues and the appearance of autoantibody to p62 in sera might be related to cell malignant manifestations. Moreover, p62 autoantibody is a significant marker for the prognosis of cancers and the evaluation of clinical treatments.

p62 Expression in primary carcinomas of the digestive system.

AIM: To characterize p62 expression and define the relationship between p62 expression and cell proliferation in primary carcinomas of the digestive system. METHODS: p62 expression was characterized in surgically resected tumor specimens from 60 patients with primary carcinomas of the digestive tract (including 22 esophageal carcinomas, 17 gastric carcinomas, and 21 colorectal carcinomas) and 40 patients with hepatocellular carcinoma (HCC) by immunohistochemistry (IHC). The cell proliferation was determined by IHC of Ki-67 in 40 patients with HCC. RESULTS: Twenty-two cases of esophageal carcinoma were histopathologically diagnosed as squamous cell carcinoma. We combined the gastric and colorectal carcinomas based on the equivalent histology. The 38 tumors in the combined groups, consisted of 17 well-differentiated, eight moderately differentiated, nine poorly differentiated carcinomas, and four mucinous adenocarcinomas. According to the criteria of Edmondson and Steiner, 40 patients with HCC were graded (2 grade I, 17 grade II and 21 grade III). p62 expression in primary carcinomas of the gastrointestinal tract (60/60,100%) was higher than that (27/40, 67.5%) of HCC (P<0.01, chi(2) = 19.63). High expression levels of p62 were positively correlated with histological grades in gastric and colorectal carcinomas (P<0.0001) and inversely associated with those in HCC (P = 0.0322). No significant correlations were observed for esophageal carcinomas (P = 0.8246). p62 expression was also detected in the cytoplasm of morphologically normal columnar epithelial cells adjacent to the cancer foci of gastric and colorectal carcinomas. In 40 HCC specimens, the mean Ki-67 labeling index (LI) was (19.6+/-16.0)%. It was (28.3+/-18.73)% in 12 cases with high p62 expression (+++), (7.53+/-14.83)% in 13 cases without p62 expression(-). Patients with a high p62 expression showed a significantly higher level of Ki-67 staining than those without p62 expression (P<0.05, t = 2.069). CONCLUSION: p62 expression is common in carcinomas of the digestive system and higher in carcinomas of the gastrointestinal tract than in primary HCC. p62 is a cellular differentiation-related protein. Cancer cells with a high p62 expression exhibited highgrowth fractions in HCC.

[Significance of a novel fetal RNA-binding protein p62 expression in hepatocellular carcinoma].

OBJECTIVE: To investigate the histological characteristics of hepatocellular carcinoma with p62 expression, and the correlation of p62 protein with biological characteristics of the cancer cells such as proliferation and metastasis. METHODS: The immunohistochemical expression of p62 and Ki-67 were studied in 40 primary hepatocellular carcinomas. RESULTS: 67.5% (27/40) exhibited positive staining of p62 protein in the cytoplasm of malignant cells, of which the strong positivity was mainly found in pathologic grade III cases. The cases with strong positive staining of p62 exhibited extensive fibrosis in the stroma and massive necrosis of the tumor. These cases also exhibited high proliferation activity, the mean Ki-67 labeling index was 28.3% +/- 15.1%, which was significantly higher than that in p62 negative ones (t = 3.087, P = 0.005). Three of five cases with lung or celiac lymph node metastasis exhibited strong positive staining of p62. CONCLUSION: There is some relationship between the expression of p62 protein, proliferation activity and metastasis of cancer cells as well as with the microenvironment which have abundant fibrous tissue in the stroma.