Characterization and evaluation of a new triosephosphate isomerase homologue from Haemaphysalis longicornis as a candidate vaccine against tick infection.

Haemaphysalis longicornis is an obligate hematophagous ectoparasite that transmits a variety of pathogens causing life­threatening diseases in humans and animals. Triosephosphate isomerase (TIM) is a key enzyme in glycometabolism, making in an interesting anti-tick vaccine candidate antigen. In this study, the open reading frame (ORF) of the TIM homologue from H. longicornis (HlTIM) was shown to consist of 747 bp encoding a protein of 248 amino acids. HlTIM gene expression was detected in all developmental stages and in all tissues of the unfed female tick by quantitative real-time PCR. The HlTIM gene was cloned and inserted into pET-32a (+) to obtain the recombinant HlTIM protein (rHlTIM) and its immunogenicity was confirmed by Western blot. ELISA results showed that rabbits immunized with rHlTIM produced a humoral immune response. A vaccine trial in rabbits against H. longicornis infestation demonstrated that the engorgement weight, oviposition and hatchability of ticks from the rH1TIM group was decreased by 8.6%, 35.4% and 17.3% respectively, compared to the histidine-tagged thioredoxin (Trx) control group. Considering the cumulative effect of vaccination on the evaluated parameters, results showed 50.9% efficacy in the rHlTIM group. The data reported here demonstrate that rHlTIM has potential for further development of a new candidate vaccine for tick control.

Evaluation on two types of paramyosin vaccines for the control of Haemaphysalis longicornis infestations in rabbits.

BACKGROUND: Haemaphysalis longicornis is an obligate hematophagous ectoparasite that transmits a variety of pathogens causing life-threatening diseases in humans and animals. Paramyosin (Pmy) is not only an invertebrate-specific myofibrillar protein but also an important immunomodulatory protein. Therefore, it is one of the ideal candidate antigens for vaccines. METHODS: We conducted two vaccine trials to evaluate the protective efficacy of Pmy recombinant protein (rPmy) and peptide vaccine (KLH-LEE). Each rabbit was immunized with three doses of rPmy or KLH-LEE adjuvanted with Freund's complete/incomplete at 500 µg/dose at 2-week intervals before challenge with 40 female H. longicornis/rabbit. PBS plus adjuvant, Trx or KLH was used as control group. The antibodies of rabbits were detected by ELISA. Then, female ticks were fed on the rabbits until detachment. RESULTS: ELISA results showed that both vaccines induced rabbits to produce antibodies. Compared with the Trx group, the engorgement weight, oviposition and hatchability of the rPmy group decreased by 8.87%, 26.83% and 38.86%, respectively. On the other hand, engorgement weight, oviposition and hatchability of female ticks in the KLH-LEE group correspondingly resulted in 27.03%, 53.15% and 38.40% reduction compared with that of the KLH group. Considering the cumulative effect of vaccination on the evaluated parameters, results showed 60.37% efficacy of the rPmy vaccine formulation and 70.86% efficacy in the KLH-LEE group. CONCLUSIONS: Pmy and particularly epitope LEE have potential for further development of an effective candidate vaccine to protect the host against tick infection. GRAPHIC ABSTARCT.

Fyn knockdown inhibits migration and invasion in cholangiocarcinoma through the activated AMPK/mTOR signaling pathway.

Cholangiocarcinoma (CCA) is a rare and fatal tumor. In previous decades, there has been a steady increase in the incidence and mortality rates of this tumor worldwide. Metastasis is regarded as the major factor that contributes to poor prognosis in CCA patients. Studies therefore aim to develop novel therapeutic targets to control CCA metastasis. Fyn is known to enhance expression and promote metastasis in various cancers, including pancreatic cancer, prostate cancer and colorectal cancer. However, the exact function and mechanism of Fyn in CCA metastasis remains unclear. In the present study, mRNA and protein expression levels of Fyn, AMP-activated protein kinase (AMPK), phosphorylated (p-)AMPK, mammalian target of rapamycin (mTOR) and p-mTOR were measured, using the reverse transcription-quantitative polymerase chain reaction and western blot analysis, in CCA tissues and cell lines. In addition, Transwell assays were used to determine the migratory and invasive abilities of human CCA QBC939, following transfection. In the present study, it was found that Fyn was overexpressed in CCA cell lines. Fyn knockdown inhibited CCA cell migration and invasion. Furthermore, it was demonstrated that Fyn knockdown induces phosphorylation of AMPK, inhibits downstream phosphorylation of mTOR, and activate the AMPK/mTOR signaling pathway. Compound C, an AMPK inhibitor, inhibited the AMPK/mTOR signaling pathway, and reversed the effect of Fyn knockdown on migration and invasion of CCA cells. In conclusion, the present study suggests that Fyn knockdown inhibits cell migration and invasion by regulating the AMPK/mTOR signaling pathway in CCA cell lines and that Fyn knockdown is a potential target for anti-CCA therapy.

Bilioenteric anastomotic stricture in patients with benign and malignant tumors: prevalence, risk factors and treatment.

BACKGROUND: Stricture formation at the bilioenteric anastomosis is a rare but important postoperative complication. However, information on this complication is lacking in the literature. In the present study, we aimed to assess its prevalence and predictive factors, and report our experience in managing bilioenteric anastomotic strictures over a ten-year period. METHODS: A total of 420 patients who had undergone bilioenteric anastomosis due to benign or malignant tumors between February 2001 and December 2011 were retrospectively reviewed. Univariate and multivariate modalities were used to identify predictive factors for anastomotic stricture occurrence. Furthermore, the treatment of anastomotic stricture was analyzed. RESULTS: Twenty-one patients (5.0%) were diagnosed with bilioenteric anastomotic stricture. There were 12 males and 9 females with a mean age of 61.6 years. The median time after operation to anastomotic stricture was 13.6 months (range, 1 month to 5 years). Multivariate analysis identified that surgeon volume (≤30 cases) (odds ratio: -1.860; P=0.044) was associated with the anastomotic stricture while bile duct size (>6 mm) (odds ratio: 2.871; P=0.0002) had a negative association. Balloon dilation was performed in 18 patients, biliary stenting in 6 patients, and reoperation in 4 patients. Five patients died of tumor recurrence, and one of heart disease. CONCLUSIONS: Bilioenteric anastomotic stricture is an uncommon complication that can be treated primarily by interventional procedures. Bilioenteric anastomosis may be performed by a surgeon in his earlier training period under the guidance of an experienced surgeon. Bile duct size >6 mm may play a protective role.