Expression and refolding of OLA Ⅰ protein with peptides derived from sheeppox virus / 生物工程学报

The aim of this study was to refold the OvisAries leukocyte antigen (OLA) class Ⅰ protein with peptides derived from sheeppox virus (SPPV) to identify SPPV T cell epitopes. Two pairs of primers were designed based on the published sequence of a sheep major histocompatibility complex Ⅰ to amplify the heavy chain gene of OLA Ⅰ α-BSP and the light chain gene of OLA Ⅰ-β2m. Both genes were cloned into a pET-28a(+) expression vector, respectively, and induced with ITPG for protein expression. After purification, the heavy chain and light chain proteins as well as peptides derived from SPPV were refolded at a ratio of 1:1:1 using a gradual dilution method. Molecular exclusion chromatography was used to test whether these peptides bind to the OLA Ⅰ complex. T-cell responses were assessed using freshly isolated PBMCs from immunized sheep through IFN-γ ELISPOT with peptides derived from SPPV protein. The results showed that the cloned heavy chain and light chain expressed sufficiently, with a molecular weight of 36.3 kDa and 16.7 kDa, respectively. The protein separated via a SuperdexTM 200 increase 10/300 GL column was collected and verified by SDS-PAGE after refolding. One SPPV CTL epitope was identified after combined refolding and functional studies based on T-cell epitopes derived from SPPV. An OLA Ⅰ/peptide complex was refolded correctly, which is necessary for the structural characterization. This study may contribute to the development of sheep vaccine based on peptides.

Progression of diagnosis and treatment in primary malignant small bowel tumor / 中华胃肠外科杂志

Primary malignant small bowel tumor as a rare kind of intestinal tumor is associated with a poor prognosis. The pathological types were various and complicated, such as adenocarcinoma, neuroendocrine tumor, malignant lymphoma, and malignant stromal tumor. The atypical early stage symptom resulted in difficult diagnosis at early stage, high misdiagnosis rate and lack of standard therapy schemes and means. In the past, X-ray, CT, MRI, and PET-CT were the main examination methods for primary small bowel tumor. However, with the development of radiology, a series of new diagnosis methods, including electronic enteroscopy, capsule endoscopy, multi-slice spiral CT enteroclysis and so on, promotes the diagnosis accurate rate. Surgery is still the most important method in the small bowel tumor treatment, and the alternative of the surgical method should depend on the tumor location, size and relationship with the adjacent organs. Application of the laparoscopic surgery for the small bowel tumor is still in the initial stage. Besides, some researches have confirmed that chemotherapy, radiotherapy, target therapy and endocrinotherapy have effects on the specific kind of small bowel tumor. Therefore this article will review the epidemiology, pathology, diagnosis and treatment of the primary malignant small bowel tumors.