Identification, recombinant expression and immunological study of Lja-SHP2 in Lampetra japonica.

The protein tyrosine phosphatase SHP2 of higher vertebrates, encoded by ptpn11 gene, catalyzes the dephosphorylation of tyrosine phosphorylation site, and plays regulatory roles in various signaling pathways by cooperating with other protein tyrosine kinase. Previous studies have shown that SHP2 plays an important role in the activation and signal transduction of T and B cells in higher vertebrates. To study the role of a SHP2 homologous molecule of lampreys (Lja-SHP2) in immune response, we cloned and expressed the open reading frame sequence of Lja-SHP2 gene in prokaryotic expression vector pET-32a. The recombinant protein was successfully expressed in E. coli and the rabbit-derived polyclonal antibody was prepared. Lampetra japonica were immunized with mixed bacteria, and the mRNA and protein of Lja-SHP2 in immune-related cells and tissues were detected by real-time quantitative PCR and Western blotting after immunization. The Lja-SHP2 mRNA and protein were not significantly affected in leukocytes and supraneural myeloid bodies, but up-regulated significantly in gill tissues (P<0.05) after challenged by mixed bacteria, which indicated that Lja-SHP2 mainly participates in the immune response of gill tissues after mixed bacteria stimulation. To further investigate whether Lja-SHP2 level was affected in three lymphocyte subsets, the B-cell mitogen lipopolysaccharide (LPS) and T-cell mitogen phytohaemagglutinin (PHA) were employed to boost the immune response in L. japonica. LPS immune stimulation increased Lja-SHP2 in leucocytes significantly compared with the control group, and but had a marginal effect on Lja-SHP2 expression in gills and supraneural myeloid bodies. PHA immune stimulation could up-regulate Lja-SHP2 level in leukocytes, gill tissues and supraneural myeloid bodies. The change of Lja-SHP2 was especially dramatical in leukocytes, which was about 2.5 times higher than that in the control group, suggesting that Lja-SHP2 is involved in the lamprey immune response mediated by PHA. Consistent with the previous finding that PHA could induce the activation of VLRA+ lymphocytes, our results showed that Lja-SHP2 might be included in the immune response of VLRA+ lymphocytes mediated by PHA in gills. This research will benefit exploring the functions of Lja-SHP2 in the immune response of lamprey and will provide clues for understanding the phylogenesis of SHP2 molecular family, and its roles in the early occurrence and evolution of adaptive immune system in higher vertebrates.

[Application progress of CRISPR/Cas9 genome editing technology in the treatment of HIV-1 infection].

The goal of gene therapy is to introduce foreign genes into human target cells in a certain way to correct or compensate diseases caused by defective or abnormal genes. Therefore, gene therapy has great practical significance in studying the treatment of persistent or latent HIV-1 infection. At present, the existing methods of gene therapy have some major defects such as limited target site recognition and high frequency of off-targets. The latest research showed that the clustered regularly interspaced short palindromic repeats (CRISPR) /CRISPR-associated nuclease 9 (Cas9) system from bacteria and archaea has been successfully reformed to a targeted genome editing tool. Thus, how to achieve the goal of treating HIV-1 infection by modifying targeted HIV-1 virus genome effectively using the CRISPR/Cas9 system has become a current research focus. Here we review the latest achievements worldwide and briefly introduce applications of the CRISPR/Cas9 genome editing technology in the treatment of HIV-1 infection, including CCR5 gene editing, removal of HIV-1 virus and activation of HIV-1 virus, in order to provide reference for the prevention and treatment of HIV-1 infection.

[Genetic basis of immune response of lymphocyte-like cells in the mucosal immune system of Lampetra japonica].

In recent years, the antigen recognition mechanism based on variable lymphocyte receptors (VLRs) was found in agnathan lamprey. To illuminate the genetic basis of immune response of lymphocyte-like cells in the mucosal immune system of lamprey and explore the evolutionary relationship of adaptive immune responses between the jawless and jawed vertebrates, we constructed cDNA libraries of lamprey (Lampetra japonica) gills before and after stimulation, and then performed high-throughput transcriptome sequencing and analysis. Through functional annotation of 88 525 assembled unigenes, 21 704 and 9769 unigenes were annotated in Gene Ontology (GO) and Kyto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. Among 999 unigenes involved in multiple pathways of immune system, 184 unigenes were highly homologous to 51 TCR (T cell receptor) and BCR (B cell receptor) signalling molecules in higher vertebrates, indicating that molecules involved in adaptive immune signalling pathways in higher vertebrates also exist in lampreys. In addition, identification of five VLRA, seven VLRB and four VLRC molecules suggest that at least three types of lymphocyte subsets are distributed in lamprey gill mucosal immune tissues. The results of real-time fluorescence quantitative PCR showed that the expression levels of Lck, Fyn and Zap70 were up-regulated after immune stimulation while those of Syk, Btk and Blnk were not changed significantly, indicating the activation of TCR-like signal transduction pathway after antigen stimulation in lamprey gill tissues. Our studies preliminaryly proved that two parallel adaptive immune systems in jawless and jawed vertebrates have common genetic basis, and also provided valuable clues to the exploration of signalling processes of VLRA⁺, VLRB⁺, and VLRC⁺ lymphocyte-like cells in response to antigens.

[Variable lymphocyte receptors: the novel tool for clinical diagnosis and therapy].

Monoclonal antibodies, which are widely applied to the diagnosis and therapy of cancers as well as autoimmune diseases, have been made significant progresses. Currently, the monoclonal antibodies for clinical applications are mostly based on the modified immunoglobulins. However, the variable lymphocyte receptors (VLRs), which are recently discovered as specific antigen receptors of jawless vertebrates, provide a new perspective for the development of antibody reagents and drugs. Compared with immunoglobulins, the antigen-binding specificity, affinity and stability of VLRs-based antibodies are better. In addition, the production technology of antigen-specific monoclonal VLRs has become more and more mature. Therefore, the VLRs have a higher clinical value and may become the next-generation antibody drug. This review focuses on the basic feature, production method and application prospect of VLRs, which provides valuable clues for the applications of VLRs in the field of clinical diagnosis and therapy.