Tumour­derived exosomes and their emerging roles in leukaemia (Review).

Exosomes are small vesicles with a diameter of ~40-100 nm that are secreted by the majority of endogenous cells under normal and pathological conditions. They contain abundant proteins, lipids, microRNAs, and biomolecules such as signal transduction molecules, adhesion factors and cytoskeletal proteins, and play an important role in exchanging materials and transmitting information between cells. Recent studies have shown that exosomes are involved in the pathophysiology of leukaemia by affecting the bone marrow microenvironment, apoptosis, tumour angiogenesis, immune escape and chemotherapy resistance. Furthermore, exosomes are potential biomarkers and drug carriers for leukaemia, impacting the diagnosis and treatment of leukaemia. The present study describes the biogenesis and general characteristics of exosomes, and then highlight the emerging roles of exosomes in different types of leukaemia. Finally, the value of clinical application of exosomes as biomarkers and drug carriers is discussed with the aim to provide novel strategies for the treatment of leukaemia.

Current progress in CAR-T cell therapy for tumor treatment.

Chimeric antigen receptor T (CAR-T) cells are a type of tumor immunotherapy that is a breakthrough technology in the clinical treatment of tumors. The basic principle of this method is to extract the patient's T cells and equip them with targeting recognition receptors of tumor cells and return them to the patient's body to recognize and kill tumor cells specifically. Most CAR-T cell therapies treat hematological diseases such as leukemia or lymphoma and achieved encouraging results. The safety and effectiveness of CAR-T cell technology in solid tumor treatment require to be improved, although it has demonstrated promising efficacy in treating hematological malignancies. It is worth noting that certain patients may experience fatal adverse reactions after receiving CAR-T cell therapy. At present, the difficulty of this therapy mainly lies in how to reduce adverse reactions and target escape effects during the course of treatment. The improvement of CAR-T cell therapy mainly focuses on improving CAR-T structure, finding suitable tumor targets and combining them with immune checkpoint inhibitors to the enhance efficacy and safety of treatment. The problems in the rapid development of CAR-T cell therapy provide both obstacles and opportunities. The present review elaborates on the clinical application of CAR-T cell technology to provide a reference for clinical practice and research on tumor treatment.

Chimeric specific antigen epitope-carrying dendritic cells induce interleukin-17(+) regulatory T cells to suppress food allergy.

BACKGROUND: The on-purpose-modulated dendritic cells (DCs) have shown charming effects on restoring immune regulatory functions in subjects with immune diseases. OBJECTIVE: This study aims to construct DCs carrying chimerical antigen (Ag) peptides (CAP-DCs) to induce interleukin (IL)-17+ inducible Tregs (iTregs) to alleviate food allergy (FA) in a murine model. METHODS: In this study, we constructed CAP-DCs. The CAP is a fusion protein, consisting of a segment of recombinant scFv of anti-DEC205 antibody and an ovalbumin (OVA) epitope (IC). A murine OVA-FA model was developed to test the effects of CAP-DCs on suppressing the allergic response in the intestine. RESULTS: The CAP-DCs are characterized as that a complex of scFv-IC is presented on the surface of the cells, moderately express CD80 and CD86 as well as IL-6, IL-23, transforming growth factor (TGF)-ß and CCR9. After being passively transferred with CAP-DCs or injection of scFv-IC, Ag-specific IL-17+ Foxp3+ iTregs were induced in the intestinal lamina propria of FA mice. The iTregs showed immune suppressive effects on Ag-specific Th2 response. FA mice were adoptively transferred with the CAP-DCs or scFv-IC injection, which resulted in a significant decrease in the number of Ag-specific Th2 cells and suppression of FA response in an Ag-specific manner. CONCLUSIONS AND CLINICAL RELEVANCE: CAP-DCs can ameliorate FA response by inducing Ag-specific IL-17+ Foxp3+ iTregs and suppressing Ag-specific Th2 response. To generate CAP-DCs has the translational potential in the treatment of FA.

[Preparation and characterization of monoclonal antibodies for human BCSC-1 protein].

AIM: To obtain monoclonal antibodies against human BCSC-1 protein for further study of the structure and function of human BCSC-1 protein. METHODS: pET-30a-BCSC-1 plasmid was constructed and transformed into E.coli BL21 (DE3) to express recombinant protein. BALB/c mice were immunized with recombinant human BCSC-1 protein, hybridoma cell lines secreting monoclonal antibodies against human BCSC-1protein were screened by regular cell fusion and subcloning approach. The specificity of these monoclonal antibodies were determined by ELISA and Western blotting. Expression of BCSC-1 protein in pcDNA3.1/v5-HisB-BCSC-1transfected MCF-7 cells was identified by Immunohistochemistry. RESULTS: Successfully constructed a prokaryotic expression vector pET30a-BCSC-1.BCSC-1 protein was expressed in E.coli BL21 (DE3). One hybridoma cell line 1B3 stable in secreting specific monoclonal antibodies wa successfully obtained. It could bind specifically to BCSC-1 protein proved by Western blotting and Immunohistochemistry assay. CONCLUSION: Monoclonal antibodies of high specificity against human BCSC-1 protein has been successfully prepared, which laid the foundation for the further study of human BCSC-1 protein.

[Establishment of the transfected cell line expressing the mouse OX40 gene and its potency to induce differentiation of B cells].

AIM: To establish HUVECs line expressing mouse OX40(CD134) and to study its promotive effect on proliferation of B cells. METHODS: The cDNA fragment encoding mouse OX40 was obtained from the total RNA of ConA-activated lymphocytes of thymus by using RT-PCR and cloned into pUCm-T vector. The cDNA was then inserted into the eukaryotic expression vector pIRES2-EGFP. The recombinant vector was transfected into HUVECs with lipofectin reagent, and the positive cellular clones were selected by G418. Expression of mouse OX40 in the transfected cells was analyzed by FCM. The differentiation of B cells in vitro induced by OX40 signal was studied by means of (3)H-TdR method. RESULTS: The cDNA fragment in the recombinant plasmid was consistent with the reported mouse OX40 cDNA in GenBank, which was confirmed by DNA sequencing, PCR and enzyme digestion. The HUVECs stably expressing the mouse OX40 were successfully cloned. The transfected cells promoted the differentiation of B cells in vitro and there existed a synergic effect between OX40/OX40L and CD40/CD40L signals. CONCLUSION: Transfected cell line expressing the mouse OX40 gene is established successfully. OX40 enhances the proliferation of B cells.