ABSTRACT
The success of adoptive T cell-based immunotherapy (ACT) in cancer is limited in part by the accumulation of myeloid-derived suppressor cells (MDSC), which block several T cell functions, including T cell proliferation and the expression of various cytotoxic mediators. Paradoxically, the inhibition of CD8+ T cell differentiation into cytotoxic populations increased their efficacy after ACT into tumor-bearing hosts. Therefore, we aimed to test the impact of conditioning CD8+ T cells with MDSC on their differentiation potential and ACT efficacy. Our results indicate that MDSC impaired the progression of CD8+ T cells into effector populations, without altering their activation status, production of IL-2, or signaling through the T cell receptor. In addition, culture of CD8+ T cells with MDSC resulted in an increased ACT anti-tumor efficacy, which correlated with a higher frequency of the transferred T cells and elevated IFNγ production. Interestingly, activated CD62L+ CD8+ T cells were responsible for the enhanced anti-tumor activity showed by MDSC-exposed T cells. Additional results showed a decreased protein synthesis rate and lower activity of the mammalian/mechanistic target of rapamycin (mTOR) in T cells conditioned with MDSC. Silencing of the negative mTOR regulator tuberous sclerosis complex-2 in T cells co-cultured with MDSC restored mTOR activity, but resulted in T cell apoptosis. These results indicate that conditioning of T cells with MDSC induces stress survival pathways mediated by a blunted mTOR signaling, which regulated T cell differentiation and ACT efficacy. Continuation of this research will enable the development of better strategies to increase ACT responses in cancer.
Subject(s)
Immunotherapy, Adoptive/methods , Myeloid Cells/immunology , T-Lymphocytes/immunology , Animals , Carcinoma, Lewis Lung/immunology , Carcinoma, Lewis Lung/therapy , Cell Communication/immunology , Cell Differentiation/immunology , Cell Line, Tumor , Female , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Thymoma/immunology , Thymoma/therapy , Thymus Neoplasms/immunology , Thymus Neoplasms/therapyABSTRACT
Extracellular matrix (ECM)is not only one of current hot-points in medical cell biology,but also one tricky part for undergraduates to learn. This article compared chapters of ECM in medical cell biology courses and spotlighted that ECM chapter was often neglected in some domes-tic universities. Then it analyzed the possible causes,such as variable arrangement of ECM section in current textbooks. Lastly,the article recommended several suggestions,including giving a timely re-vision of the old ECM knowledge,designing an appropriate strategy for teaching,enumerating certain representative diseases to improve the ECM education. It appealed our teachers to pay more attention to how to make the module of ECM master well in near future.
ABSTRACT
Objective To prepare and identify monoclonal antibody against LRR-WSC domain of polycystin-1 and to investigate the distribution of polycystin-1 in kidney tissues and kidney cell lines. Methods BALB/c mice were immunized with fusion protein PC1-e of polycystin-1 LRR-WSC domain. The splenocytes were fused with myeloma cells by PEG 4000 and the hybridomas were selected in HAT medium. The hybridoma clones secreting antibodies against polycystin-1 LRR-WSC domain were detected by enzyme-linked immunosorbent assay ( ELISA) and cloned by limiting dilution. The specificity of anti-polycystin-1 LRR-WSC domain monoclonal antibody from hybridoma was verified by ELISA and Western blot. The distribution of polycystin-1 in tissues and cells was detected by immunohistochemical method. Results One cell line of hybridoma secreting monoclonal antibody against polycystin-1 was established. Western blot analysis showed that the monoclonal antibody reacted strongly and specifically to polycystin-1 LRR-WSC domain. Distribution of polycystin-1 in fetal kidney was localized in tubular epithelium. In normal adult kidney tissues, our study showed that polycystin-1 was mainly expressed in the medullary collecting ducts and distal convoluted tubules. Positive staining was also found in the majority of cyst-lining epithelial ceEs of cystic tissue from autosomal dominant polycystic kidney disease ( ADPKD) patients. Expressions of polycystin-1 were found in either ADPKD cyst-lining epithelia cell line and LLC-PK1, clearly plasma membrane and intracytoplasmic staining of polycystin-1 were observed. Conclusion Specific monoclonal antibody against polycystin-1 LRR-WSC domain were obtained. The antibody is important to researching the mechanism of ADPKD. The distribution of polycystin-1 in kidney tissues and cells show that polycystin-1 was important in tubular elongation and the maintenance of tubular architecture.
