Chimeric Antigen Receptor (CAR) Treg: A Promising Approach to Inducing Immunological Tolerance

Cellular therapies with polyclonal regulatory T-cells (Tregs) in transplantation and autoimmune diseases have been carried out in both animal models and clinical trials. However, The use of large numbers of polyclonal Tregs with unknown antigen specificities has led to unwanted effects, such as systemic immunosuppression, which can be avoided via utilization of antigen-specific Tregs. Antigen-specific Tregs are also more potent in suppression than polyclonal ones. Although antigen-specific Tregs can be induced in vitro, these iTregs are usually contaminated with effector T cells during in vitro expansion. Fortunately, Tregs can be efficiently engineered with a predetermined antigen-specificity via transfection of viral vectors encoding specific T cell receptors (TCRs) or chimeric antigen receptors (CARs). Compared to Tregs engineered with TCRs (TCR-Tregs), CAR-modified Tregs (CAR-Tregs) engineered in a non-MHC restricted manner have the advantage of widespread applications, especially in transplantation and autoimmunity. CAR-Tregs also are less dependent on IL-2 than are TCR-Tregs. CAR-Tregs are promising given that they maintain stable phenotypes and functions, preferentially migrate to target sites, and exert more potent and specific immunosuppression than do polyclonal Tregs. However, there are some major hurdles that must be overcome before CAR-Tregs can be used in clinic. It is known that treatments with anti-tumor CAR-T cells cause side effects due to cytokine “storm” and neuronal cytotoxicity. It is unclear whether CAR-Tregs would also induce these adverse reactions. Moreover, antibodies specific for self- or allo-antigens must be characterized to construct antigen-specific CAR-Tregs. Selection of antigens targeted by CARs and development of specific antibodies are difficult in some disease models. Finally, CAR-Treg exhaustion may limit their efficacy in immunosuppression. Recently, innovative CAR-Treg therapies in animal models of transplantation and autoimmune diseases have been reported. In this mini-review, we have summarized recent progress of CAR-Tregs and discussed their potential applications for induction of immunological tolerance

Shikonin Prolongs Allograft Survival via Induction of CD4+FoxP3+ Regulatory T Cells

A transplanted organ is usually rejected without any major immunosuppressive treatment because of vigorous alloimmune responsiveness. However, continuous global immunosuppression may cause severe side effects, including nephrotoxicity, tumors, and infections. Therefore, it is necessary to seek novel immunosuppressive agents, especially natural ingredients that may provide sufficient efficacy in immunosuppression with minimal side effects. Shikonin is a bioactive naphthoquinone pigment, an ingredient originally extracted from the root of Lithospermum erythrorhizon. Previous studies have shown that shikonin regulates immunity and exerts anti-inflammatory effects. In particular, it can ameliorate arthritis in animal models. However, it is unclear whether shikonin inhibits alloimmunity or allograft rejection. In this study and for the first time, we demonstrated that shikonin significantly prolonged the survival of skin allografts in wild-type mice. Shikonin increased the frequencies of CD4+Foxp3+ regulatory T cells (Tregs) post-transplantation and induced CD4+Foxp3+ Tregs in vitro as well. Importantly, depleting the Tregs abrogated the extension of skin allograft survival induced by shikonin. It also decreased the frequencies of CD8+CD44highCD62Llow effector T cells and CD11c+CD80+/CD11c+CD86+ mature DCs after transplantation. Moreover, we found that shikonin inhibited the proliferation of T cells in vitro and suppressed their mTOR signaling. It also reduced the gene expression of pro-inflammatory cytokines, including IFNγ, IL-6, TNFα, and IL-17A, while increasing the gene expression of anti-inflammatory mediators IL-10, TGF-β1, and indoleamine-2, 3-dioxygenase (IDO) in skin allografts. Further, shikonin downregulated IDO protein expression in skin allografts and DCs in vitro. Taken together, shikonin inhibits allograft rejection via upregulating CD4+Foxp3+ Tregs. Thus, shikonin is a novel immunosuppressant that could be potentially used in clinical transplantation

Mangiferin Attenuates Murine Lupus Nephritis by Inducing CD4+Foxp3+ Regulatory T Cells via Suppression of mTOR Signaling

Background/Aims: Lupus nephritis (LN) is an autoimmune glomerulonephritis that frequently develops secondary to systemic lupus erythematosus. Patients with LN require extensive treatments with global immunosuppressive agents. However, long-term treatment with conventional immunosuppressants may cause various side effects. Therefore, it’s important to seek alternative drugs for treating LN. Here we aimed to investigate the immunoregulatory effects of mangiferin (MG), an ingredient that was originally extracted from natural herbs, including Mangifera Indica Linn. and Rhizoma Anemarrhenae. Methods: FasL-deficient B6/ gld mice were used as a spontaneous LN model. The serum anti-dsDNA Ab and creatinine levels were analyzed via ELISA. Renal histology and immunopathology were determined using H&E and PAS staining, immunofluorescence (IgG and C3), and IHC staining (CD3 and a-SMA). Cytokine gene expression was measured by RT-PCR assays while effector T cells and Tregs were enumerated by flow analysis. Finally, the proliferation and apoptosis of T cells were measured by CFSE staining and flow analysis while their mTOR signaling was detected through Western blotting. Results: We found that administration of MG ameliorated LN in lupus-prone B6/gld mice by reducing the urinary protein and serum creatinine levels, diminishing T cell infiltration in kidneys and improving renal immunopathology. MG also significantly lowered the percentages of CD44highCD62Llow effector T cells in B6/gld mice. Importantly, treatments with MG augmented CD4+FoxP3+ Treg frequencies in spleens, lymph nodes and kidneys of B6/gld mice. It also induced CD4+FoxP3+ Tregs from CD3+ T cells in vitro and promoted Treg proliferation. Furthermore, it inhibited CD3+ T cell proliferation in vitro and suppressed their phosphorylation of mTOR and its downstream P70S6K. However, MG did not promote T cell apoptosis, implying that it is not cytotoxic. Depletion of CD4+CD25+FoxP3+ Tregs in B6/gld mice abrogated its therapeutic effects on LN. Conclusion: MG exerts a novel therapeutic effect on murine LN via upregulating CD4+FoxP3+ Tregs, downregulating mTOR/p70S6K pathway and improving renal immunopathology. It may be useful for treating LN in clinic

Polyphyllin I suppresses the gastric cancer growth by promoting cancer cell ferroptosis

Background: Ferroptosis is a new form of regulated cell death characterized by the accumulation of iron-dependent lipid peroxides and membrane damages. Recent studies have identified an important role for cancer cell ferroptosis in antitumor therapy. On the other hand, polyphyllin I (PPI) has been reported to exert antitumor effects on some types of cancers. However, it remains unknown whether or not PPI regulates cancer cell ferroptosis.Methods: Two types of human gastric cancer cells (AGS and MKN-45) were used to establish tumor xenograft models in nude mice that were treated with polyphyllin I (PPI) to observe tumor growth, while cells also were cultured for in vitro studies. Ferroptosis, based on the intracellular ROS/lipid ROS production and accumulation of ferrous ions, was detected using a fluorescence microscope and flow cytometer, while the expression of NRF2/FTH1 was measured using Western blotting assays.Results: Here we found that PPI inhibited the gastric cancer growth in vivo and in vitro while increasing the intracellular reactive oxygen species (ROS)/lipid peroxides and ferrous ions in the gastric cancer cells. PPI also decreased the levels of nuclear factor erythroid 2-related factor 2 (NRF2) and ferritin heavy chain 1 (FTH1) in gastric cancer cells in vitro. Moreover, liproxstain-1, an inhibitor of cell ferroptosis, mostly reversed the cell ferroptosis and tumor growth arrest induced by PPI. Finally, the effects of PPI on cancer cell ferroptosis were diminished by the overexpression of NRF2.Conclusion: For the first time, our results have demonstrated that PPI exerts its antitumor activity on the gastric cancer by, at least partially, inducing cancer cell ferroptosis via regulating NRF2/FTH1 pathway. These findings may be implicated for clinical replacement therapy of the gastric cancer

Table_1_Molecular characterization of chicken astrovirus and pathogenicity of a novel isolate in China.pdf

As an enteric virus, chicken astrovirus has been related to various kinds of diseases in chickens, including white chick syndrome, runting-stunting syndrome, severe kidney disease, urate deposits and visceral gout, generating economic losses in the poultry industry globally. The complete ORF2 gene of 31 CAstV isolates in six provinces of China during 2020–2022 was characterized and analyzed with the purpose of better understanding the molecular epidemiology and genetic diversity of CAstV field isolates. Phylogenetic analysis which was based on the complete ORF2 (capsid) amino acid sequence of 31 CAstV isolates and 57 reference strains indicated that 2 isolates belonged to subgroup Ai, 10 isolates belonged to subgroup Bi, 3 isolates belonged to subgroup Bii, 5 isolates belonged to subgroup Biii, 7 isolates belonged to subgroup Biv, 3 isolates belonged to subgroup Bv, and one isolate (JS202103) belonged to a new B subgroup. In addition, the novel CAstV strain JS202103 was successfully isolated in vitro, and its whole genome shared 76.9–94.3% identity with the 29 CAstV reference strains. JS202103 caused hatchability reduction, dead embryos, kidney disease and visceral gout in chicken embryos. Moreover, this is the also the initial study focusing on diverse CAstV strains including subgroups Biii, Biv, and Bv circulate in China. The current work contributes to improving our understanding of CAstV isolates in China, and it will also provide references for developing efficient measures to control this virus.</p

Efficient Estimation of the Nonparametric Mean and Covariance Functions for Longitudinal and Sparse Functional Data

<p>We consider the estimation of mean and covariance functions for longitudinal and sparse functional data by using the full quasi-likelihood coupling a modification of the local kernel smoothing method. The proposed estimators are shown to be consistent, asymptotically normal, and semiparametrically <i>efficient</i> in terms of their linear functionals. Their superiority to the competitors is further illustrated numerically through simulation studies. The method is applied to analyze AIDS study and atmospheric study. Supplementary materials for this article are available online.</p

Teaching Reform and Practice of Chinese Medicine Course Based on National Standard and Ideological and Political Theories Teaching in All Courses

Under the new situation, how to integrate the ideological and political theories teaching in all courses for Chinese medicine major and meet the requirements of national standards for teaching quality, improve the training quality of Chinese medicine talents and strengthen the connotative development of Chinese medicine higher education are urgent issues to be solved in Chinese medicine colleges. This paper introduces the practical experience of teaching reform of traditional Chinese medicine courses based on national standards of teaching quality and ideological and political theories teaching in all courses from the aspects of curriculum setting, teaching content, teaching methods and teaching practice, which can provide reference for teaching reform of other professional courses based on national standards of teaching quality and ideological and political theories teaching in all courses