Jun Wang

Transforming growth factor beta (TGF-β) is a pleiotropic cytokine and participates in multiple cellular processes, such as cell development, proliferation, epithelial mesenchymal transition (EMT), and immune responses through SMAD-dependent or SMAD-independent signaling pathways. Notably, TGF-β signaling plays a dual role in tumors, acting as a potent tumor suppressor during early tumorigenesis by inducing apoptosis or cell-cycle arrest while promoting tumor transformation, progression and metastasis in advanced stage through multidimensional mechanisms. Moreover, it is abundant and functions as a master immune checkpoint in the tumor microenvironment (TME), fostering the development of numerous targeted therapies to rectify its aberrant activity in tumors in the past decades. Thus, a comprehensive overview of the pathologic roles, molecular mechanisms and therapeutic potentials of TGF-β signaling in tumors will benefit both the basic and clinical cancer research. Here, we review the complex biology and context-dependent functions of the TGF-β superfamily in regard to tumor, highlighting how it regulates the latter’s development, growth, and dissemination by mainly targeting tumor cells, tumor-associated fibroblasts and various immune cells. We also summarize recent advances in the preclinical and clinical development of different types of TGF‑β‑targeting agents, and discuss their therapeutic potentials and challenges as well as approaches to improve the safety and efficacy of TGF-β pathway-targeted therapy in cancers. Through the summary of known knowledge and the latest updates, this review may provide a general picture on the biological functions of TGF-β in tumors, and facilitate the clinical implications of TGF-β-targeted therapy in tumor patients.

Efficacy of radiation therapy is compromised by hematopoietic and immune impairments, with elusive underlying causes. This study aimed to elucidate Usp11’s role in radiation-induced injuries and uncover related mechanisms. Utilized ARS mouse model to observe survival rates of Usp11^−/− (KO) mice post-TBI (Total Body Irradiation). Assessed lymphocyte and MZ B (Marginal Zone B) cell rates using histological analysis, single-cell sequencing, immunofluorescence (IF), immunohistochemistry (IHC), and flow cytometry (FCM). Conducted Co-IP and ubiquitination experiments for mechanism elucidation. Quantified IgM and IgG using ELISA and FC. Explored public databases for potential correlation molecules. Our findings indicated that Usp11^−/− mice exhibited improved survival rates following TBI, with the spleen playing a pivotal role. HE staining revealed a wider marginal zone in the spleen of Usp11^+/+ mice post-irradiation. Single-cell sequencing, IF, IHC, and FCM analyses revealed a higher survival rate of MZ B cells in Usp11^−/− mice after irradiation. Furthermore, treatment with the Usp11 inhibitor, mitoxantrone, successfully targeted and inhibited Usp11, thereby alleviating the reduction in MZ B cells in the spleen following total body irradiation. Mechanistically, Usp11 sustained the survival of MZ B cells by regulating the ubiquitination of Notch’s ligands, DLL1 and JAG2, thereby promoting immune cell remodeling in the spleen. In conclusion, Usp11 played a crucial role in modulating immune system damage induced by ionizing radiation, primarily through ubiquitination of Notch ligands. This study provides insights into radiation-induced immune injuries and suggests Usp11 as a potential therapeutic target.

The complex composition and dynamic change of the tumor microenvironment (TME), mainly consisting of tumor cells, immune cells, stromal cells, and extracellular components, significantly impede the effector function of cytotoxic T lymphocytes (CTL), thus representing a major obstacle for tumor immunotherapies. In this review, we summarize and discuss the impacts and underlying mechanisms of major elements in the TME (different cell types, extracellular matrix, nutrients and metabolites, etc.) on the infiltration, survival, and effector functions of T cells, mainly CD8+ CTLs. Moreover, we also highlight recent advances that may potentiate endogenous antitumor immunity and improve the efficacy of T cell–based immunotherapies in patients with cancer by manipulating components inside/outside of the TME. A deeper understanding of the effects and action mechanisms of TME components on the tumor-eradicating ability of CTLs may pave the way for discovering new targets to augment endogenous antitumor immunity and for designing combinational therapeutic regimens to enhance the efficacy of tumor immunotherapies in the clinic.

Oncolytic virus (OV) is increasingly being recognized as a novel vector in cancer immunotherapy. Increasing evidence suggests that OV has the ability to change the immune status of tumor microenvironment, so called transformation of 'cold' tumors into 'hot' tumors. The improved anti-tumor immunity can be induced by OV and further enhanced through the combination of various immunomodulators. The Neo-2/15 is a newly de novo synthesized cytokine that functions as both IL-2 and IL-15. However, it specifically lacks the binding site of IL-2 receptor α subunit (CD25), therefore unable to induce the Treg proliferation. In present study, a recombinant vesicular stomatitis virus expressing the Neo-2/15 (VSV^M51R-Neo-2/15) was generated. Intratumoral delivery of VSV^M51R-Neo-2/15 efficiently inhibited tumor growth in mice without causing the IL-2-related toxicity previously observed in clinic. Moreover, treatment with VSV^M51R-Neo-2/15 increased the number of activated CD8⁺ T cells but not Treg cells in tumors. More tumor-bearing mice were survival with VSV^M51R-Neo-2/15 treatment, and the surviving mice displayed enhanced protection against tumor cell rechallenge due to the induced anti-tumor immunity. In addition, combination therapy of OV and anti-PD-L1 immune checkpoint inhibitors further enhanced the anti-tumor immune response. These findings suggest that our novel VSV^M51R-Neo-2/15 can effectively inhibit the tumor growth and enhance the sensitivity to immune checkpoint inhibitors, providing promising attempts for further clinical trials.

Background: Loss-of-function mutations of ZBTB24 cause immunodeficiency, centromeric instability, and facial anomalies syndrome 2 (ICF2). ICF2 is a rare autosomal recessive disorder with immunological defects in serum antibodies and circulating memory B cells, resulting in recurrent and sometimes fatal respiratory and gastrointestinal infections. The genotype–phenotype correlation in patients with ICF2 indicates an essential role of ZBTB24 in the terminal differentiation of B cells. Methods: We used the clustered regularly interspaced short palindromic repeats (CRISPER)/Cas9 technology to generate B cell specific Zbtb24-deficient mice and verified the deletion specificity and efficiency by quantitative polymerase chain reaction (Q-PCR) and western blotting analyses in fluorescence-activated cell sorting (FACS)-sorted cells. The development, phenotype of B cells and in vivo responses to T cell dependent or independent antigens post immunization were analyzed by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Adoptive transfer experiment in combination with in vitro cultures of FACS-purified B cells and RNA-Seq analysis were utilized to specifically determine the impact of Zbtb24 on B cell biology as well as the underlying mechanisms. Results: Zbtb24 is dispensable for B cell development and maintenance in naive mice. Surprisingly, B cell specific deletion of Zbtb24 does not evidently compromise germinal center reactions and the resulting primary and secondary antibody responses induced by T cell dependent antigens (TD-Ags), but significantly inhibits T cell independent antigen-elicited antibody productions in vivo. At the cellular level, Zbtb24-deficiency specifically impedes the plasma cell differentiation of B1 cells without impairing their survival, activation and proliferation in vitro. Mechanistically, Zbtb24-ablation attenuates heme biosynthesis partially through mTORC1 in B1 cells, and addition of exogenous hemin abrogates the differentiation defects of Zbtb24-null B1 cells. Conclusions: Zbtb24 seems to regulate antibody responses against TD-Ags B cell extrinsically, but it specifically promotes the plasma cell differentiation of B1 cells via heme synthesis in mice. Our study also suggests that defected B1 functions contribute to recurrent infections in patients with ICF2.

Loss-of-function mutations of ZBTB24 cause the Immunodeficiency, Centromeric Instability and Facial Anomalies syndrome 2 (ICF2). ICF2 is a rare autosomal recessive disorder with immunological defects in serum antibodies and circulating memory B cells, indicating an essential role of ZBTB24 in the terminal differentiation of B cells. Here we generated B-cell specific Zbtb24-deficient mice and systemically investigated its role in B cell development and function both in vivo and in vitro . Zbtb24 is dispensable for B cell development & maintenance in naive mice. Surprisingly, B-cell specific deletion of Zbtb24 does not evidently compromise germinal center reactions and the resulting primary & secondary antibody responses induced by T-cell dependent antigens, but significantly inhibits T-cell independent antigen-elicited antibody productions in vivo . At the cellular level, Zbtb24-deficiency specifically impedes the plasma cell differentiation of B1 cells without impairing their survival, activation and proliferation in vitro . Mechanistically, Zbtb24-ablation attenuates heme biosynthesis partially through mTORC1 in B1 cells, and addition of exogenous hemin abrogates the differentiation defects of Zbtb24-null B1 cells. Our study suggests that the defected B1 functions may contribute to recurrent infections in ICF2 patients, and discloses a B1-specific role of Zbtb24 in regulating plasma cell differentiation and antibody production, which is relevant for barrier defenses against invading pathogens.

Background: ABCA1 (ATP-binding cassette transporter A1) mediates cholesterol efflux to apo AI to maintain cellular cholesterol homeostasis. The current study aims to investigate whether T-cell–specific deletion of ABCA1 modulates the phenotype/function of T cells and the development of atherosclerosis. Methods: Mice with T-cell–specific deletion of ABCA1 on low-density lipoprotein receptor knockout ( Ldlr ^−/− ) background ( Abca1 ^CD4-/CD4- Ldlr ^−/− ) were generated by multiple steps of (cross)-breedings among Abca1 ^flox/flox , CD4- Cre , and Ldlr ^−/− mice. Results: Deletions of ABCA1 greatly suppressed cholesterol efflux to apo AI but slightly reduced membrane lipid rafts on T cells probably due to the upregulation of ABCG1. Moreover, ABCA1 deficiency impaired TCR (T-cell receptor) signaling and inhibited the survival and proliferation of T cells as well as the formation of effector memory T cells. Despite the comparable levels of plasma total cholesterol after Western-type diet feeding, Abca1 ^{CD4-/CD4 -} Ldlr ^−/− mice showed significantly attenuated arterial accumulations of T cells and smaller atherosclerotic lesions than Abca1 ^+/+ Ldlr ^−/− controls, which were associated with reduced surface CCR5 (CC motif chemokine receptor 5) and CXCR3 (CXC motif chemokine receptor 3), decreased antiapoptotic Bcl-2 (B-cell lymphoma 2) and Bcl-xL (B-cell lymphoma extra-large), and hampered abilities to produce IL (interleukin)-2 and IFN (interferon)-γ by ABCA1-deficient T cells. Conclusions: ABCA1 is essential for T-cell cholesterol homeostasis. Deletion of ABCA1 in T cells impairs TCR signaling, suppresses the survival, proliferation, differentiation, and function of T cells, thereby providing atheroprotection in vivo.

Given the importance of B lymphocytes in inflammation and immune defense against pathogens, mice transgenic for Cre under the control of Cd19 promoter (Cd19^Cre/+ mice) have been widely used to specifically investigate the role of loxP-flanked genes in B cell development/function. However, impacts of expression/insertion of the Cre transgene on the phenotype and function of B cells have not been carefully studied. Here, we show that the number of marginal zone B and B1a cells was selectively reduced in Cd19^Cre/+ mice, while B cell development in the bone marrow and total numbers of peripheral B cells were comparable between Cd19^Cre/+ and wild type C57BL/6 mice. Notably, humoral responses to both T cell-dependent and independent antigens were significantly increased in Cd19^Cre/+ mice. We speculate that these differences are mainly attributable to reduced surface CD19 levels caused by integration of the Cre-expressing cassette that inactivates one Cd19 allele. Moreover, our literature survey showed that expression of Cd19^Cre/+ alone may affect the development/progression of inflammatory and anti-infectious responses. Thus, our results have important implications for the design and interpretation of results on gene functions specifically targeted in B cells in the Cd19^Cre/+ mouse strain, for instance, in the context of (auto) inflammatory/infectious diseases.