On the basis of the mechanisms of action and characteristics of immune effects, immunity is generally divided into innate and adaptive immunity. Adaptive immunity is associated with the response to non-self entities and is characterized by high specificity and memory. In contrast, innate immunity is believed to lack memory. However, an increasing number of studies have sought to challenge this traditional immunological dogma and have shown that innate immune cells respond to secondary stimulation more strongly and rapidly than to the primary triggers, thus providing evidence of the immune memory in innate immunity. Macrophages, which are among the most important innate immune cells, can also acquire memory that facilitates the mediation of recall responses. Macrophage memory is a relatively new concept that is revolutionizing our understanding of macrophage biology and immunological memory and could lead to a new class of vaccines and immunotherapies. In this review, we describe the characteristics and mechanisms of macrophage memory, as well as its key roles in various diseases.

Adoptive regulatory T cell (Treg) trasfer represents a potential therapeutic option to control immune responses in organ transplantation, graft vs host disease, and autoimmunity, including type 1 diabetes. Treg for adoptive therapy are traditionally sorted and expanded in vitro with high doses of IL-2, showing stability and suppressive capacity, but with some limitations in terms of long-term survival once infused in patients. Here, we tested a novel expansion protocol in which we added IL-7 (IL-7 method, IL-7M) to the traditional standard method (StM) using IL-2. We showed that naïve Treg express significant levels of CD127 and robustly respond to IL-7 by phosphorylating STAT-5. Naive Treg expanded with the IL-7M were highly enriched in CD45RA +CD62L +CD95 + showing a reduction in the final cell yield and suppressive function. Treg expanded with the IL-7M preserved telomere length and were more resistant to cytokine withdrawal and fas-mediated apoptosis. Overall our data indicate that it is possible to expand naïve Treg in the presence of IL-7 to generate a final Treg product enriched in poorly differentiated CD45RA + cells and with better resistance to stress and apoptosis, potentially improving the long-term survival of Treg in adoptive transfer protocols.

Objectives: Although various studies have been performed on the function of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in RA, the results were conflicting. Here we were trying to clarify the role of PMN-MDSCs in the pathogenesis of RA and its specific mechanisms. Methods: We detected the frequencies and counts of PMN-MDSCs, TNF- + B cells, and Ki67 + B cells in spleens and inflamed joints of collagen-induced arthritis (CIA) mice using flow cytometry. The pathological role of PMN-MDSCs was examined by anti-Ly6G neutralizing antibodies against PMN-MDSCs or adoptive transfer of PMN-MDSCs. And the modulation of PMN-MDSCs on B cells was conducted by coculture assays, RNA-Seq, RT-qPCR, etc. The mechanism of BAFF regulating B cells was verified through Western Blot and flow cytometry. Results: PMN-MDSCs accumulated in the spleens and joints of CIA mice. PMN-MDSCs depletion could alleviate the arthritis severity, which was accompanied by decreased TNF- secretion and proliferation of B cells. And its adoptive transfer also facilitated disease progress. Furthermore, PMN-MDSCs from CIA mice had higher expression level of BAFF, which regulated TNF- expression, proliferation and apoptosis of B cells in vitro. What’s more, BAFF promoted phosphorylation of BTK/NF-B signaling pathway. And Ibrutinib (BTK inhibitor) could reverse the effect of BAFF on TNF- expression. Conclusions: Our study suggested that PMN-MDSCs enhanced disease severity of CIA and manipulated TNF- expression, proliferation and apoptosis of B cells via BAFF, furthermore, BAFF promoted TNF- expression through BTK/NF-B signaling pathway, which demonstrated a novel pathogenesis of PMN-MDSC in CIA.

Hepatocellular carcinoma has been a serious threat to human life and health, and there is an urgent need for new treatments to prolong the overall survival time of patients. The liver plays an immunomodulatory function due to its unique physiological structural characteristics; therefore, following surgical resection and radiotherapy, immunotherapeutic options have shown great potential in the treatment of hepatocellular carcinoma in recent years, and adoptive cellular immunotherapy is developing rapidly in the treatment of hepatocellular carcinoma. In this review we summarize the latest research on adoptive cell therapy for hepatocellular carcinoma, focusing on chimeric antigen receptor (CAR) T cells and T cell receptor-engineered (TCR) T cells, and then briefly discuss tumor infiltrating lymphocytes (TILs), natural killer (NK) cells and cytokine-induced killer cells (CIKs). The aim is to provide readers with a comprehensive understanding of the current status of HCC adoptive cellular immunotherapy and new therapeutic strategies being developed, in the hope of providing new ideas for the clinical management of hepatocellular carcinoma.

According to reports, gut microbiota and metabolites regulate intestinal immune microenvironment. In recent years, an increasing number of studies reported that bile acids (BAs) of intestinal flora origin affects T helper cells and Treg cells. Th17 cells play a pro-inflammatory role and Treg cells usually act an immunosuppressive role. In this review, we emphatically summarized the influence and corresponding mechanism of different configurations of the LCA and DCA on intestinal Th17 cells, Treg cells and intestinal immune microenvironment. The regulation of BAs receptors G protein-coupled bile acid receptor 1 (GPBAR1/TGR5) and farnesoid X receptor (FXR) on immune cells and intestinal environment are elaborated. Furthermore, the potential clinical applications above were also concluded in three aspects. These above will help researchers better understand the effects of gut flora on the intestinal immune microenvironment via BAs and contribute to the development of new targeted drugs.

NLR family pyrin domain containing 2 (NLRP2) is a novel member of the Nod-like receptor (NLR) family. However, our understanding of NLRP2 has long been ambiguous. NLRP2 may have a role in the innate immune response, but its specific  functions remain controversial. Although NLRP2 can initiate inflammasome and promote inflammation, it can also downregulate inflammatory signals. Additionally, NLRP2 has been reported to function in the reproductive system and shows high expression in the placenta. However, the exact role of NLRP2 in the reproductive system is unclear. Here, we highlight the most current progress on NLRP2 in inflammasome activation, effector function, and regulation of nuclear factor-κB. And we discuss functions of NLRP2 in inflammatory diseases, reproductive disorders, and the potential implication of NLRP2 in human diseases.