Immune checkpoint molecules in prevention and development of asthma.

Allergic asthma is a respiratory disease initiated by type-2 immune responses characterized by secretion of alarmins, interleukin-4 (IL-4), IL-5, and IL-13, eosinophilic inflammation, and airway hyperresponsiveness (AHR). Immune checkpoints (ICPs) are inhibitory or stimulatory molecules expressed on different immune cells, tumor cells, or other cell types that regulate immune system activation and maintain immune homeostasis. Compelling evidence indicates a key role for ICPs in both the progression and prevention of asthma. There is also evidence of asthma development or exacerbation in some cancer patients receiving ICP therapy. The aim of this review is to provide an updated overview of ICPs and their roles in asthma pathogenesis, and to assess their implications as therapeutic targets in asthma.

The Role of Immune Checkpoint Receptors in Regulating Immune Reactivity in Lupus.

Immune checkpoint receptors with co-stimulatory and co-inhibitory signals are important modulators for the immune system. However, unrestricted co-stimulation and/or inadequate co-inhibition may cause breakdown of self-tolerance, leading to autoimmunity. Systemic lupus erythematosus (SLE) is a complex multi-organ disease with skewed and dysregulated immune responses interacting with genetics and the environment. The close connections between co-signaling pathways and SLE have gradually been established in past research. Also, the recent success of immune checkpoint blockade in cancer therapy illustrates the importance of the co-inhibitory receptors in cancer immunotherapy. Moreover, immune checkpoint blockade could result in substantial immune-related adverse events that mimic autoimmune diseases, including lupus. Together, immune checkpoint regulators represent viable immunotherapeutic targets for the treatment of both autoimmunity and cancer. Therefore, it appears reasonable to treat SLE by restoring the out-of-order co-signaling axis or by manipulating collateral pathways to control the pathogenic immune responses. Here, we review the current state of knowledge regarding the relationships between SLE and the co-signaling pathways of T cells, B cells, dendritic cells, and neutrophils, and highlight their potential clinical implications. Current clinical trials targeting the specific co-signaling axes involved in SLE help to advance such knowledge, but further in-depth exploration is still warranted.

Strategies for Bispecific Single Chain Antibody in Cancer Immunotherapy.

Genetic engineering has resulted in more than 50 recombinant bispecific antibody formats over the past two decades. Bispecific scFv antibodies represent a successful and promising immunotherapy platform that retargets cytotoxic T cells to tumor cells, with one scFv directed to tumor-associated antigens and the other to T cells. Based on this antibody construct, strategies for both specific tumor targeting and T cell activation are reviewed here. Three distinct types of tumor antigens are considered to optimize specificity and safety in bispecific scFv based treatment: cancer-testis antigens, neo-antigens and virus-associated antigens. In terms of T cell activation, although CD3 has been widely applied in bispecific scFvs being developed, CD28 and CD137 among co-stimulatory signals are also ideal candidates to be evaluated. Besides, LIGHT and HIV-Tat101 have drawn much attention as their potential roles in modulating antitumor responses.

Immune intervention with anti-CD80 bivalent antibody in pristane-induced mouse model of lupus nephritis / 中华微生物学和免疫学杂志

Objective To study the therapeutic effect of anti-CD80 bivalent antibody on mouse lu-pus nephritis and to explore the possible molecular mechanism. Methods A mouse model of lupus nephritis was established through intraperitoneal injection of 0. 5 ml of pristine in female C57BL/6J mice. Appearance of urinary protein and significantly increased levels of peripheral antinuclear antibody ( ANA) and anti-doub-le-stranded DNA ( anti-dsDNA) antibody in the fourth month after injection indicated that the mouse model was established successfully. Then the mice were divided into two groups including anti-CD80 bivalent anti-body intervention group (injected with 200μg of anti-CD80 bivalent antibody at day 1, 3, 5, 8 and 15, fol-lowed by three times of injection with an interval of one month) and model group ( injected with the same protein using the same strategy). A normal control group was set up accordingly. Albustix test paper was used to monitor the dynamic changes in mouse urinary protein. Flow cytometry was used to analyze the acti-vation of immune-related cells in spleen. Levels of autoantibodies ( ANA and anti-dsDNA) and levels of IFN-γ and IL-4 in serum were detected by indirect immunofluorescence assay. Renal tissue samples were an-alyzed with hematoxylin and eosin ( HE) staining and immunocomplex ( IC) assay. Results Urinary pro-tein level of the anti-CD80 bivalent antibody intervention group was significantly lower than that of the model group (P<0. 05). Activated macrophages, dendritic cells, neutrophils and B cells in spleen tissues of the anti-CD80 bivalent antibody intervention group were significantly less than those of the model group ( P<0. 05), and the numbers of CD4+ and CD154+ T cells were significantly less than those of the model group (P<0. 05). Positive rates and titers of ANA and dsDNA in serum samples of the intervention group were lower than those of the model group (P<0. 05). Levels of IFN-γand IL-4 in serum samples of the interven-tion group were decreased as compared with those of the model group (P<0. 05). HE staining and immuno-fluorescence assay showed that glomerular inflammatory injury and necrosis were alleviated and kidney im-mune complex deposition was reduced after anti-CD80 bivalent antibody intervention. Conclusion Anti-CD80 bivalent antibody specifically binds to the CD80 molecule on antigen presenting cell surface, blocks the CD80/CD28 co-stimulatory signaling pathway and down-regulates the body′s immune response, which al-leviates and reverses the lupus-like nephritis-induced pathological damages in mice.

Immune intervention with anti-CD80 bivalent antibody in pristane-induced mouse model of lupus nephritis / 中华微生物学和免疫学杂志

Objective To study the therapeutic effect of anti-CD80 bivalent antibody on mouse lu-pus nephritis and to explore the possible molecular mechanism. Methods A mouse model of lupus nephritis was established through intraperitoneal injection of 0. 5 ml of pristine in female C57BL/6J mice. Appearance of urinary protein and significantly increased levels of peripheral antinuclear antibody ( ANA) and anti-doub-le-stranded DNA ( anti-dsDNA) antibody in the fourth month after injection indicated that the mouse model was established successfully. Then the mice were divided into two groups including anti-CD80 bivalent anti-body intervention group (injected with 200μg of anti-CD80 bivalent antibody at day 1, 3, 5, 8 and 15, fol-lowed by three times of injection with an interval of one month) and model group ( injected with the same protein using the same strategy). A normal control group was set up accordingly. Albustix test paper was used to monitor the dynamic changes in mouse urinary protein. Flow cytometry was used to analyze the acti-vation of immune-related cells in spleen. Levels of autoantibodies ( ANA and anti-dsDNA) and levels of IFN-γ and IL-4 in serum were detected by indirect immunofluorescence assay. Renal tissue samples were an-alyzed with hematoxylin and eosin ( HE) staining and immunocomplex ( IC) assay. Results Urinary pro-tein level of the anti-CD80 bivalent antibody intervention group was significantly lower than that of the model group (P<0. 05). Activated macrophages, dendritic cells, neutrophils and B cells in spleen tissues of the anti-CD80 bivalent antibody intervention group were significantly less than those of the model group ( P<0. 05), and the numbers of CD4+ and CD154+ T cells were significantly less than those of the model group (P<0. 05). Positive rates and titers of ANA and dsDNA in serum samples of the intervention group were lower than those of the model group (P<0. 05). Levels of IFN-γand IL-4 in serum samples of the interven-tion group were decreased as compared with those of the model group (P<0. 05). HE staining and immuno-fluorescence assay showed that glomerular inflammatory injury and necrosis were alleviated and kidney im-mune complex deposition was reduced after anti-CD80 bivalent antibody intervention. Conclusion Anti-CD80 bivalent antibody specifically binds to the CD80 molecule on antigen presenting cell surface, blocks the CD80/CD28 co-stimulatory signaling pathway and down-regulates the body′s immune response, which al-leviates and reverses the lupus-like nephritis-induced pathological damages in mice.

Are Microglial Cells the Regulators of Lymphocyte Responses in the CNS?

The infiltration of immune cells in the central nervous system is a common hallmark in different neuroinflammatory conditions. Accumulating evidence indicates that resident glial cells can establish a cross-talk with infiltrated immune cells, including T-cells, regulating their recruitment, activation and function within the CNS. Although the healthy CNS has been thought to be devoid of professional dendritic cells (DCs), numerous studies have reported the presence of a population of DCs in specific locations such as the meninges, choroid plexuses and the perivascular space. Moreover, the infiltration of DC precursors during neuroinflammatory situations has been proposed, suggesting a putative role of these cells in the regulation of lymphocyte activity within the CNS. On the other hand, under specific circumstances, microglial cells are able to acquire a phenotype of DC expressing a wide range of molecules that equip these cells with all the necessary machinery for communication with T-cells. In this review, we summarize the current knowledge on the expression of molecules involved in the cross-talk with T-cells in both microglial cells and DCs and discuss the potential contribution of each of these cell populations on the control of lymphocyte function within the CNS.

Characterization of surface phenotypic molecules of teleost dendritic cells.

Dendritic cells (DCs) are among the most important professional antigen-presenting cells (APCs) that participate in various biological activities in mammals. However, evidence of the existence of DCs in teleost fish and other lower vertebrates remains limited. In this study, phenotypic and functional characteristics of teleost DCs were described in a zebrafish model. An improved method to efficiently enrich DCs was established. Immunofluorescence staining revealed that the surface phenotypic hallmarks of mammalian DCs, including MHC-II, CD80/86, CD83, and CD209, were distributed on the surfaces of zebrafish DCs (DrDCs). Functional analysis results showed that DrDCs could initiate antigen-specific CD4(+) T cell activation, in which MHC-II, CD80/86, CD83, and CD209 are implicated. Hence, teleost DCs exhibit conserved immunophenotypes and functions similar to those of their mammalian counterparts. Our findings contributed to the current understanding of the evolutionary history of DCs and the DC-regulatory mechanisms of adaptive immunity.