Therapeutic effects of anti-B7-H3 antibody in an ovalbumin-induced mouse asthma model

Abatacept (Cytotoxic T Lymphocyte Antigen 4-Fragment Crystallizable) Reduces Allergic Inflammation of Ovalbumin-Sensitized Mice

BACKGROUND

Abatacept (Aba) is a cytotoxic T-lymphocyte antigen-4 and fragment crystallizable fusion protein. Aba blocks B7/Cluster of differentiation 28 - cytotoxic T-lymphocyte antigen-4 costimulatory pathway, inhibits cluster of differentiation 4+ T-cell activation, and is used as an anti-inflammatory drug.

OBJECTIVES

We conducted this study to assess the effectiveness of Aba in the treatment of allergic rhinitis (AR) in a mouse model.

METHODS

We divided 40 four-week-old BALB/c mice into four groups: control group (n = 10), positive control group (AR, n = 10), Aba group (AR + Aba, n = 10), and dexamethasone group (AR + Dex, n = 10). Mice in each group were challenged intranasally with daily ovalbumin (OVA) administration. Episodes of sneezing and nose rubbing were counted. Mice were sacrificed on day 42 and cytokines were measured in nasal lavage fluid. Nasal mucosae of five mice from each group were used for reverse transcriptase-polymerase chain reaction and western blot assay. Samples were collected from five mice from each group for histological analysis.

RESULTS

Symptoms of AR significantly improved in the AR + Aba and AR + Dex groups compared with the AR group. Fewer eosinophils and goblet cells were seen in the AR + Aba and AR + Dex groups compared with the AR group. Both the AR + Aba and AR + Dex groups showed a significant decrease in nasal T helper 2 cytokine levels, including interleukin (IL)-4, IL-5, IL-13 and T cell activation related IL-17A, and interferon gamma (IFN- γ). Total immunoglobulin (Ig) E and OVA-specific IgG1 levels were also significantly lower in the AR + Aba and AR + Dex groups. OVA-specific IgE level was also significantly lower in the AR + Aba than AR group.

CONCLUSIONS

Aba suppresses allergic inflammation and appears to be a good treatment for AR.

MiR-29b regulates Th2 cell differentiation in asthma by targeting inducible B7-H3 and STAT3

BACKGROUND

MicroRNAs play an important role in T cell responses. However, how microRNAs regulate Th cells in asthma remains poorly defined.

OBJECTIVE

In this study, we investigated the mechanism and pathways of miR-29b regulating Th cells in asthma, in order to find new targets for asthma.

METHODS

We detected miR-29b, B7-H3 and STAT3 in the peripheral blood of children with asthma, explored the relationship between these molecules and their effects on T cells through in vitro cell culture, and verified it by animal model.

RESULTS

MiR-29b levels were decreased in the peripheral blood mononuclear cells from children with asthma. Vitro studies found that the expression of miR-29b in macrophages was decreased and the expression of B7-H3 and STAT3 was increased after house dust mite (HDM) stimulation. After down-regulation of miR-29b in macrophages, the expressions of B7-H3 and STAT3 in macrophages were increased and T cells differentiate into Th2 cells. After the addition of B7-H3 or STAT3 antibodies, the differentiation of naive T cells into Th2 cells was reduced. In OVA induced mice asthmatic model, after the up-regulation of miR-29b in lung, the expression of B7-H3 and STAT3 decreased in the lung tissues of mice, and the expression of Th2 cells and type II cytokine decreased simultaneously. The pathological changes of lung tissues were also alleviated.

CONCLUSION

The expression of miR-29b is decreased in asthmatic children. MiR-29b can inhibit Th2 cell differentiation by inhibiting B7-H3 and STAT3 pathways at the same time, and reduce asthmatic immune inflammation.

MicroRNA-29 mediates anti-inflammatory effects and alleviation of allergic responses and symptoms in mice with allergic rhinitis

BACKGROUND

To investigate the role of microRNA-29 (miR-29) in mice with allergic rhinitis (AR) and its underlying mechanism.

METHODS

AR model was established in BALB/c mice by intraperitoneal sensitization and intranasal challenge with ovalbumin (OVA). miRNA expression was examined in the nasal mucosa tissues of mice and patients with AR, and miRNA-29 was found to be downregulated. To unveil the role of miRNA-29 in AR, it was overexpressed in the nasal mucosa of AR mice by intranasal administration of miRNA-29 agomir. The symptoms of nasal rubbing and sneezing were recorded and evaluated. miR-29 expression, OVA-specific immunoglobulin E (IgE) concentration, pro-inflammatory cytokines levels, eosinophils number, and cleaved caspase-3 and CD276 expression were examined in nasal mucosa tissues and nasal lavage fluid (NALF) by qRT-PCR, ELISA, hematoxylin and eosin staining, western blotting, or immunohistochemistry, respectively. TUNEL assay was used to analyze nasal mucosa cells apoptosis.

RESULTS

Decreased expression of miR-29 was observed in AR, the symptoms of which were alleviated by overexpressing miR-29. In addition, overexpression of miR-29 markedly reduced the concentration of OVA-specific IgE, the levels of IL-4, IL-6, IL-10, and IFN-γ, the pathological alterations and eosinophils infiltration in the nasal mucosa. Furthermore, restoration of miR-29 expression reduced nasal mucosa cell apoptosis. Moreover, overexpression of miR-29 significantly attenuated CD276 mRNA and protein levels in nasal mucosa cells.

CONCLUSION

MiR-29 mediated antiallergic effects in OVA-induced AR mice by decreasing inflammatory response, probably through targeting CD276. MiRNA-29 may serve as a potential novel therapeutic target for the treatment of AR.

B7-H3 Immune Checkpoint Protein in Human Cancer

B7-H3 belongs to the B7 family of immune checkpoint proteins, which are important regulators of the adaptive immune response and emerging key players in human cancer. B7-H3 is a transmembrane protein expressed on the surface of tumor cells, antigen presenting cells, natural killer cells, tumor endothelial cells, but can also be present in intra- and extracellular vesicles. Additionally, B7-H3 may be present as a circulating soluble isoform in serum and other body fluids. B7-H3 is overexpressed in a variety of tumor types, in correlation with poor prognosis. B7-H3 is a promising new immunotherapy target for anti-cancer immune response, as well as a potential biomarker. Besides its immunoregulatory role, B7-H3 has intrinsic pro-tumorigenic activities related to enhanced cell proliferation, migration, invasion, angiogenesis, metastatic capacity and anti-cancer drug resistance. B7-H3 has also been found to regulate key metabolic enzymes, promoting the high glycolytic capacity of cancer cells. B7-H3 receptors are still not identified, and little is known about the molecular mechanisms underlying B7-H3 functions. Here, we review the current knowledge on the involvement of B7-H3 in human cancer.

B7-H3: A promising therapeutic target for autoimmune diseases

B7-H3 as a newly identified costimulatory molecule that belongs to B7 ligand family, is broadly expressed in both lymphoid and non-lymphoid tissues. The overexpression of B7-H3 has been verified to be correlated with the poor prognosis and poor clinical outcome of several human cancers. In recent years, researchers reveal that B7-H3 is involved in the pathogenesis of various autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), Sjögren's syndrome (SS), ankylosing spondylitis (AS), etc. In this review, we will discuss the biological function of B7-H3 and summarize the progress made over past years regarding its role in the occurrence and development of autoimmune diseases. The insights gained from these findings could serve as the foundation for future therapies of these diseases.

Role of B7H3/IL-33 Signaling in Pulmonary Fibrosis-induced Profibrogenic Alterations in Bone Marrow

Rationale: The impact of lung insult on the bone marrow (BM) and subsequent disease is unknown.Objectives: To study alterations in the BM in response to lung injury/fibrosis and examine their impact on subsequent lung insult.Methods: BM cells from control or bleomycin-treated donor mice were transplanted into naive mice, which were subsequently evaluated for bleomycin-induced pulmonary fibrosis. In addition, the effect of prior bleomycin treatment on subsequent fibrosis was examined in wild-type and B7H3-knockout mice. Samples from patients with idiopathic pulmonary fibrosis were analyzed for potential clinical relevance of the findings.Measurements and Main Results: Recipient mice transplanted with BM from bleomycin-pretreated donors showed significant exacerbation of subsequent fibrosis with increased B7H3+ cell numbers and a T-helper cell type 2-skewed phenotype. Pretreatment with a minimally fibrogenic/nonfibrogenic dose of bleomycin also caused exacerbation, but not in B7H3-deficient mice. Exacerbation was not observed if the mice received naive BM cell transplant after the initial bleomycin pretreatment. Soluble B7H3 stimulated BM Ly6Chi monocytic cell expansion in vitro and caused similar expansion in the lung in vivo. Notably, soluble B7H3 was elevated in plasma of patients with idiopathic pulmonary fibrosis and in BAL fluid in those with acute exacerbation. Finally, ST2 deficiency diminished the bleomycin-induced B7H3 and IL-13 upregulation, suggesting a role for type 2 innate lymphoid cells.Conclusions: Pulmonary fibrosis caused significant alterations in BM with expansion and activation of monocytic cells, which enhanced fibrosis when transplanted to naive recipients with potential mediation by a novel role for B7H3 in the pathophysiology of pulmonary fibrosis in both mice and humans.

Intranasal Treatment With 1, 25-Dihydroxyvitamin D3 Alleviates Allergic Rhinitis Symptoms in a Mouse Model

PURPOSE

Vitamin D is a potent immunomodulator. However, its role in the pathogenesis of allergic rhinitis is unclear.

METHODS

The aim of this study was to evaluate the antiallergic effect of intranasally applied vitamin D in an allergic rhinitis mouse model. BALB/c mice were intraperitoneally sensitized with ovalbumin (OVA) and alum before they were intranasally challenged with OVA. Then, they were intranasally administered 1, 25-dihydroxyvitamin D3 (0.02 μg) or solvent. Allergic symptom scores, eosinophil infiltration, cytokine mRNA levels (interleukin [IL]-4, IL-5, IL-10, IL-13 and interferon-γ) in the nasal tissue, and serum total immunoglobulin E (IgE) and OVA-specific IgE, IgG1, and IgG2a were analyzed and compared with negative and positive control groups. Cervical lymph nodes (LNs) were harvested for flow cytometry analysis and cell proliferation assay.

RESULTS

In the treatment group, allergic symptom scores, eosinophil infiltration, and mRNA levels of IL-4 and IL-13 were significantly lower in the nasal tissue than in the positive control group. The IL-5 mRNA level, serum total IgE, and OVA-specific IgE and IgG1 levels decreased in the treatment group; however, the difference was not significant. In the cervical LNs, CD86 expression had been down-regulated in CD11c⁺major histocompatibility complex II-high (MHCII^high) in the treatment group. Additionally, IL-4 secretion in the lymphocyte culture from cervical LNs significantly decreased.

CONCLUSIONS

The results confirm the antiallergic effect of intranasal 1,25-dihydroxyvitamin D3. It decreases CD 86 expression among CD11c⁺MHCII^high cells and T-helper type 2-mediated inflammation in the cervical LNs. Therefore, topically applied 1,25-dihydroxyvitamin D3 can be a future therapeutic agent for allergic rhinitis.

The role of miR-29c/B7-H3 axis in children with allergic asthma

Background

MicroRNAs play roles in the pathogenesis of bronchial asthma. However, the mechanism of miR-29c in allergic asthma remains unclear. This study is to elucidate the regulation of Th cell differentiation by miR-29c in mononuclear macrophages.

Methods

A total of 52 children with asthma exacerbation and 26 children as controls were enrolled in the study. CD14⁺ monocytes were isolated from the peripheral blood. Differential expressions of microRNAs were evaluated using microarray analysis and miR-29c expression in monocytes was determined by qRT-PCR. The plasma B7-H3 was determined by ELISA. Transfection studies and luciferase reporter assay were performed to confirm target gene of miR-29c and its function.

Results

Compared to controls, 88 miRNAs in blood monocytes were up-regulated and 41 miRNAs down-regulated including miR-29c in asthma children. Children with asthma exacerbation had significantly lower level of miR-29c and higher level of plasma B7-H3 compared to controls (both P < 0.05). Functional studies based on luciferase reporter assay and immunofluorescence staining suggest that B7-H3 is the direct target of miR-29c and transfection anti-miR-29c into macrophages could enhance ROR-γt and GATA-3 expression in co-cultured CD4⁺ T cells and increase levels of IL-4 and IL-17 in supernatants.

Conclusion

The axis of miR-29c/B7-H3 plays an important role in children with asthma through regulating Th2/Th17 cell differentiation and may provide new targets for treatment of asthma.

B7-H3 participates in the development of Asthma by augmentation of the inflammatory response independent of TLR2 pathway

B7-H3, a new member of the B7 superfamily, acts as both a T cell costimulator and coinhibitor. Recent studies identified B7-H3 plays a critical role in the development of asthma. But the definitive mechanism is not clear. In this study, we further report that B7-H3 participates in the development of OVA-induced asthma in a murine model. And study its mechanism through the vitro and vivo experiment. Exogenous administration of B7-H3 strongly amplified the inflammatory response and augmented proinflammatory cytokines in vitro and vivo. These B7-H3–associated proinflammatory effects were not dependent on TLR2 signaling, as airway inflammation, eosinophils infiltration and cytokins (IL-4, IL-5, IL-13 and IFN-gamma) augment were still amplified in TLR2-deficient mice after administrated recombinant mouse B7-H3. These results indicated an important role for B7-H3 in the development of Th1 and Th2 cells in a murine model of asthma and its proinflammatory effects are not dependent on TLR2 signaling.