MAP3K19 Affects TWEAK-Induced Response in Cultured Bronchial Epithelial Cells and Regulates Allergic Airway Inflammation in an Asthma Murine Model

The mitogen-activated protein kinase (MAPK) signaling pathway is involved in the epithelial-mesenchymal transition (EMT) and asthma; however, the role of mitogen-activated protein kinase kinase kinase 19 (MAP3K19) remains uncertain. Therefore, we investigated the involvement of MAP3K19 in in vitro EMT and ovalbumin (OVA)-induced asthma murine models. The involvement of MAP3K19 in the EMT and the production of cytokines and chemokines were analyzed using a cultured bronchial epithelial cell line, BEAS-2B, in which MAP3K19 was knocked down using small interfering RNA. We also evaluated the involvement of MAP3K19 in the OVA-induced asthma murine model using Map3k19-deficient (MAP3K19-/-) mice. Transforming growth factor beta 1 (TGF-β1) and tumor necrosis factor-like weak inducer of apoptosis (TWEAK) induced the MAP3K19 messenger RNA (mRNA) expression in the BEAS-2B cells. The knockdown of MAP3K19 enhanced the reduction in E-cadherin mRNA and the production of regulated upon activation normal T cell express sequence (RANTES) via stimulation with TWEAK alone or with the combination of TGF-β1 and TWEAK. Furthermore, the expression of MAP3K19 mRNA was upregulated in both the lungs and tracheas of the mice in the OVA-induced asthma murine model. The MAP3K19-/- mice exhibited worsened eosinophilic inflammation and an increased production of RANTES in the airway epithelium compared with the wild-type mice. These findings indicate that MAP3K19 suppressed the TWEAK-stimulated airway epithelial response, including adhesion factor attenuation and RANTES production, and suppressed allergic airway inflammation in an asthma mouse model, suggesting that MAP3K19 regulates allergic airway inflammation in patients with asthma.

Effect of Japanese Cedar Pollen Sublingual Immunotherapy on Asthma Patients with Seasonal Allergic Rhinitis Caused by Japanese Cedar Pollen

Allergen immunotherapy is a promising treatment for allergic diseases that induce immune tolerance through the administration of specific allergens. In this study, we investigate the efficacy of sublingual immunotherapy (SLIT) in asthmatic patients with SAR-JCP and the dynamics of the parameters before and after treatment in a real-world setting. This was a prospective single-center observational study. Patients with asthma and SAR-JCP (n = 24) were recruited for this study and assessed using symptom questionnaires before SLIT and a year after the SLIT. In addition, a respiratory function test, forced oscillation technique, and blood sampling test were performed during the off-season before and after SLIT. The one-year SLIT for asthma patients with SAR-JCP significantly improved not only allergic rhinitis symptoms, but also asthma symptoms during the JCP dispersal season, and significantly improved airway resistance during the off-season. The change in the asthma control test and the visual analog scale score during the season before and after SLIT was negatively and positively correlated with the change in peripheral blood γδ T cells off-season before and after SLIT, respectively. It was suggested that improvement in asthma symptoms during the JCP dispersal season after SLIT was associated with reduced peripheral blood γδ T cells.

Blockade of costimulatory CD27/CD70 pathway promotes corneal allograft survival

PURPOSE

To determine whether the CD27/CD70 pathway plays a significant role in corneal allograft rejection by investigating the effect of blocking the CD27/CD70 pathway by anti-CD70 antibody on corneal allograft survival.

METHODS

Orthotopic penetrating keratoplasty was performed using C57BL/6 donor grafts and BALB/c recipients. Expression of CD27 and CD70 on rejected cornea was examined by immunohistochemistry. Corneal transplant recipients received intraperitoneal injection of anti-CD70 antibody (FR70) or control rat IgG. Alloreactivity was measured by mixed lymphoid reaction (MLR) in recipients administered control rat IgG and those administered anti-CD70 antibody. Corneal expression of IFN-γ and IL-12 was also examined in both groups. Graft opacity was assessed over an 8-week period and graft survival was evaluated using Kaplan-Meier survival curves. Proportion of CD4⁺CD44⁺ memory T cells in lymph nodes was measured by flow cytometry.

RESULTS

CD4⁺CD27⁺ cells and CD11c⁺CD70⁺ cells were present in rejected cornea. Anti-CD70 antibody administration suppressed alloreactivity in corneal allograft recipients, and inhibited IFN-γ expression in recipient cornea (p < 0.05). Anti-CD70 antibody suppressed opacity score of recipient cornea and prolonged corneal allograft survival (p < 0.05). Proportion of CD4⁺CD44⁺ memory T cells in recipient lymph nodes was reduced by anti-CD70 antibody treatment.

CONCLUSION

The CD27/CD70 pathway plays a significant role in corneal allograft rejection by initiating alloreactive Th1 cells and preserving memory T cells. Anti-CD70 antibody administration prolongs corneal allograft survival indicating the potential therapeutic effect of CD27/CD70 pathway blockade on corneal allograft rejection.

CD27 Promotes CD4+ Effector T Cell Survival in Response to Tissue Self-Antigen

Signaling through CD27 plays a role in T cell activation and memory. However, it is currently unknown how this costimulatory receptor influences CD4⁺ effector T (Teff) cells in inflamed tissues. In the current study, we used a murine model of inducible self-antigen expression in the epidermis to elucidate the functional role of CD27 on autoreactive Teff cells. Expression of CD27 on Ag-specific Teff cells resulted in enhanced skin inflammation when compared with CD27-deficient Teff cells. CD27 signaling promoted the accumulation of IFN-γ and IL-2-producing T cells in skin draining lymph nodes in a cell-intrinsic fashion. Surprisingly, this costimulatory pathway had minimal effect on early T cell activation and proliferation. Instead, signaling through CD27 resulted in the progressive survival of Teff cells during the autoimmune response. Using BH3 profiling to assess mitochondrial cell priming, we found that CD27-deficient cells were equally as sensitive as CD27-sufficient cells to mitochondrial outer membrane polarization upon exposure to either BH3 activator or sensitizer peptides. In contrast, CD27-deficient Teff cells expressed higher levels of active caspase 8. Taken together, these results suggest that CD27 does not promote Teff cell survival by increasing expression of antiapoptotic BCL2 family members but instead acts by preferentially suppressing the cell-extrinsic apoptosis pathway, highlighting a previously unidentified role for CD27 in augmenting autoreactive Teff cell responses.

Cutting Edge: Anti-TIM-3 Treatment Exacerbates Pulmonary Inflammation and Fibrosis in Mice

Promising results of immune checkpoint inhibitors have indicated the use of immunotherapy against malignant tumors. However, they cause serious side effects, including autoimmune diseases and pneumonitis. T cell Ig and mucin domain (TIM)-3 is a new candidate immune checkpoint molecule; however, the potential toxicity associated with anti-TIM-3 treatment is unknown. In this study, we investigated the pathological contribution of anti-TIM-3 mAb in a bleomycin-induced lung inflammation and fibrosis model. Anti-TIM-3-treated mice showed more severe inflammation and peribronchiolar fibrosis compared with control IgG-treated mice. Anti-TIM-3 mAb was associated with increased numbers of myofibroblasts, collagen deposition, and TGF-β1 production in lungs. TIM-3 expression was only detected on alveolar macrophages that protect against fibrosis by apoptotic cell clearance. Treatment with anti-TIM-3 mAb inhibited the phagocytic ability of alveolar macrophages in vivo, resulting in the defective clearance of apoptotic cells in lungs. In summary, anti-TIM-3 mAb treatment might cause pneumonitis and it should be used with caution in clinical settings.

Crystal structure of CD27 in complex with a neutralizing noncompeting antibody

CD27 is a T-cell and B-cell co-stimulatory glycoprotein of the tumor necrosis factor (TNF) receptor superfamily that is dependent on the availability of the TNF-like ligand CD70. Therapeutic approaches to treating autoimmune diseases and cancers with antagonistic and agonistic anti-CD27 monoclonal antibodies (mAbs), respectively, have recently been developed. Mouse anti-human CD27 mAb 2177 shows potency in neutralizing CD70-induced signaling; however, it does not block the binding of soluble CD70. To provide insight into the mechanism of action of the mAb, the crystal structure of the CD27 extracellular domain in complex with the Fab fragment of mAb 2177 was determined at 1.8 Å resolution. CD27 exhibits the assembly of cysteine-rich domains characteristic of the TNF receptor superfamily. The structure reveals a unique binding site of mAb 2177 at the edge of the receptor molecule, which allows the mAb to sterically block the cell-bound form of CD70 from reaching CD27 while leaving the ligand epitope clear. This mode of action suggests a potential dual use of mAb 2177 either as an antagonist or as an agonist.

Characteristics of alveolar macrophages from murine models of OVA-induced allergic airway inflammation and LPS-induced acute airway inflammation

BACKGROUND

 Macrophages include the classically activated pro-inflammatory M1 macrophages (M1s) and alternatively activated anti-inflammatory M2 macrophages (M2s). The M1s are activated by both interferon-γ and Toll-like receptor ligands, including lipopolysaccharide (LPS), and have potent pro-inflammatory activity. In contrast, Th2 cytokines activate the M2s, which are involved in the immune response to parasites, promotion of tissue remodeling, and immune regulatory functions. Although alveolar macrophages (AMs) play an essential role in the pulmonary immune system, little is known about their phenotypes.

METHODS

 Quantitative reverse transcription polymerase chain reaction and flow cytometry were used to define the characteristics of alveolar macrophages derived from untreated naïve mice and from murine models of both ovalbumin (OVA)-induced allergic airway inflammation and LPS-induced acute airway inflammation. AMs were co-cultured with CD4(+) T cells and were pulsed with tritiated thymidine to assess proliferative responses.

RESULTS

 We characterized in detail murine AMs and found that these cells were not completely consistent with the current M1 versus M2-polarization model. OVA-induced allergic and LPS-induced acute airway inflammation promoted the polarization of AMs towards the current M2-skewed and M1-skewed phenotypes, respectively. Moreover, our data also show that CD11c(+) CD11b(+) AMs from the LPS-treated mice play a regulatory role in antigen-specific T-cell proliferation in vitro.

CONCLUSIONS

 These characteristics of AMs depend on the incoming pathogens they encounter and on the phase of inflammation and do not correspond to the current M1 versus M2-polarization model. These findings may facilitate an understanding of their contributions to the pulmonary immune system in airway inflammation.