Sema6D forward signaling impairs T cell activation and proliferation in head and neck cancer.

Immune checkpoint inhibitors (ICIs) are indicated for a diverse range of cancer types, and characterizing the tumor immune microenvironment is critical for optimizing therapeutic strategies, including ICIs. T cell infiltration and activation status in the tumor microenvironment greatly affects the efficacy of ICIs. Here, we show that semaphorin 6D (Sema6D) forward signaling, which is reportedly involved in coordinating the orientation of cell development and migration as a guidance factor, impaired the infiltration and activation of tumor-specific CD8+ T cells in murine oral tumors. Sema6D expressed by nonhematopoietic cells was responsible for this phenotype. Plexin-A4, a receptor for Sema6D, inhibited T cell infiltration and partially suppressed CD8+ T cell activation and proliferation induced by Sema6D stimulation. Moreover, mouse oral tumors, which are resistant to PD-1-blocking treatment in wild-type mice, showed a response to the treatment in Sema6d-KO mice. Finally, analyses of public data sets of human head and neck squamous cell carcinoma, pan-cancer cohorts, and a retrospective cohort study showed that SEMA6D was mainly expressed by nonhematopoietic cells such as cancer cells, and SEMA6D expression was significantly negatively correlated with CD8A, PDCD1, IFNG, and GZMB expression. Thus, targeting Sema6D forward signaling is a promising option for increasing ICI efficacy.

Tumor-derived semaphorin 4A improves PD-1-blocking antibody efficacy by enhancing CD8+ T cell cytotoxicity and proliferation.

Immune checkpoint inhibitors (ICIs) have caused revolutionary changes in cancer treatment, but low response rates remain a challenge. Semaphorin 4A (Sema4A) modulates the immune system through multiple mechanisms in mice, although the role of human Sema4A in the tumor microenvironment remains unclear. This study demonstrates that histologically Sema4A-positive non-small cell lung cancer (NSCLC) responded significantly better to anti-programmed cell death 1 (PD-1) antibody than Sema4A-negative NSCLC. Intriguingly, SEMA4A expression in human NSCLC was mainly derived from tumor cells and was associated with T cell activation. Sema4A promoted cytotoxicity and proliferation of tumor-specific CD8+ T cells without terminal exhaustion by enhancing mammalian target of rapamycin complex 1 and polyamine synthesis, which led to improved efficacy of PD-1 inhibitors in murine models. Improved T cell activation by recombinant Sema4A was also confirmed using isolated tumor-infiltrating T cells from patients with cancer. Thus, Sema4A might be a promising therapeutic target and biomarker for predicting and promoting ICI efficacy.

Persistence of SARS-CoV-2 neutralizing antibodies and anti-Omicron IgG induced by BNT162b2 mRNA vaccine in patients with autoimmune inflammatory rheumatic disease: an explanatory study in Japan.

Background: Autoimmune inflammatory rheumatic disease (AIRD) patients are at high risk of the coronavirus disease 2019 (COVID-19), but the medium-term effects of immunosuppressants on vaccine efficacy are unknown. We investigated the duration of humoral responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wild-type and Omicron variant in AIRD patients administered with two doses of the BNT162b2 (Pfizer-BioNTech) vaccine. Methods: Serum-neutralizing antibody (NAb) and anti-receptor-binding domain (RBD)/spike antibody levels were measured. Short- and medium-term effects of immunosuppressants were analyzed pre-vaccination (Term 1) and 14-42 days (Term 2) and 100-200 days (Term 3) after the second vaccination. Findings: From Feb 1, 2021, to Feb 28, 2022, 439 AIRD patients and 146 healthy controls were investigated. The seropositivity rate and log10-NAb titers were significantly lower in AIRD patients than in controls at Terms 2 and 3. In rheumatoid arthritis patients, tumor necrosis factor-α inhibitors (TNFis) at Term 3, and older age, glucocorticoids, and abatacept at Terms 2 and 3 were risk factors for reduced responses. Anti-Omicron RBD/spike IgG levels strongly correlated with NAb titers. Interpretation: Glucocorticoids, TNFis, and abatacept treatments negatively affect the longevity of humoral responses to SARS-CoV-2, including Omicron, after two vaccine doses. These findings may inform the timing of additional vaccination for AIRD patients. Funding: Cloud Funding of Peace Winds Japan; Center of Innovation Program from the Ministry of Education, Culture, Sports, Science and Technology of Japan; Japan Society for the Promotion of Science KAKENHI; Japan Agency for Medical Research and Development; Kansai Economic Federation; Mitsubishi Zaidan; and Research Grant from Japan Agency for Medical Research and Development-Core Research for Evolutional Science and Technology.

SLE stratification based on BAFF and IFN-I bioactivity for biologics and implications of BAFF produced by glomeruli in lupus nephritis.

OBJECTIVE: B-cell activating factor (BAFF) is implicated in SLE pathogenesis. Blocking BAFF signalling has contributed to reducing glucocorticoid dosage and preventing organ damage. However, clinical characteristics of patients who may benefit from this therapy are not yet fully elucidated. Therefore, we identified patients with high BAFF-bioactivity to investigate their clinical characteristics and BAFF-producing cells. METHODS: We established the reporter cell for BAFF and investigated the clinical characteristics of SLE patients with high BAFF-bioactivity. We identified BAFF-expressing kidney cells using publicly available scRNA-seq data and immunohistological analysis. SLE patients were stratified based on the bioactivity of BAFF and type-I IFN (IFN-I) to identify associated characteristic clinical manifestations. RESULTS: SLE patients, especially patients with LN, had significantly higher serum BAFF-bioactivity than healthy controls (HC) and non-LN patients. Additionally, single-cell-RNA-seq data and immunohistological analysis of kidney samples from LN patients revealed that BAFF is expressed in glomerular macrophages and mesangial cells. Notably, BAFF bioactivity was elevated in the urine of LN patients compared with that of non-LN patients, while no IFN-I bioactivity was detected in the urine. Furthermore, SLE stratification based on bioactivities of serum BAFF and IFN-I revealed the clinical characteristics of patients: high BAFF represented patients with LN and high IFN-I represented patients with blood and skin manifestations. CONCLUSIONS: Monitoring urinary BAFF-bioactivity may be valuable in diagnosing LN. Furthermore, stratification based on serum BAFF and IFN-I bioactivities may allow the identification of appropriate patients for biologics targeting BAFF and IFN-I.

Next-generation proteomics of serum extracellular vesicles combined with single-cell RNA sequencing identifies MACROH2A1 associated with refractory COVID-19.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is widespread; however, accurate predictors of refractory cases have not yet been established. Circulating extracellular vesicles, involved in many pathological processes, are ideal resources for biomarker exploration. METHODS: To identify potential serum biomarkers and examine the proteins associated with the pathogenesis of refractory COVID-19, we conducted high-coverage proteomics on serum extracellular vesicles collected from 12 patients with COVID-19 at different disease severity levels and 4 healthy controls. Furthermore, single-cell RNA sequencing of peripheral blood mononuclear cells collected from 10 patients with COVID-19 and 5 healthy controls was performed. RESULTS: Among the 3046 extracellular vesicle proteins that were identified, expression of MACROH2A1 was significantly elevated in refractory cases compared to non-refractory cases; moreover, its expression was increased according to disease severity. In single-cell RNA sequencing of peripheral blood mononuclear cells, the expression of MACROH2A1 was localized to monocytes and elevated in critical cases. Consistently, single-nucleus RNA sequencing of lung tissues revealed that MACROH2A1 was highly expressed in monocytes and macrophages and was significantly elevated in fatal COVID-19. Moreover, molecular network analysis showed that pathways such as "estrogen signaling pathway," "p160 steroid receptor coactivator (SRC) signaling pathway," and "transcriptional regulation by STAT" were enriched in the transcriptome of monocytes in the peripheral blood mononuclear cells and lungs, and they were also commonly enriched in extracellular vesicle proteomics. CONCLUSIONS: Our findings highlight that MACROH2A1 in extracellular vesicles is a potential biomarker of refractory COVID-19 and may reflect the pathogenesis of COVID-19 in monocytes.

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force.

Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection.

DOCK2 is involved in the host genetics and biology of severe COVID-19.

Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge1-5. Here we conducted a genome-wide association study (GWAS) involving 2,393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3,289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target.

Bronchoalveolar lavage fluid reveals factors contributing to the efficacy of PD-1 blockade in lung cancer.

Bronchoalveolar lavage is commonly performed to assess inflammation and identify responsible pathogens in lung diseases. Findings from bronchoalveolar lavage might be used to evaluate the immune profile of the lung tumor microenvironment (TME). To investigate whether bronchoalveolar lavage fluid (BALF) analysis can help identify patients with non-small cell lung cancer (NSCLC) who respond to immune checkpoint inhibitors (ICIs), BALF and blood were prospectively collected before initiating nivolumab. The secreted molecules, microbiome, and cellular profiles based on BALF and blood analysis of 12 patients were compared with regard to therapeutic effect. Compared with ICI nonresponders, responders showed significantly higher CXCL9 levels and a greater diversity of the lung microbiome profile in BALF, along with a greater frequency of the CD56+ subset in blood T cells, whereas no significant difference in PD-L1 expression was found in tumor cells. Antibiotic treatment in a preclinical lung cancer model significantly decreased CXCL9 in the lung TME, resulting in reduced sensitivity to anti-PD-1 antibody, which was reversed by CXCL9 induction in tumor cells. Thus, CXCL9 might be associated with the lung TME microbiome, and the balance of CXCL9 and lung TME microbiome could contribute to nivolumab sensitivity in patients with NSCLC. BALF analysis can help predict the efficacy of ICIs when performed along with currently approved examinations.

Recovery from prolonged thrombocytopenia in patients with TAFRO syndrome: case series and literature review.

TAFRO syndrome is a newly proposed disease that is characterised by thrombocytopenia, anasarca, fever, reticulin fibrosis (or renal dysfunction), and organomegaly. Generally, high doses of corticosteroids are recommended for the initial treatment of TAFRO syndrome; however, some patients experience prolonged refractory thrombocytopenia after initiating such therapies. If corticosteroid treatment alone is ineffective, additional immunosuppressive therapies such as cyclosporine A are recommended. Since long-term use of immunosuppressive therapies with TAFRO syndrome sometimes causes serious infection, it is important to recognise the time to recovery from thrombocytopenia. In this study, we investigated how long it took to recover from thrombocytopenia, to aid clinicians in decision-making regarding the need to strengthen treatment for prolonged thrombocytopenia. Here, we describe three of our patients with TAFRO syndrome exhibiting prolonged thrombocytopenia. We also investigated the median period to recovery from this complication (defined as the time to increase the platelet count above 50,000/µL) after the initiation of high-dose corticosteroid treatment in our 3 cases and 38 peer-reviewed cases. We found that it took our patients 61 days to recover from thrombocytopenia; in comparison, our investigation of the 38 peer-reviewed case reports revealed a median recovery time of 47.5 days among previously reported patients. We showed the time to recovery from thrombocytopenia in patients with TAFRO syndrome for the first time. Our findings ought to be useful for decision-making among clinicians regarding the administration of other immunosuppressive treatments in addition to corticosteroid.

Pathological and therapeutic implications of eosinophil-derived semaphorin 4D in eosinophilic chronic rhinosinusitis.

BACKGROUND: Eosinophilic chronic rhinosinusitis (ECRS) is a subtype of chronic rhinosinusitis. Clinical markers for ECRS disease activity and treatment strategies have not been sufficiently established. Although semaphorins are originally identified as neuronal guidance factors, it is becoming clear that they play key roles in immune regulation and inflammatory diseases. OBJECTIVE: We sought to investigate the pathological functions and therapeutic potential of semaphorin 4D (SEMA4D) in ECRS. METHODS: Serum soluble SEMA4D levels in patients with paranasal sinus diseases were measured by ELISA. The expression of SEMA4D in blood cells and nasal polyp tissues was assessed by flow cytometry and immunohistochemistry, respectively. Generation of soluble SEMA4D was evaluated in matrix metalloproteinase-treated eosinophils. Endothelial cells were stimulated with recombinant SEMA4D, followed by eosinophil transendothelial migration assays. Allergic chronic rhinosinusitis was induced in mice using Aspergillus protease with ovalbumin. The efficacy of treatment with anti-SEMA4D antibody was evaluated histologically and by nasal lavage fluid analysis. RESULTS: Serum soluble SEMA4D levels were elevated in patients with ECRS and positively correlated with disease severity. Tissue-infiltrated eosinophils in nasal polyps from patients with ECRS stained strongly with anti-SEMA4D antibody. Cell surface expression of SEMA4D on eosinophils from patients with ECRS was reduced, which was due to matrix metalloproteinase-9-mediated cleavage of membrane SEMA4D. Soluble SEMA4D induced eosinophil transendothelial migration. Treatment with anti-SEMA4D antibody ameliorated eosinophilic infiltration in sinus tissues and nasal lavage fluid in the ECRS animal model. CONCLUSIONS: Eosinophil-derived SEMA4D aggravates ECRS. Levels of serum SEMA4D reflect disease severity, and anti-SEMA4D antibody has therapeutic potential as a treatment for ECRS.

Anti-receptor activator of nuclear factor κB ligand antibody treatment increases osteoclastogenesis-promoting IL-8 in patients with rheumatoid arthritis.

The receptor activator of nuclear factor κB ligand (RANKL) is an important factor for osteoclastogenesis and contributes to the pathology of rheumatoid arthritis (RA); thus, the anti-RANKL antibody (Ab) has been expected to protect joint destruction in RA patients. IL-8 also has osteoclastogenic activity; however, the role of IL-8 in the bone pathology of RA as well as the relation between IL-8 and RANKL remain unclear. In the present study, clinical observation revealed serum IL-8 levels of 611 pg ml-1 in RA patients with anti-RANKL Ab and 266 pg ml-1 in the same patients without anti-RANKL Ab. In vitro assay showed that anti-RANKL Ab induced production of IL-8 from pre-osteoclast-like cells (OCLs), and IL-8 promoted the formation of OCLs from peripheral monocytes even without RANKL activity. We further showed that treatment with FK506 (tacrolimus) possibly inhibits the increase in IL-8 levels in RA patients with anti-RANKL Ab, and in vitro assay confirmed that FK506 suppressed IL-8 production in pre-OCLs. These results suggest that inhibition of RANKL induces the change in osteoclastogenesis-promoting factor from RANKL to IL-8, and FK506 may be a valuable combination drug to support the use of anti-RANKL Ab in treatment of RA.

A distinct subpopulation of CD25- T-follicular regulatory cells localizes in the germinal centers.

T-follicular helper (Tfh) cells differentiate through a multistep process, culminating in germinal center (GC) localized GC-Tfh cells that provide support to GC-B cells. T-follicular regulatory (Tfr) cells have critical roles in the control of Tfh cells and GC formation. Although Tfh-cell differentiation is inhibited by IL-2, regulatory T (Treg) cell differentiation and survival depend on it. Here, we describe a CD25- subpopulation within both murine and human PD1+CXCR5+Foxp3+ Tfr cells. It is preferentially located in the GC and can be clearly differentiated from CD25+ non-GC-Tfr, Tfh, and effector Treg (eTreg) cells by the expression of a wide range of molecules. In comparison to CD25+ Tfr and eTreg cells, CD25- Tfr cells partially down-regulate IL-2-dependent canonical Treg features, but retain suppressive function, while simultaneously up-regulating genes associated with Tfh and GC-Tfh cells. We suggest that, similar to Tfh cells, Tfr cells follow a differentiation pathway generating a mature GC-localized subpopulation, CD25- Tfr cells.