Particulate matter (PM) present in the atmosphere can exacerbate respiratory diseases, leading to growing societal demands for solutions. Previous researches have revealed that biological responses differ depending on the type and composition of PM, and the biological responses induced by each type of PM are gradually being elucidated. However, the spatial localization of PM within the lungs and the spatial relationship between biological responses and PM remain insufficiently understood. This paper introduces a method for visualizing PM localization as identifying particles and the potential for combining this method with the visualization of biological responses induced by PM.

The endotoxin scattering photometry (ESP) method was reported at 13th Annual meeting at Kagoshima. On the contrary endotoxin assay is usually used LAL reagent reaction evoked by endotoxin, ESP method use entirely different theory and process to compare ordinary assay such as turbidimetric assay. Many clinical and theoretical papers were issued, but the problem is no machine for common use of ESP assay.

For clinical use for endotoxin evaluation, we have developed rapid and high sensitive endotoxin assay machine by using back-scatter detection style of ESP method. We here show endotoxin and β-glucan assay by using this new machine comparing turbidimetric assay.

Fibroblast activation protein-α (FAP) is a serine protease expressed by fibroblasts. This study investigated the impact of FAP expressed in cancer-associated fibroblasts (CAF) in colorectal cancer (CRC) on tumor immunity. FAP expression at the invasive margin (IM) was assessed by immunohistochemistry (IHC) in surgically resected CRC cases (n = 178). Based on FAP expression at the IM, patients were classified into a high-expression group (n = 87) and a low-expression group (n = 93). The low-expression group showed a significantly higher density of CD3-positive cells per unit area at the IM (p < 0.01) and a positive correlation with the Immunoscore (p = 0.02). Overall survival (OS) and disease-free survival (DFS) were significantly prolonged in the low-expression group (p < 0.01, p = 0.04). Single-cell RNA sequencing (scRNA-seq) data from 10 CRC samples (20,114 cells) were analyzed, and CAF clusters were classified into FAP-high (FAP-H, n = 5) and FAP-low (FAP-L, n = 5) groups based on the proportion of FAP-expressing cells and mean expression levels. In the FAP-L group, C-X-C motif chemokine ligand 12 (CXCL12) expression was reduced. Gene set enrichment analysis (GSEA) revealed associations of the FAP-L group with immune-related geneset, including INTERFERON GAMMA RESPONSE (NES = −1.72, Padj < 0.01), ALLOGRAFT REJECTION (NES = −1.66, Padj < 0.01), and INTERFERON ALPHA RESPONSE (NES = −1.55, Padj = 0.01). FAP in CAF may induce immunosuppression in the tumor microenvironment (TME) via CXCL12, modulating antitumor immunity in CRC.

Clostridioides difficile（CD）is one of the intestinal commensal bacteria that reside in the human gut microbiota. However, when antimicrobial agents disrupt the symbiotic balance of the microbiota, this drug-resistant bacterium can proliferate, leading to CD infection, which is accompanied by symptoms such as fever and diarrhea. In severe cases, pseudomembranous colitis can be induced. Symptoms of CDI are thought to be mainly caused by TcdA and TcdB produced by CD.

Although CD is an obligate anaerobic Gram-positive bacillus, there have been no reports examining its behavior under hypoxic conditions. In this study, we investigated how CD affects mouse bone marrow-derived macrophage（s BMDMs）when infecting them under hypoxic conditions.

We found that protein attenuation occurred with CD infection under hypoxia in macrophages. This protein reduction doesn’t depend on TcdA/B. Moreover, both apoptosis and necrosis were markedly enhanced under hypoxia. We also found that CD infection under hypoxic conditions resulted in a relative reduction in protein expression levels compared with the control group. In addition, hypoxia was associated with suppression of polyubiquitination during CD infection.

These results suggest that CD specifically induces cell death under hypoxic conditions, including the degradation of inflammatory cytokines and apoptosis. These findings not only enhance our understanding of CD pathogenicity in a physiologically relevant context but may also inform the development of targeted therapies or preventive strategies for managing infections under different tissue oxygen conditions.

Anastomotic leakage (AL) after colorectal surgery (CRS) is a serious postoperative complication that leads to intraabdominal sepsis. An accurate method for early prediction of AL has not been established, and it is usually diagnosed 6-12.7 days postoperatively.

Previous studies have explored various biomarkers for the early prediction of AL, such as markers of ischemia, microbiological biomarkers and inflammation parameters in drainage fluid, and serum markers. However, they all face challenges regarding accuracy and rapidity, and none have yet been put into practical use.

Measuring endotoxin (ET) a component of Gram-negative bacteria in drainage fluid may be useful for predicting AL by directly detecting leakage of gastrointestinal contents from anastomotic sites.

We previously reported that using an ET-specific limulus amebocyte lysate (LAL) reagents and measuring ET levels in drainage fluid collected 1-5 hours after CRS (POD0) via the recently developed endotoxin scattering photometry (ESP) assay allows for highly sensitive AL prediction. However, the ESP assay is not practical for clinical use. The turbidimetric assay using LIMUSAVE^®, which is widely used in Japan, is clinically applicable. We present selected data from our findings.

ET values measured in POD0 drainage fluid using ET-specific LAL reagents suggest the potential for serving as a good predictor of AL after CRS. We consider the ability to utilize the clinically available LIMUSAVE^® particularly significant.

Periodontitis is a chronic inflammatory disease caused by oral bacterial infection. Some oral bacteria induce inflammatory cytokines, including IL-1β, IL-6, and TNFα, release in immune cells. However, the mechanisms underlying cytokine release are poorly understood. The Janus kinase (JAK) pathway is crucial in triggering the inflammatory signaling involving STAT/IL-6 signaling. JAK/STAT inhibitors are anti-inflammatory drugs that suppress autoimmune diseases such as inflammatory bowel disease or cancer. However, there are no reports that these inhibitors affect periodontitis. We first tried to detect the inflammasome activation caused by Porphyromonas gingivalis (P. gingivalis), a periodontitis-associated bacterium, infection in bone marrow-derived macrophages (BMDMs) treated with JAK inhibitors. JAK inhibitors enhanced inflammasome activation in P. gingivalis infection. We also examined other periodontitis-associated bacteria and found that Tannerella forsythia (T. forsythia) induces inflammasome activation in BMDMs, like P. gingivalis infection. However, STAT inhibitors, which are downstream of JAK, did not enhance inflammasome activation in P. gingivalis infection. These data suggest that the JAK pathway inhibits inflammasome activation by oral bacterial infection in a STAT-independent manner.

Antimicrobial peptide LL-37 was discovered as a molecule that exerts bactericidal effects on microorganisms such as bacteria. However, because it acts on immune cells to modulate cytokine production and cell death, it is now attracting attention as a multifunctional host defense molecule. Recently, it has been revealed that SASP factors (senescence-associated secretory phenotype), such as inflammatory cytokines are released from senescent cells, and involved in the enhanced inflammatory response associated with aging. Moreover, it has also been reported that removal of senescent cells attenuates the inflammatory response. Therefore, in this study, we investigated how LL-37 acts on senescent cells, focusing on release of SASP factors and induction of cell death.

Treatment of A549 alveolar epithelial cells with a DNA synthesis inhibitor (etoposide) induced a senescent cell-like morphology (flattened and enlarged), and increased expression of SASP markers (p21 and β-galactosidase). Interestingly, treatment of senescent A549 cells with LL-37 induced the production of a proinflammatory cytokine IL-6 (a SASP factor). Furthermore, LL-37 induced the apoptosis but not necrosis of senescent A549 cells. These observations suggest that antimicrobial peptide LL-37 acts on senescent cells to induce IL-6 production and apoptosis, thereby enhancing rather than attenuating inflammatory responses.

Toll-like receptors (TLRs) are innate immune receptors that recognize pathogen-derived molecules and initiate immune responses. They are type-I transmembrane proteins whose ligand-recognition domains are located on the extracellular side or within the lumen of intracellular compartments. For TLRs to respond appropriately, they must be transported to compartments suitable for ligand recognition. Traditionally, TLRs have been classified according to their ligands into “cell surface–localized TLRs” and “intracellularly localized TLRs”. The former primarily recognize lipids or proteins, whereas the latter recognize nucleic acids. However, with the establishment of useful monoclonal antibodies, it has become evident that this classification does not fully capture their complexity. In this review, we describe the mechanisms governing TLR subcellular localization, as well as soluble forms of TLRs that are present in extracellular fluids such as serum.