Targeted deletion of CD244 on monocytes promotes differentiation into anti-tumorigenic macrophages and potentiates PD-L1 blockade in melanoma.

BACKGROUND: In the myeloid compartment of the tumor microenvironment, CD244 signaling has been implicated in immunosuppressive phenotype of monocytes. However, the precise molecular mechanism and contribution of CD244 to tumor immunity in monocytes/macrophages remains elusive due to the co-existing lymphoid cells expressing CD244. METHODS: To directly assess the role of CD244 in tumor-associated macrophages, monocyte-lineage-specific CD244-deficient mice were generated using cre-lox recombination and challenged with B16F10 melanoma. The phenotype and function of tumor-infiltrating macrophages along with antigen-specific CD8 T cells were analyzed by flow cytometry and single cell RNA sequencing data analysis, and the molecular mechanism underlying anti-tumorigenic macrophage differentiation, antigen presentation, phagocytosis was investigated ex vivo. Finally, the clinical feasibility of CD244-negative monocytes as a therapeutic modality in melanoma was confirmed by adoptive transfer experiments. RESULTS: CD244fl/flLysMcre mice demonstrated a significant reduction in tumor volume (61% relative to that of the CD244fl/fl control group) 14 days after tumor implantation. Within tumor mass, CD244fl/flLysMcre mice also showed higher percentages of Ly6Clow macrophages, along with elevated gp100+IFN-γ+ CD8 T cells. Flow cytometry and RNA sequencing data demonstrated that ER stress resulted in increased CD244 expression on monocytes. This, in turn, impeded the generation of anti-tumorigenic Ly6Clow macrophages, phagocytosis and MHC-I antigen presentation by suppressing autophagy pathways. Combining anti-PD-L1 antibody with CD244-/- bone marrow-derived macrophages markedly improved tumor rejection compared to the anti-PD-L1 antibody alone or in combination with wild-type macrophages. Consistent with the murine data, transcriptome analysis of human melanoma tissue single-cell RNA-sequencing dataset revealed close association between CD244 and the inhibition of macrophage maturation and function. Furthermore, the presence of CD244-negative monocytes/macrophages significantly increased patient survival in primary and metastatic tumors. CONCLUSION: Our study highlights the novel role of CD244 on monocytes/macrophages in restraining anti-tumorigenic macrophage generation and tumor antigen-specific T cell response in melanoma. Importantly, our findings suggest that CD244-deficient macrophages could potentially be used as a therapeutic agent in combination with immune checkpoint inhibitors. Furthermore, CD244 expression in monocyte-lineage cells serve as a prognostic marker in cancer patients.

Fatal outcome of severe fever with thrombocytopenia syndrome (SFTS) and severe and critical COVID-19 is associated with the hyperproduction of IL-10 and IL-6 and the low production of TGF-ß.

Severe fever with thrombocytopenia syndrome virus (SFTSV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause the hyperproduction of inflammatory cytokines, which have pathological effects in patient including severe or fatal cytokine storms. To characterize the effect of SFTSV and SARS-CoV-2 infection on the production of cytokines in severe fever with thrombocytopenia syndrome (SFTS) and COVID-19 patients, we performed an analysis of cytokines in SFTS and COVID-19 patients and also investigated the role of interleukin-10 (IL-10) in vitro studies: lipopolysaccharide-induced THP-1-derived macrophages, SFTSV infection of THP-1 cells, and SARS-CoV-2 infection of THP-1 cells. In this study, we found that levels of both IL-10 and IL-6 were significantly elevated, the level of transforming growth factor-ß (TGF-ß) was significantly decreased and IL-10 was elevated earlier than IL-6 in severe and critical COVID-19 and fatal SFTS patients, and inhibition of IL-10 signaling decreased the production of IL-6 and elevated that of TGF-ß. Therefore, the hyperproduction of IL-10 and IL-6 and the low production of TGF-ß have been linked to cytokine storm-induced mortality in fatal SFTS and severe and critically ill COVID-19 patients and that IL-10 can play an important role in the host immune response to severe and critical SARS-CoV-2 and fatal SFTSV infection.

Tocilizumab therapy for IL-6 increment in a patient with non-fatal severe fever with thrombocytopenia syndrome.

We report the administration of an anti-interleukin (IL)-6 antibody in a case of severe fever with thrombocytopenia syndrome (SFTS) with an increase in IL-6. On the day of admission, SFTS viral load and IL-6 concentration were 93 831 copies/ml and 5.4 pg/ml, respectively, and tocilizumab was administered. SFTS viral load decreased to 17 821.1 copies/ml on the 3rd day of admission, while IL-6 levels increased to 104.9 pg/ml; SFTS viral load and IL-6 levels had decreased to 2876.4 copies/ml and 48.2 pg/ml on 7th day of admission, respectively. The patient fully recovered no tocilizumab adverse events.

Bacteroides fragilis Enterotoxin Upregulates Matrix Metalloproteinase-7 Expression through MAPK and AP-1 Activation in Intestinal Epithelial Cells, Leading to Syndecan-2 Release.

Bacteroides fragilis enterotoxin (BFT) produced by enterotoxigenic B. fragilis (ETBF) causes colonic inflammation. BFT initially contacts intestinal epithelial cells (IECs) and affects the intestinal barrier. Although molecular components of the gut epithelial barrier such as metalloproteinase-7 (MMP-7) and syndecan-2 are known to be associated with inflammation, little has been reported about MMP-7 expression and syndecan-2 shedding in response to ETBF infection. This study explores the role of BFT in MMP-7 induction and syndecan-2 release in IECs. Stimulating IECs with BFT led to the induction of MMP-7 and the activation of transcription factors such as NF-κB and AP-1. MMP-7 upregulation was not affected by NF-κB, but it was related to AP-1 activation. In BFT-exposed IECs, syndecan-2 release was observed in a time- and concentration-dependent manner. MMP-7 suppression was associated with a reduction in syndecan-2 release. In addition, suppression of ERK, one of the mitogen-activated protein kinases (MAPKs), inhibited AP-1 activity and MMP-7 expression. Furthermore, the suppression of AP-1 and ERK activity was related to the attenuation of syndecan-2 release. These results suggest that a signaling cascade comprising ERK and AP-1 activation in IECs is involved in MMP-7 upregulation and syndecan-2 release during exposure to BFT.

IL-6 and IL-10 Levels, Rather Than Viral Load and Neutralizing Antibody Titers, Determine the Fate of Patients With Severe Fever With Thrombocytopenia Syndrome Virus Infection in South Korea.

Severe fever with thrombocytopenia syndrome (SFTS) is a new tick-borne viral disease, and most SFTS virus (SFTSV) infections occur via bites from the tick Haemaphysalis longicornis; however, SFTSV transmission can also occur through close contact with an infected patient. SFTS is characterized by acute high fever, thrombocytopenia, leukopenia, elevated serum hepatic enzyme levels, gastrointestinal symptoms, and multiorgan failure and has a 16.2 to 30% mortality rate. In this study, we found that age, dyspnea rates, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase, multiorgan dysfunction score (MODS), viral load, IL-6 levels, and IL-10 levels were higher in patients with fatal disease than in patients with nonfatal disease during the initial clinical course of SFTS. In addition, we found that IL-6 and IL-10 levels, rather than viral load and neutralizing antibody titers, in patients with an SFTSV infection strongly correlated with outcomes (for severe disease with an ultimate outcome of recovery or death).

The first case of abdominal mycotic aneurysm caused by K1 hypervirulent Klebsiella pneumoniae in a healthy adult.

Incidence of hypervirulent Klebsiella pneumoniae (hvKp) infection has been steadily increasing in the Asia-Pacific rim. The characteristic of hvKp infection is its ability to cause multiple site infections and unpredictable metastatic spread in the community. We describe the first case of mycotic aneurysm caused by hvKp serotype K1 in a previously healthy man and review the literature. Of a total of 13 cases, including our case, three cases were related to hvKp. Among patients with hvKp, the level of mycotic aneurysm in most patients was the infrarenal aorta, and they underwent an aortic graft or coil embolization. All strains were susceptible to most antimicrobial agents, except ampicillin. Early detection of hvKp can help to prevent the metastatic spread of pathogens and be useful for optimal patient care and epidemiologic research.

Bacteroides fragilis Enterotoxin Induces Sulfiredoxin-1 Expression in Intestinal Epithelial Cell Lines Through a Mitogen-Activated Protein Kinases- and Nrf2-Dependent Pathway, Leading to the Suppression of Apoptosis.

Enterotoxigenic Bacteroides fragilis is a causative agent of colitis and secrets enterotoxin (BFT), leading to the disease. Sulfiredoxin (Srx)-1 serves to protect from oxidative damages. Although BFT can generate reactive oxygen species in intestinal epithelial cells (IECs), no Srx-1 expression has been reported in ETBF infection. In this study, we explored the effects of ETBF-produced BFT on Srx-1 induction in IECs. Treatment of IECs with BFT resulted in increased expression of Srx-1 in a time-dependent manner. BFT treatment also activated transcriptional signals including Nrf2, AP-1 and NF-κB, and the Srx-1 induction was dependent on the activation of Nrf2 signals. Nrf2 activation was assessed using immunoblot and Nrf2-DNA binding activity and the specificity was confirmed by supershift and competition assays. Suppression of NF-κB or AP-1 signals did not affect the upregulation of Srx-1 expression. Nrf2-dependent Srx-1 expression was associated with the activation of p38 mitogen-activated protein kinases (MAPKs) in IECs. Furthermore, suppression of Srx-1 significantly enhanced apoptosis while overexpression of Srx-1 significantly attenuated apoptosis during exposure to BFT. These results imply that a signaling cascade involving p38 and Nrf2 is essential for Srx-1 upregulation in IECs stimulated with BFT. Following this upregulation, Srx-1 may control the apoptosis in BFT-exposed IECs.

Prevalence of Pseudoexfoliation Syndrome in an Isolated Island Population of Korea: The Woodo Study.

PURPOSE: To determine the prevalence and clinical characteristics of pseudoexfoliation syndrome (PXS) within Korean population living in Woodo Island. METHODS: Among the 625 residents aged 50 years or older, 305 residents (197 women and 108 men) participated in the study; a response rate of 48.8%. Participants filled out questionnaires on life style. Intraocular pressure and corneal endothelial cell function was measured. Both pupils were dilated. Fundus photographs and stereo disc photographs were taken. Vertical cup-to-disc ratio was determined. Pure tone audiometry threshold was measured at 0.5, 1, 2, 4, and 6 kHz of frequencies for each ear. RESULTS: The prevalence rate of PXS among Woodo Island residents older than 50 years significantly increased with age, from 1.0% [95% confidence interval (CI), 0%-2.8%] in participants aged 50 to 59 years to 23.3% (95% CI, 8.2%-38.5%) in those aged over 80 years (P<0.001). The prevalence of PXS showed no significant difference between men and women in all age groups. The age-standardized prevalence rate of PXS was 10.4% (95% CI, 8.0%-12.8%), with a rate of 9.4% (95% CI, 5.8%-13.1%) in men and 14.9% (95% CI, 11.3%-18.4%) in women. PXS did not show significant association with smoking, outdoor activity, and occupation, except alcohol consumption. PXS showed significant decrease in endothelial cell density. Pure tone audiometry test of PXS group revealed statistically significant decrease in 1, 2 kHz. CONCLUSIONS: The prevalence of PXS was 10.4% in the 50 years and older age group, and tended to increase with age. Decrease in corneal endothelial function and selective hearing loss was correlated in PXE patients, supporting impairment of systemic endothelial function in PXE syndrome.

A case of unusual septic knee arthritis with Brucella abortus after arthroscopic meniscus surgery.

We present a 51-year-old male patient with Brucella abortus septic arthritis in the right knee following arthroscopic meniscus surgery. He had eaten a traditional dish of raw minced cattle conceptus (bovine fetus) that was prepared after the cow was slaughtered. Despite treatment with empirical antibiotics and debridement of the postoperative surgical wound, the infection persisted without improvement. Polymerase chain reaction sequencing identified Brucella abortus from tissue samples obtained from the patient. After confirmation of the diagnosis of brucellar infection, antibiotics were replaced with doxycycline and rifampin, which were used for 4 months. In patients with a non-specific arthralgia who eat raw meat or live close to animals, it is important to consider the possibility of septic arthritis due to infection with Brucella spp.

B-cell-activating factor is elevated in serum of patients with myasthenia gravis.

INTRODUCTION: Myasthenia gravis (MG) is a B-cell-mediated autoimmune disease. B-cell-activating factor (BAFF) is a major factor in B-cell development and activation. In this study we investigated serum BAFF levels in MG patients. METHODS: We compared the serum BAFF levels of 20 MG patients with gender-matched healthy controls. We assayed serum concentrations of BAFF and anti-acetylcholine receptor antibody (AChR) titers. RESULTS: Serum BAFF levels of MG patients with AChR antibodies were significantly higher than those of healthy controls. A significant positive correlation was observed between serum BAFF levels and anti-AChR antibody titers. BAFF values did not correlate with disease severity. CONCLUSIONS: BAFF may play a major role in the pathogenesis of MG, and it may provide a potential target for therapy in patients with MG. Muscle Nerve 54: 1030-1033, 2016.

Association between serum mercury concentration and leukocyte differential count in children.

There have been a number of animal studies on the immunological effects of mercury. However, there is a lack of studies investigating the effects of mercury in children. We investigated the association between serum mercury and leukocyte differential count in Korean children. The relationship between mercury and leukocyte differential count (segment, lymphocyte, monocyte, basophil, and eosinophil counts) was analyzed by multivariate linear analysis adjusted for sex, BMI, parental smoking, lead, cadmium, and allergic sensitization in 311 children. Mercury showed a positive correlation with lymphocyte count (coefficient 113.8, 95% confidence interval 26.7-200.9). However, mercury was not associated with total leukocyte, segment, monocyte, basophil, or eosinophil count. Mercury was associated with the increased of lymphocyte count in Korean children. Further studies will be required to ascertain the clinical significance of this association.

Histamine skin reactivity increases with body mass index in Korean children.

OBJECTIVE: Histamine skin prick testing is most commonly used to diagnose immunoglobulin E (IgE)-mediated allergic diseases, and histamine reactivity is used as a standardized positive control in the interpretation of a skin prick test. However, reactivity to histamine differs among individuals for reasons that are poorly understood. The present study aimed to evaluate the potential association between body mass index (BMI) and histamine skin reactivity in children. METHODS: A total of 451 children (246 boys, 205 girls) aged 7-8 years were enrolled in this study. The skin prick test was performed with 26 aeroallergens commonly found in Korea. Other information was collected, including sex, age, BMI, parental allergy history, and parental smoking status. Multivariate analysis was used to confirm the association between histamine skin reactivity and BMI. RESULTS: The histamine wheal size was revealed to be associated with BMI (Spearman's Rho 0.161, p<0.001). This association was confirmed by multivariate analysis, after adjusting for sex, age, parental allergy history, parental smoking status, and allergic sensitization (coefficient B 0.071, 95% confidence interval 0.030-0.112). CONCLUSIONS: Skin responses to histamine were primarily correlated with increased BMI. Further studies are needed to understand the clinical implication of BMI when interpreting the results of skin prick test.

Three cases of postoperative septic arthritis caused by Mycobacterium conceptionense in the shoulder joints of immunocompetent patients.

Mycobacterium conceptionense is a species member of Mycobacterium fortuitum complex, a potential pathogen of increasing clinical importance among opportunistic infections. This species causes a wide spectrum of cutaneous and extracutaneous diseases. In this report, we describe three patients who underwent shoulder surgery with postoperative joint infection by M. conceptionense.

Skin and Soft Tissue Infection due to Rapidly Growing Mycobacteria: Case Series and Literature Review.

BACKGROUND: Nontuberculous mycobacteria (NTM) are ubiquitous in soil and water. Most NTM cause disease in humans only rarely unless some aspect of host defense is impaired. Recently, rapidly growing mycobacteria (RGM) is not uncommon, and the prevalence of RGM infection has been increasing. RGM causes a wide spectrum of pulmonary and extrapulmonary diseases and has been shown as an important source for opportunistic infection. MATERIALS AND METHODS: We report 5 patients of skin and soft tissue infection due to RGM in tertiary medical center in Jeju Island and analyzed 21 patients of skin and soft tissue infection due to RGM in Republic of Korea. Clinical, microbiological and epidemiological data were collected from each patient. NTM isolates were identified using conventional and molecular methods including 16S rDNA gene sequencing. RESULTS: The mean age of the RGM patients (n=26) was 54.9 ± 15.9 years and 73% were women. Mycobacterium fortuitum complex was the most common (12/26). Antimicrobial resistance for clarithromycin and quinolone were 12% and 60%, respectively. Clarithromycin based therapy was done in 46%. The mean duration of treatment was 21.2 ± 8.7 weeks. CONCLUSIONS: Many cases can be cured after therapy for 4-7 month with at least 2 or 3 antibiotics according to in vitro susceptibility. Recent increasing of NTM cases suggests that species and subspecies identification is epidemiologically important, especially related to medical procedure, and surgery.

Immunohistochemical localization of galectin-3 in the granulomatous lesions of paratuberculosis-infected bovine intestine.

The presence of galectin-3 was immunohistochemically quantified in bovine intestines infected with paratuberculosis (Johne's disease) to determine whether galectin-3 was involved in the formation of granulation tissue associated with the disease. Mycobacterium avium subsp. paratuberculosis infection was histochemically confirmed using Ziehl-Neelsen staining and molecularly diagnosed through rpoB DNA sequencing. Galectin-3 was detected in the majority of inflammatory cells, possibly macrophages, in the granulomatous lesions within affected tissues, including the ileum. These findings suggest that galectin-3 is associated with the formation of chronic granulation tissues in bovine paratuberculosis, probably through cell adhesion and anti-apoptosis mechanisms.

Differences in pancreatic immunohistochemical staining profiles of TGF-beta1, MMP-2, and TIMP-2 between autoimmune and alcoholic chronic pancreatitis.

OBJECTIVES: Tumor growth factor beta (TGF-beta) is an immunosuppressive cytokine and has been implicated in a variety of disease processes, including those in autoimmune disease. Tumor growth factor beta is also involved in fibrosis by regulating matrix metalloproteinases (MMPs) and the tissue inhibitor of MP (TIMP). The purpose of this study was to compare the expression patterns of TGF-beta1, MMP-2, and TIMP-2 between autoimmune chronic pancreatitis (AIP) and alcoholic chronic pancreatitis (ACP) by immunohistochemical staining of pancreatic tissue specimens. METHODS: Pancreatic tissue specimens were obtained from 16 of 57 patients who had a diagnosis of AIP at the Asan Medical Center. Pancreatic tissue specimens of ACP were obtained from 10 patients who were surgically treated. Immunohistochemical staining was performed with antibodies specific for TGF-beta1, MMP-2, and TIMP-2. RESULTS: The degree of immunohistochemical staining for TGF-beta1 was significantly weaker in AIP than in ACP in the pancreatic ductal epithelial and mononuclear cells (P = 0.029 and P = 0.018, respectively). CONCLUSIONS: This finding suggests that there may be a defect in the function of regulatory T (Treg) cells, which normally prevents autoimmune disease progression via a suppressor mechanism. Further studies are needed to identify the type of regulatory T cell involved in this process.

Activation of mitogen-activated protein kinases is involved in the induction of interferon beta gene in macrophages infected with Orientia tsutsugamushi.

We investigated the role of MAPK in IFN-beta gene expression in macrophages after infection with Orientia tsutsugamushi. ERK1/2 became phosphorylated in Orientia-stimulated macrophages. Selective inhibition of ERK1/2 and p38 MAPK could all significantly reduce Orientia-stimulated IFN-beta mRNA expression. Orientia inactivation by heat abolished IFN-beta mRNA induction only, whereas cytochalasin D treatment completely blocked both IFN-beta and chemokine expression, suggesting requirement of cellular internalization by viable bacteria for IFN-beta gene induction. In conclusion, our data indicate that MAPK pathways are required to induce maximal IFN-beta gene expression in macrophages during Orientia infection.

Cellular protection of morin against the oxidative stress induced by hydrogen peroxide.

Flavonoids are a class of secondary metabolites abundantly found in fruits and vegetables. In addition, flavonoids have been reported as potent antioxidants with beneficial effects against oxidative stress-related diseases such as cancer, aging, and diabetes. The present study was carried out to investigate the cytoprotective effects of morin (2',3,4',5,7-pentahydroxyflavone), a member of the flavonoid group, against hydrogen peroxide (H(2)O(2))-induced DNA and lipid damage. Morin was found to prevent the cellular DNA damage induced by H(2)O(2) treatment, which is shown by the inhibition of 8-hydroxy-2'-deoxyguanosine (8-OHdG) formation (a modified form of DNA base), inhibition of comet tail (a form of DNA strand breakage), and decrease of nuclear phospho histone H2A.X expression (a marker for DNA strand breakage). In addition, morin inhibited membrane lipid peroxidation, which is detected by inhibition of thiobarbituric acid reactive substance (TBARS) formation. Morin was found to scavenge the intracellular reactive oxygen species (ROS) generated by H(2)O(2) treatment in cells, which is detected by a spectrofluorometer, flow cytometry, and confocal microscopy after staining of 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA). Morin also induces an increase in the activity of catalase and protein expression. The results of this study suggest that morin protects cells from H(2)O(2)-induced damage by inhibiting ROS generation and by inducing catalase activation.

Chemokine and cytokine production in susceptible C3H/HeN mice and resistant BALB/c mice during Orientia tsutsugamushi infection.

To understand the pathogenesis of scrub typhus, we examined chemokine and cytokine production in susceptible (C3H/HeN) and resistant (BALB/c) mice after infection with O. tsutsugamushi Gilliam. C3H/HeN mice produced high levels of chemokines macrophage inflammatory proteins 1 alpha (MIP-1 alpha ), MIP-2, monocyte chemoattractant protein 1 (MCP-1), and cytokines gamma-interferon (IFN-gamma ), interleukin-12 (IL-12), IL-10, and tumor necrosis factor alpha (TNF-alpha ) in response to O. tsutsugamushi infection, compared to BALB/c mice. Chemokine profiles in infected mice correlated well with the kinetics of inflammatory cell infiltration. Hyperproduction of chemokines and cytokines was observed in another susceptible-infection model (BALB/c-Karp). These results suggest that hyperproduction of chemokines and cytokines are associated with susceptibility during O. tsutsugamushi infection.