Induction Of IL-6 Research Articles

Pro-inflammatory effects of inhaled Great Salt Lake dust particles

BackgroundClimate change and human activities have caused the drying of marine environments around the world. An example is the Great Salt Lake in Utah, USA which is at a near record low water level. Adverse health effects have been associated with exposure to windblown dust originating from dried lakebed sediments, but mechanistic studies evaluating the health effects of these dusts are limited.ResultsMonitoring data and images highlight the impact of local crustal and Great Salt Lake sediment dusts on the Salt Lake Valley/Wasatch front airshed. Great Salt Lake sediment and derived PM< 3.1 (quasi-PM2.5 or qPM2.5) contained metals/salts, natural and anthropogenic chemicals, and bacteria. Exposure of mice via inhalation and oropharyngeal aspiration caused neutrophilia, increased expression of mRNA for Il6, Cxcl1, Cxcl2, and Muc5ac in the lungs, and increased IL6 and CXCL1 in bronchoalveolar lavage. Inhaled GSLD qPM2.5 caused a greater neutrophilic response than coal fly ash qPM2.5 and was more cytotoxic to human airway epithelial cells (HBEC3-KT) in vitro. Pro-inflammatory biomarker mRNA induction was replicated in vitro using HBEC3-KT and differentiated monocyte-derived (macrophage-like) THP-1 cells. In HBEC3-KT cells, IL6 and IL8 (the human analogue of Cxcl1 and Cxcl2) mRNA induction was attenuated by ethylene glycol-bis(β-aminoethyl ether)-N, N,N′,N’-tetraacetic acid (EGTA) and ruthenium red (RR) co-treatment, and by TRPV1 and TRPV3 antagonists, but less by the Toll-like Receptor-4 (TLR4) inhibitor TAK-242 and deferoxamine. Accordingly, GSLD qPM2.5 activated human TRPV1 as well as other human TRP channels. Dust from the Salton Sea playa (SSD qPM2.5) also stimulated IL6 and IL8 mRNA expression and activated TRPV1 in vitro, but inhibition by TRPV1 and V3 antagonists was dose dependent. Alternatively, responses of THP-1 cells to the Great Salt Lake and Salton Sea dusts were partially mediated by TLR4 as opposed to TRPV1. Finally, “humanized” Trpv1N606D mice exhibited greater neutrophilia than C57Bl/6 mice following GSLD qPM2.5 inhalation.ConclusionsDust from the GSL playa and similar dried lakebeds may affect human respiratory health via activation of TRPV1, TRPV3, TLR4, and oxidative stress.

Thyroid peroxidase antibodies: prevalence and assessment of immunological parameter in the context of search for new predictive markers of hypothyroidism

BACKGROUND:The annual incidence of autoimmune pathologies is increasing. Studying the causes of their development and preventive measures are important. Despite the availability of analysis of antibodies to thyroid peroxidase (TPOAb), statistical data of the prevalence of AIT is incorrect. An identification of key molecular mechanisms is important for developing effective diagnostic and preventive strategies for preventing progression hypothyroidism. AIM:Assessment of the prevalence of TPOAb and the search for correlations of immunological parameters and the degree of thyroid dysfunction in AIT. MATERIALS AND METHODS:We examined 580 people over the age of 18. We measured serum levels of TSH, freeT4, TPOAb, did thyroid ultrasound, collected anamnesis. Part of them we evaluated immunological parameters: Treg; Breg; B10-lymphocytes; IFNγ, IL-17, IL-4 T lymphocytes. RESULTS:An increased level of TPOAb was detected in 143 individuals (24.7%). 73 (51.41%) of them had nodular goiter, 60 (41.96%) had hypothyroidism. We found significant differences between people with high level of TPOAb and healthy individuals in levels of TSH, ultrasound’s signs of autoimmune changes and information about having 3 or more children (p 0,001). We found significant correlation in level of TPOAb and having many children (p=0,037). We found a difference in count of Breg (in vitro incubation with additional activation) in the group of people with high levels of TPOAb and healthy donors, but without low level of IL-10 expression. We didn’t find significant differences in count of Treg, but degree of Treg’s induction was reduced when we added a specific activator. Impaired functional activity can be reason of it. CONCLUSION:Prevalence of high level of TPOAb – 24.6%. Women with 3 or more children had higher prevalence of high level of TPOAb, and significant correlation with level of TPOAb. Having many children can be risk factor of developing AIT. The study showed the expected difference in the amount of Breg in the group of people with high level of TPOAb, however, lower induction of IL-10 wasn’t observed. Further fundamental research is needed with larger target samples of individuals with AIT in the search for new prognostic markers of the development and progression of the disease.

Attenuation of skin injury by a MARCO targeting PLGA nanoparticle

Cutaneous exposure to the DNA alkylating class of chemotherapeutic agents including nitrogen mustard (NM) leads to both skin injury and systemic inflammation. Circulating myeloid subsets recruited to the skin act to further exacerbate local tissue damage while interfering with the wound healing process. We demonstrate herein that intravenous delivery of poly(lactic-co-glycolic acid) immune-modifying nanoparticles (PLGA-IMPs) shortly after NM exposure restricts accumulation of macrophages and inflammatory monocytes at the injury site, resulting in attenuated skin pathology. Furthermore, PLGA-IMPs induce an early influx and local enrichment of Foxp3+ regulatory T cells (Treg) in the skin lesions critical for the suppression of myeloid cell-pro-inflammatory responses via induction of IL-10 and TGF-β in the cutaneous milieu. Functional depletion of CD4+ Tregs ablates the efficacy of PLGA-IMPs accompanied by a loss of local accumulation of anti-inflammatory cytokines essential for wound healing. Thus, in severe skin trauma, PLGA-IMPs may have therapeutic potential via modulation of inflammatory myeloid cells and regulatory T lymphocytes.

Antimalarial Drug Artemotil Promotes Induction of Type 1 Regulatory T Cells.

Artemisinin and its derivatives, used as front-line anti-malarial drugs, exhibit anti-inflammatory properties. They were found to suppress the generation and function of Th1 and Th17 cells while promoting the generation of Foxp3 + regulatory T cells (Tregs). However, the specific role of Artemotil (β-arteether) in modulating the generation and functions of CD4 + T cells, particularly Type 1 regulatory T cells (Tr1), remains to be explored. Tr1 cells are one of the key cell types that are essential for regulating inflammatory response through IL-10. In this study, we report that Artemotil selectively promotes generation of Tr1 cells induced by IL-27 by upregulating signature genes of Tr1 cells, such as c-Maf, AhR, prdm1, IRF-1, and Batf, while inhibiting the Th1, Th2, and Th17 cells generation. We found that co-administration of Artemotil with anti-CD3 antibody increases the induction of IL-10 and frequency of Tr1 cells while suppressing Th1 and Th17 cells in vivo. Artemotil suppresses T-cell-induced enteropathy and alleviates the signs of colitis associated with the increased frequencies of Tr1 cells. Taken together, our data suggest that Artemotil provides protection in T-cell-mediated colitis by increasing the expansion of Tr1 cells and inhibiting the generation of Th1 and Th17 cells.

Fungal symbiont transmitted by free-living mice promotes type 2 immunity.

The gut mycobiota is crucial for intestinal homeostasis and immune function1. Yet its variability and inconsistent fungal colonization of laboratory mice hinders the study of the evolutionary and immune processes that underpin commensalism2,3. Here, we show that Kazachstania pintolopesii is a fungal commensal in wild urban and rural mice, with an exceptional ability to colonize the mouse gastrointestinal tract and dominate the gut mycobiome. Kazachstania pintolopesii colonization occurs in a bacteria-independent manner, results in enhanced colonization resistance to other fungi and is shielded from host immune surveillance, allowing commensal presence. Following changes in the mucosal environment, K. pintolopesii colonization triggers a type 2 immune response in mice and induces gastrointestinal eosinophilia. Mechanistically, we determined that K. pintolopesii activates type 2 immunity via the induction of epithelial IL-33 and downstream IL-33-ST2 signalling during mucus fluctuations. Kazachstania pintolopesii-induced type 2 immunity enhanced resistance to helminth infections or aggravated gastrointestinal allergy in a context-dependent manner. Our findings indicate that K. pintolopesii is a mouse commensal and serves as a valuable model organism for studying gut fungal commensalism and immunity in its native host. Its unnoticed presence in mouse facilities highlights the need to evaluate its influence on experimental outcomes and phenotypes.

Therapeutic BCG vaccine protects against long COVID: The BATTLE randomized clinical trial.

Bacillus Calmette-Guérin (BCG) injected during the COVID-19 convalescence period was safe and enhanced recovery from anosmia and dysgeusia in the acute phase. To report the long-term results of the BATTLE trial, BCG vaccine in adults with mild COVID-19. Design: Double-blind, placebo-controlled, randomized (1:1) clinical trial. BCG intradermal vaccine and placebo. A total of 157 BCG and 142 placebo recipients participated in the 6-month follow-up, and 97 BCG and 95 placebo recipients participated in the 12-month follow-up. Long COVID symptoms and mechanistic analyses. BCG reduced hearing problems at 6 months (odds ratio [OR]=0.26) and sleeping, concentration, memory, and vision problems at 12 months (OR=0.45, 0.36, 0.38, and 0.36, respectively). Sensitivity analyses confirmed that long COVID-19 symptoms were reduced at the 6- and 12-month follow-ups (p=0.010 and 0.031, respectively). BCG's crossover interaction paradoxically increased hair loss in women and decreased it in men at 6 months (p=0.032). BCG immunomodulation is likely mediated through inhibition of Fas ligand expression in the blood and increased induction of IL6, IL10, interferon-induced transmembrane protein 3, and angiotensin-converting enzyme 2 in cultured human macrophages. Long-term follow-up of the BATTLE trial participants revealed that BCG protects against long COVID development if administered within the COVID-19 convalescence period. The response to BCG was subject-specific, including a paradoxical crossover interaction based on sex. Not tested for previous mycobacterial exposure; loss to follow-up, particularly at 12 months.

Discovery of Novel PROTAC-Based HPK1 Degraders with High Potency and Selectivity for Cancer Immunotherapy.

Hematopoietic progenitor kinase 1 (HPK1, MAP4K1), a serine/threonine (SER/THR) kinase, has been identified as a negative immune regulator of T-cell receptor signaling. Deprivation of the HPK1 function suppresses tumor growth, providing an attractive strategy for cancer immunotherapy. Herein, we present a novel PROTAC-based HPK1 degrader compound DD205-291 with high selectivity and potency. DD205-291 showed a dose-dependent inhibition of SLP-76 phosphorylation and an induction of IL-2 and IFN-γ. Compared with other inhibitors, DD205-291 exhibited good efficacy and a favorable safety profile in the MC38 model. Specifically, oral administration of DD205-291 at 0.5 mg/kg in combination with anti-PD1 resulted in significant suppression with a TGI value of 91.0%. Furthermore, DD205-291 exhibited a low risk of cardiotoxicity and a wide safety window. This research effort demonstrates that DD205-291 is a promising preclinical candidate (PCC) for potential mono- and comboimmunotherapy of cancer.

Modulatory effects of inorganic mercury (Hg (II)) and lead (Pb (II)) on immune responses of Pekin ducklings (Anas platyrhynchos domesticus) upon a viral-like immune challenge

Trace metal contamination is ubiquitous around the world and may affect the health of wildlife. Divalent trace metals, including ions of mercury (Hg) and lead (Pb), have been shown to be immunotoxic to avian species. However, little is known about the immunomodulatory effects of trace metal exposure on viral infections, especially in young birds, who may be more sensitive. Therefore, the objective of the current study is to provide more insights in the causality between trace metal exposure and the effects of exposure on the immune responses in young waterfowls. Pekin duckling was used as an animal model to investigate the effects of inorganic divalent Hg (II) and Pb (II) on avian immune responses upon a viral-like challenge with double-stranded RNA. Our results indicate that Hg (II) altered the immune gene expression 24 h post-challenge, as reflected by induction of pro-inflammatory genes IL-8, iNOS, TLR3 and TLR7, and a significant decrease of microRNA-155. Ducklings exposed to Pb (II) showed lower levels of natural antibodies, reduced white blood cell counts and lower heterophil proportions 24 h post-challenge. Although inorganic divalent Hg (II) and Pb (II) showed specific differential effects on the immune response of Pekin ducklings, the overall adverse immunomodulatory outcomes in both cases point to inflammation, impaired B-cell function, and weaker immunocompetence.

Wnt/β-catenin maintains epithelial IL-33 in the colonic stem and progenitor cell niche and drives its induction in colitis

Interleukin (IL)–33 is a key responder to intestinal injury and inflammation. In the colon, it is expressed by several cell populations, with the specific cellular source likely determining its role. The colonic epithelium expresses IL-33; however, the factors controlling its production and the specific epithelial lineage(s) expressing IL-33 are poorly understood. We recently reported that colonic epithelial IL-33 is induced by inhibition of glycogen synthase kinase-3β (GSK3β), but the signaling pathway mediating this induction is unknown. Here we tested the role of Wnt/β-catenin signaling in regulating colonic epithelial IL-33 at homeostasis and in injury-induced colitis. Transcriptomic analysis shows that epithelial IL-33 localizes to stem and progenitor cells. Ligand activation of Wnt/β-catenin signaling induced IL-33 in colonic organoid and cell cultures. Furthermore, small-molecule disruption of β-catenin interaction with cyclic AMP response element binding protein (CBP) prevented epithelial IL-33 induction. Antagonism of CBP/β-catenin signaling also prevented rapid epithelial IL-33 induction in dextran sodium sulfate (DSS)-mediated colitis, and was associated with maintenance of crypt-expressed host defense peptides. Together, these findings show β-catenin-driven production of epithelial IL-33 is an early response to colonic injury that shapes the crypt base defense response and suggest an immunoregulatory role for the stem cell niche in tissue injury.

Multi-drug resistant Staphylococcus epidermidis from chronic wounds impair healing in human wound model.

Venous leg ulcers (VLUs) represent one of the most prevalent types of chronic wounds characterised by perturbed microbiome and biofilm-forming bacteria. As one of the most abundant skin-commensal, Staphylococcus epidermidis is known as beneficial for the host, however, some strains can form biofilms and hinder wound healing. In this study, S. epidermidis distribution in VLUs and associated resistome were analysed in ulcer tissue from patients. Virulence of S. epidermidis isolates from VLUs were evaluated by whole genome sequencing, antimicrobial susceptibility testing, in vitro biofilm and binding assays, and assessment of biofilm-forming capability and pro-inflammatory potential using human ex vivo wound model. We demonstrated that S. epidermidis isolates from VLUs inhibit re-epithelialization through biofilm-dependent induction of IL-1β, IL-8, and IL-6 which was in accordance with impaired healing outcomes observed in patients. High extracellular matrix binding ability of VLU isolates was associated with antimicrobial resistance and expression levels of the embp and sdrG, responsible for bacterial binding to fibrinogen and fibrin, respectively. Finally, we showed that S. epidermidis from VLUs demonstrate pathogenic features with ability to impair healing which underscores the emergence of treatment-resistant virulent lineages in patients with chronic ulcers.

Unveiling the Immunomodulatory and regenerative potential of iPSC-derived mesenchymal stromal cells and their extracellular vesicles

Induced pluripotent stem cell (iPSC)-derived mesenchymal stromal cells (iMSCs) offer a promising alternative to primary mesenchymal stromal cells (MSCs) and their derivatives, particularly extracellular vesicles (EVs), for use in advanced therapy medicinal products. In this study we evaluated the immunomodulatory and regenerative potential of iMSCs as well as iMSC-EVs, alongside primary human umbilical cord-derived mesenchymal stromal cells (hUCMSCs). Our findings demonstrate that iMSCs exhibit comparable abilities to hUCMSCs in regulating lymphocyte proliferation and inducing an anti-inflammatory phenotype in monocytes. We also observed decreased TNFα levels and increased IL-10 induction, indicating a potential mechanism for their immunomodulatory effects. Furthermore, iMSC-EVs also showed effective immunomodulation by inhibiting T cell proliferation and inducing macrophage polarization similar to their parental cells. Additionally, iMSC-EVs exhibited pro-regenerative potential akin to hUCMSC-EVs in in vitro scratch assays. Notably, priming iMSCs with pro-inflammatory cytokines significantly enhanced the immunomodulatory potential of iMSC-EVs. These results underscore the considerable promise of iMSCs and iMSCs-EVs as an alternate source for MSC-derived therapeutics, given their potent immunomodulatory and regenerative properties.

Microbiome-derived metabolite effects on intestinal barrier integrity and immune cell response to infection.

The gut microbiota exerts a significant influence on human health and disease. While compositional changes in the gut microbiota in specific diseases can easily be determined, we lack a detailed mechanistic understanding of how these changes exert effects at the cellular level. However, the putative local and systemic effects on human physiology that are attributed to the gut microbiota are clearly being mediated through molecular communication. Here, we determined the effects of gut microbiome-derived metabolites l-tryptophan, butyrate, trimethylamine (TMA), 3-methyl-4-(trimethylammonio)butanoate (3,4-TMAB), 4-(trimethylammonio)pentanoate (4-TMAP), ursodeoxycholic acid (UDCA), glycocholic acid (GCA) and benzoate on the first line of defence in the gut. Using in vitro models of intestinal barrier integrity and studying the interaction of macrophages with pathogenic and non-pathogenic bacteria, we could ascertain the influence of these metabolites at the cellular level at physiologically relevant concentrations. Nearly all metabolites exerted positive effects on barrier function, but butyrate prevented a reduction in transepithelial resistance in the presence of the pathogen Escherichia coli, despite inducing increased apoptosis and exerting increased cytotoxicity. Induction of IL-8 was unaffected by all metabolites, but GCA stimulated increased intra-macrophage growth of E. coli and tumour necrosis-alpha (TNF-α) release. Butyrate, 3,4-TMAB and benzoate all increased TNF-α release independent of bacterial replication. These findings reiterate the complexity of understanding microbiome effects on host physiology and underline that microbiome metabolites are crucial mediators of barrier function and the innate response to infection. Understanding these metabolites at the cellular level will allow us to move towards a better mechanistic understanding of microbiome influence over host physiology, a crucial step in advancing microbiome research.

The Immune Regulatory Functions in B Cells Are Restored by CpG to Reduce Experimental Food Allergy.

Dysfunctional immune regulation contributes to the pathogenesis of food allergy (FA). The mechanism behind regulatory B-cell dysfunction is unclear. CpG has immune regulatory functions. The purpose of this study is to use CpG to recover the immune suppressive functions of B cells in mice with FA. An FA mouse model was created using ovalbumin as the specific antigen. Flow cytometry was used to isolate B cells from the intestinal tissues. The immune regulatory functions of B cells were assessed using immunological approaches. The results showed that the FA response was linked to low IL-10 levels in gut lavage fluids of FA mice. FA mouse intestinal B cells produced lower amounts of IL-10 as compared with B cells isolated from naïve control mice. Impaired immune suppressive functions were observed in B cells isolated from the FA mouse intestine. The inducibility of the Il10 expression in naïve B cells of the intestine of FA mice was defective. The induction of Il10 expression in FA B cells could be restored by CpG through regulating the methylation status of the Cmip promoter. CpG promoted the therapeutic efficacy of allergen specific immunotherapy by restoring the induction of IL-10+ B cells in the intestine. The expression of Il10 in B cells of the FA mouse intestine was impaired. Administration of CpG could restore the expression of Il10 in B cells in the intestine and promote immunotherapy for FA.

Brugia malayi filarial helminth-derived extracellular vesicles suppress antigen presenting cell function and antigen-specific CD4+ T cell responses.

Live microfilariae (mf) and mf-derived extracellular vesicles (EVs) have been shown to modulate human antigen presenting cell (APC) function, most notably by suppressing the induction of IL-12 (and other pro-inflammatory cytokines) following activation with LPS and interferon-y. To explore further how EVs alter human APC function, we studied the effect ofmf and EVs on human elutriated monocyte-derived dendritic cells (DC) following exposure to Mf, mf-derived excretory/secretory (E/S) products, E/S depleted of EVs through ultracentrifugation and purified EVs. After demonstrating that the measurable responses induced by live mf could be recapitulated by EVs and EV-containing E/S, we next performed RNAseq analysis of human DC following exposure to live mf, EVs, E/S, or EV-depleted E/S. In our analyses of the data for the DC, using a false discovery rate (FDR)<0.05, EV-exposed DC had induced the expression of 212 differentially expressed genes (DEGs) when compared to unexposed DC and 157 when compared to E/S-depleted EVs. These genes were enriched in GO biological processes associated with neutrophil degranulation and 15 DEGs associated with KEGG Lysosome pathways. IPA analysis point to immune dysregulation. We next aimed to understand the intracellular processes altered by EVs and the effect these have on effector T cells. When SARS CoV-2 Membrane-specific CD4+ TCLs were assessed following EV conditioning of autologous DC and activation with the SARS CoV-2-Membrane peptide pool, we found conditioning reduced the frequency of SARS CoV-2 Membrane-specific CD3+ CD4+ CD154+ cells (p=.015). Similarly, EV-conditioning of SARS CoV-2 Membrane-specific CD3+ CD4+ cells induced fewer cell capable of producing IFN-γ (p=.045). Taken together, our data suggest a modulatory role of EVs on APC function that likely leads to defects in T cell effector function.

A Synbiotic Combining Chitin-Glucan and Lactobacillus acidophilus NCFM Induces a Colonic Molecular Signature Soothing Intestinal Pain and Inflammation in an Animal Model of IBS.

Chitin-glucan (CG) is a new generation of prebiotic. Lactobacillus acidophilus NCFM® (NCFM) is a probiotic with the ability to decrease abdominal pain. We evaluate the functional and molecular gastrointestinal responses to a synbiotic administration combining CG and NCFM in a rat model of long-lasting colon hypersensitivity. The intracolonic pressure was assessed during the 9-week experiment in animals receiving CG in association or not with NCFM and compared to that in Lacticaseibacillus paracasei Lpc-37®-treated animals and control rats receiving tap water. The effects of the synbiotic were evaluated using the Wallace score, the quantification of colon myeloperoxidase (MPO) and the master genes driving analgesia and inflammation. CG 1.5 alone and NCFM 109 colony forming units (CFU) alone similarly decreased the visceral pain sensitivity. Lpc-37 had no significant effect. The best profile of pain perception inhibition was obtained with the combination of CG 1.5 g and NCFM 109 CFU, confirming a synbiotic property. This synbiotic treatment significantly reduced macroscopic colonic lesions and MPO concentrations, and induced master genes involved in analgesia (CB1, CB2, MOR, PPARα), with a downregulation of inflammatory cytokines (IL-1β, TNFα) and an induction of IL-10 and PPARγ. In conclusion, CG 1.5 g + NCFM 109 CFU significantly decreased visceral pain perception and intestinal inflammation through the regulation of master genes.

5114 Establishment of Thyroid Storm Mouse Model and Therapeutic Effects of Ghrelin

Abstract Disclosure: C. Kurimoto: None. Y. Furukawa: None. T. Akamizu: None. A. Doi: None. K. Takeshima: None. S. Morita: None. H. Iwakura: None. H. Ariyasu: None. H. Furuta: None. M. Nishi: None. T. Matsuoka: None. Context: Thyroid storm (TS), a life-threatening condition that can damage multiple organs, is caused by a combination of thyrotoxicosis and severe physical stresses. Infection is the most common triggering factor. Hypercytokinemia is a suggested background, but the pathological condition is unclear and there are no appropriate animal models. Further, TS has limited therapeutic options. Objectives: We aimed to confirm the hypercytokinemia in patients with TS, establish a TS model mouse by triiodothyronine and lipopolysaccharide administration, and explore the therapeutic effects of ghrelin on TS. Methods: We evaluated serum IL-6 levels as a representative marker of hypercytokinemia in patients with TS. As a TS model, C57BL/6 mice were titrated with triiodothyronine and lipopolysaccharide to develop a lethal model with approximately 30% survival at 24 hours. We assessed the survival ratio, mouse sepsis scores and blood biomarkers (IL-6, metanephrine, alanine aminotransferase) and evaluated the effects of ghrelin on these parameters. Results: Serum IL-6 was increased in patients with TS compared with those with Graves' disease without TS (55.7 ± 69.0 vs. 3.13 ± 1.41 pg/mL, P &amp;lt; .05, n=4 each). Next, we titrated the doses of T3 and LPS, aiming to achieve a survival rate of approximately 30% at 24 hours after administration. Two out of five mice in the T3 3.0 mg/kg group died, while none of the eight mice in the T3 1.0 mg/kg group died. Therefore, we determined that the appropriate T3 dose for the TS mouse model is 1.0 mg/kg, which is not lethal when administered alone. In the T3 1.0 mg/kg group (n=8), serum FT3 levels were approximately three times higher (15.3 ± 4.5 vs. 4.5 ± 0.7pg/ml) than those in the control group (n=8). Next, different doses of LPS was added to the T3 group. Survival at 24 hours post-dose was 60% in the T3 + LPS 0.2 mg/kg group (n=5) and 33% in the T3 + LPS 0.5 mg/kg group (n=5), while survival was 100% in the LPS 0.5 mg/kg alone group (n=5),. Based on these findings, the dosage for the murine TS model was determined to be “triiodothyronine 1.0 mg/kg and lipopolysaccharide 0.5 mg/kg”. This TS model group had increased mouse sepsis score, serum IL-6, metanephrine and alanine aminotransferase. In this model, the ghrelin at 300 µg/kg improved the survival rate to 66.7% (P &amp;lt; .01, vs. 0% [saline-treated group]) as well as the mouse sepsis score, and it decreased the serum IL-6 and metanephrine. Conclusion: We confirmed the hypercytokinemia in patients with TS. Next, we established a lethal model simulating TS by inducing “thyrotoxicosis” by exogenous administration of thyroid hormones, and by inducing “sepsis” by intraperitoneal administration of LPS. The model mice exhibited similar pathophysiological status to human TS associated with induction of serum IL-6 and other biomarkers, which were improved by ghrelin. Presentation: 6/1/2024

The iNKT cell ligand α-GalCer prevents murine septic shock by inducing IL10-producing iNKT and B cells.

α-galactosylceramide (α-GalCer), a prototypical agonist of invariant natural killer T (iNKT) cells, stimulates iNKT cells to produce various cytokines such as IFNγ and IL4. Moreover, repeated α-GalCer treatment can cause protective or pathogenic outcomes in various immune-mediated diseases. However, the precise role of α-GalCer-activated iNKT cells in sepsis development remains unclear. To address this issue, we employed a lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced murine sepsis model and two alternative models. Sepsis was induced in wild-type (WT) C57BL/6 (B6) mice by three methods (LPS/D-GalN, α-GalCer/D-GalN, and cecal slurry), and these mice were monitored for survival rates. WT B6 mice were intraperitoneally injected with α-GalCer or OCH (an IL4-biased α-GalCer analog) one week prior to the induction of sepsis. To investigate the effects of α-GalCer-mediated iNKT cell activation on sepsis development, immune responses were analyzed by flow cytometry using splenocytes and liver-infiltrating leukocytes. In addition, a STAT6 inhibitor (AS1517499) and an IL10 inhibitor (AS101) were employed to evaluate the involvement of IL4 or IL10 signaling. Furthermore, we performed B cell adoptive transfers to examine the contribution of α-GalCer-induced regulatory B (Breg) cell populations in sepsis protection. In vivo α-GalCer pretreatment polarized iNKT cells towards IL4- and IL10-producing phenotypes, significantly attenuating LPS/D-GalN-induced septic lethality in WT B6 mice. Furthermore, α-GalCer pretreatment reduced the infiltration of immune cells to the liver and attenuated pro-inflammatory cytokine production. Treatment with a STAT6 inhibitor was unable to modulate disease progression, indicating that IL4 signaling did not significantly affect iNKT cell-mediated protection against sepsis. This finding was confirmed by pretreatment with OCH, which did not alter sepsis outcomes. However, interestingly, prophylactic effects of α-GalCer on sepsis were significantly suppressed by treatment with an IL10 antagonist, suggesting induction of IL10-dependent anti-inflammatory responses. In addition to IL10-producing iNKT cells, IL10-producing B cell populations were significantly increased after α-GalCer pretreatment. Overall, our results identify α-GalCer-mediated induction of IL10 by iNKT and B cells as a promising option for controlling the pathogenesis of postoperative sepsis.

Reversing Pdgfrβ signaling restores metabolically active beige adipocytes by alleviating ILC2 suppression in aged and obese mice

ObjectivePlatelet Derived Growth Factor Receptor Beta (Pdgfrβ) suppresses the formation of cold temperature-induced beige adipocytes in aged mammals. We aimed to determine if deleting Pdgfrβ in aged mice could rejuvenate metabolically active beige adipocytes by activating group 2 innate lymphoid cells (ILC2), and whether this effect could counteract diet-induced obesity-associated beige fat decline. MethodsWe employed Pdgfrβ gain-of-function and loss-of-function mouse models targeting beige adipocyte progenitor cells (APCs). Our approach included cold exposure, metabolic cage analysis, and age and diet-induced obesity models to examine beige fat development and metabolic function under varied Pdgfrβ activity. ResultsAcute cold exposure alone enhanced metabolic benefits in aged mice, irrespective of beige fat generation. However, Pdgfrβ deletion in aged mice reestablished the formation of metabolically functional beige adipocytes, enhancing metabolism. Conversely, constitutive Pdgfrβ activation in young mice stymied beige fat development. Mechanistically, Pdgfrβ deletion upregulated IL-33, promoting ILC2 recruitment and activation, whereas Pdgfrβ activation reduced IL-33 levels and suppressed ILC2 activity. Notably, diet-induced obesity markedly increased Pdgfrβ expression and Stat1 signaling, which inhibited IL-33 induction and ILC2 activation. Genetic deletion of Pdgfrβ restored beige fat formation in obese mice, improving whole-body metabolism. ConclusionsThis study reveals that cold temperature exposure alone can trigger metabolic activation in aged mammals. However, reversing Pdgfrβ signaling in aged and obese mice not only restores beige fat formation but also renews metabolic function and enhances the immunological environment of white adipose tissue (WAT). These findings highlight Pdgfrβ as a crucial target for therapeutic strategies aimed at combating age- and obesity-related metabolic decline.

Influence of oipA Phase Variation on Virulence Phenotypes Related to Type IV Secretion System in Helicobacter pylori.

oipA, an outer membrane protein of Helicobacter pylori, is linked to IL-8 induction and gastric inflammation, but its role is debated due to inconsistent findings. This study aims to explore the role of oipA phase variation in modulating the virulence traits of H. pylori, a bacterium strongly associated with the development of gastric cancer. American clinical isolate AH868 strain for naturally occurring phase variations of the oipA gene, and G27 strain for invitro-induced phase variations were used to elucidate oipA's impact on key virulence phenotypes, including cell elongation, CagA phosphorylation, and IL-8 induction. Using AH868 strain, natural oipA phase variation does not affect cell elongation and IL-8 induction. Interestingly, however, invitro-induced oipA phase variations in G27 strain uncovered that 9.4% of oipA "Off" transformants exhibit reduced cell elongation while all maintaining consistent IL-8 induction levels. Additionally, complementation of oipA "Off to On" status restores the cell elongation phenotype in 12.5% of transformants, highlighting the importance of oipA in maintaining normal cell morphology. Crucially, these variations in cell elongation are not linked to changes in bacterial adherence capabilities. Furthermore, the study shows a correlation among oipA phase variation, cell elongation, and CagA phosphorylation, suggesting that oipA influences the functionality of the Type IV secretion system. Whole-genome sequencing of selected transformants reveals genetic variations in bab paralogue, cagY gene, and other genomic regions, underscoring the complex genetic interactions that shape H. pylori's virulence. Our research provides new insights into the subtle yet significant role of oipA phase variation in H. pylori pathogenicity, emphasizing the need for further studies to explore the intricate molecular mechanisms involved. This understanding could pave the way for targeted therapeutic strategies to mitigate the impact of H. pylori on human health.

Abstract P395: Activated T cells from Bph/2 Mice Have an Attenuated Cytokine Response to a Polyclonal T Cell Activator Compared to T cells from Bpn/3 Mice

Numerous studies point to a role for the immune system in various animal models of hypertension. However, there is little known about the immune system of Bph/2 mice, a spontaneously hypertensive mouse model. To address this, the purpose of the current study was a comprehensive comparison of the cytokine response of activated T cells from Bph/2 mice and Bpn/3 normotensive controls. To implement this, we quantified cytokine secretion from cell supernatants from anti-CD3/anti-CD28-activated splenocytes derived from either Bph/2 mice or the normotensive Bpn/3 control mice. In comparison to Bph/2 mice, activated T cells from Bpn/3 mice secreted greater levels of cytokines including, IL-2, IL-3, IL-4, IL-5, IFNγ, GM-CSF, TNFβ and TNFα. We noticed a particularly marked discrepancy in Th17 cytokines where T cells from Bph/2 mice had little to no induction of IL-17F (0 ± 0 pg/ml), IL-21 (1.388 ± 1.388 pg/ml) and IL-22 (1.922 ± 0.633 pg/ml ) in comparison to T cells from Bpn/3 mice (IL-17F: 2.972 ± 1.525 pg/ml; IL-21: 16.48 ± 8.368 pg/ml; IL-22: 62.84 ± 15.94 pg/ml) which showed a measurable induction of these cytokines. Likewise, the IL-17A response was lower in T cells from Bph/2 mice (19.23 ± 5.576 pg/ml) compared to those from Bpn/3 mice (55.79 ± 11.32 pg/ml). There was also a notable disparity in the secretion of TNFβ where T cells from Bpn/3 mice (543.6 ± 175.8 pg/ml) showed a robust response versus the response of T cells from Bph/2 mice (20.64 ± 16.43 pg/ml), which was less than 10% than that of T cells from Bpn/3 mice. Interestingly, while T cells from Bph/2 mice had much lower induction of the signature Th2 cytokine, IL-4 (Bpn/3: 326.2 ± 59.18 pg/ml vs. Bph/2: 130.3 ± 21.58 pg/ml), there was little difference in IL-9 (Bpn/3: 12.9 ± 1.689 pg/ml vs. Bph/2: 19.06 ± 2.903 pg/ml), which is also associated with a Th2 response. We also found that Bph/2 mice had a diminished chemokine response as compared to T cells from Bpn/3 mice. Overall, the data suggest that polyclonally activated T cells from Bph/2 mice have a weaker cytokine/chemokine response as compared to T cells from Bpn/3 mice which may be due to an overall attenuated activation of T cells from Bph/2 mice.