Interferon-γ Production Research Articles

SON-1010: an albumin-binding IL-12 fusion protein that improves cytokine half-life, targets tumors, and enhances therapeutic efficacy.

Cytokines have been promising cancer immunotherapeutics for decades, yet only two are licensed to date. Interleukin-12 (IL-12) is a potent regulator of cell-mediated immunity that activates NK cells and interferon-γ (IFNγ) production. It plays a central role in multiple pathways that can enhance cancer cell death and modify the tumor microenvironment (TME). Attempts to dose rIL-12 were initially successful but IFNγ toxicity in Phase 2 complicated further development in the late 1990s. Since then, better dosing strategies have been developed, but none have achieved the level of cancer control seen in preclinical models. We set out to develop a novel strategy to deliver fully functional IL-12 and other biologics to the TME by binding albumin, taking advantage of its ability to be concentrated and retained in the tumor. Single-chain variable fragments (scFv) were identified from a human phage display library that bound human, mouse, and cynomolgus macaque serum albumin, both at physiologic and acidic conditions. These were taken through a series of steps to identify strongly binding molecules that don't interfere with the normal physiology of albumin to bind FcRn, giving it prolonged half-life in serum, along with SPARC/GP60, which allows albumin to target the TME. A final molecule was chosen and a single mutation was made that minimizes the potential for immunogenicity. This fully human albumin-binding (FHAB®) domain was characterized and manufacturing processes were developed to bring the first drug candidate into the clinic. Once identified, the murine form of mIL12-FHAB was studied preclinically to understand its mechanism of action and biodistribution. It was found to be much more efficient at blocking tumor growth compared to murine IL-12, while stimulating significant IFNγ production with minimal toxicity. SON-1010, which uses the human IL-12 sequence, passed through all of the characterization and required toxicology and is currently being studied in the clinic. We identified and developed a platform technology with prolonged half-life that can target IL-12 and other immune modulators to the TME. Safety and efficacy are being studied using SON-1010 as monotherapy and in combination with checkpoint blockade strategies.

The performance of a new rapid interferon gamma release assay based on fluorescence immunochromatography for Mycobacterium tuberculosis infection testing in village doctors in China.

The AIMTB rapid test assay is an emerging test, which adopted a fluorescence immunochromatographic assay to measure interferon-γ (IFN-γ) production following stimulation of effector memory T cells in whole blood by mycobacterial proteins. The aim of this article was to explore the ability of AIMTB rapid test assay in detecting Mycobacterium tuberculosis (MTB) infection compared with the widely applied QuantiFERON-TB Gold Plus (QFT-Plus) test among rural doctors in China. In total, 511 participants were included in the survey. The concordance between the QFT-Plus test and the AIMTB rapid test assay was 94.47% with a Cohen's kappa coefficient (κ) of 0.84 (95% CI, 0.79-0.90). Improved concordance between the two tests was observed in males and in participants with 26 or more years of service as rural doctors. The quantitative values of the QFT-Plus test was higher in individuals with a result of QFT-Plus-/AIMTB+ as compared to those with a result of QFT-Plus-/AIMTB- (p<0.001). Overall, our study found that there was an excellent consistency between the AIMTB rapid test assay and the QFT-Plus test in a Chinese population. As the AIMTB rapid test assay is fast and easy to operate, it has the potential to improve latent tuberculosis infection testing and treatment at the community level in resource-limited settings.

Caspase-1 in Cx3cr1-expressing cells drives an IL-18-dependent T cell response that promotes parasite control during acute Toxoplasma gondii infection.

Inflammasome activation is a robust innate immune mechanism that promotes inflammatory responses through the release of alarmins and leaderless cytokines, including IL-1α, IL-1β, and IL-18. Various stimuli, including infectious agents and cellular stress, cause inflammasomes to assemble and activate caspase-1. Then, caspase-1 cleaves targets that lead to pore formation and leaderless cytokine activation and release. Toxoplasma gondii has been shown to promote inflammasome formation, but the cell types utilizing caspase-1 and the downstream effects on immunological outcomes during acute in vivo infection have not been explored. Here, using knockout mice, we examine the role of caspase-1 responses during acute T. gondii infection globally and in Cx3cr1-positive populations. We provide in vivo evidence that caspase-1 expression is critical for, IL-18 release, optimal interferon-γ (IFN-γ) production, monocyte and neutrophil recruitment to the site of infection, and parasite control. Specifically, we find that caspase-1 expression in Cx3cr1-positive cells drives IL-18 release, which potentiates CD4+ T cell IFN-γ production and parasite control. Notably, our Cx3cr1-Casp1 knockouts exhibited a selective T cell defect, mirroring the phenotype observed in Il18 knockouts. In further support of this finding, treatment of Cx3cr1-Casp1 knockout mice with recombinant IL-18 restored CD4+ T cell IFN-γ responses and parasite control. Additionally, we show that neutrophil recruitment is dependent on IL-1 receptor accessory protein (IL-1RAP) signaling but is dispensable for parasite control. Overall, these experiments highlight the multifaceted role of caspase-1 in multiple cell populations contributing to specific pathways that collectively contribute to caspase-1 dependent immunity to T. gondii.

Meibomian gland lipid alterations and ocular surface sequela in Awat2 knockout murine model of meibomian gland dysfunction and evaporative dry eye disease

PurposeThere is an urgent need for animal models of meibomian gland dysfunction (MGD) and evaporative dry eye disease (EDED) to understand their pathophysiology and investigate novel therapeutics. This study sought to further define the acyl-CoA: wax alcohol acyltransferase 2 knockout (Awat2 KO) mouse as a model of EDED using a combination of novel clinical, biochemical, and biophysical endpoints. MethodsWildtype and Awat2 KO mice between 1 and 18 months of age were used. Ocular examinations and advanced imaging were performed. The lipidomic composition and in situ melting temperature of meibum were determined. qPCR was performed to define ocular surface gene and pro-inflammatory transcript expression. Dynamic contact angle goniometry was performed to assess the adherence capability of the ocular surface. ResultsAwat2 KO mice have mild, white, hyperreflective corneal opacities of the anterior stroma and significantly enlarged apical epithelial cells (P = 0.0004). In Awat2 KO meibum, wax esters were 9–10 times lower than in wildtype meibum. Additionally, meibum melting temperature increased from 32° to 47 °C (P < 0.0001), leading to impaired meibum secretion and dilation of the central duct. Awat2 KO corneal epithelia had significantly decreased mucin expression (Muc1 and Muc4, P = 0.0043) and increased interferon-γ production (P = 0.0303). Awat2 KO globes have a significantly shortened time of droplet adherence to their ocular surface (P = 0.0053), indicating a decreased tear film adherence capacity. Wildtype corneal epithelia does not express Awat2, indicating that the EDED phenotype is secondary to the loss of Awat2 from the meibomian glands. ConclusionsAwat2 KO mice recapitulate many of features of human MGD and EDED, representing a model to test novel therapeutics.

Vitamin D treatment distinctly modulates cytokine production by peripheral blood mononuclear cells among patients with chronic cardiac and indeterminate clinical forms of Chagas disease.

Chagas disease is caused by the protozoan Trypanosoma cruzi and is clinically divided into acute and chronic phases. Chronic Chagas cardiomyopathy is the most studied manifestation of the disease. Vitamin D deficiency has been suggested as a risk factor for cardiovascular disease. No studies demonstrate the action of this hormone in the cells of patients with chronic Chagas heart disease. To evaluate the in vitro immunomodulatory effect of vitamin D on peripheral blood mononuclear cellsof patients with the different chronic clinical forms of Chagas disease. Evaluating vitamin D's in vitro effect on blood cells by producing cytokines. Thirteen patients of the undetermined form (IND), 13 of the mild cardiac form (CARD1) and 14 of the severe cardiac form (CARD2) of Chagas disease, and 12 with idiopathic heart disease (CARDid) were included. The cells obtained from peripheral blood were treated in vitro with vitamin D (1 × 10-7 M) for 24 h and cytokines were dosed in the culture supernatant. Although it was not possible to demonstrate statistically significant differences between the groups studied, our data showed that the cells treated with vitamin D modify (p < .05) the production of interferon-γ(IFN-γ) (decrease in IND), tumor necrosis factor-α (TNF-α) (decreased in CARD1 and CARDid),interleukin(IL)-6 (increased in all groups), and IL-10 (decreased in CARD1, CARD2, and CARDid) when compared to untreated cells. In vitro treatment with vitamin D distinctly modulated the production of cytokines by mononuclear cells of peripheral blood among patients with chronic and indeterminate cardiac clinical forms of Chagas disease.

IL-18 primes T cells with an antigen-inexperienced memory phenotype for proliferation and differentiation into effector cells through Notch signaling.

Recent studies have revealed that a subset of CD8+ T cells exhibit innate features and can be activated by cytokines. However, the precise mechanisms underlying the proliferation and differentiation of these cells remain unclear. Here, we demonstrated that CD44highCD8+ T cells in the mouse spleen express functional interleukin-18 (IL-18) receptors, whereas CD44lowCD8+ T cells do not. In response to IL-18 stimulation, these cells activated various metabolic pathways, upregulated the expression of surface molecules, such as c-Kit (CD117), CD25, and PD-1, and induced progression through the G1/S phase in the cell cycle. IL-18-primed cells, expressing a high-affinity receptor for IL-2, exhibited robust proliferation in response to IL-2 and underwent differentiation into effector cells. The splenic CD44highCD8+ T cells exhibited high expression levels of CD122, CD62L, CCR7, and CXCR3, along with CD5, indicating their potential for migration to the lymph nodes, where they could undergo expansion and terminal differentiation into effector cells. Additionally, in a tumor model, administration of IL-18 increased the accumulation of CD8+ T cells in both the lymph nodes and tumors. It is noteworthy that stimulation of CD44highCD8+ T cells with IL-18 upregulated the Notch-1 receptor and c-Myc. Moreover, inclusion of γ-secretase inhibitors attenuated the effect of IL-18 on both proliferation and interferon-γ production in the cells. These results demonstrate that IL-18 primes CD44highCD122highCXCR3highCD62LhighCD8+ T cells for expansion and differentiation into effector cells in a Notch signaling-dependent manner.

In vitro-irradiated cancer vaccine enhances anti-tumor efficacy of radiotherapy and PD-L1 blockade in a syngeneic murine breast cancer model

Background and PurposeLocal radiotherapy (RT) exerts immunostimulatory effects by inducing immunogenic cell death. However, it remains unknown whether in vitro–irradiated tumor cells can elicit anti-tumor responses and enhance the efficacy of local RT and immune checkpoint inhibitors when injected in vivo. Methods and MaterialsWe tested the “in vitro–irradiated cancer vaccine (ICV)”, wherein tumor cells killed by varying doses of irradiation and their supernatants are intravenously injected. We examined the efficacy of combining local RT (24 Gy in three fractions), PD-L1 blockade, and the ICV in a murine breast cancer model. The immune cell profiles were analyzed via flow cytometry and immunohistochemistry. The cytokine levels were measured by multiplex immunoassays. ResultsThe ICV significantly increased the effector memory phenotype and interferon-γ production capacity in splenic CD8+ T cells. The in vitro–irradiated products contained immune response-related molecules. When combined with local RT and PD-L1 blockade, the ICV significantly delayed the growth of irradiated and non-irradiated tumors. The triple combination therapy increased the proportions of CD8+ T cells and effector memory CD8+ T cells while decreasing the proportion of CTLA-4+ exhausted CD8+ T cells within tumor microenvironment. Additionally, plasma level of interferon-γ and proliferation of effector T cells in the spleen and tumor-draining lymph nodes were significantly increased by the triple combination therapy. ConclusionsThe ICV enhanced the therapeutic efficacy of local RT and PD-L1 blockade by augmenting anti-tumor immune responses. Our findings suggest a therapeutic potential of in vitro–irradiation products of tumor cells.

Experimentally investigated “CoronaDerm-PS”-driven SARS-CoV-2-specific cellular immunity and safety

Novel coronavirus disease 2019, caused by the SARS-CoV-2, initiate humoral and cellular immune responses against diverse virus antigens. The assessment of SARS-CoV-2-specific is mainly carried out in routine practice by determining specific immunoglobulins. However, high variability in S-protein structure in new genovariants of SARS-CoV-2 virus and the lack of correlation between specific antibodies and CD8+ T-lymphocytes underlie false negative responses, and mass assessment of cellular immunity is complicated due to the complexity of applying ELISPOT and cytofluorometry techniques. To solve this issue, a diagnostic method was developed for assessing SARS-CoV-2-specific cellular immune response, which is based on a skin test followed by evaluating a delayed-type hypersensitivity reaction involving antigen-specific memory T-lymphocytes. A diagnostic preparation CoronaDerm-PS is based on Cord_PS, which is a hybrid recombinant protein consisting of parts of the SARS-CoV-2 structural proteins S, M, N, E. The specific activity of this chimeric antigen was analyzed in cultured T-lymphocyte activation test by assessing interferon-γ production using cytofluorometry. To investigate the chimeric antigen specific activity, a preclinical safety study with CoronaDerm-PS preparation in experimental animals was conducted. A dose-dependent developing skin reaction was observed in 90–100% of guinea pigs vaccinated by EpiVacCorona, CoviVac, Gam-COVID-Vac, which confirms a potential for assessing post-vaccination cellular immunity using CoronaDerm-PS preparation. Upon this, the presence of functionally active T-cell-antigenic epitopes in the recombinant polypeptide allows to evaluate SARS-CoV-2-specific response illustrated by detected response after Gam-COVID-Vac (S-protein) and EpiVacCorona (N-protein) vaccination. Thus, a skin test based on CoronaDerm-PS preparation may be a promising diagnostic tool for rapid mass screening requiring no specialized laboratory equipment for assessing populational SARS-CoV-2-specific immunity. Such a test is distinguished by advantages such as ease of analysis, high specificity and sensitivity. The final decision-making on using this test in a real-world practice may achieved after conducting further clinical safety and effectiveness trials.

P-015 Impaired spermatogenesis in colitis: the role of interferon-γ mediated ferroptosis in sertoli cells by colitic CD4+ T cells

Abstract Study question Does colitis have an impact on spermatogenesis and what could be the potential mechanism? Summary answer Colitis causes sertoli cell ferroptosis and disrupts spermatogenesis in mice due to the migration of colitic CD4+ T cells that produce interferon-γ. What is known already In recent years, there has been a significant increase in rheumatic and inflammatory diseases. Epidemiological data reveals that dysregulated immune conditions can directly or indirectly impact male fertility and sexual function in patients of reproductive age. Inflammatory bowel disease (IBD), which encompasses Crohn’s disease and ulcerative colitis, is a chronic, recurring gastrointestinal inflammatory disorder characterized by bloody stools and weight loss. A study from a Swedish national cohort showed that IBD patients had diminished sperm fertility and increased sperm DNA fragmentation compared to healthy individuals. However, the precise mechanisms underlying male fertility problems in IBD remain unclear. Study design, size, duration In this study, C57BL/6 mice were kept under specific pathogen-free conditions. A murine colitis model that simulates human colitis histological features and symptoms was created using Dextran Sulfate Sodium (DSS). To establish the model, 2-2.5% DSS was added to the mice’s drinking water from days 0 to 7, followed by a three-day recovery period. Participants/materials, setting, methods Testis, epididymis and colon sections were stained with hematoxylin and eosin for histological analysis. The localization and phenotype of infiltrated lymphocytes in epididymis and testis were studied by immunostaining and flow cytometry. Sperm functions including motility, viability, and DNA integrity were assessed by standard assays. Iron, malondialdehyde, and reactive oxygen species (ROS) levels were analysed by commercial kit. Main results and the role of chance Colitis was found to impair male fertility in DSS-induced colitic mice, causing testis and epididymis tissue damage along with inflammatory cell infiltration. Colitis altered the immune cell phenotypes in the testis and epididymis. The proportion and absolute cell count of CD4+ T cells and CD19+ B cells increased after colon inflammation. Testicular sertoli cells in colitic mice exhibited ferroptosis, characterized by increased levels of iron deposition, malondialdehyde, and ROS. We assessed sperm parameters from the cauda epididymis of mice. Compared to the control group, there were significant reduction in sperm concentration, motility, viability and DNA integrity in the group with murine colitis induction. Consistently, we observed lower numbers of active pups from the fathers of the colitis group compared to control mice. CD4+ T cells with interferon-γ producing capabilities accumulated in the testes of colitis mice. Leukocyte flow cytometric analysis and parabiotic mouse model further demonstrated that colitis promoted pathogenic CD4+ T cells migration to the testis through circulation. The treatment of anti-CD4 antibody, anti-interferon-γ antibody or ferroptosis inhibitor can attenuate the colitis-associated testis pathologies. Limitations, reasons for caution Our study was conducted exclusively in mice. The pathogenic effect and the corresponding mechanism of colitis on male fertility in humans still needs to be confirmed. Wider implications of the findings Our team identified the mechanism linking dysregulated gut immune cell activity to testicular dysfunction. By identifying specific molecules on colitic immune cells, which allow their infiltration into the testis, may pave the way for a new therapeutic approach potentially improving the prognosis of colitis and related fertility impairments. Trial registration number not applicable

The Candida albicans quorum-sensing molecule farnesol alters sphingolipid metabolism in human monocyte-derived dendritic cells.

Candida albicans, an opportunistic fungal pathogen, produces the quorum-sensing molecule farnesol, which we have shown alters the transcriptional response and phenotype of human monocyte-derived dendritic cells (DCs), including their cytokine secretion and ability to prime T cells. This is partially dependent on the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ), which has numerous ligands, including the sphingolipid metabolite sphingosine 1-phosphate. Sphingolipids are a vital component of membranes that affect membrane protein arrangement and phagocytosis of C. albicans by DCs. Thus, we quantified sphingolipid metabolites in monocytes differentiating into DCs by High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Farnesol increased the activity of serine palmitoyltransferase, leading to increased levels of 3-keto-dihydrosphingosine, dihydrosphingosine, and dihydrosphingosine 1-phosphate and inhibited dihydroceramide desaturase by inducing oxidative stress, leading to increased levels of dihydroceramide and dihydrosphingomyelin species and reduced ceramide levels. Accumulation of dihydroceramides can inhibit mitochondrial function; accordingly, farnesol reduced mitochondrial respiration. Dihydroceramide desaturase inhibition increases lipid droplet formation, which we observed in farnesol-treated cells, coupled with an increase in intracellular triacylglycerol species. Furthermore, inhibition of dihydroceramide desaturase with either farnesol or specific inhibitors impaired the ability of DCs to prime interferon-γ-producing T cells. The effect of farnesol on sphingolipid metabolism, triacylglycerol synthesis, and mitochondrial respiration was not dependent on PPAR-γ. In summary, our data reveal novel effects of farnesol on sphingolipid metabolism, neutral lipid synthesis, and mitochondrial function in DCs that affect their instruction of T cell cytokine secretion, indicating that C. albicans can manipulate host cell metabolism via farnesol secretion.IMPORTANCECandida albicans is a common commensal yeast, but it is also an opportunistic pathogen which is one of the leading causes of potentially lethal hospital-acquired infections. There is growing evidence that its overgrowth in the gut can influence diseases as diverse as alcohol-associated liver disease and COVID-19. Previously, we found that its quorum-sensing molecule, farnesol, alters the phenotype of dendritic cells differentiating from monocytes, impairing their ability to drive protective T cell responses. Here, we demonstrate that farnesol alters the metabolism of sphingolipids, important structural components of the membrane that also act as signaling molecules. In monocytes differentiating to dendritic cells, farnesol inhibited dihydroceramide desaturase, resulting in the accumulation of dihydroceramides and a reduction in ceramide levels. Farnesol impaired mitochondrial respiration, known to occur with an accumulation of dihydroceramides, and induced the accumulation of triacylglycerol and oil bodies. Inhibition of dihydroceramide desaturase resulted in the impaired ability of DCs to induce interferon-γ production by T cells. Thus, farnesol production by C. albicans could manipulate the function of dendritic cells by altering the sphingolipidome.

Development and characterization of a multimeric recombinant protein using the spike protein receptor binding domain as an antigen to induce SARS-CoV-2 neutralization.

SARS-CoV2 virus, responsible for the COVID-19 pandemic, has four structural proteins and 16 nonstructural proteins. S-protein is one of the structural proteins exposed on the virus surface and is the main target for producing neutralizing antibodies and vaccines. The S-protein forms a trimer that can bind the angiotensin-converting enzyme 2 (ACE2) through its receptor binding domain (RBD) for cell entry. The goal of this study was to express in HEK293 cells a new RBD recombinant protein in a constitutive and stable manner in order to use it as an alternative immunogen and diagnostic tool for COVID-19. The protein was designed to contain an immunoglobulin signal sequence, an explanded C-terminal section of the RBD, a region responsible for the bacteriophage T4 trimerization inducer, and six histidines in the pCDNA-3.1 plasmid. Following transformation, the cells were selected with geneticin-G418 and purified from serum-fre culture supernatants using Ni2+-agarand size exclusion chromatography. The protein was structurally identified by cross-linking and circular dichroism experiments, and utilized to immunize mice in conjuction with AS03 or alum adjuvants. The mice sera were examined for antibody recognition, receptor-binding inhibition, and virus neutralization, while spleens were evaluated for γ-interferon production in the presence of RBD. The protein released in the culture supernatant of cells, and exhibited a molecular mass of 135 kDa with a secondary structure like the monomeric and trimeric RBD. After purification, it formed a multimeric structure comprising trimers and hexamers, which were able to bind the ACE2 receptor. It generated high antibody titers in mice when combined with AS03 adjuvant (up to 1:50,000). The sera were capable of inhibiting binding of biotin-labeled ACE2 to the virus S1 subunit and could neutralize the entry of the Wuhan virus strain into cells at dilutions up to 1:2000. It produced specific IFN-γ producing cells in immunized mouse splenocytes. Our data describe a new RBD containing protein, forming trimers and hexamers, which are able to induce a protective humoral and cellular response against SARS-CoV2. These results add a new arsenal to combat COVID-19, as an alternative immunogen or antigen for diagnosis.

The Role of Interferon-γ in Autoimmune Polyendocrine Syndrome Type 1

BackgroundAutoimmune polyendocrine syndrome type 1 (APS-1) is a life-threatening, autosomal recessive syndrome caused by autoimmune regulator (AIRE) deficiency. In APS-1, self-reactive T cells escape thymic negative selection, infiltrate organs, and drive autoimmune injury. The effector mechanisms governing T-cell–mediated damage in APS-1 remain poorly understood.MethodsWe examined whether APS-1 could be classified as a disease mediated by interferon-γ. We first assessed patients with APS-1 who were participating in a prospective natural history study and evaluated mRNA and protein expression in blood and tissues. We then examined the pathogenic role of interferon-γ using Aire−/−Ifng−/− mice and Aire−/− mice treated with the Janus kinase (JAK) inhibitor ruxolitinib. On the basis of our findings, we used ruxolitinib to treat five patients with APS-1 and assessed clinical, immunologic, histologic, transcriptional, and autoantibody responses.ResultsPatients with APS-1 had enhanced interferon-γ responses in blood and in all examined autoimmunity-affected tissues. Aire−/− mice had selectively increased interferon-γ production by T cells and enhanced interferon-γ, phosphorylated signal transducer and activator of transcription 1 (pSTAT1), and CXCL9 signals in multiple organs. Ifng ablation or ruxolitinib-induced JAK–STAT blockade in Aire−/− mice normalized interferon-γ responses and averted T-cell infiltration and damage in organs. Ruxolitinib treatment of five patients with APS-1 led to decreased levels of T-cell–derived interferon-γ, normalized interferon-γ and CXCL9 levels, and remission of alopecia, oral candidiasis, nail dystrophy, gastritis, enteritis, arthritis, Sjögren’s-like syndrome, urticaria, and thyroiditis. No serious adverse effects from ruxolitinib were identified in these patients.ConclusionsOur findings indicate that APS-1, which is caused by AIRE deficiency, is characterized by excessive, multiorgan interferon-γ–mediated responses. JAK inhibition with ruxolitinib in five patients showed promising results. (Funded by the National Institute of Allergy and Infectious Diseases and others.)

Plasma Gelsolin Inhibits Natural Killer Cell Function and Confers Chemoresistance in Epithelial Ovarian Cancer.

Plasma gelsolin (pGSN) overexpression in ovarian cancer (OVCA) disarms immune function, contributing to chemoresistance. The aim of this study was to investigate the immunoregulatory effects of pGSN expression on natural killer (NK) cell function in OVCA. OVCA tissues from primary surgeries underwent immunofluorescent staining of pGSN and the activated NK cell marker natural cytotoxicity triggering receptor 1 to analyze the prognostic impact of pGSN expression and activated NK cell infiltration. The immunoregulatory effects of pGSN on NK cells were assessed using apoptosis assay, cytokine secretion, immune checkpoint-receptor expression, and phosphorylation of STAT3. In OVCA tissue analyses, activated NK cell infiltration provided survival advantages to patients. However, high pGSN expression attenuated the survival benefits of activated NK cell infiltration. In the in vitro experiment, pGSN in OVCA cells induced NK cell death through cell-to-cell contact. pGSN increased T-cell immunoglobulin and mucin-domain-containing-3 expression (TIM-3) on activated NK cells. Further, it decreased interferon-γ production in activated TIM-3+ NK cells, attenuating their anti-tumor effects. Thus, increased pGSN expression suppresses the anti-tumor functions of NK cells. The study provides insights into why immunotherapy is rarely effective in patients with OVCA and suggests novel treatment strategies.

Cytokine Response of Natural Killer Cells to Hepatitis B Virus Infection Depends on Monocyte Co-Stimulation.

Hepatitis B virus (HBV) is a major driver of chronic hepatic inflammation, which regularly leads to liver cirrhosis or hepatocellular carcinoma. Immediate innate immune cell response is crucial for the rapid clearance of the infection. Here, natural killer (NK) cells play a pivotal role in direct cytotoxicity and the secretion of antiviral cytokines as well as regulatory function. The aim of this study was to further elucidate NK cell responses triggered by an HBV infection. Therefore, we optimized HBV in vitro models that reliably stimulate NK cells using hepatocyte-like HepG2 cells expressing the Na+-taurocholate co-transporting polypeptide (NTCP) and HepaRG cells. Immune cells were acquired from healthy platelet donors. Initially, HepG2-NTCP cells demonstrated higher viral replication compared to HepaRG cells. Co-cultures with immune cells revealed increased production of interferon-γ and tumor necrosis factor-α by NK cells, which was no longer evident in isolated NK cells. Likewise, the depletion of monocytes and spatial separation from target cells led to the absence of the antiviral cytokine production of NK cells. Eventually, the combined co-culture of isolated NK cells and monocytes led to a sufficient cytokine response of NK cells, which was also apparent when communication between the two immune cell subpopulations was restricted to soluble factors. In summary, our study demonstrates antiviral cytokine production by NK cells in response to HBV+ HepG2-NTCP cells, which is dependent on monocyte bystander activation.

Examining the antitumorigenic effects of Ruminococcus gnavus

Abstract Melanoma is one of the most commonly occurring cancers in the world, with increasing occurrence over the past several decades. Common treatment regimens for melanoma include immune checkpoint inhibitor (ICI) therapy, which enhances interferon-γ production in CD8 T cells (Tc1). Despite showing efficacy in some patients, a majority of melanoma patients are resistant to ICI therapy. Prior studies have demonstrated the ability of the gut microbiota to impact Tc1 antitumor responses and ICI therapy efficacy. In analyzing top gut bacteria enriched in ICI-responders, Ruminococcus gnavus (R. gnavus) is a commonly identified species. Here we demonstrate the tumor restraining properties of R. gnavus in subcutaneous, spontaneous, and metastatic cancer models. Further, gnotobiotic monocolonization experiments demonstrate the ability for this bacterium to restrain tumor growth independent of a complex microbiome. Analyzing the mechanism behind how R. gnavus causes melanoma growth suppression in our model, we have demonstrated requirements of bacterial viability and aryl hydrocarbon receptor (AHR) activation. Colonization with R. gnavus at various tumor timepoints was able to induce a significant Tc1 response locally in the tumor and systemically in lymphoid organs. Finally, we found R. gnavus colonization to facilitate ICI efficacy in our model. This study uncovers a potential mechanism of how a common ICI-response associated bacterium enhances ICI efficacy in melanoma.

In vitro evaluation of the platelet adhesion and interferon-γ production capacity of mononuclear cells coming in contact with a hydrophilic polymer-embedded polysulfone dialyzer

BackgroundA polysulfone dialysis membrane containing both polyvinylpyrrolidone (PVP) and the novel hydrophilic polymer (NV polymer) has been developed in an attempt to modify the blood contact surface of the membrane. In the present study, we performed an in vitro evaluation of the NV polymer-embedded membrane (NV membrane), focusing on the adhesion of blood cells to the membrane and the interferon (IFN)-γ production capacity of peripheral blood mononuclear cells coming in contact with the membrane.MethodsTwo membranes, the NV membrane and the conventional membrane embedded with PVP alone (CX), were evaluated simultaneously by dividing the porcine blood obtained from the same animal into two portions. The blood cell adhesion to the membranes was evaluated by measuring the hemoglobin concentrations and lactate dehydrogenase (LDH) activities in the eluates extracted from the membranes. The IFN-γ production capacity in response to phytohemagglutinin stimulation of mononuclear cells coming in contact with either membrane was evaluated.ResultsBoth the hemoglobin concentration and LDH activity, corrected by excluding erythrocytes from the eluate, were about 25% lower in the eluate from the NV membrane than in the eluate from the CX membrane. The IFN-γ production capacity of the mononuclear cells coming in contact with dialysis membrane remained unchanged for the case of the NV membrane, while it decreased for the case of the CX membrane.ConclusionsA lower degree of adhesion of blood cells to the membrane and a lower degree of reduction in the IFN-γ production capacity of mononuclear cells coming in contact with the membrane were observed for the NV membrane, as compared with the PVP membrane, which may suggest improved biocompatibility of the NV membrane.

Mesothelin CAR-T cells expressing tumor-targeted immunocytokine IL-12 yield durable efficacy and fewer side effects

Chimeric antigen receptor (CAR)-modified T cell therapy has achieved remarkable efficacy in treating hematological malignancies, but it confronts many challenges in treating solid tumors, such as the immunosuppressive microenvironment of the solid tumors. These factors reduce the antitumor activity of CAR-T cells in clinical trials. Therefore, we used the immunocytokine interleukin-12 (IL-12) to enhance the efficacy of CAR-T cell therapy. In this study, we engineered CAR-IL12R54 T cells that targeted mesothelin (MSLN) and secreted a single-chain IL-12 fused to a scFv fragment R54 that recognized a different epitope on mesothelin. The evaluation of the anti-tumor activity of the CAR-IL12R54 T cells alone or in combination with anti-PD-1 antibody in vitro and in vivo was followed by the exploration of the functional mechanism by which the immunocytokine IL-12 enhanced the antitumor activity. CAR-IL12R54 T cells had potency to lyse mesothelin positive tumor cells in vitro. In vivo studies demonstrated that CAR-IL12R54 T cells were effective in controlling the growth of established tumors in a xenograft mouse model with fewer side effects than CAR-T cells that secreted naked IL-12. Furthermore, combination of PD-1 blockade antibody with CAR-IL12R54 T cells elicited durable anti-tumor responses. Mechanistic studies showed that IL12R54 enhanced Interferon-γ (IFN-γ) production and dampened the activity of regulatory T cells (Tregs). IL12R54 also upregulated CXCR6 expression in the T cells through the NF-κB pathway, which facilitated T cell infiltration and persistence in the tumor tissues. In summary, the studies provide a good therapeutic option for the clinical treatment of solid tumors.

Viperin inhibits interferon-γ production to promote Mycobacterium tuberculosis survival by disrupting TBK1-IKKε-IRF3-axis and JAK-STAT signaling

Objectives and designAs an interferon-inducible protein, Viperin has broad-spectrum antiviral effects and regulation of host immune responses. We aim to investigate how Viperin regulates interferon-γ (IFN-γ) production in macrophages to control Mycobacterium tuberculosis (Mtb) infection.MethodsWe use Viperin deficient bone-marrow-derived macrophage (BMDM) to investigate the effects and machines of Viperin on Mtb infection.ResultsViperin inhibited IFN-γ production in macrophages and in the lung of mice to promote Mtb survival. Further insight into the mechanisms of Viperin-mediated regulation of IFN-γ production revealed the role of TANK-binding kinase 1 (TBK1), the TAK1-dependent inhibition of NF-kappa B kinase-epsilon (IKKε), and interferon regulatory factor 3 (IRF3). Inhibition of the TBK1-IKKε-IRF3 axis restored IFN-γ production reduced by Viperin knockout in BMDM and suppressed intracellular Mtb survival. Moreover, Viperin deficiency activated the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway, which promoted IFN-γ production and inhibited Mtb infection in BMDM. Additionally, a combination of the anti-TB drug INH treatment in the absence of Viperin resulted in further IFN-γ production and anti-TB effect.ConclusionsThis study highlights the involvement of TBK1-IKKε-IRF3 axis and JAK-STAT signaling pathways in Viperin-suppressed IFN-γ production in Mtb infected macrophages, and identifies a novel mechanism of Viperin on negatively regulating host immune response to Mtb infection.

Increased levels of villus-derived exosomal miR-29a-3p in normal pregnancy than uRPL patients suppresses decidual NK cell production of interferon-γ and exerts a therapeutic effect in abortion-prone mice

ObjectiveRecurrent pregnancy loss (RPL) patients have higher absolute numbers of decidual natural killer (dNK) cells with elevated intracellular IFN-γ levels leading to a pro-inflammatory cytokine milieu, which contributes to RPL pathogenesis. The main objective of this study was twofold: first to explore the regulatory effects and mechanisms of villus-derived exosomes (vEXOs) from induced abortion patients or RPL patients at the level of intracellular IFN-γ in dNK cells; second to determine the validity of application of vEXOs in the treatment of unexplained RPL (uRPL) through in vitro experiments and mouse models.MethodsExosomes were isolated from villus explants by ultracentrifugation, co-cultured with dNK cells, and purified by enzymatic digestion and magnetically activated cell sorting. Flow cytometry, enzyme-linked immunosorbent assays, and RT-qPCR were used to determine IFN-γ levels. Comparative miRNA analysis of vEXOs from induced abortion (IA) and uRPL patients was used to screen potential candidates involved in dNK regulation, which was further confirmed by luciferase reporter assays. IA-vEXOs were electroporated with therapeutic miRNAs and encapsulated in a China Food and Drug Administration (CFDA)-approved hyaluronate gel (HA-Gel), which has been used as a clinical biomaterial in cell therapy for > 30 years. In vivo tracking was performed using 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyaine iodide (DiR) labelling. Tail-vein and uterine horn injections were used to evaluate therapeutic effects of the engineered exosomes in an abortion-prone mouse model (CBA/J × DBA/2 J). Placental growth was evaluated based on placental weight. IFN-γ mRNA levels in mouse placentas were measured by RT-qPCR.ResultsIFN-γ levels were significantly higher in dNK cells of uRPL patients than in IA patients. Both uRPL-vEXOs and IA-vEXOs could be efficiently internalized by dNK cells, whereas uRPL-vEXOs could not reduce the expression of IFN-γ by dNK cells as much as IA-vEXOs. Mechanistically, miR-29a-3p was delivered by vEXOs to inhibit IFN-γ production by binding to the 3′ UTR of IFN-γ mRNA in dNK cells. For in vivo treatment, application of the HA-Gel effectively prolonged the residence time of vEXOs in the uterine cavity via sustained release. Engineered vEXOs loaded with miR-29a-3p reduced the embryo resorption rate in RPL mice with no signs of systemic toxicity.ConclusionOur study provides the first evidence that villi can regulate dNK cell production of IFN-γ via exosome-mediated transfer of miR-29a-3p, which deepens our understanding of maternal–fetal immune tolerance for pregnancy maintenance. Based on this, we developed a new strategy to mix engineered vEXOs with HA-Gel, which exhibited good therapeutic effects in mice with uRPL and could be used for potential clinical applications in uRPL treatment.Graphical

Crohn's disease treatment and memory T-cell subset changes: insights from a case series.

Crohn's disease (CD) is a chronic inflammatory bowel disease with significant morbidity, affecting millions worldwide. The intricacies of immune responses in CD, especially post-treatment, remain a vital area of exploration. While memory T (Tm)-cell subsets play a pivotal role in adaptive immunity, their specific function in patients with CD after treatment is not well-understood. This study aims to investigate the effect and function of Tm-cell subsets in these patients, addressing a crucial knowledge gap in the context of CD therapeutics. A total of eight patients diagnosed with CD were selected based on predefined inclusion criteria. All patients were treated with either anti-inflammatory agents, immunosuppressive drugs, or a combination of both. For comparison, healthy donors were enrolled based on exclusion of autoimmune or inflammatory diseases. Peripheral blood mononuclear cells (PBMCs) and lymphocytes were isolated from blood and lymph node tissue respectively. The phenotype and cytokine production of T lymphocytes from both CD patients and healthy donors were analyzed using flow cytometry. Statistical comparisons of the outcomes between CD patients and healthy donors were made using Mann-Whitney test (two-tailed) and Student t-test. Post-treatment CD patients exhibited an altered T cell distribution with a notable increase in CD8+ T cells in PBMCs (P=0.0005), and altered frequencies of CD4+ and CD8+ T cells in mesenteric lymph nodes (MLNs). Tm cells showed decreased interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) production, with significant alterations in the frequency of IFN-γ-producing CD8+ stem cell-like Tm (Tscm) cells in lesions of the MLNs from patients with CD (CD-M-Lys) compared to healthy MLNs from patients with CD (N-M-Lys) (P=0.0152). Differences in tissue-resident Tm (Trm)-cell subset frequencies were observed between the MLNs and small intestinal mucosa in CD patients. The treatments with anti-inflammatory agents and/or immunosuppressive drugs have a significant effect on the frequency and function of Tm-cell subsets. Clinically, these findings suggest a potential therapeutic avenue in modulating Tm-cell responses, which might be particularly beneficial for conditions where immune response modulation is crucial. Further clinical studies are warranted to explore the full therapeutic implications of these findings.