[Stevens-Johnson syndrome in a patient with positive lymphocyte transformation test]. / Síndrome de Stevens-Johnson en una paciente con prueba positiva de transformación linfocitaria.

BACKGROUND: Stevens-Johnson syndrome is a severe drug reaction. Sulfonamides have been associated with drug reactions, complications, sequelae, even death. CASE REPORT: A 40-year-old female patient with a medical history of endometriosis and recently diagnosed chronic inflammatory ulcerative colitis. She was treated at the Allergology service of the San Juan de Dios Hospital of the Costa Rican Social Security Fund, and after 20 days of treatment with sulfasalazine she had a severe drug reaction on the skin, compatible with Stevens-Johnson syndrome. The lymphocyte transformation test was positive, confirming sulfasalazine as the causative agent. CONCLUSION: The lymphocyte transformation test is a useful method that can confirm the causative agent and prevent important complications in the future.

ANTECEDENTES: El síndrome de Stevens-Johnson es una reacción medicamentosa severa. Las sulfamidas se han asociado con reacciones medicamentosas, complicaciones, secuelas, incluso la muerte. REPORTE DE CASO: Paciente femenina de 40 años, con antecedentes médicos de endometriosis y colitis ulcerativa crónica inflamatoria de reciente diagnóstico. Fue atendida en el servicio de Alergología del Hospital San Juan de Dios de la Caja Costarricense del Seguro Social, y luego de 20 días de tratamiento con sulfasalazina tuvo una reacción medicamentosa severa en la piel, compatible con síndrome de Stevens-Johnson. La prueba de transformación linfocitaria resultó positiva, con lo que se confirmó la sulfasalazina como el agente causal. CONCLUSIÓN: La prueba de transformación linfocitaria es un método útil que puede confirmar el agente causal y prevenir complicaciones importantes a futuro.

Ionic mitigation of CD4+ T cell metabolic fitness, Th1 central nervous system autoimmunity and Th2 asthmatic airway inflammation by therapeutic zinc.

T helper (Th) cells provide immunity to pathogens but also contribute to detrimental immune responses during allergy and autoimmunity. Th2 cells mediate asthmatic airway inflammation and Th1 cells are involved in the pathogenesis of multiple sclerosis. T cell activation involves complex transcriptional networks and metabolic reprogramming, which enable proliferation and differentiation into Th1 and Th2 cells. The essential trace element zinc has reported immunomodulatory capacity and high zinc concentrations interfere with T cell function. However, how high doses of zinc affect T cell gene networks and metabolism remained so far elusive. Herein, we demonstrate by means of transcriptomic analysis that zinc aspartate (UNIZINK), a registered pharmaceutical infusion solution with high bioavailability, negatively regulates gene networks controlling DNA replication and the energy metabolism of murine CD3/CD28-activated CD4+ T cells. Specifically, in the presence of zinc, CD4+ T cells show impaired expression of cell cycle, glycolytic and tricarboxylic acid cycle genes, which functionally cumulates in reduced glycolysis, oxidative phosphorylation, metabolic fitness and viability. Moreover, high zinc concentrations impaired nuclear expression of the metabolic transcription factor MYC, prevented Th1 and Th2 differentiation in vitro and reduced Th1 autoimmune central nervous system (CNS) inflammation and Th2 asthmatic airway inflammation induced by house dust mites in vivo. Together, we find that higher zinc doses impair the metabolic fitness of CD4+ T cells and prevent Th1 CNS autoimmunity and Th2 allergy.

Beneficial effects of citrulline enteral administration on sepsis-induced T cell mitochondrial dysfunction.

Severe sepsis induces a sustained immune dysfunction associated with poor clinical behavior. In particular, lymphopenia along with increased lymphocyte apoptosis and decreased lymphocyte proliferation, enhanced circulating regulatory T cells (Treg), and the emergence of myeloid-derived suppressor cells (MDSCs) have all been associated with persistent organ dysfunction, secondary infections, and late mortality. The mechanisms involved in MDSC-mediated T cell dysfunction during sepsis share some features with those described in malignancies such as arginine deprivation. We hypothesized that increasing arginine availability would restore T cell function and decrease sepsis-induced immunosuppression. Using a mouse model of sepsis based on cecal ligation and puncture and secondary pneumonia triggered by methicillin-resistant Staphylococcus aureus inoculation, we demonstrated that citrulline administration was more efficient than arginine in increasing arginine plasma levels and restoring T cell mitochondrial function and proliferation while reducing sepsis-induced Treg and MDSC expansion. Because there is no specific therapeutic strategy to restore immune function after sepsis, we believe that our study provides evidence for developing citrulline-based clinical studies in sepsis.

Progesterone Inhibits the Establishment of Activation-Associated Chromatin During TH1 Differentiation.

TH1-mediated diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA) improve during pregnancy, coinciding with increasing levels of the pregnancy hormone progesterone (P4), highlighting P4 as a potential mediator of this immunomodulation. Here, we performed detailed characterization of how P4 affects the chromatin and transcriptomic landscape during early human TH1 differentiation, utilizing both ATAC-seq and RNA-seq. Time series analysis of the earlier events (0.5-24 hrs) during TH1 differentiation revealed that P4 counteracted many of the changes induced during normal differentiation, mainly by downregulating key regulatory genes and their upstream transcription factors (TFs) involved in the initial T-cell activation. Members of the AP-1 complex such as FOSL1, FOSL2, JUN and JUNB were particularly affected, in both in promoters and in distal regulatory elements. Moreover, the changes induced by P4 were significantly enriched for disease-associated changes related to both MS and RA, revealing several shared upstream TFs, where again JUN was highlighted to be of central importance. Our findings support an immune regulatory role for P4 during pregnancy by impeding T-cell activation, a crucial checkpoint during pregnancy and in T-cell mediated diseases, and a central event prior to T-cell lineage commitment. Indeed, P4 is emerging as a likely candidate involved in disease modulation during pregnancy and further studies evaluating P4 as a potential treatment option are needed.

The Natural Cytotoxicity Receptor NKp44 (NCR2, CD336) Is Expressed on the Majority of Porcine NK Cells Ex Vivo Without Stimulation.

Natural killer (NK) cells have been studied extensively in humans and mice for their vital role in the vertebrate innate immune system. They are known to rapidly eliminate tumors or virus infected cells in an immune response utilizing their lytic properties. The natural cytotoxicity receptors (NCRs) NKp30 (NCR3), NKp44 (NCR2), and NKp46 (NCR1) are important mediators of NK-cell cytotoxicity. NKp44 expression was reported for NK cells in humans as well as in some non-human primates and found exclusively on activated NK cells. Previously, no information was available on NKp44 protein expression and its role in porcine lymphocytes due to the lack of species-specific monoclonal antibodies (mAbs). For this study, porcine-specific anti-NKp44 mAbs were generated and their reactivity was tested on blood and tissue derived NK cells in pigs of different age classes. Interestingly, NKp44 expression was detected ex vivo already on resting NK cells; moreover, the frequency of NKp44+ NK cells was higher than that of NKp46+ NK cells in most animals analyzed. Upon in vitro stimulation with IL-2 or IL-15, the frequency of NKp44+ NK cells, as well as the intensity of NKp44 expression at the single cell level, were increased. Since little is known about swine NK cells, the generation of a mAb (clone 54-1) against NKp44 will greatly aid in elucidating the mechanisms underlying the differentiation, functionality, and activation of porcine NK cells.

Chloroquine Suppresses Effector B-Cell Functions and Has Differential Impact on Regulatory B-Cell Subsets.

Objectives: Chloroquine (CQ) is approved for treatment of B-cell mediated diseases such as rheumatoid arthritis and systemic lupus erythematosus. However, the exact mode of action in these diseases has not been studied and it remains unclear which effect CQ has on B-cells. Thus, it was the aim of this study to investigate to which extent CQ affects functionality of effector and regulatory B-cell. Methods: For this purpose, B-cells were isolated from peripheral blood of healthy controls and renal transplant patients. B-cells were stimulated in presence or absence of CQ and Interleukin-10 (IL-10) and Granzyme B (GrB) secretion were assessed. In addition, effector functions such as plasma cell formation, and Immunoglobulin G (IgG) secretion were studied. Results: CQ suppressed Toll-Like-Receptor (TLR)-9 induced B-cell proliferation in a dose-dependent manner. IL-10pos regulatory B-cells were suppressed by CQ already at low concentrations whereas anti-IgG/IgM-induced GrB secreting regulatory B-cells were less susceptible. Plasma blast formation and IgG secretion was potently suppressed by CQ. Moreover, purified B-cells from renal transplant patients were also susceptible to CQ-induced suppression of effector B-cell functions as observed by diminished IgG secretion. Conclusion: In conclusion, CQ had a suppressive effect on IL-10 regulatory B-cells whereas GrB secreting regulatory B-cells were less affected. Effector functions of B-cells such as plasma blast formation and IgG secretion were also inhibited by CQ. Effector B-cells derived from renal transplant patients already under immunosuppression could be suppressed by CQ. These findings may partly explain the clinical efficacy of CQ in B-cell mediated autoimmune diseases. The application of CQ in other disease contexts where suppression of effector B-cells could offer a benefit, such as renal transplantation, may hypothetically be advantageous.

Restricting tumor lactic acid metabolism using dichloroacetate improves T cell functions.

BACKGROUND: Lactic acid produced by tumors has been shown to overcome immune surveillance, by suppressing the activation and function of T cells in the tumor microenvironment. The strategies employed to impair tumor cell glycolysis could improve immunosurveillance and tumor growth regulation. Dichloroacetate (DCA) limits the tumor-derived lactic acid by altering the cancer cell metabolism. In this study, the effects of lactic acid on the activation and function of T cells, were analyzed by assessing T cell proliferation, cytokine production and the cellular redox state of T cells. We examined the redox system in T cells by analyzing the intracellular level of reactive oxygen species (ROS), superoxide and glutathione and gene expression of some proteins that have a role in the redox system. Then we co-cultured DCA-treated tumor cells with T cells to examine the effect of reduced tumor-derived lactic acid on proliferative response, cytokine secretion and viability of T cells. RESULT: We found that lactic acid could dampen T cell function through suppression of T cell proliferation and cytokine production as well as restrain the redox system of T cells by decreasing the production of oxidant and antioxidant molecules. DCA decreased the concentration of tumor lactic acid by manipulating glucose metabolism in tumor cells. This led to increases in T cell proliferation and cytokine production and also rescued the T cells from apoptosis. CONCLUSION: Taken together, our results suggest accumulation of lactic acid in the tumor microenvironment restricts T cell responses and could prevent the success of T cell therapy. DCA supports anti-tumor responses of T cells by metabolic reprogramming of tumor cells.

Proteomic analysis in primary T cells reveals IL-7 alters T cell receptor thresholding via CYTIP/cytohesin/LFA-1 localisation and activation.

The ability of the cellular immune system to discriminate self from foreign antigens depends on the appropriate calibration of the T cell receptor (TCR) signalling threshold. The lymphocyte homeostatic cytokine interleukin 7 (IL-7) is known to affect TCR thresholding, but the molecular mechanism is not fully elucidated. A better understanding of this process is highly relevant in the context of autoimmune disease therapy and cancer immunotherapy. We sought to characterise the early signalling events attributable to IL-7 priming; in particular, the altered phosphorylation of signal transduction proteins and their molecular localisation to the TCR. By integrating high-resolution proximity- phospho-proteomic and imaging approaches using primary T cells, rather than engineered cell lines or an in vitro expanded T cell population, we uncovered transduction events previously not linked to IL-7. We show that IL-7 leads to dephosphorylation of cytohesin interacting protein (CYTIP) at a hitherto undescribed phosphorylation site (pThr280) and alters the co-localisation of cytohesin-1 with the TCR and LFA-1 integrin. These results show that IL-7, acting via CYTIP and cytohesin-1, may impact TCR activation thresholds by enhancing the co-clustering of TCR and LFA-1 integrin.

Republication: A Prospective Observational Study of Adoptive Immunotherapy for Cancer Using Zoledronate-Activated Killer (ZAK) Cells - An Analysis for Patients With Incurable Pancreatic Cancer.

BACKGROUND/AIM: Adoptive immunotherapy (AIT) using autologous zoledronate-activated killer (ZAK) cells has been performed for developing a novel modality of cancer treatment. In this study, data series from incurable pancreatic cancer were analyzed. PATIENTS AND METHODS: Patients were treated with AIT using intravenous administration of ZAK cells every 3 to 4 weeks in combination with standard chemotherapy and possible clinical benefits were examined. RESULTS: Seventy-five patients were treated. A median overall survival (OS) time of 6.7 months was achieved for all patients and 13.1 months for those treated 5 times or more, that increased to 14.6 and 18.3 months, respectively, when the previous treatment period of chemotherapy alone was included in the analysis. The disease control rate was 58.5 %. Multivariate regression analysis showed a significant positive correlation between the survival and baseline value of lymphocyte percentage in white blood cell counts (p=0.031). CONCLUSION: The data suggest that AIT using ZAK cells in combination with chemotherapy is safe and feasible and may be effective in prolonging survival for patients with incurable pancreatic cancer. The lymphocyte percentage at baseline may be a good biomarker for predicting the survival benefit of ZAK cell AIT.

Metformin ameliorates chronic colitis in a mouse model by regulating interferon-γ-producing lamina propria CD4+ T cells through AMPK activation.

Metformin, a commonly prescribed drug for type 2 diabetes mellitus, has been shown to activate AMP-activated protein kinase (AMPK). Notably, AMPK activation has recently been observed to be associated with anti-inflammatory responses. Metformin is also reported to elicit anti-inflammatory responses in CD4+ T cells, resulting in improvement in experimental chronic inflammatory diseases, such as systemic lupus erythematosus. To investigate the effect of metformin on inflammatory bowel disease (IBD), we developed a T cell-transfer model of chronic colitis in which SCID mice were injected with CD4+ CD45RBhigh T cells to induce colitis. We examined the effects of metformin via in vitro and in vivo experiments on lamina propria (LP) CD4+ T cells. We observed that metformin suppresses the frequency of interferon (IFN) -γ-producing LP CD4+ T cells in vitro, which were regulated by AMPK activation, a process possibly induced by the inhibition of oxidative phosphorylation. Furthermore, we examined the effects of metformin on an in vivo IBD model. Metformin-treated mice showed AMPK activation in LP CD4+ T cells and ameliorated colitis. Our study demonstrates that metformin-induced AMPK activation in mucosal CD4+ T cells contributes to the improvement of IBD by suppressing IFN-γ production. Moreover, our results indicate that AMPK may be a target molecule for the regulation of mucosal immunity and inflammation. Thus, AMPK-activating drugs such as metformin may be potential therapeutic agents for the treatment of IBD.

Control of Memory Phenotype T Lymphocyte Homeostasis: Role of Costimulation.

Foxp3+ T regulatory cells (Tregs), CD4+Foxp3- T cells, and CD8+ T cells are composed of naive phenotype (NP) and memory phenotype (MP) subsets. Ten to 20% of each MP T cell population are cycling (Ki-67+) in vivo. We investigated the contribution of costimulatory (CD28) and coinhibitory (CTLA-4, PD-1) receptors on MP T cell homeostatic proliferation in vivo in the mouse. Blockade of CD28-CD80/CD86 signaling completely abolished MP Tregs and profoundly inhibited MP CD4+Foxp3- T cell proliferation, but it did not affect MP CD8+ T cell proliferation. Marked enhancement of homeostatic proliferation of MP Tregs and MP CD4+Foxp3- T cells was seen after blocking CTLA4-CD80/CD86 interactions and PD-1-PD-L1/2 interactions, and greater enhancement was seen with blockade of both pathways. The CD28 pathway also played an important role in the expansion of Tregs and MP T cells after treatment of mice with agonistic Abs to members of the TNF receptor superfamily, which can act directly (anti-GITR, anti-OX40, anti-4-1BB) or indirectly (anti-CD40) on T cells. Induction of a cytokine storm by blocking the interaction of NK inhibitory receptors with MHC class I had no effect on Treg homeostasis, enhanced MP CD4+ proliferation, and expansion in a CD28-dependent manner, but it enhanced MP CD8+ T cell proliferation in a CD28-independent manner. Because MP T cells exert potent biologic effects primarily before the induction of adaptive immune responses, these findings have important implications for the use of biologic agents designed to suppress autoimmune disease or enhance T effector function in cancer that may have negative effects on MP T cells.

The toxin mimic FS48 from the salivary gland of Xenopsylla cheopis functions as a Kv1.3 channel-blocking immunomodulator of T cell activation.

The Kv1.3 channel has been widely demonstrated to play crucial roles in the activation and proliferation of T cells, which suggests that selective blockers could serve as potential therapeutics for autoimmune diseases mediated by T cells. We previously described that the toxin mimic FS48 from salivary gland of Xenopsylla cheopis downregulates the secretion of proinflammatory factors by Raw 264.7 cells by blocking the Kv1.3 channel and the subsequent inactivation of the proinflammatory MAPK/NF-κB pathways. However, the effects of FS48 on human T cells and autoimmune diseases are unclear. Here, we described its immunomodulatory effects on human T cells derived from suppression of Kv1.3 channel. Kv1.3 currents in Jurkat T cells were recorded by whole-cell patch-clamp, and Ca2+ influx, cell proliferation, and TNF-α and IL-2 secretion were measured using Fluo-4, CCK-8, and ELISA assays, respectively. The in vivo immunosuppressive activity of FS48 was evaluated with a rat DTH model. We found that FS48 reduced Kv1.3 currents in Jurkat T cells in a concentration-dependent manner with an IC50 value of about 1.42 µM. FS48 also significantly suppressed Kv1.3 protein expression, Ca2+ influx, MAPK/NF-κB/NFATc1 pathway activation, and TNF-α and IL-2 production in activated Jurkat T cells. Finally, we show that FS48 relieved the DTH response in rats. We therefore conclude that FS48 can block the Kv1.3 channel and inhibit human T cell activation, which most likely contributes to its immunomodulatory actions and highlights the great potential of this evolutionary-guided peptide as a drug template in future studies.

Biphasic effect of mechanical stress on lymphocyte activation.

Mechanical forces can modulate the immune response, mostly described as promoting the activation of immune cells, but the role and mechanism of pathological levels of mechanical stress in lymphocyte activation have not been focused on before. By an ex vivo experimental approach, we observed that mechanical stressing of murine spleen lymphocytes with 50 mmHg for 3 h induced the nuclear localization of NFAT1, increased C-Jun, and increased the expression of early activation marker CD69 in resting CD8+ cells. Interestingly, 50 mmHg mechanical stressing induced the nuclear localization of NFAT1; but conversely decreased C-Jun and inhibited the expression of CD69 in lymphocytes under lipopolysaccharide or phorbol 12-myristate 13-acetate/ionomycin stimulation. Additionally, we observed similar changes trends when comparing RNA-seq data of hypertensive and normotensive COVID-19 patients. Our results indicate a biphasic effect of mechanical stress on lymphocyte activation, which provides insight into the variety of immune responses in pathologies involving elevated mechanical stress.

Octyl gallate decrease lymphocyte activation and regulates neutrophil extracellular traps release.

BACKGROUND: Inflammation is a complex mechanism with an objective to destroy and eliminate the invading microorganisms. During acute inflammation, the neutrophils are the major cells involved in this process and, although they defend the organism, must die to not generate damage. The two major mechanisms that drive neutrophils to death are: apoptosis and a novel mechanism recently discovered denominated NETosis. This process is a "suicidal mechanism", in which the cells release "neutrophil extracellular traps" (NETs) during the inflammatory response. Octyl gallate (OG) is one of the gallic acid derivates, with several protective effects, such as antioxidant and anti-inflammatory in cancer models. Thus, this study aimed to investigate the action of OG on the proliferation of lymphocytes, neutrophils activation, and its effectiveness in an experimental sepsis model. METHODS: Lymphocytes and neutrophils were obtained from healthy donors. Cell viability, apoptosis, NETs release and antioxidant capacity of OG were observed. In addition, survival was evaluated in an experimental model of sepsis in C57BL/6 mice. RESULTS: Our study demonstrated, for the first time, that the OG can act as an inhibitor of reactive oxygen species (ROS) release, NETs formation in primary human neutrophils and, modulates the lipopolysaccharide (LPS) effect in neutrophil apoptosis. The OG also inhibited peripheral blood mononuclear cells (PBMCs) proliferation in vitro. Despite the positive results, we did not observe an increase in the survival of septic animals. CONCLUSIONS: The pharmacological potential of OG, modulating activation of neutrophils and lymphocytes, suggests the use as an adjuvant therapeutic strategy in inflammatory diseases.

Effect of topical application of lipopolysaccharide on contact hypersensitivity.

Lipopolysaccharide (LPS) is the principal component of the outer membrane of gram-negative bacteria. The prior oral administration of LPS attenuates inflammatory responses, such as intestinal injury and atopic dermatitis, in mouse models; however, the underlying mechanism remains unclear. Here, we examined the effect of topical LPS application on allergic contact dermatitis and its mechanism of action using a murine contact hypersensitivity (CHS) model. Prolonged LPS application to the skin significantly suppressed 2,4-dinitrofluorobenzene (DNFB)-induced CHS. LPS application to the skin also reduced the phagocytosis of fluorescein isothiocyanate (FITC)-dextran by Langerhans and dendritic cells. Cutaneous cell migration into the skin-draining lymph nodes (LNs) induced by FITC painting was reduced by LPS application. During the CHS response, DNFB application induced T-cell proliferation and inflammatory cytokine production in skin-draining LNs, whereas prolonged LPS application inhibited DNFB-induced T-cell growth and interferon gamma production, indicating suppression of DNFB-induced sensitization. These results suggest that prolonged LPS application suppressed DNFB-induced sensitization and subsequently CHS response. Our findings imply that topical application of LPS may prevent allergic dermatitis such as CHS.

A T cell inflammatory phenotype is associated with autoimmune toxicity of the PI3K inhibitor duvelisib in chronic lymphocytic leukemia.

Several PI3Kδ inhibitors are approved for the therapy of B cell malignancies, but their clinical use has been limited by unpredictable autoimmune toxicity. We have recently reported promising efficacy results in treating chronic lymphocytic leukemia (CLL) patients with combination therapy with the PI3Kδγ inhibitor duvelisib and fludarabine cyclophosphamide rituximab (FCR) chemoimmunotherapy, but approximately one-third of patients develop autoimmune toxicity. We show here that duvelisib FCR treatment in an upfront setting modulates both CD4 and CD8 T cell subsets as well as pro-inflammatory cytokines. Decreases in naive and central memory CD4 T cells and naive CD8 T cells occur with treatment, while activated CD8 T cells, granzyme positive Tregs, and Th17 CD4 and CD8 T cells all increase with treatment, particularly in patients with toxicity. Cytokines associated with Th17 activation (IL-17A and IL-21) are also relatively elevated in patients with toxicity. The only CLL feature associated with toxicity was increased priming for apoptosis at baseline, with a significant decrease during the first week of duvelisib. We conclude that an increase in activated CD8 T cells with activation of Th17 T cells, in the context of lower baseline Tregs and greater CLL resistance to duvelisib, is associated with duvelisib-related autoimmune toxicity.

Evidence of immunogenic cancer cell death induced by honey-processed Astragalus polysaccharides in vitro and in vivo.

Honey-processed Astragalus is a dosage form of Radix Astragalus mixed with honey by a traditional Chinese medicine processing method which improves immune activity. This pharmacological activity of honey-processed Astragalus polysaccharide (HP-APS) might be due to structural changes during the honey roasting process. Previously, we have prepared and characterized HP-APS and preliminarily found its anti-inflammatory effects. However, whether the pharmacodynamic activity of HP-APS induces tumor cell apoptosis and the mechanisms responsible for the immunogenic death (ICD) have not been elucidated. Here, A549, MC38 and B16 cells were used to evaluate the cells viability, apoptosis and cell cycles, respectively. Cellular immunogenic cell death-related molecules calreticulin (CRT), Heat Shock Proteins (HSP)70, major histocompatibility complex I (MHC-I), and co-stimulator molecules CD80/CD86 were determined by flow cytometry. The extracellular ATP release was also detected. B16-OVA and MC38-OVA cells were treated with HP-APS and co-cultivated with OT1 mouse of CD3+T cells for assessment of proliferation, in mice model, and the establishment of C57BL/B6 mouse model bearing B16 cells for assessment of HP-APS the regulation of immune activity in vivo. Our results showed that HP-APS has an inhibitory effect on tumor cell proliferation, which induces tumor cell apoptosis, preventing cells-transforming from G1 phase to S phase in cell cycles. Furthermore, HP-APS could effectively increase the expression of HSP70, CRT, MHC-I, CD86, CD80 and ATP release. T cell proliferation index is significantly improved. CD3 cell proliferation in OT1 mice was significantly increased from the 4th generation to the 5th generation. Moreover, the results have also shown that HP-APS could inhibit tumor growth by increasing immune cell infiltration in the tumor tissues. In the mouse melanoma model with HP-APS treatment, the tumor weight and volume were significantly reduced, and the growth of melanoma was inhibited. CD8+ T is significantly increased. The ratio of CD4+ T and CD8+ T cells numbers are also significantly increased in mouse spleen, but it is less than PD-1 alone treatment separately. Altogether, these findings suggest that HP-APS exerts anti-tumor effects, and that its underlying mechanisms might be associated with the expression of immunogenicity cell death related molecules and the immunomodulatory effects of immune cells.

Neoadjuvant STING Activation, Extended Half-life IL2, and Checkpoint Blockade Promote Metastasis Clearance via Sustained NK-cell Activation.

Combination immunotherapy treatments that recruit both innate and adaptive immunity have the potential to increase cancer response rates by engaging a more complete repertoire of effector mechanisms. Here, we combined intratumoral STimulator of INterferon Genes (STING) agonist therapy with systemically injected extended half-life IL2 and anti-PD-1 checkpoint blockade (hereafter CIP therapy) to drive innate and adaptive antitumor immunity in models of triple-negative breast cancer. Unlike treatment with the individual components, this trivalent immunotherapy halted primary tumor progression and led to long-term remission for a majority of animals in two spontaneously metastasizing orthotopic breast tumor models, though only as a neoadjuvant therapy but not adjuvant therapy. CIP therapy induced antitumor T-cell responses, but protection from metastatic relapse depended on natural killer (NK) cells. The combination of STING agonists with IL2/anti-PD-1 synergized to stimulate sustained granzyme and cytokine expression by lung-infiltrating NK cells. Type I IFNs generated as a result of STING agonism, combined with IL2, acted in a positive-feedback loop by enhancing the expression of IFNAR-1 and CD25 on lung NK cells. These results suggest that NK cells can be therapeutically targeted to effectively eliminate tumor metastases.See related Spotlight by Demaria, p. 3.

Vitamin D supplementation induces CatG-mediated CD4+ T cell inactivation and restores pancreatic ß-cell function in mice with type 1 diabetes.

Type 1 diabetes (T1D) is a chronic autoimmune disease accompanied by the immune-mediated destruction of pancreatic ß-cells. In this study, we aimed to explore the regulatory effects of vitamin D (VD) supplementation on pancreatic ß-cell function by altering the expression of bioinformatically identified cathepsin G (CatG) in T1D mice. A T1D mouse model was established in nonobese diabetic (NOD) mice, and their islets were isolated and purified. Pancreatic mononuclear cells (MNCs) were collected, from which CD4+ T cells were isolated. The levels of interleukin (IL)-2, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in the supernatant of mouse pancreatic tissue homogenate were assessed using ELISA. Immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelin (TUNEL) staining were conducted to evaluate the effects of VD supplementation on pancreatic tissues of T1D mice. The pancreatic ß-cell line MIN6 was used for in vitro substantiation of findings in vivo. VD supplementation reduced glucose levels and improved glucose tolerance in T1D mice. Furthermore, VD supplementation improved pancreatic ß-cell function and suppressed immunological and inflammatory reactions in the T1D mice. We documented overexpression of CatG in diabetes tissue samples, and then showed that VD supplementation normalized the islet immune microenvironment through downregulating CatG expression in T1D mice. Experiments in vitro subsequently demonstrated that VD supplementation impeded CD4+ T activation by downregulating CatG expression and thereby enhanced pancreatic ß-cell function. Results of the present study elucidated that VD supplementation can downregulate the expression of CatG and inhibit CD4+ T cell activation, thereby improving ß-cell function in T1D.NEW & NOTEWORTHY We report that vitamin D (VD) supplementation downregulates CatG expression and inhibits CD4+ T cell activation, thereby improving ß-cell function in type 1 diabetes (T1D). This study deepens our understanding of the pathogenesis of T1D and clarifies molecular events underlying the alleviatory effect of VD for immunotherapy against T1D.

Effect of SARS-CoV-2 seropositivity on antigen - specific cytokine and chemokine responses in latent tuberculosis.

SARS-CoV-2 and latent Mycobacterium tuberculosis infection are both highly co-prevalent in many parts of the globe. Whether exposure to SARS-CoV-2 influences the antigen specific immune responses in latent tuberculosis has not been investigated. We examined the baseline, mycobacterial antigen and mitogen induced cytokine and chemokine responses in latent tuberculosis (LTBI) individuals with or without SARS-CoV-2 seropositivity, LTBI negative individuals with SARS-CoV-2 seropositivity and healthy control (both LTBI and SARS-CoV-2 negative) individuals. Our results demonstrated that LTBI individuals with SARS-CoV-2 seropositivity (LTBI+/IgG +) were associated with increased levels of unstimulated and TB-antigen stimulated IFNγ, IL-2, TNFα, IL-17, IL-1ß, IL-6, IL-12, IL-4, CXCL1, CXCL9 and CXCL10 when compared to those without seropositivity (LTBI+/IgG-). In contrast, LTBI+/IgG+ individuals were associated with decreased levels of IL-5 and IL-10. No significant difference in the levels of cytokines/chemokines was observed upon mitogen stimulation between the groups. SARS-CoV-2 seropositivity was associated with enhanced unstimulated and TB-antigen stimulated but not mitogen stimulated production of cytokines and chemokines in LTBI+ compared to LTBI negative individuals. Finally, most of these significant differences were not observed when LTBI negative individuals with SARS-CoV-2 seropositivity and controls were examined. Our data clearly demonstrate that both baseline and TB - antigen induced cytokine responses are augmented in the presence of SARS-CoV-2 seropositivity, suggesting an augmenting effect of prior SARS-CoV-2 infection on the immune responses of LTBI individuals.