Interleukin-12 is produced by dendritic cells and mediates T helper 1 development as well as interferon-gamma production by T helper 1 cells

Impaired Proliferation of CD8+ T Cells Stimulated with Monocyte-Derived Dendritic Cells Previously Matured with Thapsigargin-Stimulated LAD2 Human Mast Cells

CD8+ T cells are essential for adaptive immunity against infection and tumors. Their ability to proliferate after stimulation is crucial to their functionality. Dendritic cells (DCs) are professional antigen-presenting cells that induce their proliferation. Here, we show that thapsigargin-induced LAD2 mast cell (MC) line-released products can impair the ability of monocyte-derived DCs to induce CD8+ T-cell proliferation and the generation of Th1 cytokine-producing T cells. We found that culture medium conditioned with LAD2 MCs previously stimulated with thapsigargin (thapsLAD2) induces maturation of DCs as determined by the maturation markers CD80, CD83, CD86, and HLA-DR. However, thapsLAD2-matured DCs produced no detectable TNFα or IL-12 during the maturation. In addition, although their surface expression of PD-L1 was comparable with the immature or TLR7/8-agonist (R848)-matured DCs, their TIM-3 expression was significantly higher than in immature DCs and even much higher than in R848-matured DCs. In addition, contrary to R848-matured DCs, the thapsLAD2-matured DCs only tended to induce enhanced proliferation of CD4+ T cells than immature DCs. For CD8+ T cells, this tendency was not even detected because thapsLAD2-matured and immature DCs comparably induced their proliferation, which contrasted with the significantly enhanced proliferation induced by R848-matured DCs. Furthermore, these differences were comparably recapitulated in the ability of the tested DCs to induce IFNγ- and IFNγ/TNFα-producing T cells. These findings show a novel mechanism of MC-mediated regulation of adaptive immune responses.

CAR-T cell therapy: a game-changer in cancer treatment and beyond

In recent years, cancer has become one of the primary causes of mortality, approximately 10 million deaths worldwide each year. The most advanced, chimeric antigen receptor (CAR) T cell immunotherapy has turned out as a promising treatment for cancer. CAR-T cell therapy involves the genetic modification of T cells obtained from the patient's blood, and infusion back to the patients. CAR-T cell immunotherapy has led to a significant improvement in the remission rates of hematological cancers. CAR-T cell therapy presently limited to hematological cancers, there are ongoing efforts to develop additional CAR constructs such as bispecific CAR, tandem CAR, inhibitory CAR, combined antigens, CRISPR gene-editing, and nanoparticle delivery. With these advancements, CAR-T cell therapy holds promise concerning potential to improve upon traditional cancer treatments such as chemotherapy and radiation while reducing associated toxicities. This review covers recent advances and advantages of CAR-T cell immunotherapy.

The immunopathogenesis of sarcoidosis

Sarcoidosis is a granulomatous multiorgan disease, thought to result from exposure to yet unidentified antigens in genetically susceptible individuals. The exaggerated inflammatory response that leads to granuloma formation is highly complex and involves the innate and adaptive immune system. Consecutive immunological studies using advanced technology have increased our understanding of aberrantly activated immune cells, mediators and pathways that influence the formation, maintenance and resolution of granulomas. Over the years, it has become increasingly clear that disease immunopathogenesis can only be understood if the clinical heterogeneity of sarcoidosis is taken into consideration, along with the distribution of immune cells in peripheral blood and involved organs. Most studies offer an immunological snapshot during disease course, while the cellular composition of both the circulation and tissue microenvironment may change over time. Despite these challenges, novel insights on the role of the immune system are continuously published, thus bringing the field forward. This review highlights current knowledge on the innate and adaptive immune responses involved in sarcoidosis pathogenesis, as well as the pathways involved in non-resolving disease and fibrosis development. Additionally, we describe proposed immunological mechanisms responsible for drug-induced sarcoid like reactions. Although many aspects of disease immunopathogenesis remain to be unraveled, the identification of crucial immune reactions in sarcoidosis may help identify new treatment targets. We therefore also discuss potential therapies and future strategies based on the latest immunological findings.

Regulation of B-cell function and expression of CD11c, T-bet, and FcRL5 in response to different activation signals

CD11c, FcRL5, or T-bet are commonly expressed by B cells expanding during inflammation, where they can make up >30% of mature B cells. However, the association between the proteins and differentiation and function in the host response remains largely unclear. We have assessed the co-expression of CD11c, T-bet, and FcRL5 in an in vitro B-cell culture system to determine how stimulation via the BCR, toll-like receptor 9 (TLR9), and different cytokines influence CD11c, T-bet, and FcRL5 expression. We observed different expression dynamics for all markers, but a largely overlapping regulation of CD11c and FcRL5 in response to BCR and TLR9 activation, while T-bet was strongly dependent on IFN-γ signaling. Investigating plasma cell differentiation and APC functions, there was no association between marker expression and antibody secretion or T-cell help. Rather the functions were associated with TLR9-signalling and B-cell-derived IL-6 production, respectively. These results suggest that the expression of CD11c, FcRL5, and T-bet and plasma cell differentiation and improved APC functions occur in parallel and are regulated by similar activation signals, but they are not interdependent.

Dynamics of ex vivo cytokine transcription during experimental Toxocara canis infection in Balb/c mice

The cytokine microenvironment is crucial in generating and polarizing the immune response. A means of monitoring this environment would be of great value for better understanding Toxocara canis immune modulation. The aim of this study was to analyze the dynamics of cytokine transcription ex vivo, during early (24-48 hours) and late (15-30 days) times post-infection, in the mesenteric lymph nodes, spleen and intestinal mucosa of Balb/c mice experimentally infected with T. canis larvae. Mice in the treated group were infected with 100 third-stage larvae (L3), whereas mice in the control group were not infected. Analyses were performed at different times: 24-48 hours post-infection (HPI), 15-30 days post-infection (DPI). IL4, IL10, IL12 and Ym1 mRNA transcriptions were analyzed through qPCR. This study showed cytokine transcription mediated by migrating larvae in the mesenteric lymph nodes and spleen at 24-48 HPI, whereas cytokine transcription in the intestinal mucosa was observed only at late times (15-30 DPI). These results suggest that the T. canis larvae migration during infection might play a role in cytokine dynamics. Since the cytokine microenvironment is crucial in modulating immune response, knowledge of cytokine dynamics during T. canis infections pave the way to better understand its interaction with the host.

Systems Biology and Cytokines Potential Role in Lung Cancer Immunotherapy Targeting Autophagic Axis

Lung cancer accounts for the highest number of deaths among men and women worldwide. Although extensive therapies, either alone or in conjunction with some specific drugs, continue to be the principal regimen for evolving lung cancer, significant improvements are still needed to understand the inherent biology behind progressive inflammation and its detection. Unfortunately, despite every advancement in its treatment, lung cancer patients display different growth mechanisms and continue to die at significant rates. Autophagy, which is a physiological defense mechanism, serves to meet the energy demands of nutrient-deprived cancer cells and sustain the tumor cells under stressed conditions. In contrast, autophagy is believed to play a dual role during different stages of tumorigenesis. During early stages, it acts as a tumor suppressor, degrading oncogenic proteins; however, during later stages, autophagy supports tumor cell survival by minimizing stress in the tumor microenvironment. The pivotal role of the IL6-IL17-IL23 signaling axis has been observed to trigger autophagic events in lung cancer patients. Since the obvious roles of autophagy are a result of different immune signaling cascades, systems biology can be an effective tool to understand these interconnections and enhance cancer treatment and immunotherapy. In this review, we focus on how systems biology can be exploited to target autophagic processes that resolve inflammatory responses and contribute to better treatment in carcinogenesis.

Evaluation of SOCS5 mRNA and its association with serum IL-12 levels and rs41379147 SNP in various subsets of allergic disorders: A case control study

BACKGROUND

The SOCS proteins act as suppressors of cytokine signaling by impeding certain signaling pathways. SOCS5, a constituent of the SOCS family, has been associated with the management of allergic reactions, primarily by impeding the signaling of interleukin-4 (IL-4), which is known to have a cardinal function in accelerating the development of an allergic reaction. The key goal of our research was to explore the probable ramifications of the SOCS5 single nucleotide polymorphism (SNP) namely rs41379147 on the expression of SOCS5 mRNA and serum IL-12 levels, as well as to analyze the interaction between SOCS5 genotypes and various clinicopathological parameters in atopic diseases.

METHODS

The study involved the enrollment of 314 subjects comprising 154 atopic individuals and 160 healthy controls. PCR-RFLP was employed to conduct SNP analysis. Real-Time PCR was employed to quantify SOCS5 mRNA. The enzyme-linked immunosorbent assay (ELISA) technique was used for the quantification of interleukin-12 and total IgE levels in the serum while as chemiluminescence was used to determine Vitamin D levels.

RESULTS

The PCR-RFLP analysis indicated a lack of statistically significant variation in genotypic and allelic frequencies between the cases and controls (p > 0.05) for - 9147 C/T SNP either in total atopy (OR-0.70, 95% CI=0.43-1.12, p =0.15), and on subgroup stratifications of chronic urticaria (OR-0.81, 95 % CI = 0.42-1.59, p = 0.61), allergic rhinitis (OR-0.63, 95 % CI = 0.33-1.19, p = 0.16) and bronchial asthma (OR-0.66,95% CI = 0.29-1.4, p=0.32). There was reduced mRNA expression of SOCS5 in total atopic cases, allergic rhinitis, bronchial asthma and chronic urticaria in comparison to controls which advocates the fact that SOCS5 has a protective role in allergic disease development. Despite the reduced amounts of IL-12 in total atopic cases and different allergic disorders in comparison to controls, IL-12 showed significant positive correlation with SOCS5 mRNA expression (p < 0.05).

CONCLUSION

SOCS5 SNP rs41379147(C/T) does not pose any significant risk towards the development of any allergic disorder and has no impact on the expression of SOCS5 and IL-12. Our study has shown the reduced mRNA expression of SOCS5 among individuals diagnosed with chronic urticaria, allergic rhinitis and bronchial asthma and the expression of SOCS5 showed complete dependence on the cytokine milieu of IL12. The modulation of SOCS5 and IL-12 may represent potential curative targets for treating the menace of allergic diseases and present promising avenues for future investigation.

Dendritic Cell Vaccines: A Shift from Conventional Approach to New Generations

In the emerging era of cancer immunotherapy, immune checkpoint blockades (ICBs) and adoptive cell transfer therapies (ACTs) have gained significant attention. However, their therapeutic efficacies are limited due to the presence of cold type tumors, immunosuppressive tumor microenvironment, and immune-related side effects. On the other hand, dendritic cell (DC)-based vaccines have been suggested as a new cancer immunotherapy regimen that can address the limitations encountered by ICBs and ACTs. Despite the success of the first generation of DC-based vaccines, represented by the first FDA-approved DC-based therapeutic cancer vaccine Provenge, several challenges remain unsolved. Therefore, new DC vaccine strategies have been actively investigated. This review addresses the limitations of the currently most adopted classical DC vaccine and evaluates new generations of DC vaccines in detail, including biomaterial-based, immunogenic cell death-inducing, mRNA-pulsed, DC small extracellular vesicle (sEV)-based, and tumor sEV-based DC vaccines. These innovative DC vaccines are envisioned to provide a significant breakthrough in cancer immunotherapy landscape and are expected to be supported by further preclinical and clinical studies.

Ready for Prime Time? Dendritic Cells in High-Grade Gliomas

High-grade gliomas are malignant brain tumors, and patient outcomes remain dismal despite the emergence of immunotherapies aimed at promoting tumor elimination by the immune system. A robust antitumor immune response requires the presentation of tumor antigens by dendritic cells (DC) to prime cytolytic T cells. However, there is a paucity of research on dendritic cell activity in the context of high-grade gliomas. As such, this review covers what is known about the role of DC in the CNS, DC infiltration of high-grade gliomas, tumor antigen drainage, the immunogenicity of DC activity, and DC subsets involved in the antitumor immune response. Finally, we consider the implications of suboptimal DC function in the context of immunotherapies and identify opportunities to optimize immunotherapies to treat high-grade gliomas.

Signaling pathways involved in the biological functions of dendritic cells and their implications for disease treatment

The ability of dendritic cells (DCs) to initiate and regulate adaptive immune responses is fundamental for maintaining immune homeostasis upon exposure to self or foreign antigens. The immune regulatory function of DCs is strictly controlled by their distribution as well as by cytokines, chemokines, and transcriptional programming. These factors work in conjunction to determine whether DCs exert an immunosuppressive or immune-activating function. Therefore, understanding the molecular signals involved in DC-dependent immunoregulation is crucial in providing insight into the generation of organismal immunity and revealing potential clinical applications of DCs. Considering the many breakthroughs in DC research in recent years, in this review we focused on three basic lines of research directly related to the biological functions of DCs and summarized new immunotherapeutic strategies involving DCs. First, we reviewed recent findings on DC subsets and identified lineage-restricted transcription factors that guide the development of different DC subsets. Second, we discussed the recognition and processing of antigens by DCs through pattern recognition receptors, endogenous/exogenous pathways, and the presentation of antigens through peptide/major histocompatibility complexes. Third, we reviewed how interactions between DCs and T cells coordinate immune homeostasis in vivo via multiple pathways. Finally, we summarized the application of DC-based immunotherapy for autoimmune diseases and tumors and highlighted potential research prospects for immunotherapy that targets DCs. This review provides a useful resource to better understand the immunomodulatory signals involved in different subsets of DCs and the manipulation of these immune signals can facilitate DC-based immunotherapy.

The inhibitory effect of oral administration of lentinan on DSS-induced inflammation is exerted by the migration of T cells activated in the ileum to the colon

Oral administration of lentinan ameliorated dextran sulfate sodium (DSS)-induced colitis through Dectin-1 receptor on intestinal epithelial cells. However, it is unclear where lentinan affects in the intestine to prevent the inflammation. We found that the administration of lentinan has induced migration of CD4+ cells from the ileum to the colon by using Kikume Green-Red (KikGR) mice in this study. This result suggests that the oral lentinan treatment could accelerate the migration of Th cells in lymphocyte from ileum into the colon during lentinan intake. Then, C57BL/6 mice were administered 2% DSS to induce colitis. The mice were administered lentinan daily via oral or rectal route before DSS administration. Its rectal administration also suppressed DSS-induced colitis, but its suppressive effects were lower compared to when orally administered, indicating that the biological responses to lentinan in the small intestine contributed to the anti-inflammatory effects. In normal mice (without DSS treatment), the expression of Il12b was significantly increased in the ileum by the oral administration of lentinan, but not by rectal one. On the other hand, no change was observed in the colon by either administration method. In addition, Tbx21 was significantly increased in the ileum. These suggested that IL-12 was increased in the ileum and Th1 cells differentiated in dependence on it. Therefore, Th1 predominant condition in the ileum could influence immunity in the colon and improve the colitis.

Immunomodulatory effects of trans-anethole-treated Staphylococcus aureus Newman strain

In our former studies based on a human whole-blood model infected with trans-anethole (TA)-treated Staphylococcus aureus Newman strain, we have observed that selected parameters/mechanisms of innate and acquired immune response were more enhanced in comparison to samples infected with non-treated bacteria. Due to this observation, the current study aimed to evaluate the concentration of selected proteins involved in both types of responses (IL-1α, IL-1β, IL-2, IL-6, IL-12, IL-17, TNF-α, IFN-γ, G-CSF, C5a, CCL1-CCL5, CXCL1, CXCL2, CXCL9-CXCL11, MMP-8, TLR2, and PGLYRP1) in healthy participants' plasma after blood stimulation of TA-treated S. aureus Newman strain. Determination of analyzed protein concentration was conducted using Luminex and ELISA assays. Based on the results, it has been proven that the immunomodulatory potential of TA-treated S. aureus Newman strain on increasing IL-1β, IL-6, TNF-α, IL-12, G-CSF, C5a, CCL2-CCL4, CXCL1, CXCL2, MMP-8 and PGLYRP1 levels in plasma. Moreover, it has been also demonstrated an association between TNF-α and CCL4 in a blood model infected with TA-treated cells. More research is warranted to find more underlying mechanisms involved in the effects of TA-treated S. aureus Newman in human blood, mainly whether the observed "immunity boost" can be regulated after bacteria elimination. Therefore, the potential of TA should be further explored to understand under which conditions it might help treat or prevent infections caused by S. aureus.

Inducible expression of interleukin-12 augments the efficacy of affinity-tuned chimeric antigen receptors in murine solid tumor models

The limited number of targetable tumor-specific antigens and the immunosuppressive nature of the microenvironment within solid malignancies represent major barriers to the success of chimeric antigen receptor (CAR)-T cell therapies. Here, using epithelial cell adhesion molecule (EpCAM) as a model antigen, we used alanine scanning of the complementarity-determining region to fine-tune CAR affinity. This allowed us to identify CARs that could spare primary epithelial cells while still effectively targeting EpCAM^high tumors. Although affinity-tuned CARs showed suboptimal antitumor activity in vivo, we found that inducible secretion of interleukin-12 (IL-12), under the control of the NFAT promoter, can restore CAR activity to levels close to that of the parental CAR. This strategy was further validated with another affinity-tuned CAR specific for intercellular adhesion molecule-1 (ICAM-1). Only in affinity-tuned CAR-T cells was NFAT activity stringently controlled and restricted to tumors expressing the antigen of interest at high levels. Our study demonstrates the feasibility of specifically gearing CAR-T cells towards recognition of solid tumors by combining inducible IL-12 expression and affinity-tuned CAR.

Transcriptome analysis of CD4+ T cells from HIV-infected individuals receiving ART with LLV revealed novel transcription factors regulating HIV-1 promoter activity

Some HIV-infected individuals receiving ART develop low-level viremia (LLV), with a plasma viral load of 50-1000 copies/mL. Persistent low-level viremia is associated with subsequent virologic failure. The peripheral blood CD4+ T cell pool is a source of LLV. However, the intrinsic characteristics of CD4+ T cells in LLV which may contribute to low-level viremia are largely unknown. We analyzed the transcriptome profiling of peripheral blood CD4+ T cells from healthy controls (HC) and HIV-infected patients receiving ART with either virologic suppression (VS) or LLV. To identify pathways potentially responding to increasing viral loads from HC to VS and to LLV, KEGG pathways of differentially expressed genes (DEGs) were acquired by comparing VS with HC (VS-HC group) and LLV with VS (LLV-VS group). Characterization of DEGs in key overlapping pathways showed that CD4+ T cells in LLV expressed higher levels of Th1 signature transcription factors (TBX21), toll-like receptors (TLR-4, -6, -7 and -8), anti-HIV entry chemokines (CCL3 and CCL4), and anti-IL-1β factors (ILRN and IL1R2) compared to VS. Our results also indicated activation of the NF-κB and TNF signaling pathways that could promote HIV-1 transcription. Finally, we evaluated the effects of 4 and 17 transcription factors that were upregulated in the VS-HC and LLV-VS groups, respectively, on HIV-1 promoter activity. Functional studies revealed that CXXC5 significantly increased, while SOX5 markedly suppressed HIV-1 transcription. In summary, we found that CD4+ T cells in LLV displayed a distinct mRNA profiling compared to that in VS, which promoted HIV-1 replication and reactivation of viral latency and may eventually contribute to virologic failure in patients with persistent LLV. CXXC5 and SOX5 may serve as targets for the development of latency-reversing agents.

IL-12p40 promotes secondary damage and functional impairment after spinal cord contusional injury

Secondary damage obstructs functional recovery for individuals who have sustained a spinal cord injury (SCI). Two processes significantly contributing to tissue damage after trauma are spinal cord hemorrhage and inflammation: more specifically, the recruitment and activation of immune cells, frequently driven by pro-inflammatory factors. Cytokines are inflammatory mediators capable of modulating the immune response. While cytokines are necessary to elicit inflammation for proper healing, excessive inflammation can result in destructive processes. The pro-inflammatory cytokines IL-12 and IL-23 are pathogenic in multiple autoimmune diseases. The cytokine subunit IL-12p40 is necessary to form bioactive IL-12 and IL-23. In this study, we examined the relationship between spinal cord hemorrhage and IL-12-related factors, as well as the impact of IL-12p40 (IL-12/IL-23) on secondary damage and functional recovery after SCI. Using in vivo magnetic resonance imaging and protein tissue analyses, we demonstrated a positive correlation between IL-12 and tissue hemorrhage. Receptor and ligand subunits of IL-12 were significantly upregulated after injury and colocalized with astrocytes, demonstrating a myriad of opportunities for IL-12 to induce an inflammatory response. IL-12p40^-/- mice demonstrated significantly improved functional recovery and reduced lesion sizes compared to wild-type mice. Targeted gene array analysis in wild-type and IL-12p40^-/- female mice after SCI revealed an upregulation of genes associated with worsened recovery after SCI. Taken together, our data reveal a pathogenic role of IL-12p40 in the secondary damage after SCI, hindering functional recovery. IL-12p40 (IL-12/IL-23) is thus an enticing neuroinflammatory target for further study as a potential therapeutic target to benefit recovery in acute SCI.

Cell atlas of the immune microenvironment in gastrointestinal cancers: Dendritic cells and beyond

Gastrointestinal (GI) cancers occur in the alimentary tract and accessory organs. They exert a global burden with high morbidity and mortality. Inside the tumor microenvironment, dendritic cells (DCs) are the most efficient antigen-presenting cells and are necessary for adaptive immune responses such as T and B-cell maturation. However, the subsets of DCs revealed before were mostly based on flow cytometry and bulk sequencing. With the development of single-cell RNA sequencing (scRNA-seq), the tumor and microenvironment heterogeneity of GI cancer has been illustrated. In this review, we summarize the classification and development trajectory of dendritic cells at the single-cell level in GI cancer. Additionally, we focused on the interaction of DCs with T cells and their effect on the response to immunotherapy. Specifically, we focused on the newly identified tumor-infiltrating dendritic cells and discuss their potential function in antitumor immunity.

Potential Therapeutic Role of Mesenchymal-Derived Stem Cells as an Alternative Therapy to Combat COVID-19 through Cytokines Storm

Medical health systems continue to be challenged due to newly emerging COVID-19, and there is an urgent need for alternative approaches for treatment. An increasing number of clinical observations indicate cytokine storms to be associated with COVID-19 severity and also to be a significant cause of death among COVID-19 patients. Cytokine storm involves the extensive proliferative and hyperactive activity of T and macrophage cells and the overproduction of pro-inflammatory cytokines. Stem cells are the type of cell having self-renewal properties and giving rise to differentiated cells. Currently, stem cell therapy is an exciting and promising therapeutic approach that can treat several diseases that were considered incurable in the past. It may be possible to develop novel methods to treat various diseases by identifying stem cells’ growth and differentiation factors. Treatment with mesenchymal stem cells (MSCs) in medicine is anticipated to be highly effective. The present review article is organized to put forward the positive arguments and implications in support of mesenchymal stem cell therapy as an alternative therapy to cytokine storms, to combat COVID-19. Using the immunomodulatory potential of the MSCs, it is possible to fight against COVID-19 and counterbalance the cytokine storm.

Dynamics of tumor-associated macrophages in a quantitative systems pharmacology model of immunotherapy in triple-negative breast cancer

Quantitative systems pharmacology (QSP) modeling is an emerging mechanistic computational approach that couples drug pharmacokinetics/pharmacodynamics and the course of disease progression. It has begun to play important roles in drug development for complex diseases such as cancer, including triple-negative breast cancer (TNBC). The combination of the anti-PD-L1 antibody atezolizumab and nab-paclitaxel has shown clinical activity in advanced TNBC with PD-L1-positive tumor-infiltrating immune cells. As tumor-associated macrophages (TAMs) serve as major contributors to the immuno-suppressive tumor microenvironment, we incorporated the dynamics of TAMs into our previously published QSP model to investigate their impact on cancer treatment. We show that through proper calibration, the model captures the macrophage heterogeneity in the tumor microenvironment while maintaining its predictive power of the trial results at the population level. Despite its high mechanistic complexity, the modularized QSP platform can be readily reproduced, expanded for new species of interest, and applied in clinical trial simulation.

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A mechanistic model of quantitative systems pharmacology in immuno-oncology

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Dynamics of tumor-associated macrophages are integrated into our previous work

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Conducting in silico clinical trials to predict clinical response to cancer therapy

Low Interleukin-12 Levels concerning Severe Malaria: A Systematic Review and Meta-Analysis

Although many studies have investigated the role of interleukin (IL)-12 cytokine in the pathogenesis of severe malaria, these studies were based on a limited number of participants, possibly affecting their outcomes. We analyzed the difference in IL-12 levels between patients with severe and uncomplicated malaria through a meta-analysis. A systematic review was conducted following the Cochrane Handbook for Systematic Reviews of Interventions and was reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. Systematic literature searches were performed between 20 February and 2 March, 2022 in PubMed, Scopus, and Embase to identify studies reporting IL-12 levels in patients with severe and uncomplicated malaria. The quality of included studies was determined using the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. The pooled mean difference (MD) in IL-12 between patients with severe and uncomplicated malaria was estimated using the DerSimonian–Laird method for the random-effects model. Altogether, 1885 potentially relevant articles were identified, and 10 studies enrolling 654 patients with severe malaria and 626 patients with uncomplicated malaria were included in the meta-analysis. Patients with severe malaria had lower mean IL-12 levels than those with uncomplicated malaria (p = 0.01, MD: −33.62, 95% confidence interval [CI]: −58.79 to −8.45, I²: 99.29%, 10 studies). In conclusion, decreased IL-12 levels might significantly contribute to the development of severe malaria. As most published literature demonstrated the role of IL-12 in animal models, human studies are required to understand the mechanisms involved in low IL-12 levels in patients with severe malaria.

Immunomodulatory effects of probiotic Lactobacillus casei on GM-CSF-adjuvanted influenza DNA vaccine

Aim: This study investigates the protective efficacy of influenza DNA vaccine combined with a granulocyte macrophage-colony stimulating factor (GM-CSF) adjuvant, and probiotic Lactobacillus casei, an oral immunomodulator, in a BALB/c mice. Materials & methods: The mice were immunized with HA1 DNA vaccine along with GM-CSF and probiotic twice within a one-week interval. Results: The results showed that both adjuvants exert a synergistic effect in enhancing the humoral and cellular immune responses of the DNA vaccine. This combination also deceased IL-6 and IL-17A levels in the lung homogenates. The protection patterns were closely associated with influenza virus-specific splenocyte proliferative and serum IgG antibody (Ab) responses. Conclusion: The Findings demonstrate L. casei modulate balanced Th1/Th2 immune responses toward HA1 DNA vaccine adjuvanted by GM-CSF.

Dendritic cell transfer for cancer immunotherapy

Dendritic cells (DCs) play a major role in cancer immunosurveillance as they bridge innate and adaptive immunity by detecting tumor-associated antigens and presenting them to T lymphocytes. The adoptive transfer of antigen loaded DCs has been proposed as an immunotherapeutic approach for the treatment of various types of cancer. Nevertheless, despite promising preclinical data, the therapeutic efficacy of DC transfer is still deceptive in cancer patients. Here we summarize recent findings in DC biology with a special focus on the development of actionable therapeutic strategies and discuss experimental and clinical approaches that aim at improving the efficacy of DC-based immunotherapies, including, but not limited to, optimized DC production and antigen loading, stimulated maturation, the co-treatment with additional immunotherapies, as well as the inhibition of DC checkpoints.

Preclinical advances and the immunophysiology of a new therapeutic chagas disease vaccine

INTRODUCTION

Chronic infection with the protozoal parasite Trypanosoma cruzi leads to a progressive cardiac disease, known as chronic Chagasic cardiomyopathy (CCC). A new therapeutic Chagas disease vaccine is in development to augment existing antiparasitic chemotherapy drugs.

AREAS COVERED

We report on our current understanding of the underlying immunologic and physiologic mechanisms that lead to CCC, including parasite immune escape mechanisms that allow persistence and the subsequent inflammatory and fibrotic processes that lead to clinical disease. We report on vaccine design and the observed immunotherapeutic effects including induction of a balanced T_H1/T_H2/T_H17 immune response that leads to reduced parasite burdens and tissue pathology. Further, we report vaccine-linked chemotherapy, a dose sparing strategy to further reduce parasite burdens and tissue pathology.

EXPERT OPINION

Our vaccine-linked chemotherapeutic approach is a multimodal treatment strategy, addressing both the parasite persistence and the underlying deleterious host inflammatory and fibrotic responses that lead to cardiac dysfunction. In targeting treatment towards patients with chronic indeterminate or early determinate Chagas disease, this vaccine-linked chemotherapeutic approach will be highly economical and will reduce the global disease burden and deaths due to CCC.

IFN-α blockade during ART-treated SIV infection lowers tissue vDNA, rescues immune function, and improves overall health

Type I IFNs (TI-IFNs) drive immune effector functions during acute viral infections and regulate cell cycling and systemic metabolism. That said, chronic TI-IFN signaling in the context of HIV infection treated with antiretroviral therapy (ART) also facilitates viral persistence, in part by promoting immunosuppressive responses and CD8+ T cell exhaustion. To determine whether inhibition of IFN-α might provide benefit in the setting of chronic, ART-treated SIV infection of rhesus macaques, we administered an anti-IFN-α antibody followed by an analytical treatment interruption (ATI). IFN-α blockade was well-tolerated and associated with lower expression of TI-IFN-inducible genes (including those that are antiviral) and reduced tissue viral DNA (vDNA). The reduction in vDNA was further accompanied by higher innate proinflammatory plasma cytokines, expression of monocyte activation genes, IL-12-induced effector CD8+ T cell genes, increased heme/metabolic activity, and lower plasma TGF-β levels. Upon ATI, SIV-infected, ART-suppressed nonhuman primates treated with anti-IFN-α displayed lower levels of weight loss and improved erythroid function relative to untreated controls. Overall, these data demonstrated that IFN-α blockade during ART-treated SIV infection was safe and associated with the induction of immune/erythroid pathways that reduced viral persistence during ART while mitigating the weight loss and anemia that typically ensue after ART interruption.

Engineering interferons and interleukins for cancer immunotherapy

Cytokines are a class of potent immunoregulatory proteins that are secreted in response to various stimuli and act locally to regulate many aspects of human physiology and disease. Cytokines play important roles in cancer initiation, progression, and elimination, and thus, there is a long clinical history associated with the use of recombinant cytokines to treat cancer. However, the use of cytokines as therapeutics has been limited by cytokine pleiotropy, complex biology, poor drug-like properties, and severe dose-limiting toxicities. Nevertheless, cytokines are crucial mediators of innate and adaptive antitumor immunity and have the potential to enhance immunotherapeutic approaches to treat cancer. Development of immune checkpoint inhibitors and combination immunotherapies has reinvigorated interest in cytokines as therapeutics, and a variety of engineering approaches are emerging to improve the safety and effectiveness of cytokine immunotherapy. In this review we highlight recent advances in cytokine biology and engineering for cancer immunotherapy.

Transcriptional changes in dendritic cells underlying allergen specific induced tolerance in a mouse model

To investigate food allergy-tolerance mechanisms induced through allergen-specific immunotherapy we used RNA-Sequencing to measure gene expression in lymph-node-derived dendritic cells from Pru p 3-anaphylactic mice after immunotherapy with glycodendropeptides at 2 nM and 5 nM, leading to permanent tolerance and short-term desensitization, respectively. Gene expression was also measured in mice receiving no immunotherapy (anaphylaxis); and in which anaphylaxis could never occur (antigen-only). Compared to anaphylaxis, the antigen-only group showed the greatest number of expression-changes (411), followed by tolerant (186) and desensitized (119). Only 29 genes changed in all groups, including Il12b, Cebpb and Ifngr1. The desensitized group showed enrichment for genes related to chronic inflammatory response, secretory granule, and regulation of interleukin-12 production; the tolerant group showed genes related to cytokine receptor activity and glucocorticoid receptor binding, suggesting distinct pathways for similar outcomes. We identified genes and processes potentially involved in the restoration of long-term tolerance via allergen-specific immunotherapy, representing potential prognostic biomarkers.

Noncognate Signals Drive Enhanced Effector CD8+ T Cell Responses through an IFNAR1-Dependent Pathway after Infection with the Prototypic Vaccine, 0ΔNLS, against Herpes Simplex Virus 1

Previous studies by our group identified a highly efficacious vaccine 0ΔNLS (deficient in the nuclear localization signal of infected cell protein 0) against HSV-1 in an experimental ocular mouse model. However, details regarding fundamental differences in the initial innate and adaptive host immune response were not explored. Here, we present a side-by-side analysis of the primary infection characterizing differences of the host immune response in mice infected with 0ΔNLS versus the parental, GFP105. The results show that local viral infection and replication are controlled more efficiently in mice exposed to 0ΔNLS versus GFP105 but clearance of infectious virus is equivalent comparing the two groups. Moreover, the 0ΔNLS-infected mice displayed enhanced effector CD8⁺ but not CD4⁺ T cell responses from the draining lymph nodes at day 7 post infection measured by IFN-γ and TNF-α production along with changes in cell metabolism. The increased effector function of CD8⁺ T cells from 0ΔNLS-infected mice was not driven by changes in antigen presentation but lost in the absence of a functional type I IFN pathway. These results are further supported by enhanced local expression of type I IFN and IFN-inducible genes along with increased IL-12 production by CD8α⁺DCs in the draining lymph nodes of 0ΔNLS-infected mice compared to the GFP105-infected animals. It was also noted the recall to HSV-1 antigen by CD8⁺ T cells was elevated in mice infected with HSV-1 0ΔNLS compared to GFP105. Collectively, the results underscore the favorable qualities of HSV-1 0ΔNLS as a candidate vaccine against HSV-1 infection. IMPORTANCE Cytotoxic T lymphocytes (CTLs) play a critical role in the clearance for many viral pathogens including herpes simplex virus 1 (HSV-1). Here, we compared the cellular innate and adaptive immune response in mice infected with an attenuated HSV-1 (0ΔNLS) found to be a highly successful experimental prophylactic vaccine to parental HSV-1 virus. We found that CD8⁺ T cell effector function is elevated in 0ΔNLS-infected mice through noncognate signals including IL-12 and type I interferon (IFN) pathways along with changes in CD8⁺ T cell metabolism whereas other factors including cell proliferation, co-stimulatory molecule expression and antigen presentation were dispensable. Thus, an increase in CTL activity established by exposure to HSV-1 0ΔNLS in comparison to parental HSV-1 likely contributes to the efficacy of the vaccine and underscores the nature of the attenuated virus as a vaccine candidate for HSV-1 infection.

Crosstalk between R848 and abortive HIV-1 RNA-induced signaling enhances antiviral immunity

Pathogens trigger multiple pattern recognition receptors (PRRs) that together dictate innate and adaptive immune responses. Understanding the crosstalk between PRRs is important to enhance vaccine efficacy. Abortive HIV-1 RNA transcripts are produced during acute and chronic HIV-1 infection and are known ligands for different PRRs, leading to antiviral and proinflammatory responses. Here, we have investigated the crosstalk between responses induced by these 58 nucleotide-long HIV-1 RNA transcripts and different TLR ligands. Costimulation of dendritic cells (DCs) with abortive HIV-1 RNA and TLR7/8 agonist R848, but not other TLR agonists, resulted in enhanced antiviral type I IFN responses as well as adaptive immune responses via the induction of DC-mediated T helper 1 (T_H 1) responses and IFNγ⁺ CD8⁺ T cells. Our data underscore the importance of crosstalk between abortive HIV-1 RNA and R848-induced signaling for the induction of effective antiviral immunity.

Immune Response to Microsporidia

Microsporidia are a group of pathogens, which can pose severe risks to the immunocompromised population, such as HIV-infected individuals or organ transplant recipients. Adaptive immunity has been reported to be critical for protection, and mice depleted of T cells are unable to control these infections. In a mouse model of infection, CD8 T cells have been found to be the primary effector cells and are responsible for protecting the infected host. Also, as infection is acquired via a peroral route, CD8 T cells in the gut compartment act as a first line of defense against these pathogens. Thus, generation of a robust CD8 T-cell response exhibiting polyfunctional ability is critical for host survival. In this chapter, we describe the effector CD8 T cells generated during microsporidia infection and the factors that may be essential for generating protective immunity against these understudied but significant pathogens. Overall, this chapter will highlight the necessity for a better understanding of the development of CD8 T-cell responses in gut-associated lymphoid tissue (GALT) and provide some insights into therapies that may be used to restore defective CD8 T-cell functionality in an immunocompromised situation.

Cytokines and Chemokines in HBV Infection

Chronic hepatitis B virus (HBV) infection remains a leading cause of hepatic inflammation and damage. The pathogenesis of chronic hepatitis B (CHB) infection is predominantly mediated by persistent intrahepatic immunopathology. With the characterization of unique anatomical and immunological structure, the liver is also deemed an immunological organ, which gives rise to massive cytokines and chemokines under pathogenesis conditions, having significant implications for the progression of HBV infection. The intrahepatic innate immune system is responsible for the formidable source of cytokines and chemokines, with the latter also derived from hepatic parenchymal cells. In addition, systemic cytokines and chemokines are disturbed along with the disease course. Since HBV is a stealth virus, persistent exposure to HBV-related antigens confers to immune exhaustion, whereby regulatory cells are recruited by intrahepatic chemokines and cytokines, including interleukin-10 and transforming growth factor β, are involved in such series of causal events. Although the considerable value of two types of available approved treatment, interferons and nucleos(t)ide analogues, effectively suppress HBV replication, neither of them is sufficient for optimal restoration of the immunological attrition state to win the battle of the functional or virological cure of CHB infection. Notably, cytokines and chemokines play a crucial role in regulating the immune response. They exert effects by directly acting on HBV or indirectly manipulating target immune cells. As such, specific cytokines and chemokines, with a potential possibility to serve as novel immunological interventions, combined with those that target the virus itself, seem to be promising prospects in curative CHB infection. Here, we systematically review the recent literature that elucidates cytokine and chemokine-mediated pathogenesis and immune exhaustion of HBV infection and their dynamics triggered by current mainstream anti-HBV therapy. The predictive value of disease progression or control and the immunotherapies target of specific major cytokines and chemokines in CHB infection will also be delineated.

Reduced Th1 response is associated with lower glycolytic activity in activated peripheral blood mononuclear cells after metabolic and bariatric surgery

BACKGROUND

Obesity promotes cellular immunometabolism changes that trigger the activation of macrophages and lymphocytes, leading to systemic inflammation. Activated leukocytes undergo metabolic reprogramming, increasing glycolytic activity.

OBJECTIVE

To examine whether the reduction in the inflammatory state associated with bariatric surgery is associated with decreased glycolytic activity in leukocytes. Setting Single-center, prospective observational study.

METHODS

This study involved 18 patients with obesity undergoing bariatric surgery. All measurements were performed preoperatively and six months postoperatively. Peripheral blood mononuclear cells and plasma were obtained to determine the glycolytic rate and mitochondrial membrane potential as surrogates of the metabolic switching and high-sensitivity C-reactive protein, adipokines, and CD69 expression as inflammatory and activation markers.

RESULTS

Glycolytic activity engaged by CD3/CD28 activation was reduced six months after bariatric surgery, associated with decreased levels of T helper (Th) 1 and Th17 signature cytokines. An overall reduction in inflammatory markers was observed, which correlated with a higher adiponectin/leptin ratio.

CONCLUSIONS

Metabolic and bariatric surgery-induced weight loss leads to reprogramming in T cells' metabolic machinery, resulting in reduced stimulation of glycolysis after activation, which may explain the decrease in systemic inflammation mediated by cytokines such as interferon-γ and interleukin-17A.

Heterogeneity in antiviral B cell responses: Lessons from the movies

Humoral and cellular responses to viral infections coexist in a dynamic equilibrium that often results in efficient viral clearance. However, in some infections one of the two responses prevails, for instance when an overactivation of cytotoxic T cells is accompanied by weak and insufficient antibody responses. Although the cellular response is usually sufficient to control a primary viral infection, in some cases clearance is not complete and persistent infections ensue. In order to design effective therapeutic or vaccination strategies aiming at inducing early and potent neutralizing antibody responses, a deep knowledge of the cellular and molecular determinants of antiviral immune responses is needed. Here, we review our understanding on the spatiotemporal dynamics of antiviral humoral immune responses, with a particular focus on recent studies using intravital imaging approaches as an insightful complement to more traditional techniques.

β-glucan from Aureobasidium pullulans augments the anti-tumor immune responses through activated tumor-associated dendritic cells

Dendritic cells (DCs) are recognized as the most potent antigen-presenting cells, capable of priming both naïve and memory T cells. Thus, tumor-resident DCs (tumor-associated DCs: TADCs) play a crucial role in the immune response against tumors. However, TADCs are also well known as a "double-edged sword" because an immunosuppressive environment, such as a tumor microenvironment, maintains the immature and tolerogenic properties of TADCs, resulting in the deterioration of the tumor. Therefore, it is essential to maintain and enhance the anti-tumoral activity of TADCs to aid tumor elimination. This study demonstrated the potential for tumor growth inhibition of Aureobasidium pullulan-derived β-glucan (AP-BG). Administration of AP-BG dramatically limited the development of different types of tumor cell lines transplanted into mice. Examination of the tumor-infiltrating leukocytes revealed that AP-BG caused high expression of co-stimulatory molecules on TADCs and enhanced the production of cytolytic granules as well as pro-inflammatory cytokines by the tumor-resident T cells. Furthermore, the syngeneic mixed lymphoid reaction assay and popliteal lymph node assay showed the significant ability of AP-BG to improve DCs' antigen-specific priming of T cells in vitro and in vivo. Taken together, β-glucan might be an immune-potentiating adjuvant for cancer treatment. This highly widely-used reagent will initiate a new way to activate DC-targeted cancer immune therapy.

Th1 polarization in the tumor microenvironment upregulates the myeloid-derived suppressor-like function of macrophages

Here, we investigated the effect of Th1 polarization in the tumor microenvironment (TME) on tumor-associated macrophage (TAM) maturation and activation. In our immunotherapy mouse model, with a Th1-dominant TME, tumors regressed in all cases, with complete regression in 80% of the cases. Monocyte-derived dendritic cells and activated CD4⁺ and CD8⁺T-cells increased in the tumor-draining lymph node, and correlated with each other in the therapeutic model. However, the cytotoxicity of tumor-infiltrating CD8⁺T-cells was slightly inhibited, whereas the number of T-cells significantly increased. Moreover, the number of TAMs increased; their maturation was inhibited; and nitrotyrosine (NT) production, as well as iNOS and arginase I expression, was increased, suggestive of the myeloid-derived suppressor cell-like immunosuppressive function of TAMs. IFN-γ knockout in the therapeutic model decreased NT production and induced macrophage maturation. Hence, Th1 polarization in the IFN-γ-dominant condition induces T-cell immune responses; however, it also enhances the immunosuppressive activity of TAMs.

The ammonia oxidizing bacterium Nitrosomonas eutropha blocks T helper 2 cell polarization via the anti-inflammatory cytokine IL-10

The prevalence of atopic diseases has been steadily increasing since the mid twentieth century, a rise that has been linked to modern hygienic lifestyles that limit exposure to microbes and immune system maturation. Overactive type 2 CD4+ helper T (Th2) cells are known to be closely associated with atopy and represent a key target for treatment. In this study, we present an initial characterization of ammonia oxidizing bacteria (AOB) Nitrosomonas eutropha D23, an environmental microbe that is not associated with human pathology, and show AOB effectively suppress the polarization of Th2 cells and production of Th2-associated cytokines (IL-5, IL-13, and IL-4) by human peripheral blood mononuclear cells (PBMC). We show that AOB inhibit Th2 cell polarization not through Th1-mediated suppression, but rather through mechanisms involving the anti-inflammatory cytokine IL-10 and the potential inhibition of dendritic cells, as evidenced by a reduction in Major Histocompatibility Complex Class II (MHC II) and CD86 expression following AOB treatment. This is the first report of immunomodulatory properties of AOB, and provides initial support for the development of AOB as a potential therapeutic for atopic diseases.

Beyond Just Peptide Antigens: The Complex World of Peptide-Based Cancer Vaccines

Peptide-based cancer vaccines rely upon the strong activation of the adaptive immune response to elicit its effector function. They have shown to be highly specific and safe, but have yet to prove themselves as an efficacious treatment for cancer in the clinic. This is for a variety of reasons, including tumour heterogeneity, self-tolerance, and immune suppression. Importance has been placed on the overall design of peptide-based cancer vaccines, which have evolved from simple peptide derivatives of a cancer antigen, to complex drugs; incorporating overlapping regions, conjugates, and delivery systems to target and stimulate different components of antigen presenting cells, and to bolster antigen cross-presentation. Peptide-based cancer vaccines are increasingly becoming more personalised to an individual's tumour antigen repertoire and are often combined with existing cancer treatments. This strategy ultimately aids in combating the shortcomings of a more generalised vaccine strategy and provides a comprehensive treatment, taking into consideration cancer cell variability and its ability to avoid immune interrogation.

Targeting Neuroinflammation in Brain Cancer: Uncovering Mechanisms, Pharmacological Targets, and Neuropharmaceutical Developments

Gliomas are one of the most lethal types of cancers accounting for ∼80% of all central nervous system (CNS) primary malignancies. Among gliomas, glioblastomas (GBM) are the most aggressive, characterized by a median patient survival of fewer than 15  months. Recent molecular characterization studies uncovered the genetic signatures and methylation status of gliomas and correlate these with clinical prognosis. The most relevant molecular characteristics for the new glioma classification are IDH mutation, chromosome 1p/19q deletion, histone mutations, and other genetic parameters such as ATRX loss, TP53, and TERT mutations, as well as DNA methylation levels. Similar to other solid tumors, glioma progression is impacted by the complex interactions between the tumor cells and immune cells within the tumor microenvironment. The immune system’s response to cancer can impact the glioma’s survival, proliferation, and invasiveness. Salient characteristics of gliomas include enhanced vascularization, stimulation of a hypoxic tumor microenvironment, increased oxidative stress, and an immune suppressive milieu. These processes promote the neuro-inflammatory tumor microenvironment which can lead to the loss of blood-brain barrier (BBB) integrity. The consequences of a compromised BBB are deleteriously exposing the brain to potentially harmful concentrations of substances from the peripheral circulation, adversely affecting neuronal signaling, and abnormal immune cell infiltration; all of which can lead to disruption of brain homeostasis. In this review, we first describe the unique features of inflammation in CNS tumors. We then discuss the mechanisms of tumor-initiating neuro-inflammatory microenvironment and its impact on tumor invasion and progression. Finally, we also discuss potential pharmacological interventions that can be used to target neuro-inflammation in gliomas.

siRNA-based identification of IBD-related targets in human monocyte-derived dendritic cells

Inflammatory bowel disease (IBD) is thought to be caused by an aberrant host response to the commensal enteric flora in genetically susceptible individuals. Dendritic cells (DCs) play a key role in the regulation of this response as they sample gut commensals. In healthy individuals DCs actively contribute to tolerance upon recognition of these resident bacteria, whereas in individuals with IBD, DCs will initiate an inflammatory response. To mimic the disease response in vitro, human monocyte-derived DCs were matured with E. coli causing the cells to produce high levels of the pro-inflammatory cytokine IL-12/IL-23p40 (p40) and low levels of the anti-inflammatory cytokine IL-10. A siRNA-based screening assay was developed and screened to identify potential therapeutic targets that shift this balance towards an immunosuppressive state with lower levels of p40 and higher levels of IL-10. The screening assay was optimized and quality controlled using non-targeting controls and positive control siRNAs targeting IL12B and TLR4 transcripts. In the primary screen, smartpool siRNAs were screened for reduction in p40 expression, induction of IL-10 levels, or increase in IL-10:p40 ratios without affecting cell viability. All potential targets were taken forward into a confirmation screen in a different DC donor in which four individual siRNAs per target were screened. At least two siRNAs per target should have an effect to be considered a valid target. This screen resulted in a concise list of ten genes, of which their role in DC maturation is currently being investigated.

Quantification of Cytokines in Lip Tissue from Infants Affected by Congenital Cleft Lip and Palate

Cleft lip and palate are amongst the most common congenital malformations worldwide presenting with variable manifestations. Previous research has been primarily focused on the genetical aspects of its complex and multifactorial etiology. In the present study, we investigated the role of cytokines as mediators of epithelial–mesenchymal crosstalk and local site inflammation in cleft affected infants. Lip material was obtained from 12 children aged before primary dentition who suffered from orofacial clefting. The quantification of 12 cytokines (Interleukin-2,4,5,6,10,12,13,17A, Tumor Necrosis Factor-α, Interferon-γ, Transforming Growth Factor beta-1 and Granulocyte-Colony Stimulating Factor) was done using ELISA. Nonparametric Spearman Rho was used to ascertain the correlation between the expression levels of different cytokines. A significantly strong positive correlation was found between IL-2 and IFN-γ coupled with an IL4/IFN-γ ratio favoring IFN-γ. These findings indicate a shift towards the preferential activation of the Th1 differentiation pathway. Further, a pathological reduction in TGFβ-1 levels was noted, which may contribute to mucosal damage. IL-6 was more highly correlated to IFN-γ and IL-12 indicating its potential proinflammatory role in cleft affected tissues. This preferential activation of Th1 cell differentiation and consistent expression of IL-2,6,13 and TNF-α in cleft patients may indicate certain underlying mechanisms for inflammation mediation at the site of clefting.

Sialic Acids and Their Influence on Human NK Cell Function

Sialic acids are sugars with a nine-carbon backbone, present on the surface of all cells in humans, including immune cells and their target cells, with various functions. Natural Killer (NK) cells are cells of the innate immune system, capable of killing virus-infected and tumor cells. Sialic acids can influence the interaction of NK cells with potential targets in several ways. Different NK cell receptors can bind sialic acids, leading to NK cell inhibition or activation. Moreover, NK cells have sialic acids on their surface, which can regulate receptor abundance and activity. This review is focused on how sialic acids on NK cells and their target cells are involved in NK cell function.

Bombyx batryticatus Protein-Rich Extract Induces Maturation of Dendritic Cells and Th1 Polarization: A Potential Immunological Adjuvant for Cancer Vaccine

Bombyx batryticatus, a protein-rich edible insect, is widely used as a traditional medicine in China. Several pharmacological studies have reported the anticancer activity of B. batryticatus extracts; however, the capacity of B. batryticatus extracts as immune potentiators for increasing the efficacy of cancer immunotherapy is still unverified. In the present study, we investigated the immunomodulatory role of B. batryticatus protein-rich extract (BBPE) in bone marrow-derived dendritic cells (BMDCs) and DC vaccine-immunized mice. BBPE-treated BMDCs displayed characteristics of mature immune status, including high expression of surface molecules (CD80, CD86, major histocompatibility complex (MHC)-I, and MHC-II), increased production of proinflammatory cytokines (tumor necrosis factor-α and interleukin-12p70), enhanced antigen-presenting ability, and reduced endocytosis. BBPE-treated BMDCs promoted naive CD4⁺ and CD8⁺ T-cell proliferation and activation. Furthermore, BBPE/ovalbumin (OVA)-pulsed DC-immunized mice showed a stronger OVA-specific multifunctional T-cell response in CD4⁺ and CD8⁺ T cells and a stronger Th1 antibody response than mice receiving differently treated DCs, which showed the enhanced protective effect against tumor growth in E.G7 tumor-bearing mice. Our data demonstrate that BBPE can be a novel immune potentiator for a DC-based vaccine in anticancer therapy.

Dendritic Cells of Leukemic Origin: Specialized Antigen-Presenting Cells as Potential Treatment Tools for Patients with Myeloid Leukemia

The prognosis of elderly patients with acute myeloid leukemia (AML) and high-grade myelodysplastic syndrome (MDS) is limited due to the lack of therapy options and high relapse rates. Dendritic cell (DC)-based immunotherapy seems to be a promising treatment tool. DC are potent antigen-presenting cells and play a pivotal role on the interface of the innate and the adaptive immune system. Myeloid leukemia blasts can be converted to DC of leukemic origin (DC_leu), expressing costimulatory molecules along with the whole leukemic antigen repertoire of individual patients. These generated DC_leu are potent stimulators of various immune reactive cells and increase antileukemic immunity ex vivo. Here we review the generating process of DC/DC_leu from leukemic peripheral blood mononuclear cells as well as directly from leukemic whole blood with "minimized" Kits to simulate physiological conditions ex vivo. The purpose of adoptive cell transfer of DC/DC_leu as a vaccination strategy is discussed. A new potential therapy option with Kits for patients with myeloid leukemia, which would render an adoptive DC/DC_leu transfer unnecessary, is presented. In summary, DC/DC_leu-based therapies seem to be promising treatment tools for patients with AML or MDS but ongoing research including trials in animals and humans have to be performed.

Actin-depolymerizing factor from Eimeria tenella promotes immunogenic function of chicken dendritic cells

Dendritic cells play a crucial role in inducing antigen-specific immunity to pathogens. During host-parasite interaction, host immune response to the parasite molecules is considered essential for recognizing novel antigens for control strategies. Therefore, in the present study, chicken dendritic cells (DCs) (ChDCs), derived from spleens were used to evaluate their capacity to proliferate and differentiate autologous T lymphocytes in response to actin-depolymerizing factor from Eimeria tenella (EtADF). Immunoblot analysis showed that recombinant EtADF protein (rEtADF) was able to interact with rat anti-rEtADF antibodies. The immunofluorescence test confirmed rEtADF binding on ChDCs surface. Flow cytometric analysis revealed that phenotypes for MHCII, CD1.1, CD11c, CD80, and CD86 were increased in ChDCs after rEtADF treatment. qRT-PCR results indicated that ChDCs triggered TLR signaling in response to rEtADF, and suppressed Wnt signaling. Transcript levels of CD83, CCL5, and CCR7 in ChDCs were improved following rEtADF treatment. In addition, rEtADF promoted DC-directed T cell proliferation and differentiation of naïve T cells into CD3⁺/CD4⁺ T cells in DC/T cell co-incubation system. Cytokine analysis of rEtADF-pulsed ChDCs showed increased levels of IL-12 and IFN-γ, while IL-10 and TGF-β remained unchanged. Moreover, rEtADF-treated ChDCs enhanced production of IFN-γ when incubated with T cells, and IL-4 secretion remained unchanged. Our findings indicted that rEtADF could facilitate the polarization of Th1 immune cells by triggering both host DCs and T cells. Our findings provide useful insights into future work aimed at anticoccidial vaccine strategies.

Mast cell-derived IL-13 downregulates IL-12 production by skin dendritic cells to inhibit the TH1 cell response to cutaneous antigen exposure

BACKGROUND

Atopic dermatitis (AD) is characterized by a skin barrier defect aggravated by mechanical injury inflicted by scratching, a T_H2 cell-dominated immune response, and susceptibility to viral skin infections that are normally restrained by a T_H1 cell response. The signals leading to a T_H2 cell-dominated immune response in AD are not completely understood.

OBJECTIVE

Our aim was to determine the role of IL-13 in initiation of the T_H cell response to cutaneously encountered antigens.

METHODS

Wild-type, Il13^-/-, Il1rl1^-/-, and Il4ra^-/- mice, as well as mice with selective deficiency of IL-13 in mast cells (MCs) were studied; in addition, dendritic cells (DCs) purified from the draining lymph nodes of tape-stripped and ovalbumin (OVA)-sensitized skin were examined for their ability to polarize naive OVA-TCR transgenic CD4⁺ T cells. Cytokine expression was examined by reverse-transcriptase quantitative PCR, intracellular flow cytometry, and ELISA. Contact hypersensitivity to dinitrofluorobenzene was examined.

RESULTS

Tape stripping caused IL-33-driven upregulation of Il13 expression by skin MCs. MC-derived IL-13 acted on DCs from draining lymph nodes of OVA-sensitized skin to selectively suppress their ability to polarize naive OVA-TCR transgenic CD4⁺ T cells into IFN-γ-secreting cells. MC-derived IL-13 inhibited the T_H1 cell response in contact hypersensitivity to dinitrofluorobenzene. IL-13 suppressed IL-12 production by mouse skin-derived DCs in vitro and in vivo. Scratching upregulated IL13 expression in human skin, and IL-13 suppressed the capacity of LPS-stimulated human skin DCs to express IL-12 and promote IFN-γ secretion by CD4⁺ T cells.

CONCLUSION

Release of IL-13 by cutaneous MCs in response to mechanical skin injury inhibits the T_H1 cell response to cutaneous antigen exposure in AD.

Immunology of IL-12: An update on functional activities and implications for disease

As its first identified member, Interleukin-12 (IL-12) named a whole family of cytokines. In response to pathogens, the heterodimeric protein, consisting of the two subunits p35 and p40, is secreted by phagocytic cells. Binding of IL-12 to the IL-12 receptor (IL-12R) on T and natural killer (NK) cells leads to signaling via signal transducer and activator of transcription 4 (STAT4) and subsequent interferon gamma (IFN-γ) production and secretion. Signaling downstream of IFN-γ includes activation of T-box transcription factor TBX21 (Tbet) and induces pro-inflammatory functions of T helper 1 (T_H1) cells, thereby linking innate and adaptive immune responses. Initial views on the role of IL-12 and clinical efforts to translate them into therapeutic approaches had to be re-interpreted following the discovery of other members of the IL-12 family, such as IL-23, sharing a subunit with IL-12. However, the importance of IL-12 with regard to immune processes in the context of infection and (auto-) inflammation is still beyond doubt. In this review, we will provide an update on functional activities of IL-12 and their implications for disease. We will begin with a summary on structure and function of the cytokine itself as well as its receptor and outline the signal transduction and the transcriptional regulation of IL-12 secretion. In the second part of the review, we will depict the involvement of IL-12 in immune-mediated diseases and relevant experimental disease models, while also providing an outlook on potential translational approaches.

The Poststroke Peripheral Immune Response Is Differentially Regulated by Leukemia Inhibitory Factor in Aged Male and Female Rodents

Background

The goal of this study was to determine whether leukemia inhibitory factor (LIF) promotes anti-inflammatory activity after stroke in a sex-dependent manner.

Methods

Aged (18-month-old) Sprague-Dawley rats of both sexes underwent sham surgery or permanent middle cerebral artery occlusion (MCAO). Animals received three doses of intravenous LIF (125 μg/kg) or PBS at 6, 24, and 48 h before euthanization at 72 h. Spleen weights were measured immediately following euthanization. Western blot was used to measure protein levels of CCL8, CD11b, CXCL9, CXCL10, IL-12 p40, IL-3, and the LIF receptor (LIFR) in spleen tissue. ELISA was used to measure IL-1β, IL-6, TNFα, and IFNγ in spleen tissue. A Griess Assay was used to indirectly quantify NO levels via measurement of nitrite. Levels of cellular markers and inflammatory mediators were normalized to the baseline (sham) group from each sex. Statistical analysis was performed using two-way ANOVA and followed by Fisher's LSD post hoc test.

Results

Aged female rats showed a significantly lower spleen weight after MCAO, but showed a significant increase in spleen size after LIF treatment. This effect was observed in aged male rats, but not to as great of an extent. CD11b levels were significantly higher in the spleens of MCAO+PBS males compared to their female counterparts, but there was no significant difference in CD11b levels between MCAO+LIF males and females. LIF significantly increased CXCL9 after LIF treatment in aged male and female rats. LIFR and IL-3 were upregulated after LIF treatment in aged females. Splenic nitrate increased after MCAO but decreased after LIF treatment in aged females. Splenic nitrate levels did not increase after MCAO but did increase after LIF treatment in aged males. The following cytokines/chemokines were not altered by sex or treatment: TNFα, IL-6, IL-12 p40, CCL8, IFNγ, and CXCL10.

Conclusions

LIF treatment after permanent MCAO induces sex-dependent effects on the poststroke splenic response and the production of proinflammatory cytokines among aged rats.

Effect of Synbiotics on Amelioration of Intestinal Inflammation Under Hypobaric Hypoxia

Khanna, Kunjan, Kamla Prasad Mishra, Sudipta Chanda, Lilly Ganju, Shashi Bala Singh, and Bhuvnesh Kumar. Effect of synbiotics on amelioration of intestinal inflammation under hypobaric hypoxia. High Alt Med Biol. 22:32-44, 2021. Aim: High-altitude exposure alters the gastrointestinal (GI) system, which may be a cause of hypobaric hypoxia (HH)-induced microbial dysbiosis. Therefore, we investigated the effect of a combination of beneficial bacteria and nondigestible fiber popularly known as "synbiotics" (Syn) to mitigate intestinal inflammation and microbial dysbiosis post-HH exposure. Methods: Syn, that is, a combination of probiotics and prebiotics, was given to male Sprague-Dawley rats 3 days prior and along with the HH exposure to assess its effect on mucosal barrier injury and inflammation. Changes in the gut microbiota and functional analysis were assessed using 16S rRNA and whole-genome sequencing (WGS) analysis. Results: Syn treatment significantly improved mucosal barrier injury in terms of decreased serum fluorescein isothiocyanate dextran from 96.1 ± 7.95 μg/ml in HH-alone group to 38.35 ± 4.55 μg/ml in HH + Syn group (p < 0.01) and decreased serum zonulin levels, that is, from 134.7 ± 19.05 ng/ml (HH alone) to 64.02 ± 7.33 ng/ml (HH + Syn) (p < 0.05), along with improvement in the intestinal villi under HH exposure. Levels of proinflammatory cytokines and chemokines significantly reduced upon Syn treatment, indicating attenuation of inflammation and immune cell migration. Syn treatment significantly reduced Th17 biased immune response preventing interleukin (IL)-17-induced inflammatory response with 8.1 ± 0.5 ng/mg protein in HH exposure group, while treatment with Syn in HH-exposed group reduced IL-17 levels to 2.01 ± 0.3 ng/mg protein (p < 0.001). Analysis of 16S rRNA showed significant (p < 0.05) alterations in Deferribacteres, Firmicutes, and Verrucomicrobia at the phylum levels, whereas Prevotella, Paenibacillus, Clostridium, Turicibacter, Bacillus, Anoxybacillus, Enterococcus, SMB53, Mucispirillum, Allobaculum, and Lactococcus were significantly altered (p < 0.05) in abundance at the genus level. WGS analysis revealed improvement in GI health by regulating functional pathways post-Syn treatment. Conclusion: Our findings indicate that Syn treatment improves intestinal barrier function and curtailed inflammation in the HH-exposed rat models, proving it to be a promising potential countermeasure for HH-induced gut problems.

The chemical biology of IL-12 production via the non-canonical NFkB pathway

Interleukin-12 (IL-12) has emerged as an attractive cytokine for cancer therapy because it has direct anti-cancer effects and additionally plays a critical role in enhancing checkpoint inhibitors. Given these multiple modes of actions, identifying means to pharmacologically induce IL-12 production in the tumor microenvironment has become important. In this review, we highlight therapeutics that promote IL-12 induction in tumor-associated myeloid cells through the non-canonical NFkB pathway. We discuss existing clinical trials and briefly examine the additional pathway targets that warrant further exploration for drug discovery.

Predicting combinations of immunomodulators to enhance dendritic cell-based vaccination based on a hybrid experimental and computational platform

Dendritic cell (DC)-based vaccines have been largely used in the adjuvant setting for the treatment of cancer, however, despite their proven safety, clinical outcomes still remain modest. In order to improve their efficacy, DC-based vaccines are often combined with one or multiple immunomodulatory agents. However, the selection of the most promising combinations is hampered by the plethora of agents available and the unknown interplay between these different agents. To address this point, we developed a hybrid experimental and computational platform to predict the effects and immunogenicity of dual combinations of stimuli once combined with DC vaccination, based on the experimental data of a variety of assays to monitor different aspects of the immune response after a single stimulus. To assess the stimuli behavior when used as single agents, we first developed an in vitro co-culture system of T cell priming using monocyte-derived DCs loaded with whole tumor lysate to prime autologous peripheral blood mononuclear cells in the presence of the chosen stimuli, as single adjuvants, and characterized the elicited response assessing 18 different phenotypic and functional traits important for an efficient anti-cancer response. We then developed and applied a prediction algorithm, generating a ranking for all possible dual combinations of the different single stimuli considered here. The ranking generated by the prediction tool was then validated with experimental data showing a strong correlation with the predicted scores, confirming that the top ranked conditions globally significantly outperformed the worst conditions. Thus, the method developed here constitutes an innovative tool for the selection of the best immunomodulatory agents to implement in future DC-based vaccines.

IL-23 costimulates antigen-specific MAIT cell activation and enables vaccination against bacterial infection

Mucosal-associated invariant T (MAIT) cells are activated in a TCR-dependent manner by antigens derived from the riboflavin synthesis pathway, including 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU), bound to MHC-related protein-1 (MR1). However, MAIT cell activation in vivo has not been studied in detail. Here, we have found and characterized additional molecular signals required for optimal activation and expansion of MAIT cells after pulmonary Legionella or Salmonella infection in mice. We show that either bone marrow-derived APCs or non-bone marrow-derived cells can activate MAIT cells in vivo, depending on the pathogen. Optimal MAIT cell activation in vivo requires signaling through the inducible T cell costimulator (ICOS), which is highly expressed on MAIT cells. Subsequent expansion and maintenance of MAIT-17/1-type responses are dependent on IL-23. Vaccination with IL-23 plus 5-OP-RU augments MAIT cell-mediated control of pulmonary Legionella infection. These findings reveal cellular and molecular targets for manipulating MAIT cell function under physiological conditions.

New Insights Into Immunological Therapy for Retinal Disorders

In the twentieth century, a conspicuous lack of effective treatment strategies existed for managing several retinal disorders, including age-related macular degeneration; diabetic retinopathy (DR); retinopathy of prematurity (ROP); retinitis pigmentosa (RP); uveitis, including Behçet's disease; and vitreoretinal lymphoma (VRL). However, in the first decade of this century, advances in biomedicine have provided new treatment strategies in the field of ophthalmology, particularly biologics that target vascular endothelial growth factor or tumor necrosis factor (TNF)-α. Furthermore, clinical trials on gene therapy specifically for patients with autosomal recessive or X-linked RP have commenced. The overall survival rates of patients with VRL have improved, owing to earlier diagnoses and better treatment strategies. However, some unresolved problems remain such as primary or secondary non-response to biologics or chemotherapy, and the lack of adequate strategies for treating most RP patients. In this review, we provide an overview of the immunological mechanisms of the eye under normal conditions and in several retinal disorders, including uveitis, DR, ROP, RP, and VRL. In addition, we discuss recent studies that describe the inflammatory responses that occur during the course of these retinal disorders to provide new insights into their diagnosis and treatment.