Macrophage cytokines: involvement in immunity and infectious diseases

Stromal vascular fraction in the treatment of myositis

Muscle regeneration is a physiological process that converts satellite cells into mature myotubes under the influence of an inflammatory environment progressively replaced by an anti-inflammatory environment, with precise crosstalk between immune and muscular cells. If the succession of these phases is disturbed, the immune system can sometimes become auto-reactive, leading to chronic muscular inflammatory diseases, such as myositis. The triggers of these autoimmune myopathies remain mostly unknown, but the main mechanisms of pathogenesis are partially understood. They involve chronic inflammation, which could be associated with an auto-reactive immune response, and gradually with a decrease in the regenerative capacities of the muscle, leading to its degeneration, fibrosis and vascular architecture deterioration. Immunosuppressive treatments can block the first part of the process, but sometimes muscle remains weakened, or even still deteriorates, due to the exhaustion of its capacities. For patients refractory to immunosuppressive therapies, mesenchymal stem cells have shown interesting effects but their use is limited by their availability. Stromal vascular fraction, which can easily be extracted from adipose tissue, has shown good tolerance and possible therapeutic benefits in several degenerative and autoimmune diseases. However, despite the increasing use of stromal vascular fraction, the therapeutically active components within this heterogeneous cellular product are ill-defined and the mechanisms by which this therapy might be active remain insufficiently understood. We review herein the current knowledge on the mechanisms of action of stromal vascular fraction and hypothesise on how it could potentially respond to some of the unmet treatment needs of refractory myositis.

The role of TRPV1 in RA pathogenesis: worthy of attention

Transient receptor potential cation channel subfamily V member 1 (TRPV1) is a Ca2+permeable, non-selective cation channel that is found primarily in sensory nerve fibres. Previous studies focused on pain transmission. However, recent studies have found that the TRPV1 channel, in addition to being associated with pain, also plays a role in immune regulation and their dysregulation frequently affects the development of rheumatoid arthritis (RA). A thorough understanding of the mechanism will facilitate the design of new TRPV1-targeted drugs and improve the clinical efficacy of RA. Here, we provide an updated and comprehensive overview of how the TRPV1 channel intrinsically regulates neuronal and immune cells, and how alterations in the TRPV1 channel in synoviocytes or chondrocytes extrinsically affect angiogenesis and bone destruction. Rapid progress has been made in research targeting TRPV1 for the treatment of inflammatory arthritis, but there is still much-uncharted territory regarding the therapeutic role of RA. We present a strategy for targeting the TRPV1 channel in RA therapy, summarising the difficulties and promising advances in current research, with the aim of better understanding the role of the TRPV1 channel in RA pathology, which could accelerate the development of TRPV1-targeted modulators for the design and development of more effective RA therapies.

Q fever immunology: the quest for a safe and effective vaccine

Q fever is an infectious zoonotic disease, caused by the Gram-negative bacterium Coxiella burnetii. Transmission occurs from livestock to humans through inhalation of a survival form of the bacterium, the Small Cell Variant, often via handling of animal parturition products. Q fever manifests as an acute self-limiting febrile illness or as a chronic disease with complications such as vasculitis and endocarditis. The current preventative human Q fever vaccine Q-VAX poses limitations on its worldwide implementation due to reactogenic responses in pre-sensitized individuals. Many strategies have been undertaken to develop a universal Q fever vaccine but with little success to date. The mechanisms of the underlying reactogenic responses remain only partially understood and are important factors in the development of a safe Q fever vaccine. This review provides an overview of previous and current experimental vaccines developed for use against Q fever and proposes approaches to develop a vaccine that establishes immunological memory while eliminating harmful reactogenic responses.

Interaction of TiO2 nanoparticles with lung fluid proteins and the resulting macrophage inflammatory response

Inhalation is a major exposure route to nanoparticles. Following inhalation, nanoparticles first interact with the lung lining fluid, a complex mixture of proteins, lipids, and mucins. We measure the concentration and composition of lung fluid proteins adsorbed on the surface of titanium dioxide (TiO2) nanoparticles. Using proteomics, we find that lung fluid results in a unique protein corona on the surface of the TiO2 nanoparticles. We then measure the expression of three cytokines (interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and macrophage inflammatory protein 2 (MIP-2)) associated with lung inflammation. We find that the corona formed from lung fluid leads to elevated expression of these cytokines in comparison to bare TiO2 nanoparticles or coronas formed from serum or albumin. These experiments show that understanding the concentration and composition of the protein corona is essential for understanding the pulmonary response associated with human exposure to nanoparticles.

Immune modulation by nutritional intervention in malnourished children: Identifying the phenotypic distribution and functional responses of peripheral blood mononuclear cells

Malnourished children are susceptible to an increased risk of mortality owing to impaired immune functions. However, the underlying mechanism of altered immune functions and its interaction with malnutrition is poorly understood. This study investigates the immune function and evaluates the effect of a particular nutritional intervention on the immune cells of undernourished children. Stunted (LAZ <-2) and at-risk of being stunted (length-for-age Z-scores, LAZ <-1 to -2) children aged between 12 and 18 months were enrolled and were provided with the daily nutritional intervention of one egg and 150 mL cow's milk for 90 days. Peripheral blood mononuclear cells (PBMCs) were isolated at enrolment and upon completion of the intervention. Phenotypic profiles for CD3+ cells, CD4+ cells, CD8+ cells, NKT cells, and B cells were similar in both cohorts, both before and after the intervention. However, activated B cells (CD25+) were increased after nutritional intervention in the at-risk of being stunted cohort. Several pro-inflammatory cytokines, IL-6, IFN-γ, and TNF-α, were elevated in the stunted children following the nutritional intervention. The results of the study indicate that nutritional intervention may have a role on activated B cells (CD25+) s in children who are at-risk of being stunted and may alter the capacity of PBMC to produce inflammatory cytokines in stunted children.

Effects of light and circadian clock on the antiviral immune response in zebrafish

The circadian clock mechanism, which is evolutionarily conserved across various organisms, plays a crucial role in synchronizing physiological responses to external conditions, primarily in response to light availability. By maintaining homeostasis of biological processes and behavior, the circadian clock serves as a key regulator. This biological mechanism also coordinates diurnal oscillations of the immune response during infections. However there is limited information available regarding the influence of circadian oscillation on immune regulation, especially in lower vertebrates like teleost fish. Therefore, the present study aimed to investigate the effects of light and the timing of infection induction on the antiviral immune response in zebrafish. To explore the relationship between the timing of infection and the response activated by viral pathogens, we used a zebrafish model infected with tilapia lake virus (TiLV). Our findings demonstrated that light availability significantly affects the antiviral immune response and the functioning of the molecular clock mechanism during TiLV infection. This is evident through alterations in the expression of major core clock genes and the regulation of TiLV replication and type I IFN pathway genes in the kidney of fish maintained under LD (light-dark) conditions compared to constant darkness (DD) conditions. Moreover, infection induced during the light phase of the LD cycle, in contrast to nocturnal infection, also exhibited similar effects on the expression of genes associated with the antiviral response. This study indicates a more effective mechanism of the zebrafish antiviral response during light exposure, which inherently involves modification of the expression of key components of the molecular circadian clock. It suggests that the zebrafish antiviral response to infection is regulated by both light and the circadian clock.

Immune response to foreign materials in spinal fusion surgery

Spinal fusion surgery is a common procedure used to stabilize the spine and treat back pain. The procedure involves the use of foreign materials such as screws, rods, or cages, which can trigger a foreign body reaction, an immune response that involves the activation of immune cells such as macrophages and lymphocytes. The foreign body reaction can impact the success of spinal fusion, as it can interfere with bone growth and fusion. This review article provides an overview of the cellular and molecular events in the foreign body reaction, the impact of the immune response on spinal fusion, and strategies to minimize its impact. By carefully considering the use of foreign materials and optimizing surgical techniques, the impact of the foreign body reaction can be reduced, leading to better outcomes for patients.

A C-type lectin-like receptor CD302 in yellow drum (Nibea albiflora) functioning in antibacterial activity and innate immune signaling

Molecular dissection of disease resistance against Vibrio harveyi infection in yellow drum at the genome-wide level uncovered a C-type lectin-like receptor cluster of differentiation CD302 (named as YdCD302) in our previous study. Here, the gene expression pattern of YdCD302 and its function in mediating the defense response to V. harveyi attack were investigated. Gene expression analysis demonstrated that YdCD302 was ubiquitously distributed in various tissues with the highest transcript abundance in liver. The YdCD302 protein exhibited agglutination and antibacterial activity against V. harveyi cells. Binding assay indicated that YdCD302 can physically interact with V. harveyi cells in a Ca2+-independent manner, and the interaction can activate reactive oxygen species (ROS) production in the bacterial cells to induce RecA/LexA-mediated cell death. After infection with V. harveyi, the expression of YdCD302 can be up-regulated significantly in the main immune organs of yellow drum and potentially further trigger the cytokines involved innate immunity. These findings provide insight into the genetic basis of the disease resistance trait in yellow drum and shed light on the functioning of the CD302 C-type lectin-like receptor in host-pathogen interactions. The molecular and functional characterization of YdCD302 is a significant step towards a better understanding of disease resistance mechanisms and the development of new strategies for disease control.

Alterations in the gut microbiome and its metabolites are associated with the immune response to mucosal immunization with Lactiplantibacillus plantarum-displaying recombinant SARS-CoV-2 spike epitopes in mice

Lactic acid bacteria (LAB) expressing foreign antigens have great potential as mucosal vaccines. Our previous study reported that recombinant Lactiplantibacillus plantarum SK156 displaying SARS-CoV-2 spike S1 epitopes elicited humoral and cell-mediated immune responses in mice. Here, we further examined the effect of the LAB-based mucosal vaccine on gut microbiome composition and function, and gut microbiota-derived metabolites. Forty-nine (49) female BALB/c mice were orally administered L. plantarum SK156-displaying SARS-CoV-2 spike S1 epitopes thrice (at 14-day intervals). Mucosal immunization considerably altered the gut microbiome of mice by enriching the abundance of beneficial gut bacteria, such as Muribaculaceae, Mucispirillum, Ruminococcaceae, Alistipes, Roseburia, and Clostridia vadinBB60. Moreover, the predicted function of the gut microbiome showed increased metabolic pathways for amino acids, energy, carbohydrates, cofactors, and vitamins. The fecal concentration of short-chain fatty acids, especially butyrate, was also altered by mucosal immunization. Notably, alterations in gut microbiome composition, function, and butyrate levels were positively associated with the immune response to the vaccine. Our results suggest that the gut microbiome and its metabolites may have influenced the immunogenicity of the LAB-based SARS-CoV-2 vaccine.

Trinity of inflammation, innate immune cells and cross-talk of signalling pathways in tumour microenvironment

Unresolved inflammation is a pathological consequence of persistent inflammatory stimulus and perturbation in regulatory mechanisms. It increases the risk of tumour development and orchestrates all stages of tumorigenesis in selected organs. In certain cancers, inflammatory processes create the appropriate conditions for neoplastic transformation. While in other types, oncogenic changes pave the way for an inflammatory microenvironment that leads to tumour development. Of interest, hallmarks of tumour-promoting and cancer-associated inflammation are striking similar, sharing a complex network of stromal (fibroblasts and vascular cells) and inflammatory immune cells that collectively form the tumour microenvironment (TME). The cross-talks of signalling pathways initially developed to support homeostasis, change their role, and promote atypical proliferation, survival, angiogenesis, and subversion of adaptive immunity in TME. These transcriptional and regulatory pathways invariably contribute to cancer-promoting inflammation in chronic inflammatory disorders and foster "smouldering" inflammation in the microenvironment of various tumour types. Besides identifying common target sites of numerous cancer types, signalling programs and their cross-talks governing immune cells' plasticity and functional diversity can be used to develop new fate-mapping and lineage-tracing mechanisms. Here, we review the vital molecular mechanisms and pathways that establish the connection between inflammation and tumour development, progression, and metastasis. We also discussed the cross-talks between signalling pathways and devised strategies focusing on these interaction mechanisms to harness synthetic lethal drug combinations for targeted cancer therapy.

Apoptotic cells for treatment of acute respiratory distress syndrome associated with COVID-19

Background

Hyper-inflammatory immune response, a hallmark of severe COVID-19, is associated with increased mortality. Acute respiratory distress syndrome (ARDS) is a common manifestation. We undertook two phase I/II studies in five and then 16 subjects with severe/critical COVID-19 to assess the safety and preliminary efficacy of apoptotic cells (Allocetra™-OTS, Enlivex Therapeutics), a cellular immunomodulatory therapy that reprograms macrophages to reduce hyper-inflammatory response severity.

Methods

Eligible patients presenting to the Emergency Room with severe COVID-19 and respiratory dysfunction received one intravenous administration of Allocetra™-OTS and were monitored for adverse events (AEs) for 28 days. The primary aim was to determine the safety profile of treatment; secondary aims were recovery from ARDS, intensive care unit (ICU) and hospital length-of-stay, and mortality. Immune modulator markers were measured to elucidate the mechanism of action of Allocetra™-OTS.

Results

21 patients with severe-critical COVID-19 of Gamma, Alpha and Delta variants, were treated with a single dose of apoptotic cells. 19/21 patients had mild-to-severe ARDS at presentation. Median age was 53 years, 16/21 were males, 16/21 were overweight/obese. No serious related adverse events (SAEs) were reported. All 21 study subjects survived to day 28 (end of study); 19/21 recovered completely. Comparable mortality rates at the hospital were 3.8%-8.9% for age- and gender-matched patients, and 39%-55% for critical patients. Recovering patients exhibited rapid ARDS resolution and parallel resolution of inflammation markers and elevated cytokines/chemokines.

Conclusion

In patients with severe/critical COVID-19 associated with ARDS, Allocetra™-OTS was safe, well-tolerated, and showed promising results for resolution of respiratory failure and inflammation.

Trial registration

https://clinicaltrials.gov/ct2/show/study/NCT04513470, https://clinicaltrials.gov/ct2/show/study/NCT04590053, Identifiers NCT04513470, NCT04590053.

Antileishmanial effects and drugability characteristics of a heterocyclic copper complex: An in silico, in vitro and molecular study

Leishmaniasis caused by the protozoan Leishmania presents a severe illness, principally in tropical and subtropical areas. Antileishmanial metal complexes, like Glucantime®️ with proven activity, are routinely studied to probe their potency. We investigated the effects of a Cu (II) homoleptic complex coordinated by two dimethyl-bipyridine ligands against Leishmania major stages in silico and in vitro. The affinity of this heterocyclic Cu (II) complex (CuDMBP) towards a parasitic metacaspase was studied by molecular docking. Key pharmacokinetic and pharmacodynamic properties of the complex were predicted using three web-based tools. CuDMBP was tested for in vitro antileishmanial activities using MTT assay, model murine macrophages, flow cytometry, and quantitative real-time polymerase chain reaction (qPCR). Molecular docking confirmed the tendency between the target macromolecule and the complex. ADMET evaluations highlighted CuDMBP's key pharmacological features, including P-glycoprotein-associated GI absorption and lack of trans-BBB permeability. MTT showed significant inhibitory effects against promastigotes. CuDMBP significantly increased the level of cellular IL-12 expression (p < 0.05), while the upregulation observed in the expression of iNOS was considered not significant (p > 0.05). It decreased the expression of IL-10 significantly (p < 0.05). Findings demonstrated that CuDMBP deserves to be introduced as a leishmanicidal candidate provided further studies are carried out.

Contactless Resolution of Inflammatory Signals in Tailored Macrophage-Based Cell Therapeutics

In recent years, nanotechnology-based microRNA (miR) therapeutic platforms have shown great promise for immunotherapy and tissue regeneration, despite the unmet challenge of achieving efficient and safe delivery of miRs. The transport of miRs offers precision and regulatory value for a myriad of biological processes and pathways, including the control of macrophage (Mφ) functions and, consequently, the inflammatory cascades Mφ are involved in. Thus, enforcement of Mφ can boost the regenerative process and provide new solutions for diverse chronic pathologies. In this study, we sought to develop a magnetically guided transporter to deliver an miR-155 antagonist to M1-primed Mφ. Furthermore, we determined its modulatory effect in reprogramming Mφ from inflammatory to pro-regenerative phenotypes, with the aim of tissue healing and regenerative medicine approaches. This strategy combines contactless and high-precision control of Mφ, anticipating new functional miR carriers for targeted strategies controlled by extracorporeal action. The magnetoplexes SPION@PEI-miR were efficiently delivered into Mφ without compromising cell viability and successfully induced miR-mediated gene silencing by enhancing the expression of anti-inflammatory markers (IL4 and IL10) and the production of M2φ-related markers (CD206 and IL4). Given its multimodal features, SPION@PEI-miR represents a simple, safe, and nonviral theranostic platform that enables imaging, tracking, and miR delivery with modulatory effects on immune cells.

Cell Reprogramming Techniques: Contributions to Cancer Therapy

The reprogramming of terminally differentiated cells over the past few years has become important for induced pluripotent stem cells (iPSCs) in the field of regenerative medicine and disease drug modeling. At the same time, iPSCs have also played an important role in human cancer research. iPSCs derived from cancer patients can be used to simulate the early progression of cancer, for drug testing, and to study the molecular mechanism of cancer occurrence. In recent years, with the application of cellular immunotherapy in cancer therapy, patient-derived iPSC-induced immune cells (T, natural killer, and macrophage cells) solve the problem of immune rejection and have higher immunogenicity, which greatly improves the therapeutic efficiency of immune cell therapy. With the continuous progress of cancer differentiation therapy, iPSC technology can reprogram cancer cells to a more primitive pluripotent undifferentiated state, and successfully reverse cancer cells to a benign phenotype by changing the epigenetic inheritance of cancer cells. This article reviews the recent progress of cell reprogramming technology in human cancer research, focuses on the application of reprogramming technology in cancer immunotherapy and the problems solved, and summarizes the malignant phenotype changes of cancer cells in the process of reprogramming and subsequent differentiation.

Epithelial multicellular clustering enabled by polarized macrophages on soft matrices

Formation of epithelial structures of variegated geometries and sizes is essential for organogenesis, tumor growth, and wound repair. Although epithelial cells are predisposed with potential for multicellular clustering, it remains unclear whether immune cells and mechanical cues from their microenvironment influence this process. To explore this possibility, we cocultured human mammary epithelial cells with prepolarized macrophages on soft or stiff hydrogels. In the presence of M1 (proinflammatory) macrophages on soft matrices, epithelial cells migrated faster and subsequently formed larger multicellular clusters compared to cocultures with M0 (unpolarized) or M2 (anti-inflammatory) macrophages. By contrast, stiff matrices disabled active clustering of epithelial cells due to their enhanced migration and cell-ECM adhesion, regardless of macrophage polarization. We found that the copresence of soft matrices and M1 macrophages reduced focal adhesions, but enhanced fibronectin deposition and nonmuscle myosin-IIA expression, which altogether optimize conditions for epithelial clustering. Upon ROCK inhibition, epithelial clustering was abrogated, indicating a requirement for optimized cellular forces. In these cocultures, TNF-α secretion was the highest with M1 macrophages and TGF-β secretion was exclusively detectable in case of M2 macrophages on soft gels, which indicated potential role of macrophage secreted factors in the observed epithelial clustering. Indeed, exogenous addition of TGF-β promoted epithelial clustering with M1 coculture on soft gels. According to our findings, optimization of both mechanical and immune factors can tune epithelial clustering responses, which could have implications in tumor growth, fibrosis, and would healing.

Epigallocatechin gallate (EGCG) inhibits lipopolysaccharide-induced inflammation in RAW 264.7 macrophage cells via modulating nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) signaling pathway

Epigallocatechin-3-gallate (EGCG) is a major bioactive compound in tea polyphenol extract. After ingestion, EGCG reaches the intestine and may commence anti-inflammation in the intestinal organ. Thus, in this paper, the anti-inflammatory effect of EGCG was studied using lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 cells. LPS induction instigated morphological deformation extensively which was normalized by EGCG. In LPS-induced macrophage cells, EGCG was found to lower cellular nitric oxide (32% of LPS group) and intercellular ROS level (45.4% of LPS group). It also suppressed the expression of IL-1β (LPS 132.6 ± 14.6, EGCG 10.67 ± 3.65), IL-6 (LPS 2994.44 ± 178.5, EGCG 408.33 ± 52.34), TNF-α (LPS 27.11 ± 2.84, EGCG 1.22 ± 0.03), and iNOS (LPS 40.45 ± 11.17, EGCG 10.24 ± 0.89). The GO function analysis identified that these differential genes involved 24 biological processes, 18 molecular functions, and 19 cellular component-related processes. KEGG pathway enrichment analysis revealed that LPS significantly affects NF-κB, TNF, and TLR signaling pathways. Western blotting revealed that EGCG diminished P-IκB/IκB ratio by 75% and p-p65/p65 by 50% compared to the LPS group. Finally, Arg-1 and CD-206 mRNA expression were determined by RT-PCR, which was consistent with the RNA-Seq result. These findings indicate that EGCG exerts an anti-inflammatory effect by reducing NO and ROS production, suppressing TLR4 protein expression, and inhibiting IκB and p65 phosphorylation.

Delineation of the distinct inflammatory signaling roles of TAK1 and JAK1/3 in the CIA model of rheumatoid arthritis

Rheumatoid arthritis (RA) is a complex autoimmune disease characterized by hyperactive immune cells within the joints, which leads to inflammation, bone degeneration, and chronic pain. For several decades, frontline immunomodulators such as the anti-tumor necrosis factor (TNF) biologics adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade) have successfully managed disease progression for many patients. However, over time, patients become refractory to these treatments requiring chronic disease to be managed with conventional and more problematic disease modifying antirheumatic drugs such as methotrexate and hydroxychloroquine, and corticosteroids. Due to the large proportion of patients who continue to fail on frontline biologic therapies, there remains an unmet need to derive novel alternative targets with improved efficacy and safety profiles to treat RA. Recent advances in the field have defined novel targets that play important roles in RA pathology, including the Janus activated kinase (JAK) and transforming growth factor beta activated kinase-1 (TAK1). Although three inhibitors of the JAK signaling pathway have been approved for the treatment of moderately to severely active RA in patients who failed on one or more anti-TNFs, at present, no FDA approved TAK1 treatments exist. Our recent discovery of a highly potent and selective, orally bioavailable TAK1 inhibitor has provided insight into the therapeutic potential of this protein kinase as a novel target for RA. Here, we show the distinct cytokine signaling of tofacitnib (Xeljanz; JAK1/3 inhibitor) compared to HS-276 (TAK1 inhibitor) in lipopolysaccharide (LPS) challenged THP-1 cells. Furthermore, in the collagen induced arthritis pre-clinical mouse model of RA, both tofacintib and HS-276 attenuated disease activity score and inflammatory cytokines in the serum. Overall, our results delineate the distinct cytokine signaling of JAK1/3 and TAK1 targeted therapies in vitro and in vivo and suggest that selective TAK1 inhibitors may provide superior therapeutic relief in RA with fewer adverse events.

Modeling of MT. P495, an mRNA-based vaccine against the phosphate-binding protein PstS1 of Mycobacterium tuberculosis

Tuberculosis (TB) is a contagious disease that predominantly affects the lungs, but can also spread to other organs via the bloodstream. TB affects about one-fourth population of the world. With age, the effectiveness of Bacillus Calmette-Guérin (BCG), the only authorized TB vaccine, decreases. In the quest for a prophylactic and immunotherapeutic vaccine, in this study, a hypothetical mRNA vaccine is delineated, named MT. P495, implementing in silico and immunoinformatics approaches to evaluate key aspects and immunogenic epitopes across the PstS1, a highly conserved periplasmic protein of Mycobacterium tuberculosis (Mtb). PstS1 elicited the potential to generate 99.9% population coverage worldwide. The presence of T- and B-cell epitopes across the PstS1 protein were validated using several computational prediction tools. Molecular docking and dynamics simulation confirmed stable epitope-allele interaction. Immune cell response to the antigen clearance rate was verified by the in silico analysis of immune simulation. Codon optimization confirmed the efficient translation of the mRNA in the host cell. With Toll-like receptors, the vaccine exhibited stable and strong interactions. Findings suggest that the MT. P495 vaccine probably will elicit specific immune responses against Mtb. This mRNA vaccine model is a ready source for further wet-lab validation to confirm the efficacy of this proposed vaccine candidate.

Cytokines, chemokines, and cells growth factors in patients with mild to moderate SARS-CoV-2 infection: A case-control study

Several biomarkers have been evaluated as predictors of severity or in directing the treatment of COVID-19, however there are no conclusive results. In this study, we evaluated serum levels of cytokines, chemokines, and cell growth factors in association with the pathobiology of mild to moderate SARS-CoV-2 infection. Serum levels of SARS-CoV-2 infected patients (n = 113) and flu symptoms individuals negative for SARS-CoV-2 (n = 58), tested by the RT-qPCR test-nasal swab were compared to healthy controls (n = 53). Results showed that the proinflammatory cytokines IL-1β, MCP-3, TNF-α, and G-CSF were increased in symptomatic patients and the cytokines IL-6 and IL-10 were associated with patients positive for SARS-CoV-2 when compared to healthy controls. Symptoms associated with COVID-19 were fever, anosmia, ageusia, and myalgia. For patients without SARS-CoV-2 infection, their major symptom was sore throat. The pathobiology of mild to moderate SARS-CoV-2 infection was associated with increasing proinflammatory cytokines and a pleiotropic IL-6 and anti-inflammatory IL-10 cytokines compared to healthy controls. Thus, knowledge about the pathophysiology and the involvement of biomarkers in the mild to moderate profile of the disease should be evaluated. Monitoring these biomarkers in patients with mild to moderate disease can help establish adequate treatment and prevention strategies for long-term COVID-19.

The Programming Effect of Plant-Based DHA, Along with Equivalent AA, on Immune System and Oral Tolerance Development in Six-Week Allergy Prone BALB/c Pups

BACKGROUND

Docosahexaenoic acid (DHA) and arachidonic acid (AA) on oral tolerance (OT) development in allergy-prone infants is less known.

OBJECTIVES

We aim to determine the effects of early life DHA supplementation (1% of total fat, from novel canola oil), along with AA, on OT toward ovalbumin (ova, egg protein) in allergy-prone BALB/c pups at 6-wk.

METHODS

Breastfeeding dams (n ≥ 10/diet) were fed DHA+AA (1% DHA, 1% AA wt/wt of total fat) or control (0% DHA, 0% AA) suckling period diet (SPD) during which pups consumed dam's milk. At 3-wk, pups from each SPD group were assigned to either the control or DHA+AA weaning diet. For OT, pups from each diet group were either orally fed ova or placebo daily from 21-25 d. Systemic immunization to ova was induced through intraperitoneal injections before euthanizing 6-wk pups. Ova-specific immunoglobulin (ova-Ig) and splenocytes ex-vivo cytokine response to different stimuli were analyzed using a 3-factor analysis of variance.

RESULTS

OT-induced suppression was seen in ova-stimulated splenocyte ex-vivo response, where ova-tolerized pups showed significantly lower total immunoglobulin (Ig)G, IgG1, interleukin (IL)-2 and IL-6 production than sucrose (placebo) pups. DHA+AA SPD was associated with 3 times lower plasma concentrations of ova-IgE (P = 0.03) than controls. DHA+AA weaning diet resulted in lower T helper type-2 cytokines (IL-4 and IL-6) with ova stimulation than controls, which may benefit OT. DHA+AA SPD resulted in significantly higher T cell cytokine response [IL-2, interferon-gamma, (IFNγ) and IL-1β] to anti-CD3/CD28 stimulation than controls. The splenocytes stimulated with lipopolysaccharide produced lower inflammatory cytokines (IFNγ, tumor necrosis factor-alpha, IL-6, and C-X-C motif ligand 1), which may be because of lower CD11b+CD68+ splenocytes proportion in pups from DHA+AA SPD than control (all P < 0.05).

CONCLUSIONS

DHA and AA in early life may influence OT in allergy-prone BALB/c mouse offspring, as they effectively promote T helper type-1 immune responses.

Immunomodulatory effects and mechanisms of the extracts and secondary compounds of Zingiber and Alpinia species: a review

Zingiber and Alpinia species (family: Zingiberaceae) are popularly used in food as spices and flavoring agents and in ethnomedicine to heal numerous diseases, including immune-related disorders. However, their ethnomedicinal uses have not been sufficiently supported by scientific investigations. Numerous studies on the modulating effects of plants and their bioactive compounds on the different steps of the immune system have been documented. This review aimed to highlight up-to-date research findings and critically analyze the modulatory effects and mechanisms of the extracts and secondary compounds of several Zingiber and Alpinia species, namely, Zingiber officinale Roscoe, Z. cassumunar Roxb., Z. zerumbet (L.) Roscoe ex Sm., Alpinia galanga Linn., A. conchigera Griff, A. katsumadai Hayata, A. oxyphylla Miq., A. officinarum Hance, A. zerumbet (Pers.) Burtt. et Smith, and A. purpurata (Viell.) K. Schum. on the immune system, particularly via the inflammation-related signaling pathways. The immunomodulating activities of the crude extracts of the plants have been reported, but the constituents contributing to the activities have mostly not been identified. Among the extracts, Z. officinale extracts were the most investigated for their in vitro, in vivo, and clinical effects on the immune system. Among the bioactive metabolites, 6-, 8-, and 10-gingerols, 6-shogaol, and zerumbone from Zingiber species and cardamomin, 1'-acetoxychavicol acetate, yakuchinone, rutin, 1,8-cineole, and lectin from Alpinia species have demonstrated strong immunomodulating effects. More experimental studies using cell and animal models of immune-related disorders are necessary to further understand the underlying mechanisms, together with elaborate preclinical pharmacokinetics, pharmacodynamics, bioavailability, and toxicity studies. Many of these extracts and secondary metabolites are potential candidates for clinical development in immunomodulating agents or functional foods to prevent and treat chronic inflammatory disorders.

Bacterial outer-membrane vesicles promote Vγ9Vδ2 T cell oncolytic activity

Background

Increasing evidence suggests the immune activation elicited by bacterial outer-membrane vesicles (OMVs) can initiate a potent anti-tumor immunity, facilitating the recognition and destruction of malignant cells. At present the pathways underlying this response remain poorly understood, though a role for innate-like cells such as γδ T cells has been suggested.

Methods

Peripheral blood mononuclear cells (PBMCs) from healthy donors were co-cultured with E. coli MG1655 Δpal ΔlpxM OMVs and corresponding immune activation studied by cell marker expression and cytokine production. OMV-activated γδ T cells were co-cultured with cancer cell lines to determine cytotoxicity.

Results

The vesicles induced a broad inflammatory response with γδ T cells observed as the predominant cell type to proliferate post-OMV challenge. Notably, the majority of γδ T cells were of the Vγ9Vδ2 type, known to respond to both bacterial metabolites and stress markers present on tumor cells. We observed robust cytolytic activity of Vγ9Vδ2 T cells against both breast and leukaemia cell lines (SkBr3 and Nalm6 respectively) after OMV-mediated expansion.

Conclusions

Our findings identify for the first time, that OMV-challenge stimulates the expansion of Vγ9Vδ2 T cells which subsequently present anti-tumor capabilities. We propose that OMV-mediated immune activation leverages the anti-microbial/anti-tumor capacity of Vγ9Vδ2 T cells, an axis amenable for improved future therapeutics.

Markers of the ageing macrophage: a systematic review and meta-analysis

Introduction

Ageing research is establishing macrophages as key immune system regulators that undergo functional decline. Due to heterogeneity between species and tissue populations, a plethora of data exist and the power of scientific conclusions can vary substantially. This meta-analysis by information content (MAIC) and systematic literature review (SLR) aims to determine overall changes in macrophage gene and protein expression, as well as function, with age.

Methods

PubMed was utilized to collate peer-reviewed literature relating to macrophage ageing. Primary studies comparing macrophages in at least two age groups were included. Data pertaining to gene or protein expression alongside method used were extracted for MAIC analysis. For SLR analysis, data included all macrophage-specific changes with age, as well as species, ontogeny and age of groups assessed.

Results

A total of 240 studies were included; 122 of which qualified for MAIC. The majority of papers focussed on changes in macrophage count/infiltration as a function of age, followed by gene and protein expression. The MAIC found iNOS and TNF to be the most commonly investigated entities, with 328 genes and 175 proteins showing consistent dysregulation with age across the literature. Overall findings indicate that cytokine secretion and phagocytosis are reduced and reactive oxygen species production is increased in the ageing macrophage.

Discussion

Collectively, our analysis identifies critical regulators in macrophage ageing that are consistently dysregulated, highlighting a plethora of targets for further investigation. Consistent functional changes with age found here can be used to confirm an ageing macrophage phenotype in specific studies and experimental models.

Expression of intra-tumoral necrosis-associated cytokine pattern correlated with prognosis and immune status in glioma

Intra-tumoral necrosis (ITN) is reported to be an independent prognostic factor in glioma. However, knowledge of ITN is mainly limited to pseudopalisadwe, while its other aspects were neglected. Therefore, a deeper understanding of ITN could be valuable for understanding its exact role in glioma. The only reliable ITN model was time-dependently achieved with the GL261 syngeneic mouse model. The ITN-associated expression pattern was enriched from RNA sequencing. TCGA glioma samples were clustered into a high-expression group (HEG) and a low-expression group (LEG) based on their pattern and their association with prognosis, clinical status, immune status, and therapeutic responsiveness were compared. Mouse glioma with ITN demonstrated invasive histology. Cytokine signaling was significantly enriched in necrotic mouse glioma compared with non-necrotic glioma tissues. Nine pro-inflammatory (IL6, PPBP, IL1A, TNFSF11, CXCL11, CXCL9, CXCL10, CXCL3, and CCL8) and two anti-inflammatory cytokine (IL1RN and IL10) genes were found to be related to ITN-associated cytokine patterns. Comparative analysis showed that HEG had a significantly shorter survival time, five differentially distributed clinical statuses, more infiltrated immune cells, greater expression of immune checkpoints, and better therapeutic responsiveness than LEG. In conclusion, the ITN-associated cytokine pattern is characteristically expressed in glioma with ITN and might indicate necrosis missed in histology diagnosis. Its expression pattern could predict the prognosis, tumor grade, immune status, and therapeutic responsiveness of glioma patients.

Immunomodulatory effect of a proprietary polyherbal formulation on healthy participants: A single- blind, randomized, placebo- controlled, exploratory clinical study

Context

Clinical study for immunity.

Aims

The present study aimed to assess the effect of proprietary polyherbal formulation (PPHF), labelled as Kofol immunity tablets (KIT) on innate and adaptive immune responses in healthy individuals, on the backdrop of COVID-19 pandemic.

Settings and Design

Single-blind, randomized, placebo-controlled, exploratory study in institutional setting.

Materials and Methods

Post Ethics Committee permission, screened healthy individuals of either sex aged 18-35 years were randomized to PPHF/Placebo for 2 months. Major assessment variables included peak expiratory flow rate (PEFR), questionnaire-based immune status, perceived stress, and quality of life (QOL) with immune-specific cell counts (CD4+, CD8+), cytokines (interferon gamma [IFN-γ], tumor necrosis factor-alpha [TNF-α], interleukin 10 [IL-10]), and oxidative stress in red blood cells (RBCs) (malondialdehyde (MDA), glutathione peroxidase [GPx]), done at day 60.

Statistical Analysis Used

Mean ± standard deviation and paired/unpaired t-test for parametric data analysis while median (range) and Wilcoxon Rank sum test/Mann-Whitney test for nonparametric data analysis, were done. Categorical data was analyzed using Chi-square test. GraphPad InStat software, version 9 was used with p < 0.05, as the level of statistical significance.

Results

Of 52 recruited, 28 individuals completed the study. PPHF significantly increased PEFR, improved immune status along with QOL compared to baseline. It also decreased perceived stress from moderate and severe grade to mild. Serum IFN-γ levels remained almost constant post-PPHF treatment. PPHF significantly decreased MDA and increased GPx in RBCs. Significant decrease and increase in TNF-α and IL-10, respectively, were seen in PPHF group. The safety parameters post-PPHF treatment remained within normal reference ranges.

Conclusions

PPHF is an efficacious and safe formulation with immunomodulatory potential.

Insulin-cobalt core-shell nanoparticles for receptor-targeted bioimaging and diabetic wound healing

Diabetic wounds represent a major issue in medical care and need advanced therapeutic and tissue imaging systems for better management. The utilization of nano-formulations involving proteins like insulin and metal ions plays significant roles in controlling wound outcomes by decreasing inflammation or reducing microbial load. This work reports the easy one-pot synthesis of extremely stable, biocompatible, and highly fluorescent insulin-cobalt core-shell nanoparticles (ICoNPs) with enhanced quantum yield for their highly specific receptor-targeted bioimaging and normal and diabetic wound healing in vitro (HEKa cell line). The particles were characterized using physicochemical properties, biocompatibility, and wound healing applications. FTIR bands at 670.35 cm^-1, 849.79, and 973.73 indicating the Co-O bending, CoO-OH bond, and Co-OH bending, respectively, confirm the protein-metal interactions, which is further supported by the Raman spectra. In silico studies indicate the presence of cobalt binding sites on the insulin chain B at 8 GLY, 9 SER, and 10 HIS positions. The particles exhibit a magnificent loading efficiency of 89.48 ± 0.049% and excellent release properties (86.54 ± 2.15% within 24 h). Further, based on fluorescent properties, the recovery process can be monitored under an appropriate setup, and the binding of ICoNPs to insulin receptors was confirmed by bioimaging. This work helps synthesize effective therapeutics with numerous wound-healing promoting and monitoring applications.

Macrophages-bone marrow mesenchymal stem cells crosstalk in bone healing

Bone healing is associated with many orthopedic conditions, including fractures and osteonecrosis, arthritis, metabolic bone disease, tumors and periprosthetic particle-associated osteolysis. How to effectively promote bone healing has become a keen topic for researchers. The role of macrophages and bone marrow mesenchymal stem cells (BMSCs) in bone healing has gradually come to light with the development of the concept of osteoimmunity. Their interaction regulates the balance between inflammation and regeneration, and when the inflammatory response is over-excited, attenuated, or disturbed, it results in the failure of bone healing. Therefore, an in-depth understanding of the function of macrophages and bone marrow mesenchymal stem cells in bone regeneration and the relationship between the two could provide new directions to promote bone healing. This paper reviews the role of macrophages and bone marrow mesenchymal stem cells in bone healing and the mechanism and significance of their interaction. Several new therapeutic ideas for regulating the inflammatory response in bone healing by targeting macrophages and bone marrow mesenchymal stem cells crosstalk are also discussed.

Goat milk extracellular vesicles: immuno-modulation effects on porcine monocyte-derived macrophages in vitro

Introduction

Extracellular vesicles (EVs) are nanometric-membrane-bound sub-cellular structures, which can be recovered from milk. Milk EVs have drawn increasing interest due to their potential biomedical applications, therefore it is important to investigate their impact on key immune cells, such as macrophages.

Methods

In this work, the immunomodulatory effects of goat milk EVs on untreated (moMФ) and classically activated (moM1) porcine monocyte-derived macrophages were investigated using flow cytometry, ELISA, and gene expression assays.

Results

These particles were efficiently internalized by macrophages and high doses (60 mg protein weight) triggered the upregulation of MHC I and MHC II DR on moMФ, but not on moM1. In moMФ, exposure to low doses (0.6 mg) of mEVs enhanced the gene expression of IL10, EBI3, and IFNB, whereas high doses up-regulated several pro-inflammatory cytokines. These nanosized structures slightly modulated cytokine gene expression on moM1. Accordingly, the cytokine (protein) contents in culture supernatants of moMФ were mildly affected by exposure to low doses of mEVs, whereas high doses promoted the increased release of TNF, IL-8, IL-1a, IL-1b, IL-1Ra, IL-6, IL-10, and IL-12. The cytokines content in moM1 supernatants was not critically affected.

Discussion

Overall, our data support a clinical application of these molecules: they polarized macrophages toward an M1-like phenotype, but this activation seemed to be controlled, to prevent potentially pathological over-reaction to stressors.

Characterization of Chemotaxis-Associated Gene Dysregulation in Myeloid Cell Populations in the Lungs during Lipopolysaccharide-Mediated Acute Lung Injury

During endotoxin-induced acute lung injury (ALI), immune cell recruitment resulting from chemotaxis is mediated by CXC and CC chemokines and their receptors. In this study, we investigated the role of chemokines and their receptors in the regulation of myeloid cell populations in the circulation and the lungs of C57BL/6J mice exhibiting LPS-mediated ALI using single-cell RNA sequencing. During ALI, there was an increase in the myeloid cells, M1 macrophages, monocytes, neutrophils, and other granulocytes, whereas there was a decrease in the residential alveolar macrophages and M2 macrophages. Interestingly, LPS triggered the upregulation of CCL3, CCL4, CXCL2/3, and CXCL10 genes associated with cellular migration of various subsets of macrophages, neutrophils, and granulocytes. Furthermore, there was an increase in the frequency of myeloid cells expressing CCR1, CCR3, CCR5, and CXCR2 receptors during ALI. MicroRNA sequencing studies of vehicle versus LPS groups identified several dysregulated microRNAs targeting the upregulated chemokine genes. This study suggests that chemokine ligand-receptors interactions are responsible for myeloid cell heterogenicity and cellular recruitment to the lungs during ALI. The single-cell transcriptomics allowed for an in-depth assessment and characterization of myeloid cells involved in immune cell trafficking during ALI.

Evaluation of the gastroprotective and ulcer healing properties by Fridericia chica (Bonpl.) L.G. Lohmann hydroethanolic extract of leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Fridericia chica (Bonpl.) L.G. Lohmann (Bignoniaceae), is a climber native to Brazil, found in all Brazilian biomes. It is mostly known in Brazil as "carajiru," and home medicines made from the leaves have been used to cure disorders including stomach ulcers and other gastrointestinal disorders.

AIM OF THE STUDY

The objective of the study was to investigate the F. chica hydroethanolic extract of leaves (HEFc) preventative and curative antiulcer gastrointestinal efficacy as well as the mechanisms of action using in vivo rodent models.

MATERIALS AND METHODS

F. chica was collected in the municipality of Juína, Mato Grosso, and its leaves were used to prepare the extract by maceration technique (70% hydroethanol in the 1:10 ratio, w/v) to obtain the HEFc. The chromatographic analysis of HEFc was carried out by High Performance Liquid Chromatography-Photo Diode Array-Electrospray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS)- LCQ Fleet™ system. To determine the potential antiulcer potential of HEFc (1, 5 and 20 mg/kg, p.o.), the gastroprotective activity was assessed in various animal models of stomach ulcers caused by acidified ethanol, water constraint stress, indomethacin, (acute), and acid acetic (chronic). Additionally, the prokinetic properties of the HEFC were assessed in mice. The gastroprotective underlying mechanisms were evaluated by the histopathological analysis and determination of gastric secretion (volume, free and total acidity), gastric barrier mucus, activation of PGs, NO, K ⁺_ATP channels, α₂-adrenoceptor, antioxidant activity (GSH, MPO and MDA), NO and mucosal cytokines (TNF-α, IL-1β, and IL-10) levels.

RESULTS

The chemical composition of HEFc was analyzed and apigenin, scutellarin, and carajurone were identified. HEFc (1, 5 and 20 mg/kg) showed effect against acute ulcers induced by HCl/EtOH with a reduction in the ulcerated area of 64.41% (p < 0.001), 54.23% (p < 0.01), 38.71% (p < 0.01), respectively. In the indomethacin experiment, there was no change in the doses tested, whereas in the water immersion restraint stress ulcer there was a reduction of lesions at doses of 1, 5, and 20 mg/kg by 80.34% (p < 0.001), 68.46% (p < 0.01) and 52.04% (p < 0.01). HEFc increased the mucus production at doses of 1 and 20 mg/kg in 28.14% (p < 0.05) and 38.36% (p < 0.01), respectively. In the pyloric ligation-induced model of gastric ulceration, the HEFc decreased the total acidity in all doses by 54.23%, 65.08%, and 44.40% (p < 0.05) and gastric secretory volume in 38.47% at dose of 1 mg/kg (p < 0,05) and increased the free acidity at the dose of 5 mg/kg by 11.86% (p < 0.05). The administration of EHFc (1 mg/kg) showed a gastroprotective effect possibly by stimulating the release of prostaglandins and activating K⁺_ATP channels and α_2-adrenoreceptors. Also, the gastroprotective effect of HEFc involved an increase in CAT and GSH activities, and a reduction in MPO activity and MDA levels. In the chronic gastric ulcer model, the HEFc (1, 5 and 20 mg/kg) decreased the ulcerated area significantly (p < 0.001) at all doses by 71.37%, 91.00%, and 93.46%, respectively. In the histological analysis, HEFc promoted the healing of gastric lesions by stimulating the formation of granulation tissue and consequently epithelialization. On the other hand, regarding the effect of HEFc on gastric emptying and intestinal transit, it was observed that the extract did not alter gastric emptying, but there was an increase in intestinal transit at the dose of 1 mg/kg (p < 0.01).

CONCLUSION

These outcomes confirmed the advantages of Fridericia chica leaves for the treatment of stomach ulcers, which are well-known. HEFc was discovered to have antiulcer characteristics through multitarget pathways, which might be related to an increase in stomach defense mechanisms and a decrease in defensive factor. HEFc can be regarded as a potential new antiulcer herbal remedy because of its antiulcer properties, which may be attributed to the mixture of flavonoids, apigenin, scutellarin and carajurone.

The multifaceted nature of IL-10: regulation, role in immunological homeostasis and its relevance to cancer, COVID-19 and post-COVID conditions

Interleukin-10 (IL-10) is a pleiotropic cytokine that has a fundamental role in modulating inflammation and in maintaining cell homeostasis. It primarily acts as an anti-inflammatory cytokine, protecting the body from an uncontrolled immune response, mostly through the Jak1/Tyk2 and STAT3 signaling pathway. On the other hand, IL-10 can also have immunostimulating functions under certain conditions. Given the pivotal role of IL-10 in immune modulation, this cytokine could have relevant implications in pathologies characterized by hyperinflammatory state, such as cancer, or infectious diseases as in the case of COVID-19 and Post-COVID-19 syndrome. Recent evidence proposed IL-10 as a predictor of severity and mortality for patients with acute or post-acute SARS-CoV-2 infection. In this context, IL-10 can act as an endogenous danger signal, released by tissues undergoing damage in an attempt to protect the organism from harmful hyperinflammation. Pharmacological strategies aimed to potentiate or restore IL-10 immunomodulatory action may represent novel promising avenues to counteract cytokine storm arising from hyperinflammation and effectively mitigate severe complications. Natural bioactive compounds, derived from terrestrial or marine photosynthetic organisms and able to increase IL-10 expression, could represent a useful prevention strategy to curb inflammation through IL-10 elevation and will be discussed here. However, the multifaceted nature of IL-10 has to be taken into account in the attempts to modulate its levels.

Designed α-sheet peptides disrupt uropathogenic E. coli biofilms rendering bacteria susceptible to antibiotics and immune cells

Uropathogenic Escherichia coli account for the largest proportion of nosocomial infections in the United States. Nosocomial infections are a major source of increased costs and treatment complications. Many infections are biofilm associated, rendering antibiotic treatments ineffective or cause additional complications (e.g., microbiome depletion). This work presents a potentially complementary non-antibiotic strategy to fight nosocomial infections by inhibiting the formation of amyloid fibrils, a proteinaceous structural reinforcement known as curli in E. coli biofilms. Despite extensive characterization of the fibrils themselves and their associated secretion system, mechanistic details of curli assembly in vivo remain unclear. We hypothesized that, like other amyloid fibrils, curli polymerization involves a unique secondary structure termed "α-sheet". Biophysical studies herein confirmed the presence of α-sheet structure in prefibrillar species of CsgA, the major component of curli, as it aggregated. Binding of synthetic α-sheet peptides to the soluble α-sheet prefibrillar species inhibited CsgA aggregation in vitro and suppressed amyloid fibril formation in biofilms. Application of synthetic α-sheet peptides also enhanced antibiotic susceptibility and dispersed biofilm-resident bacteria for improved uptake by phagocytic cells. The ability of synthetic α-sheet peptides to reduce biofilm formation, improve antibiotic susceptibility, and enhance clearance by macrophages has broad implications for combating biofilm-associated infections.

Designing a multi-epitopes subunit vaccine against human herpes virus 6A based on molecular dynamics and immune stimulation

Human Herpesvirus 6A (HHV-6A) is a prevalent virus associated with various clinical manifestations, including neurological disorders, autoimmune diseases, and promotes tumor cell growth. HHV-6A is an enveloped, double-stranded DNA virus with a genome of approximately 160-170 kb containing a hundred open-reading frames. An immunoinformatics approach was applied to predict high immunogenic and non-allergenic CTL, HTL, and B cell epitopes and design a multi-epitope subunit vaccine based on HHV-6A glycoprotein B (gB), glycoprotein H (gH), and glycoprotein Q (gQ). The stability and correct folding of the modeled vaccines were confirmed through molecular dynamics simulation. Molecular docking found that the designed vaccines have a strong binding network with human TLR3, with K_d values of 1.5E-11 mol/L, 2.6E-12 mol/L, 6.5E-13 mol/L, and 7.1E-11 mol/L for gB-TLR3, gH-TLR3, gQ-TLR3, and the combined vaccine-TLR3, respectively. The codon adaptation index values of the vaccines were above 0.8, and their GC content was around 67 % (normal range 30-70 %), indicating their potential for high expression. Immune simulation analysis demonstrated robust immune responses against the vaccine, with approximately 650,000/ml combined IgG and IgM antibody titer. This study lays a strong foundation for developing a safe and effective vaccine against HHV-6A, with significant implications for treating associated conditions.

An immunoregulator nanomedicine approach for the treatment of tuberculosis

Introduction: A nanoparticle composed of a poly (lactic-co-glycolic acid) (PLGA) core and a chitosan (CS) shell with surface-adsorbed 1,3 β-glucan (β-glucan) was synthesized. The exposure response of CS-PLGA nanoparticles (0.1 mg/mL) with surface-bound β-glucan at 0, 5, 10, 15, 20, or 25 ng or free β-glucan at 5, 10, 15, 20, or 25 ng/mL in macrophage in vitro and in vivo was investigated. Results: In vitro studies demonstrate that gene expression for IL-1β, IL-6, and TNFα increased at 10 and 15 ng surface-bound β-glucan on CS-PLGA nanoparticles (0.1 mg/mL) and at 20 and 25 ng/mL of free β-glucan both at 24 h and 48 h. Secretion of TNFα protein and ROS production increased at 5, 10, 15, and 20 ng surface-bound β-glucan on CS-PLGA nanoparticles and at 20 and 25 ng/mL of free β-glucan at 24 h. Laminarin, a Dectin-1 antagonist, prevented the increase in cytokine gene expression induced by CS-PLGA nanoparticles with surface-bound β-glucan at 10 and 15 ng, indicating a Dectin-1 receptor mechanism. Efficacy studies showed a significant reduction in intracellular accumulation of mycobacterium tuberculosis (Mtb) in monocyte-derived macrophages (MDM) incubated with on CS-PLGA (0.1 mg/ml) nanoparticles with 5, 10, and 15 ng surface-bound β-glucan or with 10 and 15 ng/mL of free β-glucan. β-glucan-CS-PLGA nanoparticles inhibited intracellular Mtb growth more than free β-glucan alone supporting the role of β-glucan-CS-PLGA nanoparticles as stronger adjuvants than free β-glucan. In vivo studies demonstrate that oropharyngeal aspiration (OPA) of CS-PLGA nanoparticles with nanogram concentrations of surface-bound β-glucan or free β-glucan increased TNFα gene expression in alveolar macrophages and TNFα protein secretion in bronchoalveolar lavage supernatants. Discussion: Data also demonstrate no damage to the alveolar epithelium or changes in the murine sepsis score following exposure to β-glucan-CS-PLGA nanoparticles only, indicating safety and feasibility of this nanoparticle adjuvant platform to mice by OPA.

Uncoding the interdependency of tumor microenvironment and macrophage polarization: insights from a continuous network approach

The balance between pro- and anti-inflammatory immune system responses is crucial to preventing complex diseases like cancer. Macrophages are essential immune cells that contribute to this balance constrained by the local signaling profile of the tumor microenvironment. To understand how pro- and anti-inflammatory unbalance emerges in cancer, we developed a theoretical analysis of macrophage differentiation that is derived from activated monocytes circulating in the blood. Once recruited to the site of inflammation, monocytes can be polarized based on the specific interleukins and chemokines in the microenvironment. To quantify this process, we used a previous regulatory network reconstructed by our group and transformed Boolean Network attractors of macrophage polarization to an ODE scheme, it enables us to quantify the activation of their genes in a continuous fashion. The transformation was developed using the interaction rules with a fuzzy logic approach. By implementing this approach, we analyzed different aspects that cannot be visualized in the Boolean setting. For example, this approach allows us to explore the dynamic behavior at different concentrations of cytokines and transcription factors in the microenvironment. One important aspect to assess is the evaluation of the transitions between phenotypes, some of them characterized by an abrupt or a gradual transition depending on specific concentrations of exogenous cytokines in the tumor microenvironment. For instance, IL-10 can induce a hybrid state that transits between an M2c and an M2b macrophage. Interferon- γ can induce a hybrid between M1 and M1a macrophage. We further demonstrated the plasticity of macrophages based on a combination of cytokines and the existence of hybrid phenotypes or partial polarization. This mathematical model allows us to unravel the patterns of macrophage differentiation based on the competition of expression of transcriptional factors. Finally, we survey how macrophages may respond to a continuously changing immunological response in a tumor microenvironment.

Role of UPRmt and mitochondrial dynamics in host immunity: it takes two to tango

The immune system of a host contains a group of heterogeneous cells with the prime aim of restraining pathogenic infection and maintaining homeostasis. Recent reports have proved that the various subtypes of immune cells exploit distinct metabolic programs for their functioning. Mitochondria are central signaling organelles regulating a range of cellular activities including metabolic reprogramming and immune homeostasis which eventually decree the immunological fate of the host under pathogenic stress. Emerging evidence suggests that following bacterial infection, innate immune cells undergo profound metabolic switching to restrain and countervail the bacterial pathogens, promote inflammation and restore tissue homeostasis. On the other hand, bacterial pathogens affect mitochondrial structure and functions to evade host immunity and influence their intracellular survival. Mitochondria employ several mechanisms to overcome bacterial stress of which mitochondrial UPR (UPR^mt) and mitochondrial dynamics are critical. This review discusses the latest advances in our understanding of the immune functions of mitochondria against bacterial infection, particularly the mechanisms of mitochondrial UPR^mt and mitochondrial dynamics and their involvement in host immunity.

Gamma-irradiation of inulin improves its biological functionality and feasibility as a functional ingredient in synbiotic food

Inulin, a dietary fibre, is widely used as a prebiotic, sugar replacer, and texture modifier in the food industry. In this study, we have shown that irradiation affects the physicochemical properties of inulin, which in turn improves its biological functionality and feasibility as a functional ingredient in synbiotic foods. The biological functionality of 25 kGy-irradiated inulin (IRI) was assessed in terms of antioxidant capacity, protective action against intracellular ROS, and prebiotic activity. Antioxidant assays revealed that irradiated inulin had improved antioxidant activity, which was even greater than that of fructooligosaccharides. Furthermore, IRI was found to be comparatively more effective in maintaining low intracellular ROS levels. The in vitro fermentation studies showed that IRI had higher bifidogenic efficacy than fructooligosaccharides and unirradiated inulin. A synbiotic low-fat yogurt containing IRI (8.5 %) was prepared. In terms of sensory attributes, the developed product was comparable to a commercially available non-synbiotic and high-fat containing product.

The acute inflammatory response of teleost fish

Acute inflammation is crucial to the immune responses of fish. The process protects the host from infection and is central to induction of subsequent tissue repair programs. Activation of proinflammatory signals reshapes the microenvironment within an injury/infection site, initiates leukocyte recruitment, promotes antimicrobial mechanisms and contributes to the resolution of inflammation. Inflammatory cytokines and lipid mediators are primary contributors to these processes. Uncontrolled or persistent induction results in delayed tissue healing. The kinetics by which inducers and regulators of acute inflammation exert their actions is essential for understanding the pathogenesis of fish diseases and identifying potential treatments. Although, a number of these are well-conserved across, others are not, reflecting the unique physiologies and life histories of members of this unique animal group.

A spatiotemporal release hydrogel based on an M1-to-M2 immunoenvironment for wound management

Cutaneous wounds remain a major clinical challenge that urgently requires the development of advanced and functional wound dressings. During the wound healing process, macrophages are well known to exhibit temporal dynamics with a pro-inflammatory phenotype at early stages and a pro-healing phenotype at late stages, thus playing an important role in regulating inflammatory responses and tissue regeneration. Meanwhile, disrupted temporal dynamics of macrophages caused by poor wound local conditions and deficiency of macrophage function always impair the wound-healing progression. Here in this work, we proposed a novel controllable strategy to construct a spatiotemporal dynamical immune-microenvironment for the treatment of cutaneous wounds. To achieve this goal, a concentric decellularized dermal hydrogel was constructed with the combination of type 1 and type 2 macrophage-associated cytokine complexes in the sheath portion and core portion, respectively. The in vitro degradation experiment exhibited a sequential cascade release of pro-inflammatory cytokines and pro-healing cytokines. The enhanced cell biocompatibility and tube formation of HUVECs were confirmed. A full-thickness skin defect model of rats was developed to analyze the effect of the spatiotemporal dynamical bioactive hydrogels on wound healing. Remarkable angiogenesis, rapid wound restoration, moderate extracellular matrix deposition and obvious skin appendage neogenesis were identified at different time points after treatment with the macrophage cytokine-based decellularized hydrogels. Consequently, the concentric decellularized hydrogels with spatiotemporal dynamics of immune cytokines have considerable potential for cell-free therapy for wound healing.

Elsholtzia bodinieri Vaniot ameliorated acute lung injury in mice by regulating pyroptosis, inflammation, oxidative stress and macrophage polarization

ETHNOPHARMACOLOGICAL RELEVANCE

Elsholtzia bodinieri Vaniot, perennial herbs, a traditional Yunnan Chinese herbal medicine. Its whole herb can be used as commonly used herbs to cure fever, headache, inflammation, indigestion etc., and its tender tip can also be used as tea in Yunnan of China. However, the protective mechanism of Elsholtzia bodinieri Vaniot on acute lung injury (ALI) still needs to be explored.

AIM OF STUDY

ALI is characterized by acute respiratory inflammation, which remains a significant source of morbidity and mortality. The current study with the aim of determining the therapeutic the efficacy of E. bodinieri Vaniot on lipopolysaccharide-induced ALI, moreover uncovered the underlying gene-regulated framework, so E. bodinieri Vaniot might serve as functional food for adjuvant therapy or therapeutic agent.

MATERIALS AND METHODS

These potential pharmacological targets of E. bodinieri Vaniot against ALI were analyzed by multiple bioinformatics databases. E. bodinieri Vaniot methanol extract (EBE) was obtained by ultrasonic-assisted extraction method, and detected by UHPLC-ESI-HRMS/MS. These pyroptosis, inflammation and oxidative stress associated factors were measured using ELISA assay, western blotting, and histopathological examination to assess the effects of EBE. EcoTyper and immunofluorescence staining were employed to estimate macrophage polarization states in ALI lungs tissue.

RESULTS

In ALI lung tissues, EBE treatment could increase B cell leukemia/lymphoma 2 (BCL2) to inhibit pyroptosis, downregulate prostaglandin-endoperoxide synthase 2 (PTGS2) to attenuate inflammation, upregulating NAD(P)H dehydrogenase, quinone 1 (NQO1) to alleviate oxidative stress and induce macrophage polarization toward the M2 phenotype.

CONCLUSION

E. bodinieri Vaniot ameliorated ALI thought regulating pyroptosis, inflammation, oxidative stress and macrophage polarization, as well as could be a promising source for therapeutic agent.

Mucosal immunization with lactiplantibacillus plantarum-displaying recombinant SARS-CoV-2 epitopes on the surface induces humoral and mucosal immune responses in mice

BACKGROUND

The use of probiotic lactic acid bacteria as a mucosal vaccine vector is considered a promising alternative compared to the use of other microorganisms because of its "Generally Regarded as Safe" status, its potential adjuvant properties, and its tolerogenicity to the host. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease (COVID-19), is highly transmissible and pathogenic. This study aimed to determine the potential of Lactiplantibacillus plantarum expressing SARS-CoV-2 epitopes as a mucosal vaccine against SARS-CoV-2.

RESULTS

In this study, the possible antigenic determinants of the spike (S1-1, S1-2, S1-3, and S1-4), membrane (ME1 and ME2), and envelope (E) proteins of SARS-CoV-2 were predicted, and recombinant L. plantarum strains surface-displaying these epitopes were constructed. Subsequently, the immune responses induced by these recombinant strains were compared in vitro and in vivo. Most surface-displayed epitopes induced pro-inflammatory cytokines [tumor necrosis factor alpha (TNF-α and interleukin (IL)-6] and anti-inflammatory cytokines (IL-10) in lipopolysaccharide-induced RAW 264.7, with the highest anti-inflammatory to pro-inflammatory cytokine ratio in the S1-1 and S1-2 groups, followed by that in the S1-3 group. When orally administered of recombinant L. plantarum expressing SARS-CoV-2 epitopes in mice, all epitopes most increased the expression of IL-4, along with induced levels of TNF-α, interferon-gamma, and IL-10, specifically in spike protein groups. Thus, the surface expression of epitopes from the spike S1 protein in L. plantarum showed potential immunoregulatory effects, suggesting its ability to potentially circumvent hyperinflammatory states relevant to monocyte/macrophage cell activation. At 35 days post immunization (dpi), serum IgG levels showed a marked increase in the S1-1, S1-2, and S1-3 groups. Fecal IgA levels increased significantly from 21 dpi in all the antigen groups, but the boosting effect after 35 dpi was explicitly observed in the S1-1, S1-2, and S1-3 groups. Thus, the oral administration of SARS-CoV-2 antigens into mice induced significant humoral and mucosal immune responses.

CONCLUSION

This study suggests that L. plantarum is a potential vector that can effectively deliver SARS-CoV-2 epitopes to intestinal mucosal sites and could serve as a novel approach for SARS-CoV-2 mucosal vaccine development.

Fabrication Procedure for a 3D Hollow Nanofibrous Bifurcated-Tubular Scaffold by Conformal Electrospinning

Electrospinning has shown great potential for the fabrication of 3D nanofibrous tubular scaffolds for bifurcated vascular grafts. However, fabrication of complex 3D nanofibrous tubular scaffolds with bifurcated or patient-specific shapes remains limited. In this study, a 3D hollow nanofibrous bifurcated-tubular scaffold was fabricated by the uniform and conformal deposition of electrospun nanofibers via conformal electrospinning. By conformal electrospinning, electrospun nanofibers are conformally deposited onto a complex shape, such as the bifurcated region, without large pores or defects. Owing to conformal electrospinning, a corner profile fidelity (F_C), a measure of conformal deposition of electrospun nanofibers at the bifurcated region, was increased 4 times at the bifurcation angle (θ_B) of 60°, and all F_C values of the scaffolds reached 100%, regardless of the θ_B. Furthermore, the thickness of the scaffolds could be controlled by varying the electrospinning time. Leakage-free liquid transfer was successfully achieved owing to the uniform and conformal deposition of electrospun nanofibers. Finally, the cytocompatibility and 3D mesh-based modeling of the scaffolds were demonstrated. Thus, conformal electrospinning can be used to fabricate leakage-free and complex 3D nanofibrous scaffolds for bifurcated vascular grafts.

Pyroptosis, apoptosis, and autophagy are involved in infection induced by two clinical Klebsiella pneumoniae isolates with different virulence

Klebsiella pneumoniae can cause widespread infections and is an important factor of hospital- and community-acquired pneumonia. The emergence of hypervirulent K. pneumoniae poses a serious clinical therapeutic challenge and is associated with a high mortality. The goal of this work was to investigate the influence of K. pneumoniae infection on host cells, particularly pyroptosis, apoptosis, and autophagy in the context of host-pathogen interactions to better understand the pathogenic mechanism of K. pneumoniae. Two clinical K. pneumoniae isolates, one classical K. pneumoniae isolate and one hypervirulent K. pneumoniae isolate, were used to infect RAW264.7 cells to establish an in vitro infection model. We first examined the phagocytosis of macrophages infected with K. pneumoniae. Lactate dehydrogenase (LDH) release test, and calcein-AM/PI double staining was conducted to determine the viability of macrophages. The inflammatory response was evaluated by measuring the pro-inflammatory cytokines and reactive oxygen species (ROS) production. The occurrence of pyroptosis, apoptosis, and autophagy was assessed by detecting the mRNA and protein levels of the corresponding biochemical markers. In addition, mouse pneumonia models were constructed by intratracheal instillation of K. pneumoniae for in vivo validation experiments. As for results, hypervirulent K. pneumoniae was much more resistant to macrophage-mediated phagocytosis but caused more severe cellular damage and lung tissues damage compared with classical K. pneumoniae. Moreover, we found increased expression of NLRP3, ASC, caspase-1, and GSDMD associated with pyroptosis in macrophages and lung tissues, and the levels were much higher following hypervirulent K. pneumoniae challenge. Both strains induced apoptosis in vitro and in vivo; the higher apoptosis proportion was observed in infection caused by hypervirulent K. pneumoniae. Furthermore, classical K. pneumoniae strongly triggered autophagy, while hypervirulent K. pneumoniae weakly activated this process. These findings provide novel insights into the pathogenesis of K. pneumoniae and may form the foundation for the future design of treatments for K. pneumoniae infection.

New cell sources for CAR-based immunotherapy

Chimeric antigen receptor (CAR) T cell therapy, in which a patient's own T lymphocytes are engineered to recognize and kill cancer cells, has achieved striking success in some hematological malignancies in preclinical and clinical trials, resulting in six FDA-approved CAR-T products currently available in the market. Despite impressive clinical outcomes, concerns about treatment failure associated with low efficacy or high cytotoxicity of CAR-T cells remain. While the main focus has been on improving CAR-T cells, exploring alternative cellular sources for CAR generation has garnered growing interest. In the current review, we comprehensively evaluated other cell sources rather than conventional T cells for CAR generation.

Comparison of oxidative stress parameters, thiol-disulfide homeostasis, and pro-inflammatory cytokines levels in patients with bipolar disorder and their first-degree relatives

BACKGROUND

In this study, we aimed to compare the oxidative stress parameters, thiol-disulfide homeostasis, and plasma pro-inflammatory cytokines levels of patients with bipolar disorder (BD), BD patients' first-degree relatives (FDRs), and the healthy controls (HCs).

METHODS

Thirty-five patients with BD, 35 FDRs of BD, and 35 healthy controls (HCs) were included. The individuals' ages varied from 28 to 58, and the groups were well-matched in terms of age and gender. The total thiol (TT), native thiol (NT), disulfide (DIS), total oxidant status (TOS), total antioxidant status (TAS), IL-1β, IL-6, and TNF-α concentrations were measured from serum samples. The oxidative stress index (OSI) was calculated using mathematical formulas.

RESULTS

TOS was significantly higher in both patients and FDRs than HCs (p < 0.01 for all pairwise comparisons). OSI, DIS, oxidized thiol, and the ratio of thiol oxidation-reduction levels were significantly higher in both patients with BD and FDRs than HCs (p < 0.01 for all pairwise comparisons). TAS, TT, NT, and reduced thiol levels were significantly lower in both patients with BD and FDRs than HCs (p < 0.01 for all pairwise comparisons). IL-1β, IL-6, and TNF-α were significantly higher in both patients and FDRs than HCs (p < 0.01 for all pairwise comparisons).

LIMITATIONS

Small sample size.

CONCLUSIONS

Early diagnosis is important for treating of bipolar disorder. TT, NT, DIS, TOS, TAS, OSI, IL1-β, IL-6, and TNF-α can be used as potential biomarkers in the early diagnosis and intervention of BD. Furthermore, oxidative/antioxidative markers and plasma pro-inflammatory cytokine parameters may guide the determination of the disease's activity and response to treatment.

Efficacy of a recombinant Lactobacillus plantarum Lp-pPG-Malt as an oral vaccine candidate against Aeromonas hydrophila infection in crucian carp

Aeromonas hydrophila (A. hydrophila), a gram-negative bacterium, causes serious diseases with various clinical symptoms in farm raised fish. Thus, different ways to prevent and control A. hydrophila infection need to be explored, including a vaccine. In this study, we evaluated the protective efficacy of an oral vaccine prepared from the A. hydrophila TPS maltoporin (Malt) with Lactobacillus plantarum (L. plantarum) against A. hydrophila infection in crucian carp (Carassius auratus). For the in vivo experiment, the oral vaccine was administered to crucian carp by feeding them fish diets containing Lp-pPG-Malt, Lp-pPG and PBS for 28 days. The enzyme-linked immunosorbent assay (ELISA), leukocyte phagocytosis assay and real-time quantitative polymerase chain reaction (RT-qPCR) were performed to measure the protective efficacy of the Lp-pPG-Malt. ELISA and leukocyte phagocytosis assay confirmed that Lp-pPG-Malt significantly enhanced the IgM level and nonspecific immune response of crucian carp compared with the control groups (Lp-pPG and PBS). The RT-qPCR results showed that the Lp-pPG-Malt increased the relative expression of immune-related genes (IL-10, IL-1β, TNF-α, IFN-γ) of crucian carp in various tissues (liver, spleen, head kidney and hind intestine). Moreover, Lp-pPG-Malt significantly increased the relative percent survival of fish after intraperitoneal injection with A. hydrophila (55%) compared with the Lp-pPG and PBS groups (0%). These findings suggest that Lp-pPG-Malt can serve as an oral vaccine candidate for A. hydrophila infection and that Malt can be used as an effective antigen in crucian carp farming.

Murine macrophage-based iNos reporter reveals polarization and reprogramming in the context of breast cancer

As part of the first line of defense against pathogens, macrophages possess the ability to differentiate into divergent phenotypes with varying functions. The process by which these cells change their characteristics, commonly referred to as macrophage polarization, allows them to change into broadly pro-inflammatory (M1) or anti-inflammatory (M2) subtypes, and depends on the polarizing stimuli. Deregulation of macrophage phenotypes can result in different pathologies or affect the nature of some diseases, such as cancer and atherosclerosis. Therefore, a better understanding of macrophage phenotype conversion in relevant models is needed to elucidate its potential roles in disease. However, there are few existing probes to track macrophage changes in multicellular environments. In this study, we generated an eGFP reporter cell line based on inducible nitric oxide synthase (iNos) promoter activity in RAW264.7 cells (RAW:iNos-eGFP). iNos is associated with macrophage activation to pro-inflammatory states and decreases in immune-suppressing ones. We validated the fidelity of the reporter for iNos following cytokine-mediated polarization and confirmed that reporter and parental cells behaved similarly. RAW:iNos-eGFP cells were then used to track macrophage responses in different in vitro breast cancer models, and their re-education from anti- to pro-inflammatory phenotypes via a previously reported pyrimido(5,4-b)indole small molecule, PBI1. Using two mouse mammary carcinoma cell lines, 4T1 and EMT6, effects on macrophages were assessed via conditioned media, two-dimensional/monolayer co-culture, and three-dimensional spheroid models. While conditioned media derived from 4T1 or EMT6 cells and monolayer co-cultures of each cancer cell line with RAW:iNos-eGFP cells all resulted in decreased fluorescence, the trends and extents of effects differed. We also observed decreases in iNos-eGFP signal in the macrophages in co-culture assays with 4T1- or EMT6-based spheroids. We then showed that iNos production is enhanced in these cancer models using PBI1, tracking increased fluorescence. Collectively, this work demonstrates that this reporter-based approach provides a facile means to study macrophage responses in complex, multicomponent environments. Beyond the initial studies presented here, this platform can be used with a variety of in vitro models and extended to in vivo applications with intravital imaging.

Surface display of major capsid protein on Bacillus subtilis spores against largemouth bass virus (LMBV) for oral administration

Largemouth bass virus (LMBV) infections resulting in enormous loss are becoming an increasing problem in the largemouth bass industry. Oral vaccination is considered to be an effective and economical measure because of the advantages of non-invasion, no size limitation, lower cost and easily-operated. Based on Bacillus subtilis (B. subtilis) spores, this study successfully constructed the CotC-LMBV recombinant B. subtilis spores and its protective efficacy and immune responses were evaluated. After challenged, the survival rate of largemouth bass orally vaccinated with CotC-LMBV spores was 53.3% and the relative percent survival (RPS) was 45.0% compared to the PBS group. In addition, the specific IgM level in serum in the CotC-LMBV group was significantly higher than in the control groups. In the spleen, the immune-related genes expression detected by quantitative real-time PCR (qRT-PCR) exhibited an increasing trend in different degrees in the CotC-LMBV group, suggesting that innate and adaptive immune responses were activated. This study indicated that oral administration of CotC-LMBV recombinant spores could stimulate an effective immune response and enhance fish immunity against LMBV infection. Therefore, oral vaccination could be an effective approach for the prevention of largemouth bass virus disease.

Current Landscape of IFN-λ: Induction, Inhibition, and Potential Clinical Applications to Treat Respiratory Viral Infections

IFN-λ or type III IFN is an important mediator of antiviral response. Several respiratory viruses induce the production of IFN-λ during their course of infection. However, they have also developed intricate mechanisms to inhibit its expression and activity. Despite a considerable amount of research on the regulatory mechanisms of respiratory viruses on the IFN-λ response, little is still known about the effect of this cytokine on immune cells and the antiviral effects of all IFN-λ isoforms, and a better understanding of the detrimental effects of IFN-λ treatment is required. Here we highlight the relevance of IFN-λ as an antiviral cytokine in the respiratory tract. Data from studies in vitro, ex vivo, experimental animal models, and ongoing clinical trials emphasize the therapeutic opportunity that IFN-λ represents to treat and prevent different types of respiratory viral infections.