Immunological decision-making: how does the immune system decide to mount a helper T-cell response?

Quercetin regulates dendritic cell activation by targeting STAT4 in the treatment of experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a class of autoimmune diseases mainly caused by the immune system attacking the myelin sheath of the axons in the nervous system. Although the pathogenesis of MS is complex, studies have shown that dendritic cells (DCs) play a vital role in the pathogenesis of MS. Quercetin (QU) has a unique advantage in clinical application, especially for treating autoimmune diseases. However, the mechanism of QU in the treatment of experimental autoimmune encephalomyelitis (EAE) remains unclear. In this study, we explore the potential role of QU in EAE. Finally, we find that QU has anti-inflammatory activities and neural protective effects in EAE. The experimental results suggest that the cellular basis for QU's function is to inhibit the activation of DCs while modulating the Th17 cell differentiation in the co-culture system. Further, QU may target STAT4 to inhibit its activation in DCs. This work will be of great significance for the future development and utilization of QU.

A low-endotoxic Salmonella enterica Gallinarum serovar delivers infectious bronchitis virus immunogens via a dual-promoter vector system that drives protective immune responses through MHC class-I and -II activation in chickens

An effective vaccine strategy is indispensable against infectious bronchitis virus (IBV) and fowl typhoid (FT), both of which threaten the poultry industry. This study demonstrates a vector system, pJHL270, designed to express antigens in prokaryotic and eukaryotic cells. The vector system stimulates immune responses via synchronized antigen presentation to MHC class-I and -II molecules to produce balanced Th1/Th2 responses. The vaccine antigens were crafted by selecting the consensus sequence of the N-terminal domain of the spike protein (S1-NTD) and a conserved immunogenic region of the nucleocapsid protein (N321-406 aa) from IBV strains circulating in South Korea. The vaccine antigen was cloned and transformed into a live-attenuated Salmonella Gallinarum (SG) strain, JOL2854 (∆lon, ∆cpxR, ∆rfaL, ∆pagL, ∆asd). Western blot analysis confirmed concurrent antigen expression in Salmonella and eukaryotic cells. Oral immunization with the SG-based IBV vaccine construct JOL2918 induced IBV antigen and Salmonella-specific humoral and cell-mediated immune responses in chickens. PBMCs collected from immunized chickens revealed that MHC class-I and -II expression had increased 3.3-fold and 2.5-fold, respectively, confirming MHC activation via bilateral antigen expression and presentation. Immunization induced neutralizing antibodies (NAbs) and reduced the viral load by 2-fold and 2.5-fold in the trachea and lungs, respectively. The immunized chickens exhibited multifaceted humoral, mucosal, and cell-mediated responses via parallel MHC class-I and -II activation as proof of a balanced Th1/Th2 immune response. The level of NAbs, viral load, and gross and histological analyses provide clear evidence that the construct provides protection against IBV and FT.

A novel approach to design chimeric multi epitope vaccine against Leishmania exploiting infected host cell proteome

Leishmaniasis is a major infectious disease having high mortality which could be attributed to lack of a suitable vaccine candidate. We propose a novel approach to design multiepitope vaccine to leishmaniasis exploiting specific membrane proteome from infected macrophage from host. The MHC-I, MHC-II and BC epitopes predicted for unique proteins from the infected macrophages and Leishmania and a MEV designed in various combinations (1a-1m). The epitope arrangements 1a, 1k, 1l, and 1 m showed a strong antigenicity profile and immune response. The molecular dynamics simulation indicate the 1k, 1l, and 1 m constructs have strong affinity toward TLR-2, TLR-3, and TLR-4. Overall the structural and immunogenicity profile suggests 1k is top candidate. Further, a computational model system with TLR-2, TLR-3, TLR-4, BCR, MHC-I and MHC-II was generated for 1k construct to understand the MEV interactions with immune components. Dihedral distribution and distance was enumerated to understand the movement of immune components towards 1k. The results indicate 1k has strong affinity for the immune response molecules especially TLR-3, BCR and MHC-II are coming in close contact with the MEV through the simulation. The study suggests that designed multi-epitope vaccine 1k has potential to induce proper immune response but warrants further studies.

Protein Kinase C (PKC) in Neurological Health: Implications for Alzheimer's Disease and Chronic Alcohol Consumption

Protein kinase C (PKC) is a diverse enzyme family crucial for cell signalling in various organs. Its dysregulation is linked to numerous diseases, including cancer, cardiovascular disorders, and neurological problems. In the brain, PKC plays pivotal roles in synaptic plasticity, learning, memory, and neuronal survival. Specifically, PKC's involvement in Alzheimer's Disease (AD) pathogenesis is of significant interest. The dysregulation of PKC signalling has been linked to neurological disorders, including AD. This review elucidates PKC's pivotal role in neurological health, particularly its implications in AD pathogenesis and chronic alcohol addiction. AD, characterised by neurodegeneration, implicates PKC dysregulation in synaptic dysfunction and cognitive decline. Conversely, chronic alcohol consumption elicits neural adaptations intertwined with PKC signalling, exacerbating addictive behaviours. By unravelling PKC's involvement in these afflictions, potential therapeutic avenues emerge, offering promise for ameliorating their debilitating effects. This review navigates the complex interplay between PKC, AD pathology, and alcohol addiction, illuminating pathways for future neurotherapeutic interventions.

Inhibition of interferon gamma impairs induction of experimental epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a muco-cutaneous autoimmune disease characterized and caused by autoantibodies targeting type VII collagen (COL7). The treatment of EBA is notoriously difficult, with a median time to remission of 9 months. In preclinical EBA models, we previously discovered that depletion of regulatory T cells (Treg) enhances autoantibody-induced, neutrophil-mediated inflammation and blistering. Increased EBA severity in Treg-depleted mice was accompanied by an increased cutaneous expression of interferon gamma (IFN-γ). The functional relevance of IFN-γ in EBA pathogenesis had been unknown. Given that emapalumab, an anti-IFN-γ antibody, is approved for primary hemophagocytic lymphohistiocytosis patients, we sought to assess the therapeutic potential of IFN-γ inhibition in EBA. Specifically, we evaluated if IFN-γ inhibition has modulatory effects on skin inflammation in a pre-clinical EBA model, based on the transfer of COL7 antibodies into mice. Compared to isotype control antibody, anti-IFN-γ treatment significantly reduced clinical disease manifestation in experimental EBA. Clinical improvement was associated with a reduced dermal infiltrate, especially Ly6G+ neutrophils. On the molecular level, we noted few changes. Apart from reduced CXCL1 serum concentrations, which has been demonstrated to promote skin inflammation in EBA, the expression of cytokines was unaltered in the serum and skin following IFN-γ blockade. This validates IFN-γ as a potential therapeutic target in EBA, and possibly other diseases with a similar pathogenesis, such as bullous pemphigoid and mucous membrane pemphigoid.

Artesunate-loaded thermosensitive chitosan hydrogel promotes osteogenesis of maxillary tooth extraction through regulating T lymphocytes in type 2 diabetic rats

BACKGROUND

Type 2 diabetes mellitus (T2DM) causes severe bone loss after tooth extraction as a hyperglycemic environment causes aberrant bone homeostasis. Artesunate (ART) is known to possess anti-inflammation and osteogenic properties. However, its osteogenesis property in alveolar bone remains unclear. This study aimed to explore the osteogenic and immunoregulatory effects of artesunate-loaded thermosensitive chitosan hydrogel (ART-loaded TCH) on maxilla tooth extraction in T2DM rats.

METHODS

T2DM rats were induced by a high-fat diet and streptozotocin. Different concentrations of ART-loaded TCH were applied in tooth extraction sockets. Bone loss and the expression of osteogenic regulatory factors (OPG, ALP, RANK) were evaluated. The immunoregulatory effects of ART-loaded TCH were observed through detecting the infiltration of T lymphocytes and their cytokines. The underlying mechanisms were explored.

RESULTS

Results showed that the 150 mg/ml ART-loaded TCH group significantly ameliorated maxilla bone height and bone mineral density when compared with the T2DM group (p < 0.05). It also improved the expression of OPG, ALP, and RANK. Although the alteration of CD4+ T, CD8+ T, and CD4+:CD8+ T ratio has no significant difference among groups, the release of Th1 and Th2 in the 150 mg/ml ART-loaded TCH group has been significantly regulated than in the T2DM group (p < 0.05). Besides, ART-loaded TCH treatment inhibited the expression of p38 MAPK and ERK1 in T2DM maxilla.

CONCLUSIONS

Therefore, the results indicated that 150 mg/ml ART-loaded TCH could be an effective method to prevent bone loss in T2DM tooth extraction rats by modulating the immunoregulation of Th1 and Th2 and the MAPK signaling pathway.

Vaginal Microbiota and HPV in Latin America: A Narrative Review

With the expansion of human microbiome studies in the last 15 years, we have realized the immense implications of microbes in human health. The human holobiont is now accepted, given the commensal relationships with bacteria, fungi, parasites, viruses, and human cells. The cervicovaginal microbiota is a specific case within the human microbiome where diversity is lower to maintain a chemical barrier of protection against infections. This narrative review focuses on the vaginal microbiome. It summarizes key findings on how native bacteria protect women from disease or predispose them to damaging inflammatory processes with an emphasis on the role of HPV infections in Latin America, one of the world's regions with the highest cervical cancer prevalence.

In silico approaches for the identification of potential allergens among hypothetical proteins from Alternaria alternata and its functional annotation

Direct exposure to the fungal species Alternaria alternata is a major risk factor for the development of asthma, allergic rhinitis, and inflammation. As of November 23rd 2020, the NCBI protein database showed 11,227 proteins from A. alternata genome as hypothetical proteins (HPs). Allergens are the main causative of several life-threatening diseases, especially in fungal infections. Therefore, the main aim of the study is to identify the potentially allergenic inducible proteins from the HPs in A. alternata and their associated functional assignment for the complete understanding of the complex biological systems at the molecular level. AlgPred and Structural Database of Allergenic Proteins (SDAP) were used for the prediction of potential allergens from the HPs of A. alternata. While analyzing the proteome data, 29 potential allergens were predicted by AlgPred and further screening in SDAP confirmed the allergic response of 10 proteins. Extensive bioinformatics tools including protein family classification, sequence-function relationship, protein motif discovery, pathway interactions, and intrinsic features from the amino acid sequence were used to successfully predict the probable functions of the 10 HPs. The functions of the HPs are characterized as chitin-binding, ribosomal protein P1, thaumatin, glycosyl hydrolase, and NOB1 proteins. The subcellular localization and signal peptide prediction of these 10 proteins has further provided additional information on localization and function. The allergens prediction and functional annotation of the 10 proteins may facilitate a better understanding of the allergenic mechanism of A. alternata in asthma and other diseases. The functional domain level insights and predicted structural features of the allergenic proteins help to understand the pathogenesis and host immune tolerance. The outcomes of the study would aid in the development of specific drugs to combat A. alternata infections.

Current Insights into Tissue Injury of Giant Cell Arteritis: From Acute Inflammatory Responses towards Inappropriate Tissue Remodeling

Giant cell arteritis (GCA) is an autoimmune disease affecting large vessels in patients over 50 years old. It is an exemplary model of a classic inflammatory disorder with IL-6 playing the leading role. The main comorbidities that may appear acutely or chronically are vascular occlusion leading to blindness and thoracic aorta aneurysm formation, respectively. The tissue inflammatory bulk is expressed as acute or chronic delayed-type hypersensitivity reactions, the latter being apparent by giant cell formation. The activated monocytes/macrophages are associated with pronounced Th1 and Th17 responses. B-cells and neutrophils also participate in the inflammatory lesion. However, the exact order of appearance and mechanistic interactions between cells are hindered by the lack of cellular and molecular information from early disease stages and accurate experimental models. Recently, senescent cells and neutrophil extracellular traps have been described in tissue lesions. These structures can remain in tissues for a prolonged period, potentially favoring inflammatory responses and tissue remodeling. In this review, current advances in GCA pathogenesis are discussed in different inflammatory phases. Through the description of these-often overlapping-phases, cells, molecules, and small lipid mediators with pathogenetic potential are described.

Exploration of the immuno-adjuvant effect and mechanism of Anemoside B4 through network pharmacology and experiment verification

BACKGROUND

Extensive investigation has been undertaken about the utilization of saponin adjuvants in vaccines intended for veterinary and human applications. AB4 is the main constituent of the traditional Chinese medicine, Pulsatilla chinensis (Bunge) Regel, and has immunomodulatory activity. However, there is a paucity of reports on AB4 as a potential adjuvant.

PURPOSE

The objective of this work was to clarify the adjuvant role of AB4 and the molecular mechanisms that underlie its immunomodulatory actions.

STUDY DESIGN AND METHODS

The immunomodulatory effects of AB4 were investigated using network pharmacological analyses. These effects were validated by evaluating the developmental status of the immune organs and by using the following techniques: ELISA for the quantification of serum-specific antibodies to determine immune-related cytokine levels; the MTS method for the assessment of proliferative activity of splenic lymphocytes; flow cytometry to analyze lymphocyte and dendritic cell activation status; and western blotting for mechanistic analysis at the protein level.

RESULTS

The network pharmacological analysis predicted a total of 52 targets and 12 pathways for AB4 to exert immunomodulatory effects. In a mouse model with immunity to OVA, the introduction of AB4 resulted in the enhancement of immunological organ growth and maturation, elevation of blood antibodies targeting OVA, and amplification of the production of cytokines associated with Th1 and Th2 immune responses. Additionally, the administration of AB4 resulted in a notable augmentation of lymphocyte proliferation and an elevation in the CD4+/CD8+ T lymphocyte ratios. Furthermore, the administration of AB4 enhanced the maturation process of DCs in the draining LNs and increased the production of co-stimulatory factors and MHC II molecules. AB4 induces the upregulation of TLR4 and IKK proteins, as well as the phosphorylation of NF-κB p65 protein within the TLR4/NF-κB signaling cascade, while concurrently suppressing the expression of IκBα protein.

CONCLUSION

The specific immunoadjuvant effects of AB4 have been demonstrated to modulate the growth and maturation of immune organs and enhance the secretion and cellular activity of pertinent immune molecules. The utilization of network pharmacology, combined within and in vivo vitro assays, clarified the adjuvant function of AB4, which potentially involves the regulation of the TLR4/NF-κB signaling pathway.

Genetic profile of adaptive immune traits and relationships with parasite resistance and productivity in Scottish Blackface sheep

Gastrointestinal (GI) parasites cause significant production losses in grazing ruminants which can be mitigated by breeding animals resistant to disease. Lymphocyte cytokine production and parasite-specific Immunoglobulin A (IgA) are adaptive immune traits associated with immunity to GI parasites. To explore the utility of these traits for selective breeding purposes, this study estimated the genetic parameters of the immune traits in sheep and assessed their relationship with disease and productivity traits. Whole blood stimulation assays were performed on 1 040 Scottish Blackface lambs at two months of age in 2016-2017. Blood was stimulated with either pokeweed mitogen (PWM), a non-specific activator of lymphocytes, and Teladorsagia circumcincta (T-ci) larval antigen to activate parasite-specific T lymphocytes. The type of adaptive immune response was determined by quantifying production of cytokines interferon-gamma (IFN-γ), interleukin (IL)-4, and IL-10, which relate to T-helper type (Th) 1, Th2 and regulatory T cell responses, respectively. Serum T-ci specific IgA was also quantified. Heritabilities were estimated for each immune trait by univariate analyses. Genetic and phenotypic correlations were estimated between different immune traits, and between immune traits vs. disease and productivity traits that were recorded at three months of age. Disease phenotypes were expressed as faecal egg counts (FEC) of nematode parasites (Strongyles and Nematodirus), faecal oocyst counts (FOC) of coccidian parasites, and faecal soiling score; production was measured as lamb live weight. Significant genetic variation was observed in all immune response traits. Heritabilities of cytokine production varied from low (0.14 ± 0.06) to very high (0.77 ± 0.09) and were always significantly greater than zero (P < 0.05). IgA heritability was found to be moderate (0.41 ± 0.09). Negative associations previously identified between IFN-γ production and FOC, and IL-4 production and strongyle FEC, were not evident in this study, potentially due to the time-lag between immune and parasitology measures. Instead, a positive genetic correlation was found between FOC and PWM-induced IFN-γ production, while a negative genetic correlation was found between FOC and T-ci induced IL-10. Live weight was negatively genetically correlated with IFN-γ responses. Overall, IFN-γ and IL-4 responses were positively correlated, providing little evidence of cross-regulation of Th1 and Th2 immunity within individual sheep. Furthermore, T-ci specific IgA was highly positively correlated with PWM-induced IL-10, indicating a possible role for this cytokine in IgA production. Our results suggest that while genetic selection for adaptive immune response traits is possible and may be beneficial for parasite control, selection of high IFN-γ responsiveness may negatively affect productivity.

Destabilisation of T cell-dependent humoral immunity in sepsis

Sepsis is a heterogeneous condition defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. For some, sepsis presents as a predominantly suppressive disorder, whilst others experience a pro-inflammatory condition which can culminate in a 'cytokine storm'. Frequently, patients experience signs of concurrent hyper-inflammation and immunosuppression, underpinning the difficulty in directing effective treatment. Although intensive care unit mortality rates have improved in recent years, one-third of discharged patients die within the following year. Half of post-sepsis deaths are due to exacerbation of pre-existing conditions, whilst half are due to complications arising from a deteriorated immune system. It has been suggested that the intense and dysregulated response to infection may induce irreversible metabolic reprogramming in immune cells. As a critical arm of immune protection in vertebrates, alterations to the adaptive immune system can have devastating repercussions. Indeed, a marked depletion of lymphocytes is observed in sepsis, correlating with increased rates of mortality. Such sepsis-induced lymphopenia has profound consequences on how T cells respond to infection but equally on the humoral immune response that is both elicited by B cells and supported by distinct CD4+ T follicular helper (TFH) cell subsets. The immunosuppressive state is further exacerbated by functional impairments to the remaining lymphocyte population, including the presence of cells expressing dysfunctional or exhausted phenotypes. This review will specifically focus on how sepsis destabilises the adaptive immune system, with a closer examination on how B cells and CD4+ TFH cells are affected by sepsis and the corresponding impact on humoral immunity.

Assessing Pediatric Cephalosporin Allergic Reactions Through Direct Graded Oral Challenges

BACKGROUND

Cephalosporins, β-lactam antibiotics, commonly cause allergic reactions.

OBJECTIVE

To assess the clinical characteristics and management of pediatric patients with suspected cephalosporin allergy using direct graded oral challenges (GOCs).

METHODS

Children referred for suspected cephalosporin allergy at 4 Canadian clinics were recruited over 10 years. Data on demographics, clinical reaction characteristics, and management were collected through a questionnaire. Patients underwent a direct GOC (initially 10% of the treatment dose, then 90% after 20 min), and reactions were monitored 1 week postchallenge. Families were contacted annually for up to 5 years to detect subsequent antibiotic reactions. Logistic regression analysis identified factors associated with positive GOC reactions.

RESULTS

Among the 136 patients reporting cephalosporin allergy, 75 (55.1%) were males with a median age of 3.9 years (interquartile range 2.3-8.7). Cefprozil represented the most common cephalosporin linked to the index reaction (67.6% of cases). Of the 136 direct GOCs, 5.1% had an immediate and 4.4% a nonimmediate reaction, respectively. Positive GOCs conducted in children with a history of skin-limited nonsevere rashes were classified as mild, benign skin rashes. Positive GOCs were more likely in children with food allergies (adjusted odds ratio 1.14; 95% confidence interval [95% CI] 1.00-1.29).

CONCLUSIONS

Direct GOCs are safe and effective for diagnosing pediatric cases that report nonvesicular skin-limited symptoms while being treated with cephalosporins.

Salt Behind the Scenes of Systemic Lupus Erythematosus and Rheumatoid Arthritis

PURPOSE OF REVIEW

Sodium is vital for human health. High salt intake is a global health problem and is associated with cardiovascular morbidity and mortality. Recent evidence suggests that both innate and adaptive immune systems are affected by sodium. In general, excess salt intake drives immune cells toward a pro-inflammatory phenotype. The incidence of autoimmune diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), is steadily increasing. As excess salt induces a pro-inflammatory state, increased salt intake may have impacts on autoimmune diseases. The relationship between salt intake and autoimmune diseases is most widely studied in patients with SLE or RA. This review aimed to summarize the relationship between salt intake and SLE and RA.

RECENT FINDINGS

Most, but not all, of these studies showed that high salt intake might promote SLE by M1 macrophage shift, increase in Th17/Treg cell ratio, activation of dendritic and follicular helper T cells, and increased secretion of pro-inflammatory cytokines. In RA, apart from driving immune cells toward a pro-inflammatory state, high salt intake also influences cellular signaling pathways, including receptor activator of nuclear factor κB ligand (RANKL), Rho GTPases, and MAPK (mitogen-activated protein kinase). There is now sufficient evidence that excess salt intake may be related to the development and progression of SLE and RA, although there are still knowledge gaps. More studies are warranted to further highlight the relationship between excess salt intake, SLE, and RA. Salt intake may affect cell types and pro-inflammatory cytokines and signaling pathways associated with the development and progression of systemic lupus erythematosus and rheumatoid arthritis. Bcl-6 B-cell lymphoma, 6 Erk extracellular signal-regulated kinases, IFN-γ interferon-gamma, JNK c-Jun N-terminal kinase, IL-4 interleukin 4, IL-6 interleukin 6, MAPK mitogen-activated protein kinase, STAT signal transducer and activator of transcription, Tnf-α tumor necrosis factor, Treg T regulatory cell.

A multicentric and nationwide predictive study role of T cell sub-population in the prevalence and prognosis of cryoglobulinemia among genotype 4 chronic hepatitis C patients

The infection caused by the hepatitis C virus (HCV) is a significant global health concern. The prevailing genotype of HCV in Egypt is 4a, commonly referred to as GT-4a. A significant proportion exceeding 50% of patients infected with HCV experience extrahepatic manifestations (EHMs), encompassing a diverse range of clinical presentations. These manifestations, including essential mixed cryoglobulinemia (MC), can serve as initial and solitary indicators of the disease. The complete understanding of the pathogenesis of EHM remains unclear, with autoimmune phenomena being recognized as the primary causative factor. In this study, we examined the predictive significance of T-cell subpopulations in relation to the occurrence and prognosis of cryoglobulinemia in HCV patients. A total of 450 CHC genotype four treatment naïve patients were enrolled in this analytic cross-sectional study after thorough clinical, laboratory, and radiological examinations. All patients underwent laboratory investigations, including testing for cryoglobulin antibodies and measurements of CD4 and CD8 levels; two groups were described according to their test results: Group 1 consists of patients who have tested positive for cryoglobulin antibodies and Group 2 consists of patients who have tested negative for cryoglobulin antibodies. The exclusion criteria encompassed individuals with HIV infection or chronic HBV infection. Additionally, pelvi-abdominal ultrasonography was performed. Our study included 450 treatment naïve CHC patients (59% male, mean age 50.8 years). The patients were categorized according to their cryoglobulin antibodys test results into two groups: group A, CHC patients with cryoglobulin antibodies (Abs) negative (364 patients), and group B, CHC patients with cryoglobulin Ab positive (86 patients). Group B demonstrated a higher average age, elevated international normalized ratio, more prolonged duration of HCV infection, lower albumin, higher alanine aminotransferase, higher aspartate aminotransferase, higher bilirubin, lower CD8, lower CD4, and lower CD4:CD8 ratio. In contrast, 27 out of 86 (31.40%) patients in group B had symptoms; 85.8% had purpura and arthralgia, 74.3% had paresthesias, 86.7% had weakness, and 12.2% had non-Hodgkin's lymphoma. The levels of CD4 and CD8 were found to be decreased in chronic HCV patients with MC. T-cell subpopulation serves as a reliable indicator for assessing the prevalence and prognosis of MC in individuals with genotype 4 chronic hepatitis C. However, additional research is needed to further understand the development and spread of various emerging infectious diseases. Nevertheless, it is noteworthy that a critical threshold may exist beyond which EHM reaches a point of no return.

Novel lipid antigens for NKT cells in cancer

Cancer immunotherapy aims to unleash the power of the immune system against tumors without the side effects of traditional chemotherapy. Immunotherapeutic methods vary widely, but all follow the same basic principle: overcome the barriers utilized by cancers to avoid immune destruction. These approaches often revolve around classical T cells, such as with CAR T cells and neoantigen vaccines; however, the utility of the innate-like iNKT cell in cancer immunotherapy has gained significant recognition. iNKT cells parallel classic T cell recognition of peptide antigens presented on MHC through their recognition of lipid antigens presented on the MHC I-like molecule CD1d. Altered metabolism and a lipogenic phenotype are essential properties of tumor cells, representing a unique feature that may be exploited by iNKT cells. In this review, we will cover properties of iNKT cells, CD1d, and lipid antigen presentation. Next, we will discuss the cancer lipidome and how it may be exploited by iNKT cells through a window of opportunity. Finally, we will review, in detail, novel lipid antigens for iNKT cells in cancer.

Interleukin-17 plays a role in dental pulp inflammation mediated by zoledronic acid: a mechanism unrelated to the Th17 immune response?

OBJECTIVE

To evaluate the influence of RORγT inhibition by digoxin on inflammatory changes related to interleukin-17 (IL-17) in the pulp of rats treated with zoledronate (ZOL).

METHODOLOGY

Forty male Wistar rats were divided into a negative control group (NCG) treated with saline solution, a positive control group (PCG) treated with ZOL (0.20 mg/kg), and three groups treated with ZOL and co-treated with digoxin 1, 2, or 4 mg/kg (DG1, 2, and 4). After four intravenous administrations of ZOL or saline solution in a 70-day protocol, the right molars were evaluated by histomorphometry (number of blood vessels, blood vessels/µm2, cells/µm2, total blood vessel area, and average blood vessel area) and immunohistochemistry (IL-17, TNF-α, IL-6, and TGF-β). The Kruskal-Wallis/Dunn test was used for statistical analysis.

RESULTS

PCG showed an increase in total blood vessel area (p=0.008) and average blood vessel area (p=0.014), and digoxin treatment reversed these changes. DG4 showed a reduction in blood vessels/µm2 (p<0.001). In PCG odontoblasts, there was an increase in IL-17 (p=0.002) and TNF-α (p=0.002) immunostaining, and in DG4, these changes were reversed. Odontoblasts in the digoxin-treated groups also showed an increase in IL-6 immunostaining (p<0.001) and a reduction in TGF-β immunostaining (p=0.002), and all ZOL-treated groups showed an increase in IL-17 (p=0.011) and TNF-α (p=0.017) in non-odontoblasts cells.

CONCLUSION

ZOL induces TNF-α- and IL-17-dependent vasodilation and ectasia, and the classical Th17 response activation pathway does not seem to participate in this process.

The Dual Role of the Innate Immune System in the Effectiveness of mRNA Therapeutics

Advances in molecular biology have revolutionized the use of messenger RNA (mRNA) as a therapeutic. The concept of nucleic acid therapy with mRNA originated in 1990 when Wolff et al. reported successful expression of proteins in target organs by direct injection of either plasmid DNA or mRNA. It took decades to bring the transfection efficiency of mRNA closer to that of DNA. The next few decades were dedicated to turning in vitro-transcribed (IVT) mRNA from a promising delivery tool for gene therapy into a full-blown therapeutic modality, which changed the biotech market rapidly. Hundreds of clinical trials are currently underway using mRNA for prophylaxis and therapy of infectious diseases and cancers, in regenerative medicine, and genome editing. The potential of IVT mRNA to induce an innate immune response favors its use for vaccination and immunotherapy. Nonetheless, in non-immunotherapy applications, the intrinsic immunostimulatory activity of mRNA directly hinders the desired therapeutic effect since it can seriously impair the target protein expression. Targeting the same innate immune factors can increase the effectiveness of mRNA therapeutics for some indications and decrease it for others, and vice versa. The review aims to present the innate immunity-related 'barriers' or 'springboards' that may affect the development of immunotherapies and non-immunotherapy applications of mRNA medicines.

Recombinant Attenuated Edwardsiella piscicida Vaccine Displaying Regulated Lysis to Confer Biological Containment and Protect Catfish against Edwardsiellosis

We implemented a unique strategy to construct a recombinant attenuated Edwardsiella vaccine (RAEV) with a biological containment phenotype that causes regulated bacterial cell wall lysis. This process ensures that the vaccine strain is not able to persist in the environment. The murA gene is responsible for the catalysis of one of the first steps in the biosynthesis of muramic acid, which is a crucial component of the bacterial cell wall. The regulated lysis phenotype was achieved by inserting the tightly regulated araC ParaBAD cassette in place of the chromosomal murA promoter. Strains with this mutation require growth media supplemented with arabinose in order to survive. Without arabinose, they are unable to synthesize the peptidoglycan cell wall. Following the colonization of fish lymphoid tissues, the murA protein is no longer synthesized due to the lack of arabinose. Lysis is subsequently achieved in vivo, thus preventing the generation of disease symptoms and the spread of the strain into the environment. Vaccine strain χ16016 with the genotype ΔPmurA180::TT araC ParaBADmurA is attenuated and shows a higher LD50 value than that of the wild-type strain. Studies have demonstrated that χ16016 induced TLR4, TLR5, TLR8, TLR9, NOD1 and NOD2-mediated NF-κB pathways and upregulated the gene expression of various cytokines, such as il-8, il-1β, tnf-a, il-6 and ifn-γ in catfish. We observed significant upregulation of the expression profiles of cd4, cd8 and mhc-II genes in different organs of vaccinated catfish. Vaccine strain χ16016 induced systemic and mucosal IgM titers and conferred significant protection to catfish against E. piscicida wild-type challenge. Our lysis RAEV is the first live attenuated vaccine candidate designed to be used in the aquaculture industry that displays this biological containment property.

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.

Initial immune response after exposure to Mycobacterium tuberculosis or to SARS-COV-2: similarities and differences

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) and Coronavirus disease-2019 (COVID-19), whose etiologic agent is severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), are currently the two deadliest infectious diseases in humans, which together have caused about more than 11 million deaths worldwide in the past 3 years. TB and COVID-19 share several aspects including the droplet- and aerosol-borne transmissibility, the lungs as primary target, some symptoms, and diagnostic tools. However, these two infectious diseases differ in other aspects as their incubation period, immune cells involved, persistence and the immunopathological response. In this review, we highlight the similarities and differences between TB and COVID-19 focusing on the innate and adaptive immune response induced after the exposure to Mtb and SARS-CoV-2 and the pathological pathways linking the two infections. Moreover, we provide a brief overview of the immune response in case of TB-COVID-19 co-infection highlighting the similarities and differences of each individual infection. A comprehensive understanding of the immune response involved in TB and COVID-19 is of utmost importance for the design of effective therapeutic strategies and vaccines for both diseases.

Single-cell RNA sequencing defines disease-specific differences between chronic nodular prurigo and atopic dermatitis

BACKGROUND

Chronic nodular prurigo (CNPG) is an inflammatory skin disease that is maintained by a chronic itch-scratch cycle likely rooted in neuroimmunological dysregulation. This condition may be associated with atopy in some patients, and there are now promising therapeutic results from blocking type 2 cytokines such as IL-4, IL-13, and IL-31.

OBJECTIVES

This study aimed to improve the understanding of pathomechanisms underlying CNPG as well as molecular relationships between CNPG and atopic dermatitis (AD).

METHODS

We profiled skin lesions from patients with CNPG in comparison with AD and healthy control individuals using single-cell RNA sequencing combined with T-cell receptor sequencing.

RESULTS

We found type 2 immune skewing in both CNPG and AD, as evidenced by CD4+ helper T cells expressing IL13. However, only AD harbored an additional, oligoclonally expanded CD8A+IL9R+IL13+ cytotoxic T-cell population, and immune activation pathways were highly upregulated in AD, but less so in CNPG. Conversely, CNPG showed signatures of extracellular matrix organization, collagen synthesis, and fibrosis, including a unique population of CXCL14-IL24+ secretory papillary fibroblasts. Besides known itch mediators such as IL31 and oncostatin M, we also detected increased levels of neuromedin B in fibroblasts of CNPG lesions compared with AD and HC, with neuromedin B receptors detectable on some nerve endings.

CONCLUSIONS

These data show that CNPG does not harbor the strong disease-specific immune activation pathways that are typically found in AD but is rather characterized by upregulated stromal remodeling mechanisms that might have a direct impact on itch fibers.

Characterization of immunomodulatory factors and cells in bronchoalveolar lavage fluid for immune checkpoint inhibitor-related pneumonitis

As immune checkpoint inhibitors (ICIs) are widely used, a series of immune-related adverse events (irAEs) have been reported, including immune checkpoint inhibitor-related pneumonitis (ICI-pneumonitis). The incidence of ICI-pneumonitis is higher in reality than in clinical trials. The diagnosis is challenging, mainly based on clinical and imaging features, and requires the exclusion of other causes. The data on the biological mechanisms of ICI-pneumonitis are scarce, resulting in little knowledge of the best treatment for ICI-pneumonitis. Bronchoalveolar lavage (BAL) may be helpful to identify the biological differences or find predictive biomarkers, and may in turn help to develop phenotype-specific targeted drugs to treat ICI-pneumonitis. Herein, we outline the characterization of immunomodulatory factors and cells in bronchoalveolar lavage fluid for ICI-pneumonitis. Through careful sorting and literature review, we find crosstalk between pathogenic Th17/Th1 cells (i.e., Th17.1) and pro-inflammatory monocytes, and activation of Th17(/Th1)/IL-17A (/IFN-γ) pathways may play a key role in the pathogenesis of ICI-pneumonitis. Disruption of the interaction between pathogenic Th17/Th1 cells and pro-inflammatory monocytes (such as, anti-IL-23) may be a potential treatment for ICI-pneumonitis. We first describe the possible pathophysiological mechanisms of ICI-pneumonitis, hoping to contribute to the optimization of diagnosis and treatment, as well as provide readers with research inspiration.

γδ T Cells and Allergic Diseases

Gamma-delta (γδ) T cells play an essential role in allergic diseases and have emerged as a potential treatment target in recent decades. To clarify the effects of γδ T cells on atopic illnesses, we reviewed the literature on the physical roles and functions of various subsets of γδ T cells, including type 1 T helper (Th1)-like, type 2 T helper- (Th2)-like, and type 17 T helper (Th17)-like γδ T cells. Mouse Vγ1 T cells increase interleukin (IL)-4 levels and trigger B cell class switching and immunoglobulin E production. Meanwhile, mouse Vγ4 T cells and human CD8lowVδ1 T cells secrete interferon-γ and exert an anti-allergy effect similar to that of Th1 cells. Moreover, mouse Vγ6 T cells produce IL-17A, while Th17-like γδ T cells enhance neutrophil and eosinophil infiltration in the acute phase of inflammation, but exert anti-inflammatory effects in the chronic phase. Human Vγ9δ2 T cells may exhibit Th1- or Th2-like characteristics in response to certain types of stimulation. In addition, the microbiota can modulate epithelial γδ T cell survival through aryl hydrocarbon receptors; these γδ T cells play crucial roles in the repair of epithelial damage, antibacterial protection, antigen tolerance, and effects of dysbiosis on allergic diseases.

Short-Chain Fatty Acids Alleviate Vancomycin-Caused Humoral Immunity Attenuation in Rabies-Vaccinated Mice by Promoting the Generation of Plasma Cells via Akt-mTOR Pathway

Mounting evidence suggests that gut microbial composition and its metabolites, including short-chain fatty acids (SCFAs), have beneficial effects in regulating host immunogenicity to vaccines. However, it remains unknown whether and how SCFAs improve the immunogenicity of the rabies vaccine. In this study, we investigated the effect of SCFAs on the immune response to rabies vaccine in vancomycin (Vanco)-treated mice and found that oral gavage with butyrate-producing bacteria (C. butyricum) and butyrate supplementation elevated RABV-specific IgM, IgG, and virus-neutralizing antibodies (VNAs) in Vanco-treated mice. Supplementation with butyrate expanded antigen-specific CD4+ T cells and IFN-γ-secreting cells, augmented germinal center (GC) B cell recruitment, promoted plasma cells (PCs) and RABV-specific antibody-secreting cells (ASCs) generation in Vanco-treated mice. Mechanistically, butyrate enhanced mitochondrial function and activated the Akt-mTOR pathway in primary B cells isolated from Vanco-treated mice, ultimately promoting B lymphocyte-induced maturation protein-1 (Blimp-1) expression and CD138+ PCs generation. These results highlight the important role of butyrate in alleviating Vanco-caused humoral immunity attenuation in rabies-vaccinated mice and maintaining host immune homeostasis. IMPORTANCE The gut microbiome plays many crucial roles in the maintenance of immune homeostasis. Alteration of the gut microbiome and metabolites has been shown to impact vaccine efficacy. SCFAs can act as an energy source for B-cells, thereby promoting both mucosal and systemic immunity in the host by inhibiting HDACs and activation of GPR receptors. This study investigates the impact of orally administered butyrate, an SCFA, on the immunogenicity of rabies vaccines in Vanco-treated mice. The results showed that butyrate ameliorated humoral immunity by facilitating the generation of plasma cells via the Akt-mTOR in Vanco-treated mice. These findings unveil the impact of SCFAs on the immune response of the rabies vaccine and confirm the crucial role of butyrate in regulating immunogenicity to rabies vaccines in antibiotic-treated mice. This study provides a fresh insight into the relationship of microbial metabolites and rabies vaccination.

Time-dependent cytokines changes in ultra-rush wasp venom immunotherapy

Venom immunotherapy (VIT) represents a potential therapeutic approach for the management of venom allergies, aiming to modify the immune response to venom allergens and enhance its precision. Previous studies have demonstrated that VIT induces a shift in T helper cell responses from Th2 to Th1, characterized by the production of IL-2 and interferon-gamma by CD4+ and CD8+ cells. In order to explore long-term pathways following VIT treatment and verify potential new outcomes, the serum concentrations of 30 cytokines were assessed in a cohort of 61 patients (18 control, 43 study group) exhibiting hypersensitivity to wasp venom. Cytokine levels were measured at 0, 2, 6, and 24 weeks after the initiation phase of VIT in the study group. The present study found no significant alterations in the levels of IL-2 and IFN-γ in the peripheral blood following VIT. However, a noteworthy finding was the substantial increase in the concentration of IL-12, a cytokine capable of promoting the differentiation of Th0 cells into Th1 cells. This observation supports the involvement of the Th1 pathway in the desensitization process induced by VIT. Additionally, the study revealed a significant rise in the levels of IL-9 and TGF-β after VIT. These cytokines may play a role in the generation of inducible regulatory T (Treg) cells, indicating their potential importance in the immune response to venom allergens and the desensitization process associated with VIT. Nevertheless, further investigations are required to comprehend the underlying mechanisms driving the VIT process comprehensively.

SARS-CoV-2 infection and pulmonary tuberculosis in children and adolescents: a case-control study

BACKGROUND

The Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) pandemic has had an impact on the global tuberculosis (TB) epidemic but evidence on the possible interaction between SARS-CoV-2 and TB, especially in children and adolescents, remains limited. We aimed to evaluate the relationship between previous infection with SARS-CoV-2 and the risk of TB in children and adolescents.

METHODS

An unmatched case-control study was conducted using SARS-CoV-2 unvaccinated children and adolescents recruited into two observational TB studies (Teen TB and Umoya), between November 2020 and November 2021, in Cape Town, South Africa. Sixty-four individuals with pulmonary TB (aged < 20 years) and 99 individuals without pulmonary TB (aged < 20 years) were included. Demographics and clinical data were obtained. Serum samples collected at enrolment underwent quantitative SARS-CoV-2 anti-spike immunoglobulin G (IgG) testing using the Abbott SARS-CoV-2 IgG II Quant assay. Odds ratios (ORs) for TB were estimated using unconditional logistic regression.

RESULTS

There was no statistically significant difference in the odds of having pulmonary TB between those who were SARS-CoV-2 IgG seropositive and those who were seronegative (adjusted OR 0.51; 95% CI: 0.23-1.11; n = 163; p = 0.09). Of those with positive SARS-CoV-2 serology indicating prior infection, baseline IgG titres were higher in individuals with TB compared to those without TB (p = 0.04) and individuals with IgG titres in the highest tertile were more likely to have pulmonary TB compared to those with IgG levels in the lowest tertile (OR: 4.00; 95%CI: 1.13- 14.21; p = 0.03).

CONCLUSIONS

Our study did not find convincing evidence that SARS-CoV-2 seropositivity was associated with subsequent pulmonary TB disease; however, the association between magnitude of SARS-CoV-2 IgG response and pulmonary TB warrants further investigation. Future prospective studies, evaluating the effects of sex, age and puberty on host immune responses to M. tuberculosis and SARS-CoV-2, will also provide more clarity on the interplay between these two infections.

Cigarette Smoke-Induced Respiratory Response: Insights into Cellular Processes and Biomarkers

Cigarette smoke (CS) poses a significant risk factor for respiratory, vascular, and organ diseases owing to its high content of harmful chemicals and reactive oxygen species (ROS). These substances are known to induce oxidative stress, inflammation, apoptosis, and senescence due to their exposure to environmental pollutants and the presence of oxidative enzymes. The lung is particularly susceptible to oxidative stress. Persistent oxidative stress caused by chronic exposure to CS can lead to respiratory diseases such as chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), and lung cancer. Avoiding exposure to environmental pollutants, like cigarette smoke and air pollution, can help mitigate oxidative stress. A comprehensive understanding of oxidative stress and its impact on the lungs requires future research. This includes identifying strategies for preventing and treating lung diseases as well as investigating the underlying mechanisms behind oxidative stress. Thus, this review aims to investigate the cellular processes induced by CS, specifically inflammation, apoptosis, senescence, and their associated biomarkers. Furthermore, this review will delve into the alveolar response provoked by CS, emphasizing the roles of potential therapeutic target markers and strategies in inflammation and oxidative stress.

Tissue-resident memory T cells mediate mucosal immunity to recurrent urinary tract infection

Urinary tract infection (UTI) is one of the most prevalent human bacterial infections. New therapeutic approaches, including vaccination and immunotherapy, are urgently needed to combat the rapid global dissemination of multidrug-resistant uropathogens. Development of therapies is impeded by an incomplete understanding of memory development during UTI. Here, we found that reducing bacterial load early in infection, by reducing the inoculum or with antibiotics after infection, completely abrogated the protective memory response. We observed a mixed T helper (T_H) cell polarization, composed of T_H1, T_H2, and T_H17 T cells, among T cells infiltrating the bladder during primary infection. Thus, we hypothesized that reducing antigen load altered T_H cell polarization, leading to poor memory. Unexpectedly, however, T_H cell polarization was unchanged in these scenarios. Instead, we uncovered a population of tissue-resident memory (T_RM) T cells that was significantly reduced in the absence of sufficient antigen. Demonstrating that T_RM cells are necessary for immune memory, transfer of lymph node- or spleen-derived infection-experienced T cells to naïve animals did not confer protection against infection. Supporting that T_RM cells are sufficient to protect against recurrent UTI, animals depleted of systemic T cells, or treated with FTY720 to block memory lymphocyte migration from lymph nodes to infected tissue, were equally protected compared with unmanipulated mice against a second UTI. Thus, we uncovered an unappreciated key role for T_RM cells in the memory response to bacterial infection in the bladder mucosa, providing a target for non-antibiotic-based immunotherapy and/or new vaccine strategies to prevent recurrent UTI.

Pathobiology of Type 2 Inflammation in Asthma and Nasal Polyposis

Asthma and nasal polyposis often coexist and are frequently intertwined by tight pathogenic links, mainly consisting of the cellular and molecular pathways underpinning type 2 airway inflammation. The latter is characterized by a structural and functional impairment of the epithelial barrier, associated with the eosinophilic infiltration of both the lower and upper airways, which can be driven by either allergic or non-allergic mechanisms. Type 2 inflammatory changes are predominantly due to the biological actions exerted by interleukins 4 (IL-4), 13 (IL-13), and 5 (IL-5), produced by T helper 2 (Th2) lymphocytes and group 2 innate lymphoid cells (ILC2). In addition to the above cytokines, other proinflammatory mediators involved in the pathobiology of asthma and nasal polyposis include prostaglandin D₂ and cysteinyl leukotrienes. Within this context of 'united airway diseases', nasal polyposis encompasses several nosological entities such as chronic rhinosinusitis with nasal polyps (CRSwNP) and aspirin-exacerbated respiratory disease (AERD). Because of the common pathogenic origins of asthma and nasal polyposis, it is not surprising that the more severe forms of both these disorders can be successfully treated by the same biologic drugs, targeting many molecular components (IgE, IL-5 and its receptor, IL-4/IL-13 receptors) of the type 2 inflammatory trait.

Innate immune cellular therapeutics in transplantation

Successful organ transplantation provides an opportunity to extend the lives of patients with end-stage organ failure. Selectively suppressing the donor-specific alloimmune response, however, remains challenging without the continuous use of non-specific immunosuppressive medications, which have multiple adverse effects including elevated risks of infection, chronic kidney injury, cardiovascular disease, and cancer. Efforts to promote allograft tolerance have focused on manipulating the adaptive immune response, but long-term allograft survival rates remain disappointing. In recent years, the innate immune system has become an attractive therapeutic target for the prevention and treatment of transplant organ rejection. Indeed, contemporary studies demonstrate that innate immune cells participate in both the initial alloimmune response and chronic allograft rejection and undergo non-permanent functional reprogramming in a phenomenon termed "trained immunity." Several types of innate immune cells are currently under investigation as potential therapeutics in transplantation, including myeloid-derived suppressor cells, dendritic cells, regulatory macrophages, natural killer cells, and innate lymphoid cells. In this review, we discuss the features and functions of these cell types, with a focus on their role in the alloimmune response. We examine their potential application as therapeutics to prevent or treat allograft rejection, as well as challenges in their clinical translation and future directions for investigation.

Molecular Markers of Blood Cell Populations Can Help Estimate Aging of the Immune System

Aging of the immune system involves functional changes in individual cell populations, in hematopoietic tissues and at the systemic level. They are mediated by factors produced by circulating cells, niche cells, and at the systemic level. Age-related alterations in the microenvironment of the bone marrow and thymus cause a decrease in the production of naive immune cells and functional immunodeficiencies. Another result of aging and reduced tissue immune surveillance is the accumulation of senescent cells. Some viral infections deplete adaptive immune cells, increasing the risk of autoimmune and immunodeficiency conditions, leading to a general degradation in the specificity and effectiveness of the immune system in old age. During the COVID-19 pandemic, the state-of-the-art application of mass spectrometry, multichannel flow cytometry, and single-cell genetic analysis have provided vast data on the mechanisms of aging of the immune system. These data require systematic analysis and functional verification. In addition, the prediction of age-related complications is a priority task of modern medicine in the context of the increase in the aged population and the risk of premature death during epidemics. In this review, based on the latest data, we discuss the mechanisms of immune aging and highlight some cellular markers as indicators of age-related immune disbalance that increase the risk of senile diseases and infectious complications.

A protein subunit vaccine elicits a balanced immune response that protects against Pseudomonas pulmonary infection

The opportunistic pathogen Pseudomonas aeruginosa (Pa) causes severe nosocomial infections, especially in immunocompromised individuals and the elderly. Increasing drug resistance, the absence of a licensed vaccine and increased hospitalizations due to SARS-CoV-2 have made Pa a major healthcare risk. To address this, we formulated a candidate subunit vaccine against Pa (L-PaF), by fusing the type III secretion system tip and translocator proteins with LTA1 in an oil-in-water emulsion (ME). This was mixed with the TLR4 agonist (BECC438b). Lung mRNA sequencing showed that the formulation activates genes from multiple immunological pathways eliciting a protective Th1-Th17 response following IN immunization. Following infection, however, the immunized mice showed an adaptive response while the PBS-vaccinated mice experienced rapid onset of an inflammatory response. The latter displayed a hypoxic lung environment with high bacterial burden. Finally, the importance of IL-17 and immunoglobulins were demonstrated using knockout mice. These findings suggest a need for a balanced humoral and cellular response to prevent the onset of Pa infection and that our formulation could elicit such a response.

Sialokinin in mosquito saliva shifts human immune responses towards intracellular pathogens

Mosquito saliva is a mix of numerous proteins that are injected into the skin while the mosquito searches for a blood meal. While mosquito saliva is known to be immunogenic, the salivary components driving these immune responses, as well as the types of immune responses that occur, are not well characterized. We investigated the effects of one potential immunomodulatory mosquito saliva protein, sialokinin, on the human immune response. We used flow cytometry to compare human immune cell populations between humanized mice bitten by sialokinin knockout mosquitoes or injected with sialokinin, and compared them to those bitten by wild-type mosquitoes, unbitten, or saline-injected control mice. Humanized mice received 4 mosquito bites or a single injection, were euthanized after 7 days, and skin, spleen, bone marrow, and blood were harvested for immune cell profiling. Our results show that bites from sialokinin knockout mosquitoes induced monocyte and macrophage populations in the skin, blood, bone marrow, and spleens, and primarily affected CD11c- cell populations. Other increased immune cells included plasmacytoid dendritic cells in the blood, natural killer cells in the skin and blood, and CD4+ T cells in all samples analyzed. Conversely, we observed that mice bitten with sialokinin knockout mosquitoes had decreased NKT cell populations in the skin, and fewer B cells in the blood, spleen, and bone marrow. Taken together, we demonstrated that sialokinin knockout saliva induces elements of a TH1 cellular immune response, suggesting that the sialokinin peptide is inducing a TH2 cellular immune response during wild-type mosquito biting. These findings are an important step towards understanding how mosquito saliva modulates the human immune system and which components of saliva may be critical for arboviral infection. By identifying immunomodulatory salivary proteins, such as sialokinin, we can develop vaccines against mosquito saliva components and direct efforts towards blocking arboviral infections.

Therapeutic potential of targeting IL-17 and its receptor signaling in neuroinflammation

T helper 17 cells are thought to significantly contribute to the neuroinflammation process during neurogenerative diseases via their signature cytokine, interleukin (IL)-17. Recently, an emerging key role of IL-17 and its receptors has been documented in inflammatory and autoimmune diseases. The clinical studies conducted on patients with neurodegenerative disease have also shown an increase in IL-17 levels in serum as well as cerebrospinal fluid samples. Therapeutic targeting of either IL-17 receptors or direct IL-17 neutralizing antibodies has shown a promising preclinical and clinical proof of concept for treating chronic autoimmune neurodegenerative diseases such as multiple sclerosis. Thus, IL-17 and its receptors have a central role in regulation of neuroinflammation and can be considered as one of the major therapeutic targets in chronic neuroinflammatory diseases.

Insight into SARS-CoV-2 Omicron variant immune escape possibility and variant independent potential therapeutic opportunities

The Omicron, the latest variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected in November 2021 in Botswana, South Africa. Compared to other variants of SARS-CoV-2, the Omicron is the most highly mutated, with 50 mutations throughout the genome, most of which are in the spike (S) protein. These mutations may help the Omicron to evade host immunity against the vaccine. Epidemiological studies suggest that Omicron is highly infectious and spreads rapidly, but causes significantly less severe disease than the wild-type strain and the other variants of SARS-CoV-2. With the increased transmissibility and a higher rate of re-infection, Omicron has now become a dominant variant worldwide and is predicted to be able to evade vaccine-induced immunity. Several clinical studies using plasma samples from individuals receiving two doses of US Food and Drugs Administration (FDA)-approved COVID-19 vaccines have shown reduced humoral immune response against Omicron infection, but T cell-mediated immunity was well preserved. In fact, T cell-mediated immunity protects against severe disease, and thus the disease caused by Omicron remains mild. In this review, I surveyed the current status of Omicron variant mutations and mechanisms of immune response in the context of immune escape from COVID-19 vaccines. I also discuss the potential implications of therapeutic opportunities that are independent of SARS-CoV-2 variants, including Omicron. A better understanding of vaccine-induced immune responses and variant-independent therapeutic interventions that include potent antiviral, antioxidant, and anti-cytokine activities may pave the way to reducing Omicron-related COVID-19 complications, severity, and mortality. Collectively, these insights point to potential research gaps and will aid in the development of new-generation COVID-19 vaccines and antiviral drugs to combat Omicron, its sublineages, or upcoming new variants of SARS-CoV-2.

Simulated Microgravity Disrupts Nuclear Factor κB Signaling and Impairs Murine Dendritic Cell Phenotype and Function

During spaceflights, astronauts face different forms of stress (e.g., socio-environmental and gravity stresses) that impact physiological functions and particularly the immune system. In this context, little is known about the effect of such stress on dendritic cells (DCs). First, we showed that hypergravity, but not chronic ultra-mild stress, a socio-environmental stress, induced a less mature phenotype characterized by a decreased expression of MHCII and co-stimulatory molecules. Next, using the random positioning machine (RPM), we studied the direct effects of simulated microgravity on either splenic DCs or Flt-3L-differentiated bone marrow dendritic cells (BMDCs). Simulated microgravity was found to reduce the BM-conventional DC (cDC) and splenic cDC activation/maturation phenotype. Consistent with this, BMDCs displayed a decreased production of pro-inflammatory cytokines when exposed to microgravity compared to the normogravity condition. The induction of a more immature phenotype in microgravity than in control DCs correlated with an alteration of the NFκB signaling pathway. Since the DC phenotype is closely linked to their function, we studied the effects of microgravity on DCs and found that microgravity impaired their ability to induce naïve CD4 T cell survival, proliferation, and polarization. Thus, a deregulation of DC function is likely to induce immune deregulation, which could explain the reduced efficiency of astronauts' immune response.

Nanoplastics induce molecular toxicity in earthworm: Integrated multi-omics, morphological, and intestinal microorganism analyses

The toxicity of nanoplastics (NPs) at relatively low concentrations to soil fauna at different organismal levels is poorly understood. We investigated the responses of earthworm (Eisenia fetida) to polystyrene NPs (90-110 nm) contaminated soil at a relatively low concentration (0.02 % w:w) based on multi-omics, morphological, and intestinal microorganism analyses. Results showed that NPs accumulated in earthworms' intestinal tissues. The NPs damaged earthworms' digestive and immune systems based on injuries of the intestinal epithelium and chloragogenous tissues (tissue level) and increased the number of changed genes in the digestive and immune systems (transcriptome level). The NPs reduced gut microorganisms' diversity (Shannon index) and species richness (Chao 1 index). Proteomic, transcriptome, and histopathological analyses showed that earthworms suffered from oxidative and inflammatory stresses. Moreover, NPs influenced the osmoregulatory metabolism of earthworms as NPs damaged intestinal epithelium (tissue level), increased aldosterone-regulated sodium reabsorption (transcriptome level), inositol phosphate metabolism (proteomic level) and 2-hexyl-5-ethyl-furan-3-sulfonic acid, and decreased betaine and myo-inositol concentrations (metabolic level). Transcriptional-metabolic and transcriptional-proteomic analyses revealed that NPs disrupted earthworm carbohydrate and arachidonic acid metabolisms. Our multi-level investigation indicates that NPs at a relatively low concentration induced toxicity to earthworms and suggests that NPs pollution has significant environmental toxicity risks for soil fauna.

The function and mechanism of action of uterine microecology in pregnancy immunity and its complications

The human microbiota influences physiology, disease, and metabolic reproduction. The origin of uterine bacteria is controversial. The main assumption is that the germs enter the uterine cavity from the vagina through the cervical canal, bloodstream, fallopian tubes, and gynecological surgical channels. Understanding the microbiota at various anatomical sites is critical to the female reproductive system and pregnancy. Today's study focuses on the role of uterine bacteria in pregnancy and embryo implantation. According to our findings, the uterine microbiome influences embryo implantation and pregnancy outcome. Pregnancy is a natural, evolutionarily selected approach to human reproduction. During pregnancy, the microbiota of the reproductive tract changes, facilitating the maintenance of pregnancy, and the human immune system undergoes a series of changes that recognize and adapt to the non-self. From the beginning of pregnancy, a non-self fetus must establish a placenta of embryonic origin to protect itself and promote growth; the VMB tends to be more stable and lactobacillus-dominated in late gestation than in early gestation. Any material that disrupts this connection, such as microbial changes, is associated with a higher risk of poor health and poor pregnancy outcomes in women (eclampsia). The presence of any material that disrupts this connection, such as microbial changes, is associated with a higher risk of poor health and poor pregnancy outcomes (preeclampsia, preterm birth, gestational diabetes, etc.). In this work, we review the last decade of relevant research to improve our understanding of the mechanisms by which the microbiota of the female reproductive tract influences female reproductive health. This work discusses the mechanisms associated with the reproductive tract microbiota and pregnancy immunity, as well as the impact of an abnormal microbiota on adverse pregnancy outcomes. Emphasis is placed on the characteristics and sources of the female vaginal, uterine, and placental microbiota and the importance of a well-stabilized local human microbiota and immune system for embryo implantation, placental development, fetal growth, and pregnancy outcome.

Immunopathological insights into villitis of unknown etiology on the basis of transplant immunology

Villitis of unknown etiology (VUE) is an inflammatory disease characterized by the infiltration of maternal CD8 +T cells into the placental villi. Although the pathogenesis of VUE is still debated, dysregulation of the immune system appears to be an important factor in the development of the disease. Interaction of maternal T cells with the fetal antigens seems to be the trigger for the VUE onset. In this context, graft vs host disease (GVHD) and allographic rejection seem to share similarities in the VUE immunopathological mechanism, especially those related to immunoregulation. In this review, we compared the immunological characteristics of VUE with allograft rejection, and GVHD favoring a better knowledge of VUE pathogenesis that may contribute to VUE therapeutics strategies in the future.

Asthma as a Systemic Disease: Cardiovascular Effects Associated with Asthma

Asthma and cardiovascular disease (CVD) pose significant public health burdens. Airway inflammation is central to asthma pathophysiology and systemic inflammation, which occurs in asthma, is central to CVD pathophysiology. Numerous robust epidemiological studies have demonstrated deleterious systemic cardiovascular effects associated with the asthma syndrome. The cardiovascular effects associated with asthma include arterial injury, atherosclerotic CVD events, atrial fibrillation, and hypertension. Asthma is a heterogeneous disease, however, and the risk of CVD is not homogeneous across the various clinical phenotypes and molecular endotypes, highlighting prior inconsistent associations of asthma and its subtypes with various forms of CVD. The mechanistic underpinnings of the increased CVD risk in asthma remain multifactorial and undefined. Collectively, this supports the need for a precision approach in the identification of individuals with asthma who remain at elevated risk of development of cardiovascular diseases to guide both diagnostic and preventive interventions to decrease CVD risk among individuals living with asthma.

Gamma-Tocotrienol Modulates Total-Body Irradiation-Induced Hematopoietic Injury in a Nonhuman Primate Model

Radiation exposure causes acute damage to hematopoietic and immune cells. To date, there are no radioprotectors available to mitigate hematopoietic injury after radiation exposure. Gamma-tocotrienol (GT3) has demonstrated promising radioprotective efficacy in the mouse and nonhuman primate (NHP) models. We determined GT3-mediated hematopoietic recovery in total-body irradiated (TBI) NHPs. Sixteen rhesus macaques divided into two groups received either vehicle or GT3, 24 h prior to TBI. Four animals in each treatment group were exposed to either 4 or 5.8 Gy TBI. Flow cytometry was used to immunophenotype the bone marrow (BM) lymphoid cell populations, while clonogenic ability of hematopoietic stem cells (HSCs) was assessed by colony forming unit (CFU) assays on day 8 prior to irradiation and days 2, 7, 14, and 30 post-irradiation. Both radiation doses showed significant changes in the frequencies of B and T-cell subsets, including the self-renewable capacity of HSCs. Importantly, GT3 accelerated the recovery in CD34⁺ cells, increased HSC function as shown by improved recovery of CFU-granulocyte macrophages (CFU-GM) and burst-forming units erythroid (B-FUE), and aided the recovery of circulating neutrophils and platelets. These data elucidate the role of GT3 in hematopoietic recovery, which should be explored as a potential medical countermeasure to mitigate radiation-induced injury to the hematopoietic system.

The Cryptococcus gattii species complex: Unique pathogenic yeasts with understudied virulence mechanisms

Members of Cryptococcus gattii/neoformans species complex are the etiological agents of the potentially fatal human fungal infection cryptococcosis. C. gattii and its sister species cause disease in both immunocompetent and immunocompromised hosts, while the closely related species C. neoformans and C. deneoformans predominantly infect immunocompromised hosts. To date, most studies have focused on similarities in pathogenesis between these two groups, but over recent years, important differences have become apparent. In this review paper, we highlight some of the major phenotypic differences between the C. gattii and neoformans species complexes and justify the need to study the virulence and pathogenicity of the C. gattii species complex as a distinct cryptococcal group.

Reinventing the human tuberculosis (TB) granuloma: Learning from the cancer field

Tuberculosis (TB) remains one of the deadliest infectious diseases in the world and every 20 seconds a person dies from TB. An important attribute of human TB is induction of a granulomatous inflammation that creates a dynamic range of local microenvironments in infected organs, where the immune responses may be considerably different compared to the systemic circulation. New and improved technologies for in situ quantification and multimodal imaging of mRNA transcripts and protein expression at the single-cell level have enabled significantly improved insights into the local TB granuloma microenvironment. Here, we review the most recent data on regulation of immunity in the TB granuloma with an enhanced focus on selected in situ studies that enable spatial mapping of immune cell phenotypes and functions. We take advantage of the conceptual framework of the cancer-immunity cycle to speculate how local T cell responses may be enhanced in the granuloma microenvironment at the site of Mycobacterium tuberculosis infection. This includes an exploratory definition of "hot", immune-inflamed, and "cold", immune-excluded TB granulomas that does not refer to the level of bacterial replication or metabolic activity, but to the relative infiltration of T cells into the infected lesions. Finally, we reflect on the current knowledge and controversy related to reactivation of active TB in cancer patients treated with immune checkpoint inhibitors such as PD-1/PD-L1 and CTLA-4. An understanding of the underlying mechanisms involved in the induction and maintenance or disruption of immunoregulation in the TB granuloma microenvironment may provide new avenues for host-directed therapies that can support standard antibiotic treatment of persistent TB disease.

Persistent Asthma Is Associated With Carotid Plaque in MESA

Background Asthma and atherosclerotic cardiovascular disease share an underlying inflammatory pathophysiology. We hypothesized that persistent asthma is associated with carotid plaque burden, a strong predictor of atherosclerotic cardiovascular disease events. Methods and Results The MESA (Multi-Ethnic Study of Atherosclerosis) enrolled adults free of known atherosclerotic cardiovascular disease at baseline. Subtype of asthma was determined at examination 1. Persistent asthma was defined as asthma requiring use of controller medications, and intermittent asthma was defined as asthma without controller medications. B-mode carotid ultrasound was performed to detect carotid plaques (total plaque score [TPS], range 0-12). Multivariable regression modeling with robust variances evaluated the association of asthma subtype and carotid plaque burden. The 5029 participants were a mean (SD) age of 61.6 (10.0) years (53% were women, 26% were Black individuals, 23% were Hispanic individuals, and 12% were Chinese individuals). Carotid plaque was present in 50.5% of participants without asthma (TPS, 1.29 [1.80]), 49.5% of participants with intermittent asthma (TPS, 1.25 [1.76]), and 67% of participants with persistent asthma (TPS, 2.08 [2.35]) (P≤0.003). Participants with persistent asthma had higher interleukin-6 (1.89 [1.61] pg/mL) than participants without asthma (1.52 [1.21] pg/mL; P=0.02). In fully adjusted models, persistent asthma was associated with carotid plaque presence (odds ratio, 1.83 [95% confidence interval, 1.21-2.76]; P<0.001) and TPS (β=0.66; P<0.01), without attenuation after adjustment for baseline interleukin-6 (P=0.02) or CRP (C-reactive protein) (P=0.01). Conclusions Participants with persistent asthma had higher carotid plaque burden and higher levels of inflammatory biomarkers, compared with participants without asthma. Adjustment for baseline inflammatory biomarkers did not attenuate the association between carotid plaque and asthma subtype, highlighting the increased atherosclerotic cardiovascular disease risk among those with persistent asthma may be multifactorial.

Fibroblast heterogeneity in pancreatic ductal adenocarcinoma: Perspectives in immunotherapy

Cancer-associated fibroblasts (CAFs), the key component in pancreatic tumor microenvironment (TME), originate from many sources and are naturally heterogeneous in phenotype and function. Numerous studies have identified their crucial role in promoting tumorigenesis through many routes including fostering cancer proliferation, angiogenesis, invasion, and metastasis. Conversely, research also indicates that subsets of CAFs express anti-tumor activity. These dual effects reflect the complexity of CAF heterogeneity and their interactions with other cells and factors in pancreatic TME. A critical component in this environment is infiltrated immune cells and immune mediators, which can communicate with CAFs. The crosstalk occurs via the production of various cytokines, chemokines, and other mediators and shapes the immunological state in TME. Comprehensive studies of the crosstalk between CAFs and tumor immune environment, particularly internal mechanisms interlinking CAFs and immune effectors, may provide new approaches for pancreatic ductal adenocarcinoma (PDAC) treatments. In this review, we explore the characteristics of CAFs, describe the interplay among CAFs, infiltrated immune cells, other mediators, and provide an overview of recent CAF-target therapies, their limitations, and potential research directions in CAF in the context of PDAC.

Modifying Orthobiological PRP Therapies Are Imperative for the Advancement of Treatment Outcomes in Musculoskeletal Pathologies

Autologous biological cellular preparations have materialized as a growing area of medical advancement in interventional (orthopedic) practices and surgical interventions to provide an optimal tissue healing environment, particularly in tissues where standard healing is disrupted and repair and ultimately restoration of function is at risk. These cellular therapies are often referred to as orthobiologics and are derived from patient's own tissues to prepare point of care platelet-rich plasma (PRP), bone marrow concentrate (BMC), and adipose tissue concentrate (ATC). Orthobiological preparations are biological materials comprised of a wide variety of cell populations, cytokines, growth factors, molecules, and signaling cells. They can modulate and influence many other resident cells after they have been administered in specific diseased microenvironments. Jointly, the various orthobiological cell preparations are proficient to counteract persistent inflammation, respond to catabolic reactions, and reinstate tissue homeostasis. Ultimately, precisely delivered orthobiologics with a proper dose and bioformulation will contribute to tissue repair. Progress has been made in understanding orthobiological technologies where the safety and relatively easy manipulation of orthobiological treatment tools has been demonstrated in clinical applications. Although more positive than negative patient outcome results have been registered in the literature, definitive and accepted standards to prepare specific cellular orthobiologics are still lacking. To promote significant and consistent clinical outcomes, we will present a review of methods for implementing dosing strategies, using bioformulations tailored to the pathoanatomic process of the tissue, and adopting variable preparation and injection volume policies. By optimizing the dose and specificity of orthobiologics, local cellular synergistic behavior will increase, potentially leading to better pain killing effects, effective immunomodulation, control of inflammation, and (neo) angiogenesis, ultimately contributing to functionally restored body movement patterns.

Immunological and Pathological Peculiarity of Severe Acute Respiratory Syndrome Coronavirus 2 Beta Variant

Diverse severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have emerged since the beginning of the COVID-19 pandemic. We investigated the immunological and pathological peculiarity of the SARS-CoV-2 beta variant of concern (VoC) compared to the ancestral strain. Comparative analysis of phenotype and pathology revealed that the beta VoC induces slower disease progression and a prolonged presymptomatic period in the early stages of SARS-CoV-2 infection but ultimately causes sudden death in the late stages of infection in the K18-hACE2 mouse model. The beta VoC induced enhanced activation of CXCL1/2-CXCR2-NLRP3-IL-1β signal cascade accelerating neutrophil recruitment and lung pathology in beta variant-infected mice, as evidenced by multiple analyses of SARS-CoV-2-induced inflammatory cytokines and transcriptomes. CCL2 was one of the most highly secreted cytokines in the early stages of infection. Its blockade reduced virus-induced weight loss and delayed mortality. Our study provides a better understanding of the variant characteristics and need for treatment. IMPORTANCE Since the outbreak of COVID-19, diverse SARS-CoV-2 variants have been identified. These variants have different infectivity and transmissibility from the ancestral strains. However, underlying molecular mechanisms have not yet been fully elucidated. In our study, the beta variant showed distinct pathological conditions and cytokine release kinetics from an ancestral strain in a mouse model. It was associated with higher neutrophil recruitment by increased levels of CXCL1/2, CXCR2, and interleukin 1β (IL-1β) at a later stage of viral infection. Our study will provide a better understanding of SARS-CoV-2 pathogenesis.

Endometrium Immunomodulation to Prevent Recurrent Implantation Failure in Assisted Reproductive Technology

After more than four decades of assisted reproductive technology (ART) practice worldwide, today more than 60% of women undergoing in vitro fertilization (IVF) treatments fail to become pregnant after the first embryo transfer and nearly 20% of patients are suffering from unexplained recurrent implantation failures (RIFs) and repeated pregnancy loss (RPL). The literature reported different causes of RIF–RPL, mainly multifactorial, endometrial and idiopathic. RIF remains a black box because of the complicated categorization and causes of this physio-pathological dysregulation of implantation and pregnancy process after ovarian stimulation. Many options were suggested as solutions to treat RIF–RPL with controversial results on their usefulness. In this article, we reviewed different possible therapeutic options to improve implantation rates and clinical outcomes. Based on our experience we believe that endometrium immunomodulation after intrauterine insemination of activated autologous peripheral blood mononuclear cells (PBMCs) or platelet-rich plasma (PRP) can be a promising therapeutic solution. On the other hand, peripheral lymphocyte balance typing, specific cytokines and interleukins profiling can be proposed as predictive biomarkers of implantation before embryo transfer.

NSAIDs affect dendritic cell cytokine production

BACKGROUND

Immunotherapy is now considered as the new pillar in treatment of cancer patients. Dendritic cells (DCs) play an essential role in stimulating anti-tumor immune responses, as they are capable of cross-presenting exogenous tumor antigens in MHCI complexes to activate naïve CD8+ T cells. Analgesics, like non-steroid anti-inflammatory drugs (NSAIDs), are frequently given to cancer patients to help relieve pain, however little is known about their impact on DC function.

METHODS

Here, we investigated the effect of the NSAIDs diclofenac, ibuprofen and celecoxib on the three key processes of DCs required for proper CD8+ cytotoxic T cell induction: antigen cross-presentation, co-stimulatory marker expression, and cytokine production.

RESULTS

Our results show that TLR-induced pro- and anti-inflammatory cytokine excretion by human monocyte derived and murine bone-marrow derived DCs is diminished after NSAID exposure.

CONCLUSIONS

These results indicate that various NSAIDs can affect DC function and warrant further investigation into the impact of NSAIDs on DC priming of T cells and cancer immunotherapy efficacy.