Th1 Responses Research Articles

Impact of Nano-Pomegranate Seed Oil on the Expression of TLR2 and TLR4 Genes in A549 Cells Sensitized with Alternaria alternata Cellular Extract

Background: Allergies impact nearly 30% of the world's population, with fungi being remarkable contributors to allergic sensitivity. Exposure to fungi allergens can trigger allergic reactions and severe asthma has been linked to hypersensitivity to fungi such as Aspergillus and Alternaria spp. Alternaria alternata, a common allergen in respiratory allergic diseases, releases proteases that initiate Th2 responses, causing inflammatory cytokine production. Given the anti-inflammatory properties of Pomegranate Seed Oil (PSO) and the potential of Nano-emulsions (NEs) to enhance drug delivery, this study investigates the impact of PSO-loaded NEs on TLR2 and TLR4 gene expression in A549 cells sensitized with A. alternata extract (ALT). Methods: A. alternata (ATCC 6663) was cultured and processed to obtain a cytosolic extract, with protein content measured using the Bradford method. Using a Soxhlet apparatus, PSO was extracted from cleaned, dried seeds and analyzed by gas chromatography. Alginate nanospheres containing PSO were prepared through a modified water-in-oil emulsification method and characterized for particle size, polydispersity index, and zeta potential. A549 cells were cultured and treated with various ALT, PSO, and PSO-loaded NEs combinations. Following treatment, RNA was extracted, and real-time RT- PCR was conducted to analyze TLR2 and TLR4 gene expression. Results: All treatment groups showed an increase in TLR2 gene expression compared to the control, with the ALT combined with PSO (P+ALT) causing the highest increase at 4.82-fold. Free PSO (P) and free NEs (NP) resulted in 3.92-fold and 2.93-fold increases, respectively, while the ALT and PSO- loaded NEs (NP+ALT) led to 2.26-fold and 2.50-fold increases. For TLR4 gene expression, the ALT treatment increased expression by 2.29-fold, but treatments containing PSO (P, P+ALT, NP+ALT) reduced TLR4 expression, with P+ALT and NP+ALT causing 0.45-fold and 0.61-fold decreases. Conclusion: The study confirms that herbal extracts like PSO selectively upregulate TLR2 and downregulate TLR4, suggesting targeted therapeutic potential in inflammation and immune modulation. PSO-loaded NEs demonstrated superior anti-inflammatory effects, supporting their development for treating inflammatory diseases and warranting further research into their molecular mechanisms and therapeutic applications.

Identification of potential antigenic proteins and epitopes for the development of a monkeypox virus vaccine: an in silico approach.

Virus assembly, budding, or surface proteins play important roles such as viral attachment to cells, fusion, and entry into cells. The present study aimed to identify potential antigenic proteins and epitopes that could be used to develop a vaccine or diagnostic assay against the Monkeypox virus (MPXV) which may cause a potential epidemic. To do this, 39 MPXV proteins (including assembly, budding, and surface proteins) were analyzed using an in silico approach. Of these 39 proteins, the F5L virus protein was found to be the best vaccine candidate due to its signal peptide properties, negative GRAVY value, low transmembrane helix content, moderate aliphatic index, large molecular weight, long-estimated half-life, beta wrap motifs, and being stable, soluble, and containing non-allergic features. Moreover, the F5L protein exhibited alpha-helical secondary structures, making it a potential "structural antigen" recognized by antibodies. The other viral protein candidates were A9 and A43, but A9 lacked beta wrap motifs, while A43 had a positive GRAVY value and was insoluble. These two proteins were not as suitable candidates as the F5L protein. The KRVNISLTCL epitope from the F5L protein demonstrated the highest antigen score (2.4684) for MHC-I, while the GRFGYVPYVGYKCI epitope from the A9 protein exhibited the highest antigenicity (1.754) for MHC-II. Both epitopes met the criteria for high antigenicity, non-toxicity, solubility, non-allergenicity, and the presence of cleavage sites. Molecular docking and dynamics (MD) simulations further validated their potential, revealing stable and energetically favorable interactions with MHC molecules. The immunogenicity assessment showed that GRFGYVPYVGYKCI could strongly induce immune responses through both IFN-γ and IL-4 pathways, suggesting its capacity to provoke a balanced Th1 and Th2 response. In contrast, KRVNISLTCL exhibited limited immunostimulatory potential. Overall, these findings lay the groundwork for future vaccine development, indicating that F5L, particularly the GRFGYVPYVGYKCI epitope, may serve as an effective candidate for peptide-based vaccine design against MPXV.

Functional characterization of macrophages and change of Th1/Th2 balance in patients with pythiosis after Pythium insidiosum antigen immunotherapy

There has been limited research into the role of the Pythium insidiosum antigen (PIA) in modulating immune response in patients with pythiosis. This study investigated the balance of T helper type 2 (Th2) and T helper type 1 (Th1) responses after receiving PIA immunotherapy in patients with pythiosis. Next, the phagocytic activity and phagocytic index of IFN-γ primed PIA-treated macrophages were examined. Furthermore, the phagocytosis of infective P. insidiosum zoospores by macrophages was investigated. This work showed that the PIA vaccine induced Th1 response and M1 macrophages in patients with vascular pythiosis who survived and those with localized pythiosis. Phagocytic activity and phagocytic index were increased considerably in localized pythiosis patients compared to vascular pythiosis patients with hematological diseases. IFN-γ priming of PIA-treated macrophages against P. insidiosum zoospores enhanced the phagocytic activity and phagocytic index in vascular and localized pythiosis patients. Macrophages engulfed P. insidiosum zoospores, but the zoospores continued germination, resulting in macrophage death. Overall, our results suggest that PIA can modulate the immune responses, contributing to higher levels of Th1-type cytokine and potentially improving the survival of patients with vascular pythiosis. This study is the first to uncover that P. insidiosum zoospores can survive within macrophages.

Human-immunodeficiency virus infection associated with the impaired Th1 and pro-inflammatory cytokine response in latent tuberculosis-infected individuals: A comparative cross-sectional study.

Tuberculosis (TB) and HIV co-infections are extensively overlapping, especially in developing countries. HIV infection is known as a major risk factor for the reactivation of latent TB into active TB. Although not fully understood and needs further study, HIV infection might enhance the reactivation of latent TB by breaching immune control mechanisms. We investigated the influence of HIV infection on the cytokine response of LTB-infected individuals. Heparinized venous blood was collected from 40 ART-naïve HIV-infected and 30 HIV-negative healthy controls for LTB screening, plasma collection, and PBMC isolation and stimulation. The level of cytokines in plasma and their production by PBMCs stimulated with purified protein derivative (PPD), staphylococcus enterotoxin B (SEB), or unstimulated PBMCs were analyzed using a cytometric bead array (CBA) assay. PPD-induced IL-2 by PBMCs was higher in LTB-infected groups compared with HIV-negative LTB-negative groups (p = 0.0015). When LTB-infected groups were co-infected with HIV (HIV+LTB+), the IL-2 (p < 0.0001) and IFN-gamma (p = 0.0144) production by PPD-stimulated PBMCs was reduced. The level of IL-2 (p = 0.0070), IL-6 (p = 0.0054), and TNF-alpha (p = 0.0045) in plasma were lower in HIV+LTB+ individuals compared with HIV-negative LTB-positive (HIV-LTB+) groups. Our findings suggested that HIV co-infection in LTB-positive individuals is associated with the diminished production of PPD-induced Th1 (IFN-gamma and IL-2) cytokines by PBMCs and in the plasma level of IL-2 and proinflammatory cytokines (IL-6 and TNF-alpha).

Neutrophil-activating protein in Bacillus spores inhibits casein allergy via TLR2 signaling

BackgroundMilk allergy commonly occurs in children, mainly caused by bovine-derived casein (CAS) protein. Neutrophil-activating protein (NAP) of Helicobacter pylori plays an immunomodulatory role with potential to suppress Th2-type immune responses. Bacillus subtilis (B. subtilis) spores are commonly used as oral vectors for drug delivery.ObjectiveTo investigate whether recombinantly expressed NAP on B. subtilis spores could be an effective treatment for CAS allergy in mouse.MethodsAfter CAS sensitization, mice were orally administered B. subtilis spores expressing recombinant NAP for 6 weeks. Allergic symptoms and parameters were evaluated after CAS challenge oral gavage, including allergic inflammation, splenic cytokines, and serum-specific antibodies. Protein levels of Toll-like receptor 2 (TLR2) and c-JUN in the jejunum tissue were measured by western blot. Bone marrow-derived macrophages (BMDMs) were stimulated with inactivated NAP spores to measure the influence on cytokine profiles in vitro.ResultsNAP recombinant spore treatment significantly reduced allergic symptoms and intestinal inflammation. Interleukin-12 and interferon-gamma levels increased, whereas serum CAS-specific IgG1 and IgE levels decreased. TLR2 and c-JUN expression levels were elevated in the jejunal tissue. Inactivated NAP spores polarized BMDMs to the M1 phenotype and enhanced cytokine expression, which were inhibited by a TLR2 neutralizing antibody.ConclusionNAP offers a new strategy in the treatment of CAS allergy by inhibiting the Th2 response, while eliciting macrophages to promote Th1 immune responses.

The role of S-nitrosoglutathione reductase (GSNOR) in T cell-mediated immunopathology of experimental autoimmune encephalomyelitis (EAE)

Previously, we reported that both S-nitrosoglutathione (GSNO), a carrier of cellular nitric oxide, and N6022, an injectable form of GSNO reductase (GSNOR) inhibitor that increases endogenous GSNO levels, alleviate experimental autoimmune encephalomyelitis (EAE) in mice by suppressing Th1 and Th17 immune responses. Building on these findings, we explored the role of GSNOR in EAE pathogenesis and evaluated the efficacy of an orally active GSNOR inhibitor (N91115) in treating the EAE disease. EAE mice exhibited heightened expression/activity of GSNOR in the spinal cord, and the knockout of the GSNOR gene resulted in much milder clinical manifestations of EAE, with lower degrees of demyelination and axonal loss, reduced microglial and astrocyte activations, as well as suppressed Th1 and Th17 cell responses, alongside bolstered Treg immune responses. Next, we evaluated the efficacy of N91115 against EAE immunopathology. Consistent with our findings in GSNOR deficient EAE mice, daily N91115 administration reduced clinical EAE severity, with less spinal cord demyelination and axonal loss compared to untreated EAE mice. Furthermore, N91115 treated EAE mice showed diminished Th1 and Th17 immune responses and enhanced Treg responses. This observation underscores the potential of increased GSNOR expression and activity as a risk factor exacerbating EAE immunopathology, while simultaneously highlighting its potential as a target for modifying the disease. Furthermore, the balanced immune regulation provided by orally active N91115 (IL-6/IL-17a vs. IL-10) presents a promising alternative to immunosuppressive drugs, reducing the risk of opportunistic infections.

Immunologic Mechanisms of BCc1 Nanomedicine Synthesized by Nanochelating Technology in Breast Tumor-bearing Mice: Immunomodulation and Tumor Suppression.

The side effects of anti-cancer chemotherapy remain a concern for patients. So, designing alternative medications seems inevitable. In this research, the immunological mechanisms of BCc1 nanomedicine on tumor-bearing mice were investigated. BALB/c mice underwent tumor transplantation and were assigned into four groups. Group 1 was orally administered with PBS buffer, Group 2 was orally administered BCc1 10 mg/kg, and Group 3 was orally administered BCc1 40 mg/kg daily, respectively. In addition, a group of mice was administered Cyclophosphamide, 20 mg/kg daily. The weight and tumor volume of mice were evaluated bi-weekly. After 24 days of treatment, cytokines and CTL assay in the spleen cell and the tumor were assessed. Furthermore, the spleen, liver, kidney, lung, gut, and uterine tissue were stained with hematoxylin and eosin. Finally, the tumor samples were stained and analyzed for FOXP3. The survival rate of mice was recorded. The results confirmed the histological safety of BCc1. This nanomedicine, especially BCc1 10 mg/kg, led to a strong IFN-γ response and suppressed TGF-β cytokine. The frequency of Treg in the tumor tissue of BCc1 nanomedicine groups was decreased. In addition, nanomedicine repressed tumor volume and tumor weight significantly, which was comparable to Cyclophosphamide. These immunologic events increased the survival rate of BCc1-treated groups. The results indicate that BCc1 nanomedicine can suppress tumor growth and thereby increase the survival rate of experimental mice. It seems a modulation in the tumor microenvironment and polarization toward a Th1 response may be involved. So, BCc1 nanomedicine is efficient for human cancer therapy.

Activation of α2B/2C adrenergic receptor ameliorates ocular surface inflammation through enhancing regulatory T cell function

There is an unmet need for effectively treating dry eye disease (DED), a T cell-mediated chronic, inflammatory ocular surface disorder. Given the potential of nonneuronal adrenergic system in modulating T cell response, we herein investigated the therapeutic efficacy and the underlying mechanisms of a specific alpha 2 adrenergic receptor agonist (AGN-762, selective for α2B/2C receptor subtypes) in a mouse model of DED. Experimental DED was treated with the AGN-762 by oral gavage, either at disease induction or after disease establishment, and showed sustained amelioration, along with reduced expression of DED-pathogenic cytokines in ocular surface tissues, decreased corneal MHC-II+CD11b+ cells and lymphoid Th17 cells, and higher function of regulatory T cells (Treg). In vitro culture of DED-derived effector T helper cells (Teff) with AGN-762 failed to suppress Th17 response, while culture of DED-Treg with AGN-762 led to enhanced suppressive function of Treg and their IL-10 production. Adoptive transfer of AGN-762-pretreated DED-Treg in syngeneic B6.Rag1-/- mice effectively suppressed DED Teff-mediated disease and Th17 response, and the effect was abolished by the neutralization of IL-10. In conclusion, our findings demonstrate that α2B/2C adrenergic receptor agonism effectively ameliorates persistent corneal epitheliopathy in DED by enhancing IL-10 production from Treg and thus restoring their immunoregulatory function.

Th1 and Th2 cytokine response of peripheral blood macrophages-lymphocyte co-culture on challenge with Bacillus Calmette-Guérin and Mycobacterium tuberculosis H37RV in different categories of tuberculosis patients

Th1 and Th2 cytokine response of peripheral blood macrophages-lymphocyte co-culture on challenge with Bacillus Calmette-Guérin and Mycobacterium tuberculosis H37RV in different categories of tuberculosis patients

Hyperglycemia-triggered lipid peroxidation destabilizes STAT4 and impairs anti-viral Th1 responses in type 2 diabetes.

Patients with type 2 diabetes (T2D) are more susceptible to severe respiratory viral infections, but the underlying mechanisms remain elusive. Here, we show that patients with T2D and coronavirus disease 2019 (COVID-19) infections, and influenza-infected T2D mice, exhibit defective T helper 1 (Th1) responses, which are an essential component of anti-viral immunity. This defect stems from intrinsic metabolic perturbations in CD4+ Tcells driven by hyperglycemia. Mechanistically, hyperglycemia triggers mitochondrial dysfunction and excessive fatty acid synthesis, leading to elevated oxidative stress and aberrant lipid accumulation within CD4+ Tcells. These abnormalities promote lipid peroxidation (LPO), which drives carbonylation of signal transducer and activator of transcription 4 (STAT4), a crucial Th1-lineage-determining factor. Carbonylated STAT4 undergoes rapid degradation, causing reduced T-bet induction and diminished Th1 differentiation. LPO scavenger ameliorates Th1 defects in patients with T2D who have poor glycemic control and restores viral control in T2D mice. Thus, this hyperglycemia-LPO-STAT4 axis underpins reduced Th1 activity in T2D hosts, with important implications for managing T2D-related viral complications.

The Role of Bacterial Toxins and Environmental Factors in the Development of Food Allergies

Food allergies (FAs) represent a significant and growing global health issue, with increasing prevalence across different age groups. This review provides a comprehensive analysis of the epidemiology, mechanisms, and risk factors involved in FA development. Currently, FAs are estimated to affect 2% of the general population, with higher rates in children (~8%). However, these figures may be inaccurate because of the reliance on self-reported data and immunoglobulin E (IgE) testing, which may not reflect clinically confirmed cases. Environmental and genetic factors, including exposure to bacterial toxins, dietary habits, and the gut microbiota, play critical roles in FA development. Specifically, Staphylococcus aureus enterotoxins are implicated in disrupting intestinal barriers and enhancing immune sensitization to allergenic proteins. This immune dysregulation promotes Th2 responses and compromises regulatory T cell function, crucial elements in allergy pathogenesis. As the prevalence of FAs continues to rise, there is a pressing need for accurate diagnostic tools, heightened public awareness, and effective prevention strategies. Further research is needed to elucidate the specific role of bacterial toxins and other environmental factors in FA development to advance clinical management approaches.

PRR adjuvants restrain high stability peptides presentation on APCs.

Adjuvants can affect APCs function and boost adaptive immune responses post-vaccination. However, whether they modulate the specificity of immune responses, particularly immunodominant epitope responses, and the mechanisms of regulating antigen processing and presentation remain poorly defined. Here, using overlapping synthetic peptides, we screened the dominant epitopes of Th1 responses in mice post-vaccination with different adjuvants and found that the adjuvants altered the antigen-specific CD4+ T-cell immunodominant epitope hierarchy. MHC-II immunopeptidomes demonstrated that the peptide repertoires presented by APCs were significantly altered by the adjuvants. Unexpectedly, no novel peptide presentation was detected after adjuvant treatment, whereas peptides with high binding stability for MHC-II presented in the control group were missing after adjuvant stimulation, particularly in the MPLA- and CpG-stimulated groups. The low-stability peptide present in the adjuvant groups effectively elicited robust T-cell responses and formed immune memory. Collectively, our results suggest that adjuvants (MPLA and CpG) inhibit high-stability peptide presentation instead of revealing cryptic epitopes, which may alter the specificity of CD4+ T-cell-dominant epitope responses. The capacity of adjuvants to modify peptide-MHC (pMHC) stability and antigen-specific T-cell immunodominant epitope responses has fundamental implications for the selection of suitable adjuvants in the vaccine design process and epitope vaccine development.

PRR adjuvants restrain high stability peptides presentation on APCs

Adjuvants can affect APCs function and boost adaptive immune responses post-vaccination. However, whether they modulate the specificity of immune responses, particularly immunodominant epitope responses, and the mechanisms of regulating antigen processing and presentation remain poorly defined. Here, using overlapping synthetic peptides, we screened the dominant epitopes of Th1 responses in mice post-vaccination with different adjuvants and found that the adjuvants altered the antigen-specific CD4+ T-cell immunodominant epitope hierarchy. MHC-II immunopeptidomes demonstrated that the peptide repertoires presented by APCs were significantly altered by the adjuvants. Unexpectedly, no novel peptide presentation was detected after adjuvant treatment, whereas peptides with high binding stability for MHC-II presented in the control group were missing after adjuvant stimulation, particularly in the MPLA- and CpG-stimulated groups. The low-stability peptide present in the adjuvant groups effectively elicited robust T-cell responses and formed immune memory. Collectively, our results suggest that adjuvants (MPLA and CpG) inhibit high-stability peptide presentation instead of revealing cryptic epitopes, which may alter the specificity of CD4+ T-cell-dominant epitope responses. The capacity of adjuvants to modify peptide–MHC (pMHC) stability and antigen-specific T-cell immunodominant epitope responses has fundamental implications for the selection of suitable adjuvants in the vaccine design process and epitope vaccine development.

Concurrent hypoxia and apoptosis imparts immune programming potential in mesenchymal stem cells: Lesson from acute graft-versus-host-disease model

BackgroundMesenchymal stem cells (MSCs) have emerged as promising candidates for immune modulation in various diseases that are associated with dysregulated immune responses like Graft-versus-Host-Disease (GVHD). MSCs are pleiotropic and the fate of MSCs following administration is a major determinant of their therapeutic efficacy.MethodsHuman MSCs were derived from bone marrow (BM) and Wharton’s Jelly (WJ) and preconditioned through exposure to hypoxia and induction of apoptosis, either sequentially or simultaneously. The immune programming potential of preconditioned MSCs was evaluated by assessing their effects on T cell proliferation, induction of Tregs, programming of effector T-cell towards Th2 phenotype, macrophage polarization in the direct co-culture of MSCs and aGVHD patients-derived PBMNCs. Additionally, efferocytosis of MSCs and relative change in the expression of immunomodulatory soluble factors were examined.ResultsOur study demonstrated that hypoxia preconditioned apoptotic MSCs (BM-MSCs, WJ-MSCs) bear more immune programming ability in a cellular model of acute Graft-versus-Host-Disease (aGVHD). Our findings revealed that WJ-MSCsHYP+APO were superior to BM-MSCsHYP+APO for immune regulation. These induced the differentiation of CD4+T-cell into Tregs, enhanced Th2 effector responses, and simultaneously mitigated Th1- and Th17 responses. Additionally, this approach led to the polarization of M1 macrophages toward an M2 phenotype.ConclusionOur study highlights the potential of WJ-MSCs conditioned with hypoxia and apoptosis concurrently, as a promising therapeutic strategy for aGVHD. It underscores the importance of considering MSC apoptosis in optimizing MSCs-based cellular therapy protocols for enhanced therapeutic efficacy in aGvHD.Graphical

Th17 and T Regulatory Cytokines in Serum, Lesional Skin, and Stimulated Peripheral Blood Mononuclear Cell Culture Supernatants from Type 1 Leprosy Reaction Patients

There are conflicting reports regarding the roles of T helper-17 (Th17) and T regulatory (Treg) cells in type 1 leprosy reactions (T1Rs). Also, literature on the correlation of immunological parameters with a validated scoring system and the effect of treatment on cytokines is lacking. Adult patients with untreated T1R and nonreactional spectrum–matched controls were included in the study for comparison of levels of Th17 and Treg pathway cytokines in serum, skin lesions (reactional), and peripheral blood mononuclear cells (PBMCs) culture supernatants. Venous blood samples were collected at baseline and after resolution of reaction (post treatment with nonsteroidal anti-inflammatory drugs [NSAIDs] or steroids) for serum cytokine estimation and PBMC stimulation assays, and lesional (reactional) skin biopsy for cytokine messenger RNA (mRNA) estimation. Thirty-two cases of T1R were recruited (23 patients completed follow-up). Serum levels of cytokines were not significantly different between cases and controls or between pre- and post-treatment samples. Tissue mRNA and Mycobacterium leprae (M. leprae) antigen–stimulated PBMC culture supernatant levels of Interleukin (IL)-17A, IL-17F, IL-6, and IL-23 were significantly higher in T1R than in controls. Levels of IL-10 and Transforming Growth Factor-beta (TGF-β) were comparable among the two groups. The levels of all cytokines were significantly reduced after treatment. There was no significant difference in magnitude of the fall between those treated with steroids versus NSAIDs. This study suggests heightened Th17 response in T1R, with a prominent inability of the regulatory cytokines IL-10 and TGF-β to control the associated inflammation. The dynamics of change after resolution of T1R were comparable between NSAID and oral steroid treatment groups.

Immunomodulatory effects of cysteamine and its potential use as a host-directed therapy for tuberculosis.

Cysteamine, a drug approved to treat cystinosis, has been proposed as a host-directed therapy for M. tuberculosis (Mtb) and SARS-CoV-2. The impact of cysteamine on the immune responses has not been fully investigated. We aimed to in vitro evaluate the immunomodulatory effects of cysteamine on peripheral blood mononuclear cells (PBMCs) using the purified protein derivative (PPD) as a recall antigen, and an unspecific stimulus as staphylococcal enterotoxin B (SEB). PBMCs isolated from subjects with tuberculosis infection (TBI), those with tuberculosis disease (TB), and healthy controls (HC) were in vitro stimulated with PPD or SEB and treated or not with cysteamine at different concentrations (50 µM-400 µM) for 6 hours (h) and 24 h. We evaluated the T helper1 (Th1) and T cytotoxic1 (Tc1) cell cytokine production by flow cytometry and immune-enzymatic assays. In HC, we also evaluated apoptosis and/or necrosis by flow cytometry. We observed an immunomodulatory effect of cysteamine at 400 µM in PBMCs from TB and TBI subjects. It significantly reduced PPD-specific Th1 responses at 24 h and at 6 h (p=0.0004 and p=0.0009, respectively), and a similar non-significant trend was observed with cysteamine at 200 µM (p=0.06 at 24 h and p=0.14 at 6 h). Moreover, cysteamine at both 400 µM (p<0.0001 and p=0.0187 at 24 h, respectively, and p<0.0001 at 6 h for both) and 200 µM (p=0.0119 and p=0.0028 at 24 h and p=0.0028 and p=0.0003 at 6 h, respectively) significantly reduced SEB-induced Th1 and Tc1 responses. Furthermore, we found that cysteamine induced morphological lymphocyte changes and significantly reduced the lymphocyte percentage in a dose- and time-dependent manner. Cysteamine at 400 µM induced 8% late apoptosis and 1.6% necrosis (p<0.05) at 24 h. In contrast, despite significant differences from untreated conditions (p<0.05), cysteamine at 400 µM for 6 h induced approximately 1% late apoptosis and 0.1% necrosis in the cells. High doses of cysteamine in vitro reduce the percentages of PPD- and SEB-induced Th1 and Tc1 cells and induce late apoptosis and necrosis. Differently, cysteamine at lower doses retains the immunomodulatory effect without affecting cell viability. These findings suggest cysteamine as a potential adjunct to antimicrobial regimens as in the TB or COVID-19 field, for its ability to reduce the inflammatory status.

Characterizing Non-T2 Asthma: Key Pathways and Molecular Implications Indicative of Attenuated Th2 Response.

Non-Type 2 (non-T2) asthma is characterized by a lack of allergic sensitization and normal to low total IgE levels. We aimed to explore molecular mechanisms and pathways differentiating non-T2 from T2-high pediatric asthma. We analyzed peripheral blood RNA samples from 11 non-T2 and 17 T2-high pediatric asthma patients using bulk RNA sequencing. Differentially expressed genes (DEGs) were identified, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, and Protein-Protein Interaction (PPI) network construction. Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) were employed to explore significance of these DEGs. We utilized independent public datasets GSE145505 to validate our findings. We investigated Th cytokine profiles in an independent cohort of pediatric patients with non-T2 asthma (n = 38) and T2-high asthma (n = 64). We demonstrated that the total serum IgE levels of children with non-T2 asthma (128.4 ± 159.5IU/mL) was significantly lower than that of those with T2-high asthma (405.8 ± 252.1IU/mL). Our analysis revealed 136 DEGs distinguishing non-T2 from T2-high asthma. IPA identified predicted inhibition of IgE-FcεRI signaling pathways in non-T2 asthma. Our DEG data showed the expression of IGHV4-39, IGLV1-40, IGLV1-47, IGLV1-44, IGHV1-69, IGLV6-57, IGLV3-19, IGLV3-1, and IGLC7 were downregulated in our non-T2 asthma patient. The non-T2 group exhibited significantly higher concentrations of IL-2, IFN-γ, IL-6, and IL-17A compared to the T2-high group. Our integrated analysis differentiated non-T2 from T2-high asthma by revealing downregulation of specific immunoglobulin genes influencing FcεRI signaling, elevated Th1 cytokines and Th17 cytokines might affect IgE associated sensitization and alter Th2 allergic response.

PI3 kinase delta governs regulatory T-cell biology and thus confers protection against atherosclerosis progression in mice

Abstract Introduction and Purpose Atherosclerosis is a chronic inflammatory disease of arteries, critically involving innate and adaptive immune cells like macrophages as well as T and B lymphocytes. Macrophages are major drivers of disease through the ingestion of lipoproteins, foam cell formation, and secretion of inflammatory mediators. Although macrophages outnumber other leukocytes in atherosclerotic plaques, T and B cells can shape the course of disease by promoting or mitigating inflammatory responses. The phosphoinositide 3-kinase delta (PI3Kd) exerts a key role in the regulation of immune responses including activation, proliferation, differentiation, and effector function of lymphocytes. Therefore, PI3Kd may represent a promising target for the modulation of inflammatory diseases. Consequently, we aimed to analyse the role of PI3Kd during atherogenesis. Methods and Results To investigate the role of haematopoietic PI3Kd in atherosclerosis, bone marrow from PI3Kd-/- or PI3Kd+/+ mice was transplanted into Ldlr-/- mice. After a 6-weeks-challenge by high fat diet, PI3Kd-/- recipient Ldlr-/- mice displayed profoundly impaired CD4+ and CD8+ T-cell numbers, CD4+ T-cell activation, CD4+ effector T-cell differentiation, and proatherogenic CD4+ T-helper (Th) 1 responses in para-aortic lymph nodes and spleen compared with PI3Kd+/+ transplanted controls. Surprisingly, the net effect of PI3Kd deficiency was a substantial increase of aortic inflammation and atherosclerosis in Ldlr-/- mice. Whereas plaque content and functions of macrophages including foam cell formation, efferocytosis, and cytokine secretion remained largely unaffected, haematopoietic PI3Kd ablation strongly reduced mature B cells and serum immunoglobulins in Ldlr-/- mice. Importantly, PI3Kd deficiency severely impaired numbers, proliferation, immunosuppressive functions, and stability of regulatory CD4+ T cells (Tregs). Consequently, adoptive transfer of PI3Kd+/+ Tregs fully restrained the atherosclerotic plaque burden in PI3Kd-/- transplanted Ldlr-/- mice without affecting B-cell numbers and serum immunoglobulins, whereas transferred PI3Kd-/- Tregs failed to relieve atherosclerosis progression. Conclusions Here, we demonstrate that PI3Kd plays a crucial role in Tregs, Th1 cells, and B cells during atherogenesis. Lack of PI3Kd signalling specifically in atheroprotective Treg responses outplays its impact on B-cell and proatherogenic Th1 responses, thus leading to aggravated atherosclerosis. Hence, PI3Kd is a key regulator of Treg biology and thereby protects against atherosclerosis, suggesting that fine-tuning PI3Kd signalling may represent a promising target for Treg-directed therapy.

A TLR7 Agonist Conjugated to a Nanofibrous Peptide Hydrogel as a Potent Vaccine Adjuvant.

Toll-like receptors (TLRs) recognize pathogen- and damage-associated molecular patterns and, in turn, trigger the release of cytokines and other immunostimulatory molecules. As a result, TLR agonists are increasingly being investigated as vaccine adjuvants. Many of these agonists are small molecules that quickly diffuse away from the vaccination site, limiting their co-localization with antigens and, thus, their effect. Here, the small-molecule TLR7 agonist 1V209 is conjugated to a positively-charged multidomain peptide (MDP) hydrogel, K2, which was previously shown to act as an adjuvant promoting humoral immunity. Mixing the 1V209-conjugated K2 50:50 with the unfunctionalized K2 produces hydrogels that retain the shear-thinning and self-healing physical properties of the original MDP while improving the solubility of 1V209 more than 200-fold compared to the unconjugated molecule. When co-delivered with ovalbumin as a model antigen, 1V209-functionalized K2 produces a robust Th2 immune response and an antigen-specific Th1 immune response superior to alum, a widely used vaccine adjuvant. Together, these results suggest that K2 MDP hydrogels functionalized with 1V209 are a promising adjuvant for vaccines against infectious diseases, especially those benefiting from a combined Th1 and Th2 immune response.

The Role of Aspergillus Antibody Detection in Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an allergic lung disorder characterized by an exaggerated immune response to fungal allergens, particularly from Aspergillus fumigatus. ABPA leads to excessive mucus production and impaired mucociliary clearance. When A. fumigatus conidia are inhaled, they germinate, release exoproteases and other substances that further impede mucociliary clearance, and activate the immune response. The immune response is known by an exaggerated Th2 response to Aspergillus antigens, leading to production of IgE antibodies, eosinophilic infiltration of the lungs, and the formation of immune complexes. These immune complexes can deposit in the lung tissue, leading to airway inflammation, bronchiectasis, and fibrosis. This disease mainly occurs in individuals diagnosed with bronchial asthma and cystic fibrosis. Increased levels of A. fumigatus total IgE and specific IgE, IgG, and IgA antibodies, play a role in diagnosing patients with ABPA.