Th1 Immunity Research Articles

Downregulation of IRF7-mediated type-I interferon response by LmCen–/– parasites is necessary for protective immunity

Leishmaniasis is a tropical disease caused by Leishmania parasites and currently has no licensed vaccines. We developed a dermotropic Leishmania major centrin gene-deleted strain (LmCen–/–) as a live attenuated vaccine. Recent studies have shown that type I interferons (IFNs) play important roles in immunity to parasitic and viral pathogens. However, their relevance in protective immunity following vaccination is not understood. We found that immunization with LmCen–/– induces a transient increase in type I IFN response along with its regulatory factor IRF7 that is downregulated 7–21 days post-immunization, coincided with the induction of a robust Th1 adaptive immune response. Challenge infection with virulent L. donovani parasites showed a significant reduction of splenic and hepatic parasite burden in IRF7–/– mice than wild type mice following immunization with LmCen–/–, suggesting that ablation of type I IFN response is a pre-requisite for the induction of LmCen–/– mediated Th1 immunity against L. donovani infection.

Environmental Low-Dose Radiation Activates Th1 Immunity through the Mitochondria-STING Pathway.

The presence of low-dose radiation (LDR) in the environment has become more prevalent. However, the effect of LDR exposure on the immune system remains elusive. Here, we interestingly found that LDR specifically elevated the percentage of CD4+IFNγ+ Th1 splenocytes, both in vitro and in vivo, without affecting the percentage of CD8+IFNγ+ Tc1 cells and regulatory T cells. A similar phenomenon was found in T cells from peripheral blood. Mechanistically, we found that LDR can induce mitochondrial damage, which stimulated the STING signaling pathway, leading to the enhanced expression of T-bet, the master transcriptional factor of Th1-cell differentiation. The specific STING signal inhibitor can abrogate the effect of LDR on Th1 differentiation, confirming the central role of the STING pathway. To further validate the immunoregulatory role of LDR, we exposed mice with whole body LDR and evaluated if LDR could protect mice against triple-negative breast cancer through enhanced antitumor immunity. As expected, LDR significantly delayed tumor development and promoted cell death. Meanwhile, LDR resulted in increased tumor-infiltrating Th1 cells, while the proportion of Tc1 and Treg cells remained unchanged. Furthermore, the infiltration of antitumor macrophages was also increased. In summary, we revealed that environmental LDR could specifically regulate Th1 T-cell activities, providing critical information for the potential application of LDR in both clinical and nonclinical settings.

Identification and expression analysis of Th2 immune-related gene IL4/13A in turbot (Scophthalmus maximus).

Th2 immunity is a primary host defense against extracellular pathogens, and different IL4/13 paralogues are involved in this immune response in fish. Here, we identified IL4/13A for further Th2 immune response providing information in turbot. The results showed that the full length of the IL4/13A gene is 1,333 bp, containing a 432-bp open reading frame (ORF) that encoded 144 amino acids. Phylogenetic analysis recently showed that turbot IL4/13A has a relationship with Dicentrarchus labrax. Moreover, syntenic analysis revealed similar neighboring genes associated with turbot IL4/13A, compared with other teleosts and mammals. In addition, IL4/13A was widely expressed in all examined tissues with the highest expression level in skin, followed by liver and gill. Finally, IL4/13A showed a general trend of upregulation in immune tissues following bacterial challenge. The significant quick induction of IL4/13A indicated its key roles to prevent pathogens. Characterizations of IL4/13A will probably contribute to understanding of Th2 immunity in fish.

Sodium oligomannate disrupts the adherence of Ribhigh bacteria to gut epithelia to block SAA-triggered Th1 inflammation in 5XFAD transgenic mice

Sodium oligomannate (GV-971), an oligosaccharide drug approved in China for treating mild-to-moderate Alzheimer’s disease (AD), was previously found to recondition the gut microbiota and limit altered peripheral Th1 immunity in AD transgenic mice. As a follow-up study, we here made advances by pinpointing a Lactobacillus murinus (L.m.) strain that highly expressed a gene encoding a putative adhesin containing Rib repeats (Ribhigh-L.m.) particularly enriched in 5XFAD transgenic mice. Mechanistically, Ribhigh-L.m. adherence to the gut epithelia upregulated fecal metabolites, among which lactate ranked as the top candidate. Excess lactate stimulated the epithelial production of serum amyloid A (SAA) in the gut via the GPR81-NFκB axis, contributing to peripheral Th1 activation. Moreover, GV-971 disrupted the adherence of Ribhigh-L.m. to gut epithelia via direct binding to Rib, which corrected the excess lactate, reduced SAA, and alleviated Th1-skewed inflammation. Together, we gained further insights into the molecular link between gut bacteria and AD progression and the mechanism of GV-971 in treating AD.

Preclinical evaluation of a universal inactivated influenza B vaccine based on the mosaic hemagglutinin-approach

We have developed a new universal influenza B vaccination strategy based on inactivated influenza B viruses displaying mosaic hemagglutinins (mHAs). Recombinant mHA viruses were constructed by replacing the four major antigenic sites of influenza B virus HAs, with those from exotic avian influenza A virus HAs. Sequential vaccination of naïve mice with mHA-based vaccines elicited higher immune responses towards the immuno-subdominant conserved epitopes of the HA than vaccination with wildtype viruses. Among the different preparations tested, mHA split vaccines were less immunogenic than their whole inactivated virus counterparts. This lower immunogenicity was overcome by the combination with adjuvants. mHA split vaccines adjuvanted with a Toll-like receptor-9 agonist (CpG 1018) increased Th1 immunity and in vivo cross-protection, whereas adjuvanting with an MF59-like oil-in-water nano-emulsion (AddaVax) enhanced and broadened humoral immune responses and antibody-mediated cross-protection. The mHA vaccines with or without adjuvant were subsequently evaluated in mice that were previously immunized to closely mimic human pre-existing immunity to influenza B viruses and the contribution of innate and cellular immunity was evaluated in this model. We believe these preclinical studies using the mHA strategy represent a major step toward the evaluation of a universal influenza B virus vaccine in clinical trials.

HSP90 Complex From OLP Lesion Induces T-Cell Polarization via Activation of Dendritic Cells.

To investigate the effects of the heat shock protein 90 (HSP90) complex from oral lichen planus (OLP) lesion tissues on dendritic cell (DC) activation and the polarization of naïve T cells. Expression of HSP90 in OLP lesions and healthy control (HC) mucosa was evaluated by single-cell RNA sequence, IHC, qRT-PCR, and immunoblotting. HSP90 complex was extracted by immunoprecipitation from oral mucosa as the agonist of DCs. Expression of IFN-α and MHC was detected by flow cytometry. After cocultured with pre-stimulated DCs, polarization of naïve T cells was investigated by cytokine analysis. HSP90 was significantly higher in the lamina propria of OLP lesion and closely related to lymphocyte infiltration. HSP90 complex of OLP lesion activated DCs via TLR9 and increased their IFN-α secretion and MHC II expression. Pre-stimulated DCs increased the proportion of Th17 cells. HSP90 complex isolated from OLP lesion activated TLR9/IFN-α of DCs and further promoted the polarization of naïve T cells toward Th17 immunity.

HMGB1/RAGE Signaling Regulates Th17/IL-17 and Its Role in Bronchial Epithelial-Mesenchymal Transformation.

Airway remodeling is one of the reasons for severe steroidresistant asthma related to HMGB1/RAGE signaling or Th17 immunity. Our study aims to investigate the relationship between the HMGB1/RAGE signaling and the Th17/IL-17 signaling in epithelial-mesenchymal transformation (EMT) of airway remodeling. CD4+ T lymphocytes were collected from C57 mice. CD4+ T cell and Th17 cell ratio was analyzed by flow cytometry. IL-17 level was detected by ELISA. The Ecadherin and α-SMA were analyzed by RT-qPCR and immunohistochemistry. The Ecadherin, α-SMA, and p-Smad3 expression were analyzed by western blot. The HMGB1/RAGE signaling promoted the differentiation and maturation of Th17 cells in a dose-dependent manner in vitro. The HMGB1/RAGE signaling also promoted the occurrence of bronchial EMT. The EMT of bronchial epithelial cells was promoted by Th17/IL-17 and the HMGB1 treatment in a synergic manner. Silencing of RAGE reduced the signaling transduction of HMGB1 and progression of bronchial EMT. HMGB1/RAGE signaling synergistically enhanced TGF-β1-induced bronchial EMT by promoting the differentiation of Th17 cells and the secretion of IL-17.

Card9 and MyD88 differentially regulate Th17 immunity to the commensal yeast Malassezia in the murine skin

The fungal community of the skin microbiome is dominated by a single genus, Malassezia. Besides its symbiotic lifestyle at the host interface, this commensal yeast has also been associated with diverse inflammatory skin diseases in humans and pet animals. Stable colonization is maintained by antifungal type 17 immunity. The mechanisms driving Th17 responses to Malassezia remain, however, unclear. Here, we show that the C-type lectin receptors Mincle, Dectin-1, and Dectin-2 recognize conserved patterns in the cell wall of Malassezia and induce dendritic cell activation in vitro, while only Dectin-2 is required for Th17 activation during experimental skin colonization in vivo. In contrast, Toll-like receptor recognition was redundant in this context. Instead, inflammatory IL-1 family cytokines signaling via MyD88 were also implicated in Th17 activation in a T cell-intrinsic manner. Taken together, we characterized the pathways contributing to protective immunity against the most abundant member of the skin mycobiome. This knowledge contributes to the understanding of barrier immunity and its regulation by commensals and is relevant considering how aberrant immune responses are associated with severe skin pathologies.

Type 1 diabetes and parasite infection: An exploratory study in NOD mice.

Microorganisms have long been suspected to influence the outcome of immune-related syndromes, particularly autoimmune diseases. Type 1 diabetes (T1D) results from the autoimmune destruction of the insulin-producing beta cells of pancreatic islets, causing high glycemia levels. Genetics is part of its aetiology, but environmental factors, particularly infectious microorganisms, also play a role. Bacteria, viruses, and parasites influence the outcome of T1D in mice and humans. We used nonobese diabetic (NOD) mice, which spontaneously develop T1D, to investigate the influence of a parasitic infection, leishmaniasis. Leishmania amazonensis is an intracellular eukaryotic parasite that replicates predominantly in macrophages and is responsible for cutaneous leishmaniasis. The implication of Th1 immune responses in T1D and leishmaniasis led us to study this parasite in the NOD mouse model. We previously constructed osteopontin knockout mice with a NOD genetic background and demonstrated that this protein plays a role in the T1D phenotype. In addition, osteopontin (OPN) has been found to play a role in the immune response to various infectious microorganisms and to be implicated in other autoimmune conditions, such as multiple sclerosis in humans and experimental autoimmune encephalomyelitis (EAE) in mice. We present herein data demonstrating the role of OPN in the response to Leishmania in NOD mice and the influence of this parasitic infection on T1D. This exploratory study aimed to investigate the environmental infectious component of the autoimmune response, including Th1 immunity, which is common to both T1D and leishmaniasis.

Association between vitamin D levels with IL-6 and IL-10 in umbilical cord blood of infants.

A worldwide issue, vitamin D deficiency affects pregnant mothers and babies everywhere, including Indonesia. It involves the adaptive immune system by controlling the production of pro-and anti-inflammatory cytokines and the balance between humoral (Th2) and cell-mediated (Th1) immunity. The aim of this study was to investigate the relationship between vitamin D and the cytokines IL-6 and IL-10 in infants. It also examined the relationship between ferritin and IL-6/IL-10 in newborns. The study collected 114 umbilical cord blood samples from term-born mothers without clinical symptoms. IL-6 and IL-10 were among the cytokine profiles measured by the enzyme-linked immunosorbent assay (ELISA). SPSS was used for statistical analysis, and an in -silico investigation was carried out to examine the molecular relationships between vitamin D and IL-6/IL-10. Using the 20 ng/mL as the cut-off for vitamin D insufficiency suggested the insignificant association of vitamin D with IL-6 (p=0.42), IL-10 (p=0.76), and ferritin (p=0.47). When the umbilical cord vitamin D level was categorized into four quartiles, the association with the highest statistical significance (quartile 4 versus quartile was observed for IL-6 (p<0.001), IL-10 (p<0.001), and ferritin (p<0.001). However, the linear regression did not suggest the significant correlations of vitamin D with IL-6 (p=0.40) and IL-10 (p=0.45). A significant correlation based on the linear regression was found between ferritin and IL-10 (p=0.03). Molecular docking studies demonstrated binding affinities of -8.04 kcal/mol for IL-6-vitamin D and -8.53 kcal/mol for IL-10 -vitamin D complexes, with stable root mean square deviation throughout the simulations. This study contributes valuable insights into the clinical and computational analysis of the relationship of vitamin D with IL-6 or IL-10.

Immunogenic Consideration of a Designed Polypeptide Against Brucellosis Compared to RB51: An In Vivo Study.

Brucellosis in livestock and its transmission to humans through the consumption of contaminated dairy products is an important issue. The introduction of new approaches using immunogenic proteins against and diagnosing brucellosis is a serious issue in human health. Brucella abortus contains five proteins including: MOXR family ATPase-α2, T9SS C-terminal target domain-containing protein, Cobyric acid synthase, Hypothetical protein, and VirB11 type IV Secretion protein, which were considered and the designed recombinant polypeptide was produced and evaluated. The pure recombinant protein ABOR with 549aa in combination with chitin as an adjuvant was injected subcutaneously into guinea pigs to evaluate their immunity responses. The results indicated that the ABOR recombinant protein induced Th1 immunity with high levels of specific IgG (IgG2a) as well as Interferon-γ (IFN-γ), Interleukin-2 (IL-2), IL-12, and Tumor Necrosis Factor-alpha (TNF-α), compared to the control group. Th1/Th2 ratio analysis demonstrated the efficacy of ABOR protein combined with chitin in stimulating cellular immunity in the animals. Designed recombinant polypeptide combined with chitin showed ability for induction of cellular and humoral immunity an guinea pigs compared to RB51 vaccine.

Effect of Polysaccharides Isolated from Saussurea salicifolia (L.) DC on Th2-Dependent Immune Response.

The effect of polysaccharides isolated from the aboveground parts of Saussurea salicifolia (L.) DC on Th2 type immune response reactions was studied. Administration of water-soluble polysaccharides presented by arabino-galacturonans (weight average molecular weight 158.49 kDa) to mice against the background of experimental Th2 immunity reduced the severity of anaphylactic and local immediate type hypersensitivity reactions. It also suppressed the production of ovalbumin-specific IgE and IgG1 and increased the stability of mast cell membranes. The studied polysaccharide complex increased IFNγ secretion and inhibited IL-4 synthesis. These findings suggest that these polysaccharides may be considered as potential anti-allergic agents that suppress the development of allergy in its early stages.

Hypertonic Saline Induces Host Protective Immune Responses against Brucella abortus Infection in Mice.

Hypertonic saline (HTS) resuscitation can enhance immune responses against various pathogens, however, the effect of HTS on brucellosis is yet to be defined. In this study, we found that HTS inhibited Brucella infection in mice by augmenting Th1 immunity. HTS treatment enhanced the serum cytokines production and the expression of nitric oxide synthase (NOS2) and nuclear factor kappa B (NF-ĸB) p50 and p65, crucial anti-Brucella effectors in splenocytes. In addition, HTS treatment also inhibited the phosphorylation of MAPK signaling, accompanied by the down-regulation of the autophagy marker LC3B-II. Due to directing an appropriate immune response, HTS treatment substantially decreased bacterial burden in spleen and liver tissues. In summary, corroborating previous studies showing the antimicrobial effects of HTS, our findings indicate that HTS treatment triggers a protective immune response against Brucella infection. Additionally, these results provide promising evidence of the immunomodulatory role of HTS in controlling bacterial infections.

Epigenetic control of commensal induced Th2 Responses and Intestinal immunopathology.

Regulation of cell autonomous IL-4 in T cells is critical to prevent dysregulated Th2 immunity to commensals and predisposition to allergy.

Variants in the Late Cornified Envelope Gene Locus Are Associated With Elevated T-helper 17 Responses in Patients With Postinfectious Lyme Arthritis.

Postinfectious Lyme arthritis (LA) is associated with dysregulated immunity and autoreactive T- and B-cell responses in joints. Here we explored the role of host genetic variation in this outcome. The frequency of 253 702 single-nucleotide polymorphisms (SNPs) was determined in 147 patients with LA (87 with postinfectious LA and 60 with antibiotic-responsive LA), and for comparison in 90 patients with erythema migrans or the general population (n = 2504). Functional outcome of candidate SNPs was assessed by evaluating their impact on clinical outcome and on immune responses in blood and synovial fluid in patients with LA. Six SNPs associated with late cornified envelope (LCE3) genes were present at greater frequency in patients with postinfectious LA compared to those with antibiotic-responsive LA (70% vs 30%; odds ratio, 2; P < .01). These SNPs were associated with heightened levels of inflammatory Th17 cytokines in serum but lower levels of interleukin 27, a regulatory cytokine, implying that they may contribute to dysregulated Th17 immunity in blood. Moreover, in patients with postinfectious LA, the levels of these Th17 mediators correlated directly with autoantibody responses in synovial fluid, providing a possible link between LCE3 SNPs, maladaptive systemic Th17 immunity, and autoreactive responses in joints. Variation in the LCE3 locus, a known genetic risk factor in psoriasis and psoriatic arthritis, is associated with dysregulated systemic Th17 immunity and heightened autoantibody responses in joints. These findings underscore the importance of host genetic predisposition and systemic Th17 immunity in the pathogenesis of postinfectious (antibiotic-refractory) Lyme arthritis.

Types of cell death and their relations to host immunological pathways.

Various immune pathways have been identified in the host, including TH1, TH2, TH3, TH9, TH17, TH22, TH1-like, and THαβ immune reactions. While TH2 and TH9 responses primarily target multicellular parasites, host immune pathways directed against viruses, intracellular microorganisms (such as bacteria, protozoa, and fungi), and extracellular microorganisms can employ programmed cell death mechanisms to initiate immune responses or execute effective strategies for pathogen elimination. The types of programmed cell death involved include apoptosis, autophagy, pyroptosis, ferroptosis, necroptosis, and NETosis. Specifically, apoptosis is associated with host anti-virus eradicable THαβ immunity, autophagy with host anti-virus tolerable TH3 immunity, pyroptosis with host anti-intracellular microorganism eradicable TH1 immunity, ferroptosis with host anti-intracellular microorganism tolerable TH1-like immunity, necroptosis with host anti-extracellular microorganism eradicable TH22 immunity, and NETosis with host anti-extracellular microorganism tolerable TH17 immunity.

Spatial transcriptomics reveals organized and distinct immune activation in cutaneous granulomatous disorders

BackgroundNon-infectious (inflammatory) cutaneous granulomatous disorders include cutaneous sarcoidosis (CS), granuloma annulare (GA), necrobiosis lipoidica (NL), and necrobiotic xanthogranuloma (NXG). These disorders share macrophage predominant inflammation histologically, but the inflammatory architecture and the pattern of extracellular matrix alteration varies. The underlying molecular explanations for these differences remain unclear. ObjectiveTo understand spatial gene expression characteristics in these disorders. MethodsWe performed spatial transcriptomics in cases of CS, GA, NL, and NXG to compare patterns of immune activation and other molecular features in a spatially resolved fashion. ResultsCS is characterized by a polarized, spatially organized T helper (Th) 1 predominant response with classical macrophage activation. GA is characterized by a mixed, but spatially organized pattern of Th1 and Th2 polarization with both classical and alternative macrophage activation. NL showed concomitant activation of Th1, Th2, and Th17 immunity with a mixed pattern of macrophage activation. Activation of type 1 immunity was shared among, CS, GA, and NL and included upregulation of IL-32. NXG showed upregulation of CXCR4-CXCL12/14 chemokine signaling and exaggerated alternative macrophage polarization. Histologic alteration of extracellular matrix correlated with hypoxia and glycolysis programs and type 2 immune activation. ConclusionsInflammatory cutaneous granulomatous disorders show distinct and spatially organized immune activation that correlate with hallmark histologic changes.

NKT cells promote Th1 immune bias to dengue virus that governs long-term protective antibody dynamics.

NKT cells are innate-like T cells, recruited to the skin during viral infection, yet their contributions to long-term immune memory to viruses are unclear. We identified granzyme K, a product made by cytotoxic cells including NKT cells, as linked to induction of Th1-associated antibodies during primary dengue virus (DENV) infection in humans. We examined the role of NKT cells in vivo using DENV-infected mice lacking CD1d-dependent (CD1ddep) NKT cells. In CD1d-KO mice, Th1-polarized immunity and infection resolution were impaired, which was dependent on intrinsic NKT cell production of IFN-γ, since it was restored by adoptive transfer of WT but not IFN-γ-KO NKT cells. Furthermore, NKT cell deficiency triggered immune bias, resulting in higher levels of Th2-associated IgG1 than Th1-associated IgG2a, which failed to protect against a homologous DENV rechallenge and promoted antibody-dependent enhanced disease during secondary heterologous infections. Similarly, Th2 immunity, typified by a higher IgG4/IgG3 ratio, was associated with worsened human disease severity during secondary infections. Thus, CD1ddep NKT cells establish Th1 polarity during the early innate response to DENV, which promotes infection resolution, memory formation, and long-term protection from secondary homologous and heterologous infections in mice, with consistent associations observed in humans. These observations illustrate how early innate immune responses during primary infections can influence secondary infection outcomes.

Card9 and MyD88 differentially regulate Th17 immunity to the commensal yeast Malassezia in the murine skin.

The fungal community of the skin microbiome is dominated by a single genus, Malassezia. Besides its symbiotic lifestyle at the host interface, this commensal yeast has also been associated with diverse inflammatory skin diseases in humans and pet animals. Stable colonization is maintained by antifungal type 17 immunity. The mechanisms driving Th17 responses to Malassezia remain, however, unclear. Here, we show that the C-type lectin receptors Mincle, Dectin-1, and Dectin-2 recognize conserved patterns in the cell wall of Malassezia and induce dendritic cell activation in vitro, while only Dectin-2 is required for Th17 activation during experimental skin colonization in vivo. In contrast, Toll-like receptor recognition was redundant in this context. Instead, inflammatory IL-1 family cytokines signaling via MyD88 were also implicated in Th17 activation in a T cell-intrinsic manner. Taken together, we characterized the pathways contributing to protective immunity against the most abundant member of the skin mycobiome. This knowledge contributes to the understanding of barrier immunity and its regulation by commensals and is relevant considering how aberrant immune responses are associated with severe skin pathologies.

Escherichia coli LTB26 mutant enhances immune responses to rotavirus antigen VP8 in a mouse model

Adjuvant is a major supplementary component of vaccines to boost adaptive immune responses. To select an efficient adjuvant from the heat-labile toxin B subunit (LTB) of E. coli, four LTB mutants (numbered LTB26, LTB34, LTB57, and LTB85) were generated by multi-amino acid random replacement. Mice have been intranasally vaccinated with human rotavirus VP8 admixed. Among the four mutants, enzyme-linked immunosorbent assay (ELISA) revealed that LTB26 had enhanced mucosal immune adjuvanticity compared to LTB, showing significantly enhanced immune responses in both serum IgG and mucosal sIgA levels. The 3D modeling analysis suggested that the enhanced immune adjuvanticity of LTB26 might be due to the change of the first LTB α-helix to a β-sheet. The molecular mechanism was studied using transcriptomic and flow cytometric (FCM) analysis. The transcriptomic data demonstrated that LTB26 enhanced immune response by enhancing B cell receptor (BCR) and major histocompatibility complex (MHC) II+-related pathways. Furthermore, LTB26 promoted Th1 and Th2-type immune responses which were confirmed by detecting IFN-γ and IL-4 expression levels. Immunohistochemical analysis demonstrated that LTB26 enhanced both Th1 and Th2 type immunity. Therefore, LTB26 was a potent mucosal immune adjuvant meeting the requirement for use in human clinics in the future.