Cell-mediated Research Articles

Differential Immune Responses of Th1 Stimulatory Chimeric Antigens of Leishmania donovani in BALB/c Mice.

Visceral leishmaniasis (VL) is the third most severe infectious parasitic disease and is caused by the protozoan parasite Leishmania. To control the spread of the disease in endemic areas where the asymptomatic patients act as reservoirs as well as in nonendemic areas, an effective vaccine is indispensable. In this direction, we have developed three chimeric proteins by the combination of three already known Th1 stimulatory leishmanial antigens, i.e., enolase, aldolase, and triose phosphate isomerase (TPI). The newly developed chimeric proteins, i.e., enolase-aldolase, TPI-enolase, and aldolase-TPI along with BCG as an adjuvant were assessed and compared, examining humoral and cellular adaptive immune responses elicited in BALB/c mice. The three chimeric antigens exhibited differential immune responses shown by differences in Th1 and Th2 cytokine production in ex vivo stimulated splenocytes of immunized mice. It was observed that all three chimeric proteins are more immunogenic than their component proteins. However, while comparing the immune response of the three chimeric proteins, aldolase-TPI exhibited a better immunogenic (Th1-type) response, as evidenced by the highest IFN-γ production, a high IgG2a antibody isotype switching, a high % population of CD8+ and CD4+ T-cells, and a significantly high expression of iNOS2. Thus, the results suggest the potential of these chimeric antigens as strong immunogens that can be harnessed in vaccine development against VL.

Neutrophils in nasal polyps exhibit transcriptional adaptation and proinflammatory roles that depend on local polyp milieu.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory upper airway disease, divided into eosinophilic CRSwNP (eCRSwNP) and noneosinophilic CRSwNP (neCRSwNP) according to eosinophilic levels. Neutrophils are major effector cells in CRSwNP, but their roles in different inflammatory environments remain largely unclear. We performed an integrated transcriptome analysis of polyp-infiltrating neutrophils from patients with CRSwNP, using healthy donor blood as a control. Additional experiments, including flow cytometry and in vitro epithelial cell and fibroblast culture, were performed to evaluate the phenotypic feature and functional role of neutrophils in CRSwNP. Single-cell RNA-sequencing analysis demonstrated that neutrophils could be classified into 5 functional subsets, with GBP5+ neutrophils occurring mainly in neCRSwNP and a high proportion of CXCL8+ neutrophils in both subendotypes. GBP5+ neutrophils exhibited significant IFN-I pathway activity in neCRSwNP. CXCL8+ neutrophils displayed increased neutrophil activation scores and mainly secreted oncostatin M (OSM), which facilitates communication with other cells. In vitro experiments showed that OSM enhanced IL-13- or IL-17-mediated immune responses in nasal epithelial cells and fibroblasts. Our findings indicate that neutrophils display transcriptional plasticity and activation when exposed to polyp tissue, contributing to CRSwNP pathogenesis by releasing OSM, which interacts with epithelial cells and fibroblasts depending on the inflammatory environment.

Botulinum toxin A dampened inflammatory response in BV-2 microglial cells

Our previous studies have demonstrated the analgesic effects of botulinum toxin type A (BoNT/A) in a pre-clinical model of rheumatoid arthritis of the temporomandibular joint, where we proposed that BoNT/A decreases the neurogenic milieu after reaching the subnucleus caudalis. However, it is unknown whether BoNT/A directly regulates microglial cell activity. Therefore, the present study investigates the effects of BoNT/A on a microglial murine cell lineage (BV-2) in different inflammatory conditions. Cellular viability and proliferation were carried out with different concentrations of BoNT/A (ranging from 0.3125 to 20 U/mL) for 24 h. Cells were primed with carrageenan (300 μg/mL) or Lipopolysaccharides (LPS) (20 ng/mL). The gene expression of IL-1β, IL-6, IL-18, TNF-α, Ikkβ, p65, Iba1 were quantified using PCR-RT. The supernatant was used to determine IL-1β, IL-6, and TNF-α levels. For all data, the significance level was set at 5%. Overall, data analysis revealed that BoNT/A 1.25 U/mL exhibited the greatest effect cell viability and proliferation. In addition, genes associated with inflammatory response in both stimuli (carrageenan and LPS) were downregulated in the presence of BoNT/A. Lastly, BoNT/A mitigates the protein levels of IL-1β and TNF-α in a time and dose-dependent manner. In conclusion, our results revealed that BoNT/A directly modulates the microglial cells' activities in an inflammatory context, opening new perspectives for using BoNT/A, considering its potential immunomodulatory effect.

(Invited) Electrode Blending Simulations Using the Mechanistic Degradation Modes Modeling Approach

Blended electrodes are becoming increasingly more popular in lithium-ion batteries, yet most modeling approaches are still lacking the ability to separate the blend components. This is problematic because the different components are not likely to degrade at the same pace. In this work, we investigated a new approach towards the simulation of blended electrodes by replicating the complex current distributions within the electrodes using a paralleling model rather than the traditional constant current method. We first investigated the impact of using a paralleling model within the mechanistic degradation modes modeling approach to replicate the current distribution more accurately within blended electrodes. Using three exemplary chemistries with electrochemical response that covers all the possible scenarios (separated, overlapping, or only partially overlapping), we demonstrated that, although the paralleling approach enhances accuracy and better replicates experimentally observed current distributions, the actual effect on the voltage response of the full cell, whether pristine or aged, was close to negligible at low rates while the computational cost was increased by two orders of magnitude and resulted in noisier results. While it might be better to use the paralleling model for simulation at higher rates or when the loss of active material on the PE is significant, the computational limitations could hinder the application of the paralleling approach in scenarios where simulation speed is crucial because of the two order of magnitude increase. Recognizing that the constant current approach is accurate enough to provide data representative of the behavior of the individual components within a blend, we generated three publicly available synthetic datasets covering more than 260,000 different degradations to enable the development of new diagnosis techniques for blended electrodes. Such techniques must enable component specific diagnosis since we showcased a significant impact of the composition of the loss of active material on the positive electrode on the cell electrochemical response. Because these variations could be confused with the one induced by other degradation modes, overlooking them could lead to false diagnosis, potentially compromising the safety of deployed systems.

Spatial dissection of tumour microenvironments in gastric cancers reveals the immunosuppressive crosstalk between CCL2+ fibroblasts and STAT3-activated macrophages

BackgroundA spatially resolved, niche-level analysis of tumour microenvironments (TME) can provide insights into cellular interactions and their functional impacts in gastric cancers (GC).ObjectiveOur goal was to translate the spatial organisation...

In vitro cyto- and geno-toxicity of asbestiform erionite from New Zealand

This work is an in vitro toxicity study of two asbestiform erionites from Kaipara and Gawler Downs in New Zealand. This study is the first, to the knowledge of the authors, to investigate the mechanisms that trigger adverse effects leading to carcinogenicity from New Zealand erionites. The effects induced by the erionite fibres from New Zealand were compared with those produced by positive (crocidolite) and negative (wollastonite) standards, and other erionite fibres described in the literature. The cytotoxicity/genotoxicity/inflammatory potential was determined by: (i) analysis of the cytotoxic potential by MTT tests on human cell lines mimicking primary cells making direct contact with fibres in the lungs, combined with apoptosis tests and cell membrane damage by fluorescence microscopy analyses; (ii) analysis of the genotoxic potential by quantification of DNA damage measuring double strand break foci by γ-H2AX nuclear staining in confocal microscopy analyses; (iii) analyses of the acute (24–72h) and early-chronic (7d) inflammatory effect by gene expression analyses of several cytokines, as well as of fibrotic and Epithelial to Mesenchymal transition (EMT) markers. The intensity of cell responses to these erionites are comparable to that of standard carcinogenic crocidolite, indicating that the two erionite fibres exhibit a significant acute toxic potential, with a particular alarming effect from the Gawler Downs sample from South Island. Our results confirm that the investigated erionites from New Zealand may represent an environmental hazard. However, further investigation is required to determine potential environmental exposure pathways by which erionite may become airborne and assess any environmental risks that may arise.

Vitamin D promotes autophagy to inhibit LPS-induced lung injury via targeting cathepsin D.

Pneumonia is a frequent-occurring event in children death. Vitamin D (VD) can alleviate inflammatory response and it might be a promising adjunct to antibiotics for the treatment of acute childhood pneumonia. This study intended to uncover the relevant mechanism of VD in pneumonia. For simulating inflammatory condition, BEAS-2B cells were induced using lipopolysaccharide (LPS). Cell viability was detected using cell counting kit-8 (CCK-8) method, and cell apoptosis was detected using flow cytometry and western blot. Inflammatory cytokines as well as oxidative stress markers were detected using enzyme-linked immunosorbent assay (ELISA) and corresponding assays. Western blot evaluated the contents of cathepsin D (CTSD), apoptosis- and autophagy-related proteins. Through real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) and western blot, the transfection efficiency of overexpression (OV)-CTSD was detected. Immunofluorescence assay detected light chain 3 (LC3II) level. Through SuperPred database analysis, VD can target CTSD. VD was revealed to suppress viability damage, inflammatory response, oxidative stress, and autophagy injury in BEAS-2B cells induced by LPS via targeting CTSD. However, the protective effects exhibited by VD against LPS-induced viability damage, inflammatory response, and oxidative stress in BEAS-2B cells were all counteracted by autophagy inhibitor 3-methyladenine (3-MA). Collectively,VD alleviated the severity of LPS-induced lung injury by promoting autophagy through targeting CTSD.

AAV-mediated co-expression of an immunogenic transgene plus PD-L1 enables sustained expression through immunological evasion

Adeno-associated virus (AAV) vectors can mediate long-term expression of immunogenic transgenes in vivo through transduction of tolerogenic cells in the liver. Tissue-targeted AAV vectors allow transduction of non-hepatic cells, but this necessitates development of strategies to minimize transgene immunogenicity. Here, we first validated that AAV capsids with tissue-specific tropism and transgene promoters enabled expression of the immunogenic protein, firefly luciferase, in liver, muscle, or adipose tissue. Cellular immunity was detectable in animals where luciferase was expressed in muscle or adipose, but not liver tissue. With the objective of enhancing tolerance of transduced non-hepatic cells, AAV vectors were engineered to co-express luciferase plus the immune checkpoint protein, PD-L1. In animals where transduced cells expressed luciferase but not PD-L1, there was incremental depletion of transduced cells over time. By contrast, the bioluminescent signal increased incrementally over the study, and was significantly greater, in the muscle and adipose tissue of animals where PD-L1 was co-expressed with luciferase. Our data demonstrate that PD-L1 co-expression facilitates persistent, tissue-targeted expression of immunogenic transgenes without transducing tolerogenic hepatic cells. Our strategy of PD-L1 co-expression may provide a versatile platform for sustained expression of immunogenic transgenes in gene and cell therapies.

Modulation of B cell receptor activation by antibody competition.

During repeated virus exposure, pre-existing antibodies can mask viral epitopes by competing with B cell receptors for antigen. Although this phenomenon has the potential to steer B cell responses away from conserved epitopes, the factors that influence epitope masking by competing antibodies remain unclear. Using engineered, influenza-reactive B cells, we investigate how antibodies influence the accessibility of epitopes on the viral surface. We find that membrane-proximal epitopes on influenza hemagglutinin are fundamentally at a disadvantage for B cell recognition because they can be blocked by both directly and indirectly competing antibodies. While many influenza-specific antibodies can inhibit B cell activation, the potency of masking depends on proximity of the targeted epitopes as well as antibody affinity, kinetics, and valency. Although most antibodies are inhibitory, we identify one that can enhance accessibility of hidden viral epitopes. Together, these findings establish rules for epitope masking that could help advance immunogen design.

Pre-clinical development of a tolerogenic peptide from glutamate decarboxylase as a candidate for antigen-specific immunotherapy in type 1 diabetes.

Dysregulation and loss of immune tolerance towards pancreatic β-cell autoantigens are features of type 1 diabetes (T1D). Until recently, life-long insulin injection was the only approved treatment for T1D, and this does not address the underlying disease pathology. Antigen-specific immunotherapy (ASI) seeks to restore tolerance and holds potential as a new therapeutic strategy for treating autoimmune diseases with well characterised antigens. Peptide ASI using processing independent CD4+ T-cell epitopes (PIPs) shows promising results in several autoimmune diseases. Here we successfully applied the principles of PIP design to the T1D autoantigen glutamate decarboxylase 65 (GAD65). Peptides spanning GAD65 predicted to be pan-HLA-DR binding were selected. Peptide P10 displayed enriched responses in peripheral blood mononuclear cells from people with T1D. The minimal epitope of the P10 peptide was fine mapped using T-cell hybridomas generated from HLA-DRB1*04:01 transgenic mice. This minimal epitope, P10Sol, was demonstrated to induce tolerance to the parent peptide in HLA-DRB1*04:01 transgenic mice using a novel activation-induced marker assay. Finally, we show that GAD65 P10Sol PIP is recognised by CD4+ T-cells from people with T1D who possess a range of HLA-DR alleles and can, therefore, be defined as a pan-DR binding peptide with therapeutic potential.

Middle Ear microRNAs Drive Mucin Gene Response.

To investigate the role of microRNA-378 (miR-378) in the regulation of mucin gene expression and inflammatory response in human middle ear epithelial cells (HMEEC) during bacterial infection by non-typeable Haemophilus influenzae (NTHi). Human middle ear epithelial cells (HMEEC) were cultured and transfected with miR-378 or control miRNA. Post-transfection, cells were exposed to NTHi lysates. mRNA levels of MUC5B, MUC5AC, and IL-8 were quantified using RT-qPCR, and promoter activity was measured via luciferase assays. The effects of miR-378 on mucin and cytokine gene expression were analyzed. Transfection with miR-378 significantly increased the expression of MUC5B (3.6 fold, p < 0.01), MUC5AC (19.1 fold, p < 0.01), and IL-8 (2.01 fold, p < 0.05) in HMEEC. NTHi exposure reduced MUC5B (1.385 fold, p < 0.05) and MUC5AC (1.61 fold, p < 0.05) gene expression in miR-378 transfected cells but significantly increased IL-8 levels (1.32 fold, p < 0.05). Luciferase assays showed that miR-378 upregulated the promoter activity of MUC5B (1.4 fold, p < 0.01) and MUC5AC (1.6 fold, p < 0.01) genes, indicating its role in transcriptional regulation. miR-378 plays a crucial role in promoting mucin overproduction and an inflammatory response in the middle ear epithelium during OM. Targeting miR-378 could offer a novel therapeutic strategy for preventing the progression from AOM to COM. na Laryngoscope, 2024.

γδ T Cell-mediated Tumor Immunity is Tightly Regulated by STING and TGF-β Signaling Pathways.

The STING pathway plays a critical role in tumor immunosurveillance. However, the precise mechanisms by which STING regulates gammadelta(γδ) T cell function during tumor progression remain unclear. Herein, we find that tumor-derived cyclic GMP-AMP (cGAMP) activates a distinct STING pathway by inducing TBK1-mediated phosphorylation of Eomes in γδ T cells during the early stage of tumor development is demonstrated. This activation leads to interferon-gamma (IFN-γ) production and consequent tumor surveillance. However, at advanced stages of tumor progression, the accumulation of immune-suppressive cytokine transforming growth factor-beta (TGF-β) downregulates STING levels, compromising the function of γδ T cells. Notably, the synergism between TGF-β inhibition and STING agonists effectively counteracts the immunosuppressive tumor microenvironment, thereby augmenting the antitumoral effects of γδ T cells. These findings present a novel mechanism involving STING-mediated IFN-γ production in γδ T cells and hold significant implications for the development of potent immunotherapeutic approaches against cancer.

PD-1 and CD73 on naive CD4+ T cells synergistically limit responses to self.

Vaccination with self- and foreign peptides induces weak and strong expansion of antigen-specific CD4+ T cells, respectively, but the mechanism is not known. In the present study, we used computational analysis of the entire mouse major histocompatibility complex class II peptidome to test how much of the naive CD4+ T cell repertoire specific for self-antigens was shaped by negative selection in the thymus and found that negative selection only partially explained the difference between responses to self and foreign. In naive uninfected and unimmunized mice, we identified higher expression of programmed cell death protein 1 (PD-1) and CD73 mRNA and protein on self-specific CD4+ T cells compared with foreign-specific CD4+ T cells. Pharmacological or genetic blockade of PD-1 and CD73 significantly increased the vaccine-induced expansion of self-specific CD4+ T cells and their transcriptomes were similar to those of foreign-specific CD4+ T cells. We concluded that PD-1 and CD73 synergistically limited CD4+ T cell responses to self. These observations have implications for the development of tolerogenic vaccines and cancer immunotherapy.

Expression of a single inhibitory member of the Ly49 receptor family is sufficient to license NK cells for effector functions.

Natural killer (NK) cells recognize target cells through germline-encoded activation and inhibitory receptors enabling effective immunity against viruses and cancer. The Ly49 receptor family in the mouse and killer immunoglobin-like receptor family in humans play a central role in NK cell immunity through recognition of MHC class I and related molecules. Functionally, these receptor families are involved in licensing and rejection of MHC-I-deficient cells through missing-self. The Ly49 family is highly polymorphic, making it challenging to detail the contributions of individual Ly49 receptors to NK cell function. Herein, we showed mice lacking expression of all Ly49s were unable to reject missing-self target cells in vivo , were defective in NK cell licensing, and displayed lower KLRG1 on the surface of NK cells. Expression of Ly49A alone on a H-2D d background restored missing-self target cell rejection, NK cell licensing, and NK cell KLRG1 expression. Thus, a single inhibitory Ly49 receptor is sufficient to license NK cells and mediate missing-self in vivo .

An LSTM network-based model with attention techniques for predicting linear T-cell epitopes of the hepatitis C virus

Hepatitis C virus (HCV) infection remains a significant global health challenge, often resulting in severe long-term physical complexity and even death. Since its discovery, HCV has exhibited substantial genetic variability, complicating vaccine development. Although some therapeutic approach have shown efficacy against certain HCV genotypes, a universally effective vaccine is still lacking. Recent research suggests that the body's cellular immune response, particularly T cell epitopes of HCV (TCE-HCVs), plays a vital role in fighting the virus. Therefore, the precise and rapid identification of TCE-HCVs is essential for chronic HCV infection. In this work, we proposed a novel TCE-HCVs prediction model AttLSTM, which combines attention mechanism and long short-term memory (LSTM). Specifically, we employed four robust feature encoding techniques: One-Hot Encoding, Global Vectors (GloVe), fastText, and Word2Vec to encode protein sequences. Additionally, k-mer embedding was utilized to help the model identify significant subsequence fragments within the protein sequences. To optimize the model's performance, irrelevant features are eliminated using the SHapley Additive exPlanations (SHAP) approach. The resulting optimal feature subset was then fed into the AttLSTM model to identify TCE-HCVs. The attention mechanism in this model dynamically captures the pairwise correlations of each neighboring target pair within a sliding window, thereby enhancing the understanding of the local environment of target residues. Extensive experiments showed that AttLSTM outperformed conventional machine learning (ML) classifiers in predictive performance. Notably, in k-fold cross-validation, AttLSTM achieved superior performance compared to existing methods with accuracy of 80.77 %, MCC of 0.632, and AUC of 0.891. This exceptional performance indicates that AttLSTM has a strong predictive capability for identifying TCE-HCVs. We anticipate that AttLSTM will expedite the rapid identification of promising TCE-HCVs, aiding in the development of diagnostic and immunotherapeutic treatments for HCV in the future. In addition, we have developed a web server for real-time prediction using our proposed model, which is available at http://attlstmhcv.xyz/.

Development and characterization of high-efficiency cell-adapted live attenuated vaccine candidate against African swine fever

African swine fever (ASF), a contagious and lethal haemorrhagic disease of domestic pigs and wild boars, poses a significant threat to the global pig industry. Although experimental vaccine candidates derived from naturally attenuated, genetically engineered, or cell culture-adapted ASF virus have been tested, no commercial vaccine is accepted globally. We developed a safe and effective cell-adapted live attenuated vaccine candidate (ASFV-MEC-01) by serial passage of a field isolate in CA-CAS-01-A cells. ASFV-MEC-01, isolated via repeated plaque purification using next-generation sequencing analysis, was obtained at passage 18 and showed significant attenuation in 4- and 6-week-old pigs. ASFV-MEC-01 conferred 100% protection against challenge with lethal parental ASFV, which correlated with high ASFV-specific humoral and cellular immune responses. Additionally, ASFV-MEC-01 was not detected in blood until 28 days post-inoculation. Global transcriptome analysis showed that ASFV-MEC-01 lacking 12 genes triggered stronger innate antiviral responses than the parental virus, as exemplified by high levels of mRNA encoding interferon regulatory and inflammatory genes in PAM cells. Ectopic expression of most deleted genes increased replication of DNA viruses by suppressing production of interferons and pro-inflammatory cytokines. Among the genes deleted from ASFV-MEC-01, MGF100-1R interacted specifically with the scaffold dimerization domain of TBK1, thereby preventing TBK1 dimerization and impairing TBK1-mediated type I IFN and NF-κB signaling. These results suggest that attenuation of ASFV-MEC-01 may be mediated by induction of stronger type I IFN and NF-κB signaling within the host innate immune system. Thus, ASFV-MEC-01 could be a safe and effective live attenuated ASFV vaccine candidate with commercial potential.

Preclinical characterization of the Omicron XBB.1.5-adapted BNT162b2 COVID-19 vaccine

As SARS-CoV-2 evolves, increasing in potential for greater transmissibility and immune escape, updated vaccines are needed to boost adaptive immunity to protect against COVID-19 caused by circulating strains. Here, we report features of the monovalent Omicron XBB.1.5-adapted BNT162b2 vaccine, which contains XBB.1.5-specific sequence changes, relative to the original BNT162b2 backbone, in the encoded prefusion-stabilized SARS-CoV-2 spike protein (S(P2)). Biophysical characterization of Omicron XBB.1.5 S(P2) demonstrated that it maintains a prefusion conformation and adopts a flexible, predominantly open, state, with high affinity for the human ACE-2 receptor. When administered as a 4th dose in BNT162b2-experienced mice, the monovalent Omicron XBB.1.5 vaccine elicited substantially higher serum neutralizing titers against pseudotyped viruses of Omicron XBB.1.5, XBB.1.16, XBB.1.16.1, XBB.2.3, EG.5.1 and HV.1 sublineages and phylogenetically distant BA.2.86 lineage than the bivalent Wild Type + Omicron BA.4/5 vaccine. Similar trends were observed against Omicron XBB sublineage pseudoviruses when the vaccine was administered as a 2-dose series in naive mice. Strong S-specific Th1 CD4+ and IFNγ+ CD8+ T cell responses were also observed. These findings, together with real world performance of the XBB.1.5-adapted vaccine, suggest that preclinical data for the monovalent Omicron XBB.1.5-adapted BNT162b2 was predictive of protective immunity against dominant SARS-CoV-2 strains.

Neurotrophic factor Neuritin modulates T cell electrical and metabolic state for the balance of tolerance and immunity.

The adaptive T cell response is accompanied by continuous rewiring of the T cell's electric and metabolic state. Ion channels and nutrient transporters integrate bioelectric and biochemical signals from the environment, setting cellular electric and metabolic states. Divergent electric and metabolic states contribute to T cell immunity or tolerance. Here, we report in mice that neuritin (Nrn1) contributes to tolerance development by modulating regulatory and effector T cell function. Nrn1 expression in regulatory T cells promotes its expansion and suppression function, while expression in the T effector cell dampens its inflammatory response. Nrn1 deficiency in mice causes dysregulation of ion channel and nutrient transporter expression in Treg and effector T cells, resulting in divergent metabolic outcomes and impacting autoimmune disease progression and recovery. These findings identify a novel immune function of the neurotrophic factor Nrn1 in regulating the T cell metabolic state in a cell context-dependent manner and modulating the outcome of an immune response.

Intranasal delivery of a subunit protein vaccine provides protective immunity against JN.1 and XBB-lineage variants.

The mucosal immune response plays a crucial role in the prevention of respiratory viruses. Given the risk of recurrent SARS-CoV-2 infections in the population, the rapid development of next-generation intranasal COVID-19 vaccines with high safety and efficacy is paramount. In the current study, we developed a protein-based intranasal vaccine comprising the XBB.1.5 receptor binding domain (RBD)-derived trimeric recombinant protein (RBDXBB.1.5-HR) and an MF59-like oil-in-water adjuvant. Intranasal administration of RBDXBB.1.5-HR vaccine elicited robust and sustained humoral immune responses in mice and rats, resulting in high levels of neutralizing antibodies against XBB-lineage subvariants, with protection lasting for at least six months. The intranasal RBDXBB.1.5-HR vaccine generated potent mucosal immune responses, characterized by the inductions of tissue-resident T (TRM) cells, local cellular immunity, germinal center, and memory B cell responses in the respiratory tract. The combination of intramuscular and intranasal delivery of the RBDXBB.1.5-HR vaccine demonstrated exceptional systemic and mucosal protective immunity. Furthermore, intranasal delivery of RBDXBB.1.5-HR vaccine as a heterologous booster shot showed more effective boosting effects after mRNA administration compared to homologous vaccination, as evidenced by the induction of superior systemic and extra mucosal immune response. Importantly, the intranasal RBDXBB.1.5-HR vaccine conferred efficient protection against the challenge with authentic EG.5.1 viruses in vivo. These findings identify the intranasal RBDXBB.1.5-HR vaccine as a potential mucosal vaccine candidate for the prevention of SARS-CoV-2 infection.

Neurotrophic factor Neuritin modulates T cell electrical and metabolic state for the balance of tolerance and immunity

The adaptive T cell response is accompanied by continuous rewiring of the T cell’s electric and metabolic state. Ion channels and nutrient transporters integrate bioelectric and biochemical signals from the environment, setting cellular electric and metabolic states. Divergent electric and metabolic states contribute to T cell immunity or tolerance. Here, we report in mice that neuritin (Nrn1) contributes to tolerance development by modulating regulatory and effector T cell function. Nrn1 expression in regulatory T cells promotes its expansion and suppression function, while expression in the T effector cell dampens its inflammatory response. Nrn1 deficiency in mice causes dysregulation of ion channel and nutrient transporter expression in Treg and effector T cells, resulting in divergent metabolic outcomes and impacting autoimmune disease progression and recovery. These findings identify a novel immune function of the neurotrophic factor Nrn1 in regulating the T cell metabolic state in a cell context-dependent manner and modulating the outcome of an immune response.