Streptococcus mutans (S. mutans), a facultative anaerobe and lactic acid-producing bacterium, has been deemed a major etiological agent of dental caries. Our previous study revealed that S. mutans cultured under air-restricted conditions accelerated the development of dental caries in adult rats, compared with those grown in routinely air-unrestricted conditions. Here, we first confirmed this enhancement in a weaning rat model that mimics early childhood caries, and then further demonstrated that air restriction not only enhanced biofilm formation of S. mutans, but also upregulated gene expression in five Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with sugar uptake and metabolism, with lactose metabolism being most pronounced. Concurrently, genes involved in the conversion of pyruvate to acetyl-CoA were downregulated, shifting metabolic flux toward lactic acid production. This effect was markedly amplified in the presence of lactose, implying a critical role for lactose-derived fermentation in cariogenicity. Collectively, these findings indicate that air-restricted culturing enhances the cariogenic metabolic activity of S. mutans, with lactose emerging as a significant dietary risk factor for dental caries.IMPORTANCEDental caries remains one of the most prevalent chronic diseases worldwide, affecting billions of individuals globally, which poses a major burden to public oral health. A systematic understanding of environmental factors that modulate the virulence of cariogenic bacteria, such as Streptococcus mutans (S. mutans), provides valuable insights into the pathogenesis of caries and informs the development of prevention strategies. Our findings demonstrate that reduced air availability dramatically enhances the cariogenicity of S. mutans in vitro and in vivo, which is mechanistically associated with metabolic reprogramming toward preferential lactose utilization. Notably, our study bridges a critical knowledge gap by elucidating how environmental air tension drives S. mutans virulence and highlights lactose metabolism as a previously overlooked risk factor, prompting reconsideration of preventive strategies for vulnerable populations.

Chikungunya virus (CHIKV), an emerging mosquito-borne alphavirus, induces debilitating polyarthralgia and myositis with no licensed specific therapeutic drugs. This study investigates the virological, immunological, and pathological consequences of targeting glycolysis and glutaminolysis during CHIKV infection. In vitro, either glucose/glutamine deprivation, or pharmacological inhibition by 2DG/DON significantly suppressed viral replication in mammalian cell lines. In vivo, however, differential tissue biodistribution dictated that neither inhibitor reduced viral loads in serum or foot tissues of acute infected mice following footpad inoculation with 10⁴ PFU CHIKV. Strikingly, DON, but not 2DG, abolished histopathological manifestations of myositis and inflammatory infiltration despite comparable viral burdens. Mechanistically, DON-mediated tissue protection was related to dual immunomodulation. DON significantly depleted splenic innate immune cells, including monocytes and macrophages, which play roles in driving tissue inflammatory infiltration cascades. Meanwhile, DON inhibited CD4 + and CD8+ T cell effector programmes, resulting in suppressed activation marker (CD44) expression and effector cell differentiation (decreased effector: naive ratio and TEM: TCM balance). The proliferative capacity (Ki-67 + cells), polyfunctional cytokine responses (IFN-γ+, TNF-α and IL-17 + cells) and cytotoxicity potential (CD107a + cells) of CD4 + and CD8+ T cells were significantly impaired by DON injection. Crucially, glutaminolysis inhibition uncoupled immunopathology from viral containment, attenuating tissue damaging immunity while preserving baseline antiviral competence. Collectively, these findings establish host glutamine metabolism as a pharmacologically tractable target for alphavirus-induced arthritis, demonstrating that selective immunometabolic modulation resolves the severe acute inflammatory pathology.

The recurrent emergence of ACE2‑using sarbecovirus underscores the need for a broadly protective vaccine. Here, we mapped the antigenic landscape of sarbecovirus receptor-binding domains (RBDs) and identified three distinct clusters. We then engineered a single “three‑in‑one” immunogen, 3Rs-NC, incorporating representative RBDs from each cluster into a single scaffold. Intranasal administration of 3Rs-NC with a flagellin-derived mucosal adjuvant (KFD), which possess excellent safety profile potential for clinical usage, elicited high titers of RBD-specific serum IgG and mucosal IgA, as well as potent neutralizing antibody responses in mice. Furthermore, KFD-adjuvanted 3Rs-NC conferred sustained protection in both the upper and lower respiratory tracts against SARS-CoV-2 Omicron BA.1 and SARS-like coronavirus WIV1. Additionally, 3Rs-NC immunization protected mice from lethal challenge of SARS-like coronavirus rRsSHC014S, with more efficient protection observed in female mice than male mice. This needle-free formulation offers a potent, broad-spectrum vaccine candidate against current and emerging ACE2-using sarbecoviruses, functioning as a modular “three-in-one” vaccine platform ready for rapid deployment in future coronavirus outbreaks.

Immunosuppression increases disease risk, and the natural compound polydatin (PD) has been reported to modulate immune-related disorders. In cyclophosphamide-induced immunosuppressed mice, PD was evaluated for its immunomodulatory effects. Immune organ indices were measured, while H&E staining and ELISA assessed spleen pathology and serum cytokine levels. The proliferation of splenic lymphocytes, both total and subpopulation, was determined using concanavalin A or lipopolysaccharide stimulation, with flow cytometry analyzing peripheral blood and splenic lymphocytes, thymic T cell subtypes, cell cycling, and bromodeoxyuridine incorporation. Western blotting was used to assess Ki67, PCNA expression, and MAPK activation. PD significantly alleviated cyclophosphamide-induced reductions in spleen and thymus indices, improved the organization of red and white pulp in the spleen, and restored TNF-α and IFN-γ levels. It reversed cyclophosphamide-induced cell cycle arrest, characterized by increased PCNA and decreased Ki67, and corrected the diminished numbers of B and T cells and the reduced CD4+/CD8+ ratio in the thymus. In vitro, PD directly promoted splenic lymphocyte proliferation and cell cycling via MAPK activation. Overall, our findings demonstrated that PD alleviated mouse immunosuppression by activating splenic lymphocyte proliferation and re-organizing thymic T cell development and differentiation.

With the persistent risk of coronavirus epidemics, the development of universal vaccines is urgently needed and challenging to achieve. In this study, we aimed to design a multivalent immunogen to provide broad protection against diverse ACE2-using sarbecoviruses, which pose a significant threat to global health. Our analysis revealed that the receptor-binding domains (RBDs) of ACE2-using sarbecoviruses segregate into three antigenically distinct clusters, including one cluster that encompasses viruses related to SARS-CoV-2. Based on these findings, we engineered a ‘three-in-one’ immunogen, designated as 3Rs-NC, which incorporates representative RBDs from all three clusters. 3Rs-NC preserved the natural epitope configuration of each monomeric RBD component, and efficiently elicited high levels of neutralizing antibodies against representative viruses and closely related sarbecoviruses. When administered intranasally with flagellin-based mucosal adjuvant KFD, 3Rs-NC induced robust and durable RBD-specific serum IgG and mucosal IgA responses in mice. Furthermore, KFD-adjuvanted 3Rs-NC conferred sustained protection in both the upper and lower respiratory tracts against SARS-CoV-2 Omicron BA.1 and SARS-like coronavirus WIV1. Additionally, 3Rs-NC immunization protected mice from lethal challenge of SARS-like coronavirus rRsSHC014S, with more efficient protection observed in female mice than male mice. This needle-free ‘three-in-one’ vaccine represents a promising candidate for a universal mucosal vaccine against ACE2-using sarbecoviruses and could serve as a foundational component of ‘three-in-one’ vaccine series to form a comprehensive coronavirus vaccine package. Highlight 1. novel ‘three-in-one’ immunogen 3Rs-NC induced a high level of neutralizing antibodies against three distinct ACE2-using Sabecovirus clusters. 2. administration of 3Rs-NC plus KFD adjuvant ( 3Rs-NC+KFDi.n) generated potent and long-lasting RBD-specific serum IgG and mucosal IgA. 3. 3Rs-NC+KFDi.n provided long-term protection in both upper- and lower-respiratory tracts in mice. 4. 3Rs-NC+KFDi.n could serve as a foundational component for next-generation coronavirus vaccine strategies. ### Competing Interest Statement The authors have declared no competing interest. Shanghai Science and Technology Innovation Action Plan, 22Y11901000 National Key R&D program of China, 2021YFC2302602 National Natural Science Foundation of China, 82341041, 32100749 Shenzhen Science and Technology Program, RCJC20210706092009004

ETHNOPHARMACOLOGICAL RELEVANCE:While the seasonal variations in the human immune function and many infectious diseases are well-known, to develop therapeutic strategies regarding such seasonality is quite challenging. However, some traditional medical practices have already taken the seasonality into account, such as the "Season Tea" (ST) decoctions investigated in the present study. AIM OF THE STUDY:We present a study of the ST decoctions from traditional Chinese medicine, which include four formulae designed for the four seasons, aiming to investigate their pharmacological commonality and distinction. MATERIALS AND METHODS:A rat model of acute pharyngitis was utilized for the pharmacological study, and the effects of the ST decoctions were evaluated through histology, biomedical assays, microarray analysis, real-time quantitative PCR and Western blot. RESULTS:The experimental data show that all of the four ST formulae display good pharmaceutical effects on acute pharyngitis, and circadian rhythm appears to be a significant pathway for investigating their pharmacological commonality and distinction. Specifically, while all of the four ST decoctions can regulate the circadian-rhythm-related genes ARNTL and BHLHE40, the regulation is along different directions with the modification of the supplements and the substrates in each ST formula. CONCLUSION:These results indicate the correlation between the acute pharyngitis and circadian rhythm, and illustrate the possibility of synergistically and subtly regulating ARNTL and BHLHE40, which is significant for relevant drug development.

Developing a mucosal vaccine against SARS-CoV-2 is critical for combatting the epidemic. Here, we investigated long-term immune responses and protection against SARS-CoV-2 for the intranasal vaccination of a triple receptor-binding domain (RBD) scaffold protein (3R-NC) adjuvanted with a flagellin protein (KFD) (3R-NC + KFDi.n). In mice, the vaccination elicited RBD-specific broad-neutralizing antibody responses in both serum and mucosal sites sustained at high level over a year. This long-lasting humoral immunity was correlated with the presence of long-lived RBD-specific IgG- and IgA-producing plasma cells, alongside the Th17 and Tfh17-biased T-cell responses driven by the KFD adjuvant. Based upon these preclinical findings, an open labeled clinical trial was conducted in individuals who had been primed with the inactivated SARS-CoV-2 (IAV) vaccine. With a favorable safety profile, the 3R-NC + KFDi.n boost elicited enduring broad-neutralizing IgG in plasma and IgA in salivary secretions. To meet the challenge of frequently emerged variants, we further designed an updated triple-RBD scaffold protein with mutated RBD combinations, which can induce adaptable antibody responses to neutralize the newly emerging variants, including JN.1. Our findings highlight the potential of the KFD-adjuvanted triple-RBD scaffold protein is a promising prototype for the development of a mucosal vaccine against SARS-CoV-2 infection.

Dental caries is a prevalent oral disease that mainly results from Streptococcus mutans. Susceptibility to S. mutans decreased rapidly after weaning in a well-known rat model. However, owing to the lack of time to establish protective immunity ahead of challenge, the weaning rat model is suboptimal for assessing prophylactic vaccines against S. mutans infection. In this study, we found that, in adult rats, S. mutans cultured under air-restricted conditions showed dramatically increased colonization efficacy and accelerated development of dental caries compared with those cultured under air-unrestricted conditions. We propose that S. mutans cultured under air-restricted conditions can be used to develop an optimal caries model, especially for the evaluation of prophylactic efficacy against S. mutans. Therefore, we used the anti-caries vaccine, KFD2-rPAc, to reevaluate the protection against the challenge of S. mutans. In immunized rats, rPAc-specific protective antibodies were robustly elicited by KFD2-rPAc before the challenge. In addition to inhibiting the initial and long-term colonization of S. mutans in vivo, KFD2-rPAc immunization showed an 83% inhibitory efficacy against the development of caries, similar to that previously evaluated in a weaning rat model. These results demonstrate that culturing under air-restricted conditions can promote S. mutans infection in adult rats, thereby helping establish a rat infection model to evaluate the prophylactic efficacy of vaccines and anti-caries drugs.

Purpose: Omalizumab is a humanized anti-immunoglobulin (Ig) E monoclonal antibody that is effective in treating some patients with chronic spontaneous urticaria (CSU) who do not respond to antihistamines. Gut microbiome plays a role in the pathogenesis of allergies and autoimmune diseases. Here, we investigated differences in the gut microbiome of adolescent CSU patients before and after omalizumab treatment, which has not been previously reported. Patients and Methods: Ten adolescent CSU patients were given 300 mg omalizumab subcutaneously in three treatments at 4-week intervals. Urticaria Activity Score (UAS7) was applied to evaluate the efficacy of each omalizumab treatment during follow-up. Fecal samples were collected before and 12 weeks after the first treatment. Total DNA of the gut microbiota in all fecal samples were extracted. The 16S rRNA gene-targeted sequencing technology was used for the analysis of the diversity and distribution of gut microbiome, followed by bioinformatics analysis. Results: UAS7 scores decreased significantly after each treatment compared with the baseline (all P < 0.0001). There were five well -controlled responders and five non-responders after three treatment sessions of omalizumab. The dominant bacteria phyla in all fecal samples were Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Alpha diversity analysis showed no significant difference before and after treatment (P > 0.05), whereas beta diversity analysis revealed a significant difference in the bacterial abundance before and after treatment (P < 0.01). The relative abundance of Alphaproteobacteria and Betaproteobacteria at the class level and Burkholderia, Rhodococcus, and Sphingomonas at the genus level decreased significantly after treatment (linear discriminant analysis > 4, P < 0.05). The functional prediction results showed that the dioxin and xylene degradation pathways were more abundant before treatment. Conclusion: Omalizumab is effective in treating CSU and the abundance of Alphaproteobacteria and Betaproteobacteria was reduced after treatment, which may help improve the treatment outcomes in adolescent CSU patients.

Dear Editor, Though COVID-19 vaccines have been developed and clinically deployed rapidly,new variants of concern(VOCs)are still emerging frequently and escalating around the world.More breakthrough infections occurred even vaccination rates are high.

TLR5 agonist flagellin is an effective mucosal adjuvant via intranasal administration. Previous studies demonstrated that the mucosal adjuvanticity of flagellin depends on TLR5 signaling of airway epithelial cells. Since dendritic cells play a central role in antigen sensitization and the initiation of primary immune responses, we wondered how dendritic cells were modulated by the intranasally administrated flagellin. In this study, a mouse model of intranasal immunization with ovalbumin, a model antigen, in the presence or absence of flagellin was utilized. We found that nasal administration of flagellin enhanced the coadministered antigen-specific antibody responses and T-cell clonal expansion in a TLR5-dependent manner. However, neither the entering of flagellin to nasal lamina propria nor the uptake of coadministered antigen by nasal resident dendritic cells was associated with TLR5 signaling. In contrast, migration of antigen-loaded dendritic cells from the nasal cavity to the cervical lymph nodes and activation of dendritic cells in the cervical lymph nodes were both enhanced through TLR5 signaling. Furthermore, for the dendritic cells, flagellin enhanced the expression of CCR7, which was pivotal for dendritic cells in the priming site migrating to draining lymph nodes. Interestingly, the migration, activation, and chemokine receptor expression levels of antigen-loaded dendritic cells were all significantly higher than that of bystander dendritic cells. In conclusion, intranasally administrated flagellin enhanced TLR5-dependent antigen-loaded dendritic cells' migration and activation but not antigen uptake.

The Corona Virus Disease 2019 (COVID-19) epidemic is a sudden public health crisis, known as an "International Emergency of Public Health Event". This study uses the bottom-up characteristics of multi-agents to construct multi-agent simulation models for COVID-19 prevention and control. The development trend of the epidemic situation under the condition that the government adopts different prevention and control measures is studied, and on this basis, the influence of temperature on the spread of the virus is discussed. The simulation results show that the multi-agent modeling method can effectively capture the emergence of complex systems. The evaluation of the effects of single measures and multiple interventions will help determine key prevention and control strategies and provide important experience and scientific basis for future epidemic prevention and control.

Chikungunya virus (CHIKV) is an emerging mosquito-transmitted alphavirus that leads to acute fever and chronic debilitating polyarthralgia. To date, the mechanism underlying chronic recurrent arthralgia is unknown. In the present study, newborn wild-type C57BL/6 mice were infected with CHIKV, and the virological and pathological features of CHIKV infection were analyzed over a period of 50 days. Acute viral infection was readily established by footpad inoculation of CHIKV at doses ranging from 10 plaque forming unit (PFU) to 106 PFU, during which inoculation dose-dependent viral RNA and skeletal muscle damage were detected in the foot tissues. However, persistent CHIKV was observed only when the mice were infected with a high dose of 106 PFU of CHIKV, in which low copy numbers (103-104) of viral positive strand RNA were continuously detectable in the feet from 29 to 50 dpi, along with a low level and progressive reduction in virus-specific CD8+ T cell responses. In contrast, viral negative strand RNA was detected at 50 dpi but not at 29 dpi and was accompanied by significant local skeletal muscle damage at 50 dpi when mild synovial hyperplasia appeared in the foot joints, although the damage was briefly repaired at 29 dpi. These results demonstrated that a high viral inoculation dose leads to viral persistence and progression to chronic tissue damage after recovery from acute infection. Taken together, these results provide a useful tool for elucidating the pathogenesis of persistent CHIKV infection and viral relapse-associated chronic arthritis.

Arthropod-borne chikungunya virus (CHIKV) infection can cause a debilitating arthritic disease in human. However, there are no specific antiviral drugs and effective licensed vaccines against CHIKV available for clinical use. Here, we developed an mRNA-lipid nanoparticle (mRNA-LNP) vaccine expressing CHIKV E2-E1 antigen, and compared its immunogenicity with soluble recombinant protein sE2-E1 antigen expressed in S2 cells. For comparison, we first showed that recombinant protein antigens mixed with aluminum adjuvant elicit strong antigen-specific humoral immune response and a moderate cellular immune response in C57BL/6 mice. Moreover, sE2-E1 vaccine stimulated 12-23 folds more neutralizing antibodies than sE1 vaccine and sE2 vaccine. Significantly, when E2-E1 gene was delivered by an mRNA-LNP vaccine, not only the better magnitude of neutralizing antibody responses was induced, but also greater cellular immune responses were generated, especially for CD8+ T cell responses. Moreover, E2-E1-LNP induced CD8+ T cells can perform cytotoxic effect in vivo. Considering its better immunogenicity and convenience of preparation, we suggest that more attention should be placed to develop CHIKV E2-E1-LNP mRNA vaccine.

[This corrects the article DOI: 10.3389/fphar.2021.730567.].

The rapid mutation and spread of SARS-CoV-2 variants urge the development of effective mucosal vaccines to provide broad-spectrum protection against the initial infection and thereby curb the transmission potential. Here, we designed a chimeric triple-RBD immunogen, 3Ro-NC, harboring one Delta RBD and two Omicron RBDs within a novel protein scaffold. 3Ro-NC elicits potent and broad RBD-specific neutralizing immunity against SARS-CoV-2 variants of concern. Notably, intranasal immunization with 3Ro-NC plus the mucosal adjuvant KFD (3Ro-NC + KFDi.n) elicits coordinated mucosal IgA and higher neutralizing antibody specificity (closer antigenic distance) against the Omicron variant. In Omicron-challenged human ACE2 transgenic mice, 3Ro-NC + KFDi.n immunization significantly reduces the tissue pathology in the lung and lowers the viral RNA copy numbers in both the lung (85.7-fold) and the nasal turbinate (13.6-fold). Nasal virologic control is highly correlated with RBD-specific secretory IgA antibodies. Our data show that 3Ro-NC plus KFD is a promising mucosal vaccine candidate for protection against SARS-CoV-2 Omicron infection, pathology and transmission potential.

Ebola virus is among the most dangerous viral pathogens, with a case fatality rate of up to 90%. Since 2013, the two largest and most complex Ebola outbreaks in West Africa have revealed the lack of investigation on this notorious virus.

Kaempferol is a natural compound that inhibits tumor development in androgenic related prostate cancer. However, it is still not clear about its phyto-androgenic activity and whether it suppresses testosterone-induced benign prostatic hyperplasia (BPH) development. In this study, molecular docking, cellular immunofluorescence staining, chromatin immunoprecipitation and dual luciferase reporter assay were performed to investigate the androgenic activity of kaempferol. Dihydrotestosterone-induced gene expression and cell proliferation were further analyzed upon treatment with kaempferol. Testosterone-induced BPH was established in rats and the effect and mechanism of action of kaempferol on BPH development was then assessed. Docking data showed that kaempferol could bind to ASN705 and THR877 residues of androgen receptor which were also the binding sites of dihydrotestosterone. The nuclear translocation of androgen receptor was promoted directly by kaempferol in androgen-dependent prostate cancer LNCaP cells. In addition, the in vivo interaction of androgen receptor with PSA promoter region and the transcriptional activity of androgen receptor were both significantly enhanced after kaempferol stimulation. However, kaempferol pretreatment suppressed dihydrotestosterone-induced effects including the transcriptional activity of androgen receptor, the expressions of PSA and AR genes and cell proliferation of LNCaP, BPH-1 and WPMY-1 cells. Consistently, kaempferol declined the prostate index and improved the pathological properties in BPH rats, and the up-regulated T level in serum from BPH rats was highly decreased after kaempferol administration. Kaempferol exhibited its androgenic-like activity and served as a selective androgen receptor modulator that contributes to androgen-related BPH development.

Polymeric immunoglobulin receptor (pIgR)-mediated polymeric immunoglobulin A (pIgA) transcytosis across mucosal epithelial cells plays an essential role in mucosal immunity. The general trafficking process has been well investigated, yet the elaborate regulatory mechanisms remain enigmatic. We identified a new pIgR interacting protein, the Rab11 effector Rab11-FIP1. Rab11-FIP1 and Rab11-FIP5 knockdown additively impaired pIgA transcytosis in both polarized and incompletely polarized cells. Moreover, Rab11-FIP1 and Rab11-FIP5 knockdown exhibited more significant inhibitory effects on pIgA transcytosis in incompletely polarized cells than in polarized cells. Interestingly, the trafficking process of pIgA in incompletely polarized cells is distinct from that in polarized cells. In incompletely polarized cells, the endocytic pIgR/pIgA was first transported from the basolateral plasma membrane to the vicinity of the centrosome where Rab11-FIP1 and Rab11-FIP5 bound to it, before the Rab11a-positive endosomes containing pIgR/pIgA, Rab11-FIP1 and Rab11-FIP5 were further transported to the apical plasma membrane via Golgi apparatus. During the trafficking process, TRIM21 mediated the K11-linked polyubiquitination of Rab11-FIP1 and the K6-linked polyubiquitination of Rab11-FIP5 to promote their activation and pIgA transcytosis. This study indicates that polyubiquitinated Rab11-FIP1 and Rab11-FIP5 mediated by TRIM21 cooperatively facilitate pIgA transcytosis and provides new insights into the intracellular trafficking process of pIgA in incompletely polarized cells.