sIgA Secretion Research Articles

Chiral Intranasal Nanovaccines as Antivirals for Respiratory Syncytial Virus.

This study aimed to develop an intranasal nanovaccine by combining chiral nanoparticles with the RSV pre-fusion protein (RSV protein) to create L-nanovaccine (L-Vac). The results showed that L-NPs increased antigen attachment in the nasal cavity by 3.83 times and prolonged its retention time to 72h. In vivo experimental data demonstrated that the intranasal immunization with L-Vac induced a 4.86-fold increase in secretory immunoglobulin A (sIgA) secretion in the upper respiratory tract, a 1.85-fold increase in the lower respiratory tract, and a 20.61-fold increase in RSV-specific immunoglobin G (IgG) titer levels in serum, compared with the commercial Alum Vac, while the neutralizing activity against the RSV authentic virus is 1.66-fold higher. The mechanistic investigation revealed that L-Vac activated the tumor necrosis factor (TNF) signaling pathway in nasal epithelial cells (NECs), in turn increasing the expression levels of interleukin-6 (IL-6) and C-C motif chemokine ligand 20 (CCL20) by 1.67-fold and 3.46-fold, respectively, through the downstream nuclear factor kappa-B (NF-κB) signaling pathway. Meanwhile, CCL20 recruited dendritic cells (DCs) and L-Vac activated the Toll-like receptor signaling pathway in DCs, promoting IL-6 expression and DCs maturation, and boosted sIgA production and T-cell responses. The findings suggested that L- Vac may serve as a candidate for the development of intranasal medicine against various types of respiratory infections.

Polysaccharide from Areca catechu L. inflorescence enhances the intestinal mucosal immunity to maintain immune homeostasis

Being the first line of defense, intestinal mucosal immunity serves as in maintaining immune homeostasis among organisms. This study investigated the impact of the areca inflorescence polysaccharide (AFP) on intestinal mucosal immunity and elucidated the mechanisms responsible for the immunomodulatory effects of AFP. The immunosuppression mouse model was established using the cyclophosphamide. The intestinal mucosal status was evaluated based on the intestinal integrity, chemical and mucosal immune barriers, and intestinal flora. According to the findings, AFP enhances intestinal integrity by up-regulating the expression of tight junction proteins and reinforcing the chemical barrier through increased mucin-2, β-defensins, and SIgA expression and secretion. Furthermore, AFP restores the mucosal immune barrier by regulating immune cells within Peyer's patches and lamina propria. AFP also reverses the intestinal flora balance and regulates its metabolism. Additionally, AFP effectively modulates the immune response in the spleen and peripheral blood. Together, these results indicated that AFP repairs mucosal damage and restores mucosal immunity, thereby preserving the immune homeostasis of organisms.

Immunomodulatory potential of Lactobacillus helveticus KLDS 1.8701 postbiotics: By regulating the Th17/Treg balance

Maintaining homeostasis of the immune system is critical to human health. Postbiotics are inactive probiotics and their metabolites. Despite their numerous health benefits, the immunomodulatory potential of postbiotics has received less attention. The aim of this study was to explore the immunomodulatory influences of Lactobacillus helveticus postbiotics on cyclophosphamide (CTX)-induced immunocompromised mice and the underlying mechanism. The results showed a notable decrease in the immune function of the mice within the immunocompromised model. After treatment with Lactobacillus helveticus KLDS 1.8701 postbiotics, the immunity of mice was restored, as evidenced by an increase in organ index, proliferative capacity of splenic lymphocytes, NK cell activity, and serum immunoglobulin. It also promoted intestinal SIgA secretion and alleviated the degree of CTX-induced damage to the intestinal mucosal barrier. Meanwhile, Lactobacillus helveticus KLDS 1.8701 postbiotics demonstrated the ability to balance T helper cells 17 (Th17) and Regulatory T cells (Treg), exerting regulatory control over the serum levels of IL-17 and TGF-β, and thereby influencing the immune response. Therefore, Lactobacillus helveticus KLDS 1.8701 may be used as a potential functional food additive to prevent and treat CTX-induced immunocompromise.

The intestinal mucosal immunity in mice enhanced by crosslinked ready-to-eat sea cucumber via regulating the SIgA secretion and gut microbiota

The protective effects of molecular crosslinked ready-to-eat sea cucumber (RSC) against immunosuppression induced by cyclophosphamide in mice were investigated. After gavage of molecular crosslinked RSC, the SIgA levels of intestinal mucosa in mice were significantly increased by 31.6% (P < 0.01), and the terminal differentiation of IgA+ B cell was promoted with the significant up-regulation of IL-6 and IL-10 levels. Moreover, the secretion mechanism of plasma cell was mainly promoted through XBP-1s pathway mediated by IRE1 (P < 0.01), rather than ATF-4 and ATF-6 pathway (P > 0.05). In addition, the diversity of intestinal flora was increased, and the imbalance of intestinal flora was improved. The Lachnospiraceae_NK4A136_group dominated in crosslinked group could promote the repair of intestinal mucosa. Therefore, molecular crosslinked RSC can alleviate the intestinal mucosal damage via promoting SIgA secretion and regulating gut microbiota of mice.

Effects of different exercise intensities or durations on salivary IgA secretion

PurposeThis study aimed to examine changes in salivary immunoglobulin A (s-IgA) secretion at different intensities or durations of acute exercise.MethodsTwelve healthy untrained young males were included in randomized crossover trials in Experiment 1 (cycling exercise for 30 min at a work rate equivalent to 35%, 55%, and 75% maximal oxygen uptake [V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}O2max]) and Experiment 2 (cycling exercise at 55% V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}O2max intensity for 30, 60, and 90 min). Saliva samples were collected at baseline, immediately after, and 60 min after each exercise.ResultsExperiment 1: The percentage change in the s-IgA secretion rate in the 75% V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}O2max trial was significantly lower than that in the 55% V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}O2max trial immediately after exercise (− 45.7%). The percentage change in the salivary concentration of cortisol, an s-IgA regulating factor, immediately after exercise significantly increased compared to that at baseline in the 75% V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}O2max trial (+ 107.6%). A significant negative correlation was observed between the percentage changes in saliva flow rate and salivary cortisol concentration (r = − 0.52, P < 0.01). Experiment 2: The percentage change in the s-IgA secretion rate in the 90-min trial was significantly lower than that in the 30-min trial immediately after exercise (−37.0%). However, the percentage change in salivary cortisol concentration remained the same.ConclusionOur findings suggest that a reduction in s-IgA secretion is induced by exercise intensity of greater than or equal to 75% V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}O2max for 30 min or exercise duration of greater than or equal to 90 min at 55% V˙\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\dot{\ ext{V}}}$$\\end{document}O2max in healthy untrained young men.

Therapeutic effect of Artemisia argyi essential oil nasal drops on avian infectious bronchitis

ABSTRACT This study aimed to explore the therapeutic activity of Artemisia argyi essential oil (AAEO) nasal drops against avian infectious bronchitis and the underlying mechanism in the avian respiratory tract. Overall, 96 14-day-old broilers were randomly divided into 4 groups: control (control), A. argyi essential oil (AAEO) control, infectious bronchitis virus (IBV), and AAEO treatment (IBV + AAEO) groups (n = 24/group). Mortality was 25% (6/24) in the IBV group compared to 4.2% (1/24) in the AAEO treatment group. The clinical symptoms of the treatment group were significantly improved compared with those of the IBV group after 5 days of treatment. The broilers recovered at the end of the experiment. AAEO treatment relieves IBV-induced tracheal mucosal edema and bleeding and inhibits viral replication in the lungs. In addition, it enhanced SIgA secretion in the tracheal mucosa and increased type I interferon release by regulating IRF7 expression. Furthermore, we explored the mechanism underlying the therapeutic effect of AAEO. It maintains TLR7 at a high level in broilers and further upregulates MyD88, IRF7, and IL–10. Thereby enhancing the immune system and anti-inflammation. Our results suggest that AAEO can be used as a therapeutic agent for IBV.

Cistanche deserticola polysaccharide-functionalized dendritic fibrous nano-silica as oral vaccine adjuvant delivery enhancing both the mucosal and systemic immunity

Oral vaccines are a safe and convenient alternative to injected vaccines and have great potential to prevent major infectious diseases. However, the harsh gastrointestinal (GI) environment, mucus barriers, low immunogenicity, and lack of effective and safe mucosal adjuvants are the major challenges for oral vaccine delivery. In recent years, nanoparticle-based strategies have become attractive for improving oral vaccine delivery. Here, the dendritic fibrous nano-silica (DFNS) grafted with Cistanche deserticola polysaccharide (CDP) nanoparticles (CDP-DFNS) were prepared and investigated how to impact the immune responses. CDP-DFNS facilitated the antigen uptake in mouse bone marrow-derived dendritic cells (BMDCs), and induce the activation of DCs in vitro. Furthermore, in vivo experiments, the result showed that the uptake efficiency by Peyer's patches (PPs) of CDP-DFNS/BSA was the best. And CDP-DFNS/BSA then significantly activated the DCs in lamina propria (LP), and T/B cells in PPs and mesenteric lymph nodes (MLNs). Moreover, the memory T cell responses in later period of vaccination was stronger than other groups. In addition, CDP-DFNS/BSA enhanced BSA-specific antibody IgG, IgA production, and SIgA secretion, was effective at inducing a strong mixed Th1/Th2 response and mucosal antibody responses. These results indicated that CDP-DFNS deserves further consideration as an oral vaccine adjuvant delivery system.

Effect of immune protein intake on salivary S-Iga secretion in athletes - A randomized crossover placebo trial -

Effect of immune protein intake on salivary S-Iga secretion in athletes - A randomized crossover placebo trial -

L-Theanine alleviates heat stress through modulation of gut microbiota and immunity.

Heat stress (HS) damages the intestines, disrupting gut microbiota and immune balance. l-Theanine (LTA), found in tea, alleviates oxidative stress and cell apoptosis under HS; however, its effects on gut microbiota and immunity under HS remain unclear. To investigate this, we administered LTA doses of 100, 200, and 400 mg·kg-1 ·d-1 to C57BL/6J mice. On day 44, the model group and LTA intervention group were subjected to continuous 7-day HS treatment for 2 h per day. The results demonstrated that LTA intervention improved food intake, body weight, and intestinal epithelium, and reduced the water intake of heat-stressed mice. It increased the abundance of Turicibacter, Faecalibaculum, Bifidobacterium, and norank_f_Muribaculaceae, while reducing that of Lachnoclostridium and Desulfovibrio. LTA intervention also increased the concentrations of amino acid and lipid metabolites, regulated macrophage differentiation stimulated by gut microbiota and metabolites, reduced the antigen presentation by macrophages to the specific immune system, promoted B-cell differentiation and sIgA secretion, inhibited pro-inflammatory factors, and enhanced intestinal defense. Mechanistically, LTA downregulated heat shock protein 70 expression and the TLR4/NF-κB/p38 MAPK signaling pathway, restoring gut microbiota and immune balance. We suggest that LTA can alleviate HS by modulating gut microbiota, metabolites, and immunity, indicating its potential as a natural active ingredient for anti-HS food products. © 2023 Society of Chemical Industry.

Intranasal administration with recombinant vaccine PRVXJ-delgE/gI/TK-S induces strong intestinal mucosal immune responses against PDCoV

Porcine deltacoronavirus (PDCoV) is a novel coronavirus that causes enteric diseases in pigs leading to substantial financial losses within the industry. The absence of commercial vaccines and limited research on PDCoV vaccines presents significant challenges. Therefore, we evaluated the safety and immunogenicity of recombinant pseudorabies virus (PRV) rPRVXJ-delgE/gI/TK-S through intranasal mucosal immunization in weaned piglets and SPF mice. Results indicated that rPRVXJ-delgE/gI/TK-S safely induced PDCoV S-specific and PRV gB-specific antibodies in piglets, with levels increasing 7 days after immunization. Virus challenge tests demonstrated that rPRVXJ-delgE/gI/TK-S effectively improved piglet survival rates, reduced virus shedding, and alleviated clinical symptoms and pathological damage. Notably, the recombinant virus reduced anti-inflammatory and pro-inflammatory responses by regulating IFN-γ, TNF-α, and IL-1β secretion after infection. Additionally, rPRVXJ-delgE/gI/TK-S colonized target intestinal segments infected with PDCoV, stimulated the secretion of cytokines by MLVS in mice, stimulated sIgA secretion in different intestinal segments of mice, and improved mucosal immune function. HE and AB/PAS staining confirmed a more complete intestinal mucosal barrier and a significant increase in goblet cell numbers after immunization. In conclusion, rPRVXJ-delgE/gI/TK-S exhibits good immunogenicity and safety in mice and piglets, making it a promising candidate vaccine for PDCoV.

Secretory IgA in patients with COVID-19 at different regimens of using multicomponent vaccine Immunovac-VP-4

The mucosal immunity performs an important function in prevention of respiratory infections including COVID-19. The search for approaches to activate the synthesis of post-infectious antibodies by correcting the factors of innate and adaptive immunity at mucous membranes of respiratory tract in patients with infection caused by the new coronavirus may be relevant for the treatment of patients with COVID-19. The aim of our study was to assess the concentrations of sIgA in the upper respiratory tract in patients with a confirmed diagnosis of Coronavirus infection caused by the COVID-19, and to evaluate the effect of an immunostimulating drug of bacterial origin upon the sIgA secretion.&#x0D; The patients were divided into two groups: group 1 (n = 45), received basic therapy; group 2 (n = 33), in addition to basic therapy, received the bacterial vaccine Immunovac-VP-4 according to a combined scheme. The biomaterial sampling was carried out by scraping of epithelial cells from the nasal mucosa, pharyngeal scraping and salivary gland secretion on days 1, 14 and 30 of the study. sIgA levels in all biological fluids were studied using ELISA technique (JSC Vector-Best, Russia).&#x0D; 14 days after the start of observation, the dynamics of sIgA levels in nasal scrapings in group 1showed a significant decrease relative to the baseline values (p = 0.02), whereas the level of sIgA remained unchanged during the specified period (p = 0.07) in the group of patients receiving, along with basic therapy, additional Immunovac-VP-4 treatment. The dynamics of sIgA level in pharyngeal scrapings in the group of patients receiving only basic therapy did not change throughout the study period. Menwhile, the group of patients receiving basic therapy supplemented with Immunovac-VP-4 showed a significant increase in sIgA levels by the 30th day of follow-up over the baseline values (p = 0.02). The level of sIgA in salivary gland secretions did not differ significantly between the study groups during the entire follow-up period.&#x0D; The results of our study showed that, in order to assess the state of mucosal immunity in patients with COVID-19, one may recommend determination of sIgA in nasal secretions. The Immunovac-VP-4 prescribed in complex therapy is accompanied by an increase in the sIgA levels at the mucous surfaces of the respiratory tract.

Lactobacillus plantarum NCU1125 mitigates intestinal barrier injury induced by cyclophosphamide in mice

A previous study demonstrated that Lactobacillus (L.) plantarum NCU1125, derived from fermented Nanfeng mandarin, survived in vitro simulated gastrointestinal digestion, suggesting potential probiotic properties. The current study aimed to investigate the efficacy of L. plantarum NCU1125 on mice of cyclophosphamide-induced intestinal barrier (including the physical, the immunologic and the microbial barriers) injury. The results showed that L. plantarum NCU1125 could repair the intestinal physical barrier through upregulating the expressions of Muc2 and tight junctions (ZO-1, occluding and claudin-1), strengthen the intestinal immunologic barrier through boosting the number of CD4+T cells (64.34%), advancing the secretion of certain cytokines (IL-6 (2.77 times), IL-10 (1.55 times), IL-17 (1.19 times), TGF-β3 (2.42 times), IgA (2.42 times) and sIgA (1.42 times)), inducing Th (RORγt (31.06%) and Foxp3 (57.82%)) and B cells differentiation (Blimp-1 (21.10%), IRF-4 (41.27%) and XBP-1 (37.18%)), and stimulating sIgA formation (joining chain (98.68%), IgA α-chain (71.61%) and pIgR (36.75%)), and reshape the microbial barrier through modulating gut microbiota and metabolism. In addition, activation of the TLR4/MyD88/NF-κB pathway by L. plantarum NCU1125 might mediate expressions of gene products involved in the intestinal physical barrier, Th cell differentiation and sIgA secretion. Moreover, L. plantarum NCU1125 was found to control intestinal inflammation by correcting the imbalance of Th17/Treg. All findings indicated that L. plantarum NCU1125 could attenuate the intestinal barrier injury caused by cyclophosphamide in mice and lay a theoretical foundation for its applications in the intestinal regulation.

Use of Streptococcus salivarius K12 in supporting the mucosal immune function of active young subjects: A randomised double-blind study.

Upper respiratory tract infections (URTI) are the most common illnesses affecting athletes, causing absences from training and competition. Salivary immunoglobulin A (sIgA) is the main immune factor in saliva, and a consistent association between low concentrations of sIgA and an increased incidence of URTIs has been reported. The oral probiotic Streptococcus salivarius K12 has been suggested to have the potential to improve oral diseases and mucosal barrier function. However, the effects of this probiotic on active young subjects performing a high-intensity training (HIT) program have not been investigated. Active young students were randomised into a treated group (S. salivarius K12) and a control (placebo) group and asked to take the product daily for 30 days. After this period, participants performed a graded exercise test and five HIT sessions, all within 3 days. They were also asked to complete the Wisconsin Upper Respiratory Symptom Survey daily to monitor URTI's presence. Before and after the 30 days, and at 0h, 24h and 72h after the last training session, saliva samples were collected to quantify sIgA level, secretion rate, and flow. The effect of S. salivarius K12 intake on these parameters was tested using an ANOVA for repeated measures. Twenty (M = 14, F = 6) young subjects (23.5 ± 2.3 years old) participated in the study. The total accumulated training load (sRPE) in the supplementation period was similar in the two groups (treated: 4345 ± 3441 AU; control: 4969 ± 4165 AU; p > 0.05). Considering both sIgA level and secretion rate, significant time (F(4,15) = 3.38; p = 0.037; F(4,15) = 6.00; p = 0.004) and time×group interactions (F(4,15) = 2.49; p = 0.049; F(4,15) = 5.01; p = 0.009) were reported, with the treated group showing higher sIgA levels at 72h post-exercise and increased secretion rate both at 0h and 72h. The number of URTI episodes was similar in the treated and control groups (χ² = 1.83; p > 0.05). This study demonstrates that relatively short-term S. salivarius K12 supplementation increased sIgA level and secretion in healthy subjects performing a demanding exercise-training programme composed of HIT sessions.

Prevalence of low energy availability and associations with seasonal changes in salivary hormones and IgA in elite male Gaelic footballers.

Evidence suggests low energy availability (LEA) is prevalent in elite male Gaelic football (GF) players. Previous research in male and female team sports found LEA may negatively impact endocrine function. The aim of this study was to examine the seasonal variations in energy availability (EA) and its associations with salivary measures in elite male GF players across the competitive season. Energy availability was assessed using field-based methods in conjunction with salivary testosterone (s-T), cortisol (s-C) and immunoglobin A (s-IgA) concentrations at pre-season (PRE), in-season (IN) and post-season (POST). 38% reported LEA at PRE, 33% at IN, and 28.5% at POST. s-C, s-T and s-IgA levels were within normal ranges at PRE, IN and POST. Salivary cortisol declined significantly from PRE to IN, remaining reduced at POST. Salivary testosterone decreased significantly from PRE to IN but was significantly elevated at POST compared to IN. Salivary IgA was significantly greater at POST than IN. No significant associations were found between s-C or s-T and EA at any time point. Pre-season s-IgA exhibited a significant inverse association with PRE EA. Decreased s-IgA flow rate and s-IgA secretion rate were significantly associated with decreased EA at PRE. Reduced carbohydrate (CHO) intake was also associated with decreased s-IgA secretion rate at PRE. This study suggests that LEA is prevalent in elite male GF players, but is not associated with s-C or s-T. However, EA is associated with s-IgA which may impact the immune system. Therefore, education and interventions surrounding the prevalence and associations of EA should be implemented in this population.

Lactobacillus fermentum (MTCC-5898) based fermented whey renders prophylactic action against colitis by strengthening the gut barrier function and maintaining immune homeostasis.

Nutritional intervention using probiotic fermented dairy product has emerged as a promising prophylactic strategy to curb inflammatory bowel diseases. Under present investigation, the potential of fermented whey prepared with probiotic Lactobacillus fermentum (LF:MTCC-5898) was investigated on dextran sodium sulfate (DSS) induced impaired intestinal barrier function in mice. Probiotic fermented whey (PFW) consumption improved the symptoms of colitis-associated with intestinal inflammation by significantly (p<0.01) diminishing the percent loss in body weight, disease activity index and spleen index with improved colon length besides hematological and histopathological score. Likewise, pre-treatment with PFW improved the barrier integrity (p<0.01) in contrast to leaky condition induced by DSS administration which increased the FITC-dextran permeability across gut epithelium. PFW consumption also provided the gut immune protection through significantly increased (p<0.05) TLR-2 expression and stimulated T-regulatory response by producing TGF-β (p<0.01) and, potently suppressed (p<0.01) inflammatory response (TNF-α, IL-4 and C-reactive protein). Further, PFW intake significantly enhanced (p<0.05) immunoglobulin (sIgA) secretion and concomitantly restored the Occludin, ZO-1 (p<0.01) and Claudin-1(p<0.05) transcriptional expression as compared to colitis mice. Additionally, immune-fluorescence further established the presence of intact actin cytoskeleton and tight junction proteins (claudin-1, occludin and ZO-1) after PFW consumption. Thus, PFW rectified the impaired and leaky barrier junctions not only through modulation of transcriptional expression of tight junction genes but also with reduced secretion of inflammatory mediators and helped in ameliorating the colitis. Hence, probiotic fermented whey prepared with L.fermentum (MTCC-5898) could be used as potential prophylactic functional food in the prevention of gut ailments.

Chitosan particle stabilized Pickering emulsion/interleukin-12 adjuvant system for Pgp3 subunit vaccine elicits immune protection against genital chlamydial infection in mice.

Considering the shortcomings in current chlamydia infection control strategies, a major challenge in curtailing infection is the implementation of an effective vaccine. The immune response induced by C. trachomatis plasmid encoded Pgp3 was insufficient against C. trachomatis infection, which requires adjuvant applications to achieve the robust immune response induced by Pgp3. There is increasing promising in developing adjuvant systems relying on the delivery potential of Pickering emulsions and the immunomodulatory effects of interleukin (IL)-12. Here, owing to the polycationic nature, chitosan particles tended to absorb on the oil/water interphase to prepare the optimized chitosan particle-stabilized Pickering emulsion (CSPE), which was designed as a delivery system for Pgp3 protein and IL-12. Our results showed that the average droplets size of CSPE was 789.47 ± 44.26 nm after a series of optimizations and about 90% antigens may be absorbed by CSPE owing to the positively charged surface (33.2 ± 3mV), and CSPE promoted FITC-BSA proteins uptake by macrophages. Furthermore, as demonstrated by Pgp3-specific antibody production and cytokine secretion, CSPE/IL-12 system enhanced significantly higher levels of Pgp3-specific IgG, IgG1, IgG2a, sIgA and significant cytokines secretion of IFN-γ, IL-2, TNF-α, IL-4. Similarly, vaginal chlamydial shedding and hydrosalpinx pathologies were markedly reduced in mice immunized with Pgp3/CSPE/IL-12. Collectively, vaccination with Pgp3/CSPE/IL-12 regimen elicited robust cellular and humoral immune response in mice resulting in an obvious reduction of live chlamydia load in the vaginal and inflammatory pathologies in the oviduct, which further propells the development of vaccines against C. trachomatis infection.

Fucoxanthin Prevents the Ovalbumin-Induced Food Allergic Response by Enhancing the Intestinal Epithelial Barrier and Regulating the Intestinal Flora

This study aimed to determine whether fucoxanthin alleviated ovalbumin (OVA)-induced food allergy (FA) and explored the possible mechanisms. The results indicated that supplementation with fucoxanthin at 10.0-20.0 mg/kg per day for 7 weeks inhibited food anaphylaxis and the production of immunoglobulin (Ig) E, IgG, histamine, and related cytokines while alleviating allergic symptoms in sensitized mice. Fucoxanthin enhanced the intestinal epithelial barrier by up-regulating tight junction (TJ) protein expression and promoting regenerating islet-derived protein III-gamma (RegIIIγ) and secretory IgA (sIgA) secretion. In addition, fucoxanthin induced the secretion of anti-inflammatory factors (interleukin (IL)-10 and transforming growth factor β (TGF-β)) by regulatory T (Treg) cells and decreased the pro-inflammatory factor levels (IL-4, tumor necrosis factor-α (TNF-α), IL-17, and IL-1β), ameliorating intestinal inflammation. Compared with the model group, beneficial bacteria, such as Lactobacillaceae, increased in the intestinal flora, while pathogenic bacteria like Helicobacteraceae, Desulfovibrionaceae, and Streptococcaceae decreased. Therefore, fucoxanthin may effectively prevent FA by enhancing the intestinal epithelial barrier and reshaping the intestinal flora.

Heat acclimation does not negatively affect salivary immunoglobulin-A and self-reported illness symptoms and wellness in recreational athletes

ABSTRACT Heat acclimation (HA) protocols repeatedly expose individuals to heat stress. As HA is typically performed close to the pinnacle event, it is essential that the protocol does not compromise immune status, health, or wellbeing. The purpose of this study was to examine the effect of HA on resting salivary immunoglobulin-A (s-IgA) and salivary cortisol (s-cortisol), self-reported upper-respiratory tract symptoms, and self-reported wellness parameters. Seventeen participants (peak oxygen uptake 53.2 ± 9.0 mL·kg−1·min−1) completed a 10-day controlled-hyperthermia HA protocol, and a heat stress test both before (HST1) and after (HST2) HA (33°C, 65% relative humidity). Resting saliva samples were collected at HST1, day 3 and 7 of the HA protocol, HST2, and at 5 ± 1 days post-HA. Upper-respiratory tract symptom data were collected weekly from one week prior to HA until three weeks post HA, and wellness ratings were reported daily throughout HA. HA successfully induced physiological adaptations, with a lower end-exercise rectal temperature and heart rate and higher whole-body sweat rate at HST2 compared to HST1. In contrast, resting saliva flow rate, s-IgA concentration, s-cortisol concentration, and s-cortisol secretion rate remained unchanged (n = 11–14, P = 0.10–0.48). Resting s-IgA secretion rate increased by 39% from HST1 to HST2 (n = 14, P = 0.03). No changes were observed in self-reported upper respiratory tract symptoms and wellness ratings. In conclusion, controlled-hyperthermia HA did not negatively affect resting s-IgA and s-cortisol, self-reported upper-respiratory tract symptoms, and self-reported wellness parameters in recreational athletes.

Purple red rice anthocyanins alleviate intestinal damage in cyclophosphamide-induced mice associated with modulation of intestinal barrier function and gut microbiota

The regulatory effects of purple red rice bran anthocyanins (PRBA) on intestinal barrier function and gut microbiota in mice were investigated. Results showed that PRBA had an ameliorative effect on intestinal barrier damage, including restoration of villus length, improvement in the number of cupped cells and promotion of sIgA secretion. PRBA stimulated the production of cytokines, reduced the levels of endotoxin (ET) and lipopolysaccharide binding protein (LBP) in serum, as well as upregulated the expression of tight junction proteins (TJs) and NF-κB pathway proteins. Furthermore, PRBA not only promoted the production of short-chain fatty acids (SCFAs), but also regulated the intestinal microbiota by increasing beneficial bacteria (Lachnospiraceae, Bacteroidaceae, Ruminococcaceae) and reducing pathogenic bacteria (Shigella) to maintained intestinal homeostasis. Above results indicated that PRBA could ameliorate cyclophosphamide-induced impairment of intestinal barrier function and dysregulation of the gut microbiota, which provides a new idea for broadening the exploitation of PRBA.

Xiong Fu Powder Regulates the Intestinal Microenvironment to Protect Bones Against Destruction in Collagen-Induced Arthritis Rat Models

BackgroundChanges in the intestinal microenvironment affected bone destruction in rheumatoid arthritis (RA), and spleen deficiency (SD) was closely related to the intestinal microenvironment. In this study, we aimed to explore the aggravation of SD on collagen-induced arthritis (CIA) and the bone protection of compound Xiong Fu powder (XFP) on CIA with SD (SD-CIA) based on the intestinal microenvironment.MethodAn SD-CIA rat model was established using Rheum officinale Baill. decoction combined with CIA and then treated with XFP. The aggravating action of SD on CIA rats and the efficacy of XFP were evaluated using AI scores, H&E staining of the joint, and level of serum anti–collagen type II antibody (Col II Ab). Bone destruction was assessed by micro-CT and TRACP staining. In addition, flow cytometry, qRT-PCR, and ELISA were used to evaluate gut mucosal immunity. Moreover, metagenomic sequencing was used to determine the distribution and function of the gut microbiota.ResultsCompared with that in CIA rats, bone destruction in SD-CIA rats was aggravated, as manifested by increased AI scores, more severe joint pathological changes and radiological damage, and increased number of osteoclasts (OCs) in the ankle joint. Meanwhile, the proportion of Tregs/Th17 cells was biased toward Th17 cells in Peyer’s patches. Furthermore, the gene levels of TNF-α, IL-1β, IL-6, and IL-17 were increased. In contrast, the expression of IL-10 and sIgA was decreased in the jejunum and ileum. XFP treatment improved bone damage and intestinal mucosal immune disorders compared with the SD-CIA group. In addition, the distribution and function of the gut microbiota were altered in the SD-CIA group. After XFP treatment, the community and function of the gut microbiota were regulated, manifested as increased abundance of several Lactobacillus species, such as L. acidophilus, which regulates the intestinal Tregs/Th17 cells and quorum sensing pathways, followed by promoting probiotic adhesion to the intestines.ConclusionSD can aggravate bone destruction in CIA rats. Compound XFP may attenuate bone destruction in SD-CIA rats by regulating the intestinal microenvironment. One of the mechanisms is the cross-talk between sIgA secretion regulated by intestinal mucosal Tregs and Th17 cells and adhesion of Lactobacillus mediated by quorum sensing.