[Xixin Decoction regulates Th17/Treg balance and transcription factor expression in senescence-accelerated mouse-prone].

This study aims to investigate the effect of Xixin Decoction on the T helper 17 cell(Th17)/regulatory T cell(Treg) ba-lance of intestinal mucosa and the expression of related transcription factors in the senescence-accelerated mouse-prone 8(SAMP8) model. Fifty 14-week male mice of SAMP8 were randomized by the random number table method into model group, probiotics group, and high-, medium-, and low-dose Xixin Decoction groups, with 10 mice in each group. Ten 14-week male mice of senescence-acce-lerated mouse-resistant 1(SAMR1) served as control group. After 10 weeks of feeding, the mice were administrated with correspon-ding drugs for 10 weeks. Morris water maze test was carried out to examine the learning and memory abilities of mice. Enzyme-linked immunosorbent assay(ELISA) was employed to determine the content of secretory immunoglobulin A(SIgA) in the intestinal mucosa, and flow cytometry to detect the percentage content of Th17 and Treg in the intestinal mucosa. Western blot was performed to determine the protein levels of retinoid-related orphan receptor gamma t(RORγt) and forkhead box p3(Foxp3) in the mouse colon tissue. Compared with control group, the escape latency of mice in model group was significantly prolonged(P<0.01), and the number of times of crossing the platform and the residence time in the target quadrant were significantly reduced within 60 s(P<0.01), intestinal mucosal SIgA content was significantly decreased(P<0.01), Th17 content was increased(P<0.05), Treg content was decreased(P<0.01), the expression of RORγt protein was increased and Foxp3 protein was decreased in colon(P<0.01). Compared with the model group, high-dose Xixin Decoction group improved the learning and memory ability(P<0.05 or P<0.01). Probiotics group and high-and medium-dose Xixin Decoction group increased the content of SIgA in intestinal mucosa(P<0.05 or P<0.01), decreased percentage content of Th17 and increased the percentage content of Treg in intestinal mucosa(P<0.05 or P<0.01). Furthermore, they down-regulated the protein level of RORγt and up-regulated the protein level of Foxp3 in the intestinal mucosa(P<0.01). In conclusion, Xixin Decoction may act on intestinal mucosal immune barrier, affect gut-brain information exchange, and improve the learning and memory ability of SAMP8 by promoting SIgA secretion and regulating the Th17/Treg balance and the expression of RORγt and Foxp3.

Effects of yeast-derived postbiotic supplementation in late gestation and lactation diets on performance, milk quality, and immune function in lactating sows.

This experiment was conducted to determine the effects of yeast-derived postbiotic (YDP) supplementation in sow diets during late gestation and lactation on the performance of sows and their offspring. At 90-d gestation, 150 sows (Landrace × Large White, parity: 3.93 ±â€…0.11) were allocated to three dietary treatments (n = 50 per treatment): 1) basal diet (control [CON]), 2) basal diet with 1.25 g/kg YDP (0.125 group), and 3) basal diet with 2.00 g/kg YDP (0.200 group). The experiment continued until the end of weaning (day 21 of lactation). Supplementation with YDP resulted in greater deposition of backfat in sows during late gestation and an increasing trend in average weaning weight of piglets than observed in the CON group (P < 0.01, P = 0.05). Supplementation with YDP decreased piglet mortality and diarrhea index in piglets (P < 0.05). In farrowing sows' serum, the glutathione peroxide content in the YDP group was lower than that in the CON group (P < 0.05); the content of immunoglobulin A (IgA) in the 0.200 group or YDP group was higher than that in the CON group (P < 0.05). In lactating sows' serum, malondialdehyde content was higher in the YDP group (P < 0.05). In day 3 milk of sows, the 0.200 group tended to increase the lactose content (P = 0.07), and tended to decrease the secretory immunoglobulin A (sIgA) content (P = 0.06) with respect to that in the CON group. The sIgA content in the YDP group was lower than that in the CON group (P < 0.05). In the milk of sows, the 0.200 group tended to increase the lactose content with respect to that in the CON group (P = 0.08); the immunoglobulin G (IgG) content in the 0.125 group or YDP group was higher than that in the CON group (P < 0.05). YDP supplementation increased the IgA content in the milk (P < 0.01). In sow placenta, the content of total anti-oxidant capacity in the YDP group was higher than that in the CON group (P = 0.05); and the content of transforming growth factor-ß in the YDP group was higher than that in the CON group (P < 0.05). In piglet serum, the content of IgG and immunoglobulin M in the 0.125 group was higher than that in the CON and 0.200 groups (P < 0.05). In summary, this study indicated that feeding sows diets supplemented with YDP from late gestation through lactation increased sows' backfat deposition in late gestation and piglets' weaning weight; decreased piglet mortality and diarrhea index in piglets; and improved maternal and offspring immunity.

Rapid fetal and reproductive tissue development in late gestation poses a challenge to sow health. Nutritional interventions have been shown to effectively improve animal performance. The present study investigated whether dietary supplementation with a yeast-derived postbiotic (YDP) during late gestation and lactation might improve the health and production performance of sows and piglets. At two tested dose levels (1.25 and 2.00 g/kg in the diet), dietary YDP supplementation increased backfat deposition in sows during late gestation and weaning weight in piglets, and decreased the diarrhea index in piglets. YDP supplementation tended to increase lactose content in sow milk. Dietary YDP supplementation improved immunity in sows at farrowing and piglets at weaning. These findings indicated that YDP use improves sows' production performance and may serve as an important approach to optimizing nutrient programs in sow production.

Matrine provides a protective effect against Eimeria tenella challenge by alleviating intestinal barrier damage.

As a virulent and harmful protozoan, Eimeria tenella (E.tenella) causes harmful chicken coccidiosis, inducing high economic losses in the chicken industry. The management of the coccidial disease has been greatly hampered by drug resistance. Matrine is an active ingredient from Ku Shen (Radix Sophorae Flavescentis), a typical pesticide in chinese medicine. The aim of this study was to examine matrine's possible effectiveness in the treatment of coccidiosis and its protective function on the intestinal barrier. The anticoccidial index (ACI), the levels of anti-oxidant indexes, and secretory immunoglobulin A (sIgA) were detected. The levels of mRNA and protein expression of Occludin, ZO-1, and Claudin-1 were determined through quantitative real-time PCR (RT-qPCR) and immunohistochemistry (IHC) analysis. Matrine exhibited a moderate ACI value, and ACI values of 122.51 and 143.42 corresponded to 5 and 10 mg/kg of matrine, respectively. Compared to the infective control group, the expression of tight junction proteins significantly increased in the matrine-treatment group by RT-PCR and IHC analysis, which are essential for the mucosal immune system and the intestinal barrier. Besides, the matrine-treatment group showed a more complete intestinal structure, fewer bleeding spots, and coccidian by histopathology analysis. We also found that, matrine significantly enhanced the antioxidant ability and significantly increased the content of sIgA. Above all, matrine was considered an efficient drug against E.tenella by the anti-oxidant efficacy, and the ability to protect the composition and function of the intestinal barrier.

Rice Water-Fried Atractylodis Rhizoma Relieves Spleen Deficiency Diarrhea by Regulating the Intestinal Microbiome.

Background: Spleen deficiency diarrhea (SDD) is a common Traditional Chinese Medicine (TCM) gastrointestinal condition, the causes of which include dysfunction of the intestinal barrier and microbiota. Rice water-fried Atractylodis Rhizoma (RAR) is a commonly used drug to treat this condition, but its mechanism remains unclear. This study explored the related mechanisms of ethanolic extract of rice water-fried Atractylodis Rhizoma (EAR) in the treatment of SDD by examining changes in the intestinal microbiota. Method: Wistar rats were randomly divided into 4 groups including the control, model, EAR low, and high-dose groups, 6 rats in each group. All rats, except the control group, were induced to develop SDD by a bitter-cold purgation method with rhubarb. The therapeutic effect of EAR on SDD was evaluated by pathological sections, inflammatory indicators (TNF-α, IL-1ß, and IL-10), gastrointestinal-related indicators (GAS, DAO, D-lactate, VIP, and SIgA), and intestinal flora (bacteria and fungi) analysis. Results: The results showed that the developed SDD rat model (model group) showed weight loss, decreased food intake, and increased fecal moisture content. Compared with those of the control group, the levels of TNF-α, IL-1ß, DAO, D-lactate, and VIP in the model group were significantly increased, but the levels of IL-10, GAS and SIgA were significantly decreased (p < 0.05). However, the indicators were significantly improved after EAR treatment, indicating that EAR maintained the balance of pro- and anti-inflammatory cytokines and reduced gastric emptying, thereby protecting intestinal barrier function, alleviating intestinal mucosal injury, and relieving SDD by regulating the release of neurotransmitters. EAR was also shown to prevent infection by promoting the accumulation of noninflammatory immunoglobulin SIgA and improving intestinal mucosal immunity to inhibit the adhesion of bacteria, viruses, and other pathogens. Intestinal microbiome analysis showed that the intestinal bacteria and fungi of SDD model rats changed greatly compared with the control group, resulting in intestinal microecological imbalance. The reversal in the composition of the flora after EAR treatment was mainly characterized by a large enrichment of beneficial bacteria represented by Lactobacillus and a decrease in the abundance of potentially pathogenic fungi represented by Aspergillus. Thus, it was speculated that EAR primarily functions to alleviate SDD by increasing the abundance of beneficial bacteria and reducing the abundance of potentially pathogenic fungi. Conclusion: The strong therapeutic effect of EAR on SDD suggests that it is a promising treatment for this condition.

Chimonanthus nitens Oliv Polysaccharides Modulate Immunity and Gut Microbiota in Immunocompromised Mice.

To investigate the immunomodulatory activities of Chimonanthus nitens Oliv polysaccharides (COP1), an immunosuppressive mouse model was generated by cyclophosphamide (CY) administration and then treated with COP1. The results demonstrated that COP1 ameliorated the body weight and immune organ (spleen and thymus) index of mice and improved the pathological changes of the spleen and ileum induced by CY. COP1 strongly stimulated the production of inflammatory cytokines (IL-10, IL-12, IL-17, IL-1ß, and TNF-α) of the spleen and ileum by promoting the mRNA expressions. Furthermore, COP1 had immunomodulatory activity by increasing several transcription factors (JNK, ERK, and P38) in the mitogen-activated protein kinase (MAPK) signaling pathway. Related to the above immune stimulatory effects, COP1 positively affected the production of short-chain fatty acids (SCFAs) and the expression of ileum tight junction (TJ) protein (ZO-1, Occludin-1, and Claudin-1), upregulated the level of secretory immunoglobulin A (SIgA) in the ileum and microbiota diversity and composition, and improved intestinal barrier function. This study suggests that COP1 may provide an alternative strategy for alleviating chemotherapy-induced immunosuppression.

Effects of alkaline mineral complex water supplementation on growth performance, inflammatory response, and intestinal barrier function in weaned piglets.

The purpose of the present study was to investigate the effects of drinking water alkaline mineral complex (AMC) supplementation on growth performance, intestinal morphology, inflammatory response, immunity, antioxidant defense system, and barrier functions in weaned piglets. In a 15-d trial, 240 weaned piglets (9.35 ± 0.86 kg) at 28 d of age (large white × landrace × Duroc) were randomly divided into two groups: the control (Con) group and the AMC group. Drinking water AMC supplementation improved (P < 0.01) final body weight (BW) and average daily gain (ADG) in weaned piglets compared to the Con group. Importantly, AMC reduced (P < 0.01) the feed-to-gain (F:G) ratio. AMC water improved the physical health conditions of piglets under weaning stress, as reflected by the decreased (P < 0.05) hair score and conjunctival score. Moreover, there was no significant (P > 0.05) difference in relatively small intestinal length, organ (liver, spleen, and kidney) indices, or gastrointestinal pH value in weaned piglets between the two groups. Of note, AMC significantly promoted the microvilli numbers in the small intestine and effectively ameliorated the gut morphology damage induced by weaning stress, as evidenced by the increased (P < 0.05) villous height (VH) and ratio of VH to crypt depth. Additionally, AMC lessened the levels of lipopolysaccharide (LPS, P < 0.01) and the contents of IL1ß (P<0.05), and TNF-α (P<0.05) in the weaned piglet small intestine. Conversely, the gut immune barrier marker, secretory immunoglobulin A (sIgA) levels in serum and small intestine mucosa were elevated after AMC water treatment (P < 0.01). Furthermore, AMC elevated the antioxidant mRNA levels of (P < 0.05) SOD 1-2, (P < 0.01) CAT, and (P < 0.01) GPX 1-2 in the small intestine. Likewise, the mRNA levels of the small intestine tight junction factors Occludin (P < 0.01), ZO-1 (P < 0.05), Claudin 2 (P < 0.01), and Claudin 5 (P<0.01) in the AMC treatment group were notably higher than those in the Con group. In conclusion, drinking water AMC supplementation has an accelerative effect on growth performance by elevating gut health by improving intestinal morphology, the inflammatory response, the antioxidant defense system, and barrier function in weaned piglets.

The piglet suffers vital physiological, environmental, and social challenges when it is weaned from the sow that can predispose the piglet to subsequent diseases and other production losses, and these challenges are responsible for serious economic losses to the swine industry. Weaning stress induces intestinal injury, decreased immunity, and digestive system dysfunction, which then reduces feed intake and inhibits the growth performance of piglets. It is well known that alternatives to antibiotics for preventing weaning stress in weaned farm animals are sorely needed. The biologically beneficial effects of alkaline mineral water are widely reported. Alkaline mineral complex (AMC), as an immunomodulator, is considered to have antistress effects in the swine industry. In addition, treatment through drinking water is considered to be an efficient and low-cost feasible disease control strategy. Drinking water AMC supplementation is expected to exert health benefits in pigs; however, the responses of weaned piglets to water supplemented with AMC have not been fully explored. Thus, this study explored the effects of drinking water AMC supplementation on growth performance and gut health in weaned piglets. Our results showed that AMC water supplementation conspicuously enhanced the growth performance by improving the gut health.

Changes in intestinal homeostasis and immunity in a cigarette smoke- and LPS-induced murine model for COPD: the lung-gut axis.

Chronic obstructive pulmonary disease (COPD) is often associated with intestinal comorbidities. In this study, changes in intestinal homeostasis and immunity in a cigarette smoke (CS)- and lipopolysaccharide (LPS)-induced COPD model were investigated. Mice were exposed to cigarette smoke or air for 72 days, except days 42, 52, and 62 on which the mice were treated with saline or LPS via intratracheal instillation. Cigarette smoke exposure increased the airway inflammatory cell numbers, mucus production, and different inflammatory mediators, including C-reactive protein (CRP) and keratinocyte-derived chemokine (KC), in bronchoalveolar lavage (BAL) fluid and serum. LPS did not further impact airway inflammatory cell numbers or mucus production but decreased inflammatory mediator levels in BAL fluid. T helper (Th) 1 cells were enhanced in the spleen after cigarette smoke exposure; however, in combination with LPS, cigarette exposure caused an increase in Th1 and Th2 cells. Histomorphological changes were observed in the proximal small intestine after cigarette smoke exposure, and addition of LPS had no effect. Cigarette smoke activated the intestinal immune network for IgA production in the distal small intestine that was associated with increased fecal sIgA levels and enlargement of Peyer's patches. Cigarette smoke plus LPS decreased fecal sIgA levels and the size of Peyer's patches. In conclusion, cigarette smoke with or without LPS affects intestinal health as observed by changes in intestinal histomorphology and immune network for IgA production. Elevated systemic mediators might play a role in the lung-gut cross talk. These findings contribute to a better understanding of intestinal disorders related to COPD.

Identification of ANXA2 on epithelial cells as a new receptor for secretory IgA using immunoprecipitation and mass spectrometry.

Secretory immunoglobulin A plays an important role in the protection against exogenous pathogens and antigens, but it has also been reported to have pathogenic potential. We previously found that secretory immunoglobulin A accumulated in the peripheral lungs during idiopathic pulmonary fibrosis and that transferrin receptor/CD71 was partially involved in secretory immunoglobulin A-induced inflammatory cytokine production in A549 cells. This study aimed to identify the receptor responsible for the induction of cytokine production by secretory immunoglobulin A-stimulated airway epithelial cells. To this end, immunoprecipitation followed by time-of-flight mass spectrometry and peptide mass fingerprinting were performed and Annexin A2 was detected as a novel receptor for secretory immunoglobulin A. Enzyme-linked immunosorbent assay demonstrated binding of secretory immunoglobulin A to Annexin A2, and flow cytometry showed robust expression of Annexin A2 on the surface of BEAS-2B cells, A549 cells, and normal human bronchial/tracheal epithelial cells. Experiments in A549 cells using Annexin A2 small interfering RNA and neutralizing antibodies suggested that Annexin A2 was partially involved in the production of interleukin-8/CXCL8 and C-C motif chemokine ligand 2/monocyte chemoattractant protein-1 induced by secretory immunoglobulin A. Immunohistochemistry using lung sections revealed clear expression of Annexin A2 on airway epithelial cells, although the staining remained equivalent in idiopathic pulmonary fibrosis, asthma, and healthy control lungs. In conclusion, we identified that Annexin A2 expressed in airway epithelial cells is a novel receptor for secretory immunoglobulin A, which is involved in cytokine synthesis.

High frequency of antimicrobial resistance and virulence gene in Shigella species isolated from pediatric patients in an Iranian Referral Hospital.

BACKGROUND: Shigella is a main cause of gastroenteritis and it is responsible for 5 to 10 % of diarrhea through the world. The aims of this study were to assess the antibiotic susceptibility pattern and the presence of 3 common virulence genes (sigA, virF, invE) of Shigella strains isolated from patients with gastroenteritis in Children's Medical Center Hospital, Tehran, Iran. METHODS: Over a period of 15 months, all Shigella species collected from the patients with gastroenteritis were entered to the study. Susceptibility testing of all isolates towards different antibiotics was performed using the disk diffusion method and the prevalence of virulence genes was detected by polymerase chain reaction (PCR) technology. RESULTS: Among a total of 183 Shigella strains, 128 Shigella sonnei (70%) and 55 S. flexneri (30%) were isolated. The resistance rate to the antibiotics in S. sonnei strains was higher than S. flexneri. The most sensitive antibiotics for S. flexneri strains were gentamicin (98%), amikacin (85%) and ciprofloxacin (82%), while high resistance rate to trimethoprim-sulfamethoxazole (96%), ampicillin (96%), nalidixic acid (64%) and cefotaxime (60%) was observed. The frequency of invE, virF and sigA gene in S. flexneri strains was 89 %, 93 % and 56 %, respectively; whereas they found in 93 %, 96 %, and 100 % of S. sonnei strains, respectively. SigA gene was identified significantly higher in the S. sonnei strains (100%). There was no significant difference between the presence of virF and invE genes among Shigella strains. CONCLUSION: The high presence of sigA gene in S. sonnei strains plays an important role in its pathogenesis, and the high frequency of invE and virF genes showed that this classical pathway regulating the expression of Shigella virulence factor genes could play a key role in the pathogenesis of this bacterium.

Induced Polyspecificity of Human Secretory Immunoglobulin A Antibodies: Is It Possible to Improve Their Ability to Bind Pathogens?

INTRODUCTION: As has been shown previously, various protein-modifying agents can change the antigen-binding properties of immunoglobulins. However, induced polyspecificity of human secretory immunoglobulin A (sIgA) has not been previously characterized in detail. METHODS: In the present study, human secretory immunoglobulin A (IgA) was exposed to buffers with acidic pH, to free heme, or to pro-oxidative ferrous ions, and the antigen-binding behavior of the native and modified IgA to viral and bacterial antigens was compared using Western blotting and enzyme-linked immunosorbent assay. The ability of these agents to modulate the antigen-binding properties of human sIgA toward a wide range of pathogen peptides was investigated using an epitope microarray. RESULTS: We have shown that acidic pH, heme, and pro-oxidative ferrous ions influenced the binding of secretory IgA in opposite directions (either increasing or decreasing); however, the strongest effect was observed when using buffers with low pH. This fraction had the highest number of affected reactivities; most of them were increased and most of the new ones were toward common pathogens. CONCLUSIONS: Thus, it was shown that all investigated treatments can alter to some degree the antigen-binding of secretory IgA, but acidic pH has the most potentially beneficial effect by increasing binding to a largest number of common pathogens' antigens.

[A prospective randomized comparative study of the efficacy and safety of a two-week bismuth-based quadrotherapy of Helicobacter pylori infection with the inclusion of the probiotic containing Bifidobacterium longum BB-46 and Enterococcus faecium ENCfa-68 ].

AIM: To study the efficacy and safety of a two-week bismuth-based quadruple of Helicobacter pylori (Hp) infection with the inclusion of a probiotic Bifiform. MATERIALS AND METHODS: An open prospective comparative randomized study included 68 Hp-positive patients: 22 with a confirmed diagnosis of peptic ulcer disease, 46 with chronic gastritis, gastroduodenitis and erosions in the pylorobulbar zone. The diagnosis and Hp infection were verified by the results of endoscopic and morphological studies, as well as using the 13C-urease breath test and determination of the Hp antigen in the feces. Depending on the therapy, the patients were randomized into 2 groups: the main group was taken 2 times a day for 14 days omeprazole 20 mg + amoxicillin 1000 mg + clarithromycin 500 mg + bismuth tripotassium dicitrate 240 mg + Bifiform 2 capsules 2 times a day; control similar therapy was carried out, but without the inclusion of Bifiform. Repeated testing for Нр was carried out one month after the termination of the course of treatment. RESULTS: When using bismuth-containing quadruple, a high frequency of Hp eradication was noted, which in the ITT analysis was 86.1 and 68.8% (p0.05) and in the PP analysis it was 93.9 and 95.7% (p0.05) in patients of the main and control groups, respectively. Side effects of drug therapy were detected in 16.7 and 43.8% (p0.05), which was the reason for the early termination of therapy as a result of their development in 5.6 and 28% (p0.05) in patients of the main and control groups, respectively. The inclusion of the probiotic Bifiform in the eradication triple therapy of Hp infection reduced the frequency of detection of colonic dysbiosis from 27.8 to 3.6% and had a positive effect on the indices of local immunity (increased content of plasma cells in the inflammatory infiltrate and a stable level of secretory immunoglobulin A in coprofiltrate). CONCLUSION: A prospective, comparative, randomized study has shown that when using a two-week bismuth-based quadruple the eradication rate exceeds 90%. The inclusion of Bifiform in the eradication scheme dramatically reduces the frequency of adverse events and increases patient compliance, and also maintains the protective factors of the gastrointestinal mucosa at a higher level.

Secretory IgA accumulated in the airspaces of idiopathic pulmonary fibrosis and promoted VEGF, TGF-ß and IL-8 production by A549 cells.

Secretory IgA (SIgA) is a well-known mucosal-surface molecule in first-line defense against extrinsic pathogens and antigens. Its immunomodulatory and pathological roles have also been emphasized, but it is unclear whether it plays a pathological role in lung diseases. In the present study, we aimed to determine the distribution of IgA in idiopathic pulmonary fibrosis (IPF) lungs and whether IgA affects the functions of airway epithelial cells. We performed immunohistochemical analysis of lung sections from patients with IPF and found that mucus accumulated in the airspaces adjacent to the hyperplastic epithelia contained abundant SIgA. This was not true in the lungs of non-IPF subjects. An in-vitro assay revealed that SIgA bound to the surface of A549 cells and significantly promoted production of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-ß and interleukin (IL)-8, important cytokines in the pathogenesis of IPF. Among the known receptors for IgA, A549 cells expressed high levels of transferrin receptor (TfR)/CD71. Transfection experiments with siRNA targeted against TfR/CD71 followed by stimulation with SIgA suggested that TfR/CD71 may be at least partially involved in the SIgA-induced cytokine production by A549 cells. These phenomena were specific for SIgA, distinct from IgG. SIgA may modulate the progression of IPF by enhancing synthesis of VEGF, TGF-ß and IL-8.

Secretory immunoglobulin A induces human lung fibroblasts to produce inflammatory cytokines and undergo activation.

Immunoglobulin (Ig)A is the most abundant immunoglobulin in humans, and in the airway mucosa secretory IgA (sIgA) plays a pivotal role in first-line defense against invading pathogens and antigens. IgA has been reported to also have pathogenic effects, including possible worsening of the prognosis of idiopathic pulmonary fibrosis (IPF). However, the precise effects of IgA on lung fibroblasts remain unclear, and we aimed to elucidate how IgA activates human lung fibroblasts. We found that sIgA, but not monomeric IgA (mIgA), induced interleukin (IL)-6, IL-8, monocyte chemoattractant protein (MCP)-1 and granulocyte-macrophage colony-stimulating factor (GM-CSF) production by normal human lung fibroblasts (NHLFs) at both the protein and mRNA levels. sIgA also promoted proliferation of NHLFs and collagen gel contraction comparable to with transforming growth factor (TGF)-ß, which is involved in fibrogenesis in IPF. Also, Western blot analysis and real-time quantitative polymerase chain reaction (PCR) revealed that sIgA enhanced production of α-smooth muscle actin (α-SMA) and collagen type I (Col I) by NHLFs. Flow cytometry showed that NHLFs bound sIgA, and among the known IgA receptors, NHLFs significantly expressed CD71 (transferrin receptor). Transfection of siRNA targeting CD71 partially but significantly suppressed cytokine production by NHLFs co-cultured with sIgA. Our findings suggest that sIgA may promote human lung inflammation and fibrosis by enhancing production of inflammatory or fibrogenic cytokines as well as extracellular matrix, inducing fibroblast differentiation into myofibroblasts and promoting human lung fibroblast proliferation. sIgA's enhancement of cytokine production may be due partially to its binding to CD71 or the secretory component.

Free and complexed-secretory immunoglobulin A triggers distinct intestinal epithelial cell responses.

Secretory immunoglobulin A (SIgA) antibodies play an important role in protecting the mucosal surfaces against pathogens and maintaining homeostasis with the commensal microbiota. Because a substantial portion of the gut microbiota is coated with SIgA, we hypothesized that microbiota-SIgA complexes are important for the maintenance of gut homeostasis. Here we investigated the relationship between microbiota-SIgA complexes and inflammatory epithelial cell responses. We used a multi-cellular three-dimensional (3D) organotypical model of the human intestinal mucosa composed of an intestinal epithelial cell line and primary human lymphocytes/monocytes, endothelial cells and fibroblasts. We also used human SIgA from human colostrum, and a prominent bacterial member of the first colonizers, Escherichia coli, as a surrogate commensal. We found that free and microbiota-complexed SIgA triggered different epithelial responses. While free SIgA up-regulated mucus production, expression of polymeric immunoglobulin receptor (pIgR) and secretion of interleukin-8 and tumoir necrosis factor-α, microbiota-complexed SIgA mitigated these responses. These results suggest that free and complexed SIgA have different functions as immunoregulatory agents in the gut and that an imbalance between the two may affect gut homeostasis.

Proliferation and Cytokine Production of Human Mesangial Cells Stimulated by Secretory IgA Isolated from Patients with IgA Nephropathy.

BACKGROUND/AIMS: IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis, and often aggravates by mucosal infection. Secretory IgA (SIgA) is the dominant immunoglobulin in mucosal immunity, and is deposited in the mesangium in IgAN. The biological effects of SIgA on mesangial cells are poorly understood. METHODS: Deposition of SIgA in frozen renal sections from IgAN patients was detected and the association between deposition of SIgA and patients characteristics was analyzed. The biological effects of SIgA and polymeric IgA (pIgA) on human renal mesangial cells were compared. We also studied the molecular mechanism of microRNA regulating the inflammatory effects of SIgA on mesangial cells. RESULTS: Fifty-five of 176 patients had SIgA deposition with higher incidence of infection history and hematuria, lower serum cystatin C, ß2 microglobulin, blood urea nitrogen and T-grade in the Oxford classification, compared with patients without SIgA deposition. SIgA stimulated mesangial cells at a higher ratio of proliferation and higher production of interleukin (IL)-6, IL-8, monocyte chemotactic protein 1, transforming growth factor-ß1 and fibronectin, compared with SIgA from healthy volunteers. The proliferation and cytokines production in mesangial cells stimulated by SIgA were significantly lower than that stimulated by pIgA. miR- 16 targeted the 3'-untranslated region of IL-6 and suppressed its translation in mesangial cells induced by SIgA. CONCLUSIONS: The biological effects of SIgA on mesangial cells differ from those of pIgA. SIgA stimulates mesangial cell proliferation and production of proinflammatory cytokines. IL-6 production is regulated by miR-16 in mesangial cells.

Effect of Human Milk and its Components on Streptococcus Mutans Biofilm Formation.

OBJECTIVE: This study investigated the effects of human breast milk and its components on the nutritional aspect of the caries process due to Streptococcus mutans UA159 biofilm formation. STUDY DESIGN: Human breast milk was collected from 11 mothers during 3-9 months postpartum. To test for the effect on biofilm formation, a 16-hour culture of S. mutans was treated with dilutions of human breast milk and several major components of human breast milk, lactose, lactoferrin, IgA, and bovine casein in sterile 96-well flat bottom microtiter plates for 24 hours. The biofilms were fixed, washed, stained with crystal violet, and extracted. Absorbance was measured to evaluate biofilm growth mass. RESULTS: Dilutions 1:10-1:2,560 of the human breast milk samples increased biofilm formation by 1.5-3.8 fold compared to the control. Lactoferrin decreased biofilm formation significantly in all dilutions (average milk concentration of 3 mg/ml). Lactose had no effect at average breast milk concentrations (60 mg/ml) except at its lowest concentration (15 mg/ml) where it was increased. IgA significantly decreased biofilm formation at its highest concentration of 2,400 µg/ml (average milk concentration 600 µg/ml). Casein caused significantly increased biofilm formation at all concentrations tested above the average milk content (2.3 mg/ml). CONCLUSIONS: The results of this study demonstrate an increase in S. mutans biofilm formation by human breast milk 3-9 months post partum. Among its major components, only casein significantly increased biofilm formation among the concentrations analyzed. Lactose had no effect except at 15 mg/ml. Lactoferrin and IgA significantly decreased S. mutans biofilm formation at their highest concentrations. This information expands the current knowledge regarding the nutritional influence of breastfeeding and validates the necessity to begin an oral hygiene regimen once the first tooth erupts.

Secretory IgA as a vaccine carrier for delivery of HIV antigen to M cells.

HIV transmission and spread in the host are based on the survival of the virus or infected cells present in mucosal secretions, and the virus' ability to cross the epithelial barrier and access immune target cells, which leads to systemic infection. Therefore, HIV-specific immunity at mucosal sites is critical for control of infection. Although mucosal delivery would ensure the best onset of protective immunity, most candidate vaccines are administered through the parenteral route. Remarkably, secretory IgA (SIgA) interacts specifically with mucosal microfold (M) cells present in gut-associated lymphoid tissues. Here we evaluate the feasibility of delivering chemically bound p24HIV antigen via SIgA into the intestinal mucosae in mice. After oral administration, p24-SIgA complexes are quickly delivered into the tissue and selectively captured by CX3CR1(+) dendritic cells. Oral immunization with p24gag linked to SIgA (p24-SIgA) adjuvanted with E. coli heat labile enterotoxin (HLT) elicits both humoral and cellular immune responses against p24 at the systemic and mucosal levels and induces efficient protection against rectal challenge with a recombinant vaccinia virus encoding gag. This is the first study which underscores the remarkable potential of SIgA to serve as a vaccine carrier for an HIV antigen in mucosal administration targeting the gastrointestinal environment.

Reinforcement of the intestinal mucus layer protects against Clostridium difficile intestinal injury in vitro.

BACKGROUND: Clostridium difficile infection is increasing in incidence and severity. Attributable factors include virulence factors, including C difficile toxins A and B, as well as host immunologic status. The mucus component of the intestinal barrier is impaired by malnutrition, shock insults, and alterations in the gut microbiome. Exogenous phosphatidylcholine (PC) administration results in reinforcement of the mucus layer and is of therapeutic benefit in chronic ulcerative colitis. We therefore studied the role of exogenous PC combined with secretory immunoglobulin A (IgA) in intestinal barrier function against C difficile infection in vitro. STUDY DESIGN: Dimeric IgA was placed in the basal chambers of mucus-producing (HT29-methotrexate) and non-mucus-producing (HT29) strains of intestinal epithelial monolayers and allowed to undergo transcytosis and, in additional experiments, exogenous colostral IgA (30 ng/mL) was added to the apical media. After subsequent coculture with PC and C difficile toxin A in the apical chamber, tumor necrosis factor-α, interleukin-6, toxin A uptake, intestinal epithelial cell monolayer permeability, and necrosis were determined. RESULTS: A significant decrease of 4- to 5-fold in tumor necrosis factor-α and interleukin-6 levels and equally significant decreases in toxin A uptake and permeability changes in the intestinal cell monolayers with mucus or PC and transcytosed or colostral IgA vs control are shown. All groups analyzed also displayed a 2- to 3-fold reduction in necrosis. CONCLUSIONS: Mucus or "exogenous" mucus in the form of PC has a synergistic role with secretory IgA in barrier defense against C difficile toxin A. Exogenous PC administration can be a therapeutic adjunct in patients with severe or recalcitrant C difficile infection.

Can salivary activity predict periodontal breakdown in A. actinomycetemcomitans infected adolescents?

OBJECTIVE: While Aggregatibacter actinomycetemcomitans (Aa) is highly associated with localised aggressive periodontitis (LAP) many Aa-carriers do not develop LAP. This study was designed to determine whether specific salivary factors could distinguish between subjects who have Aa initially and remain healthy (H/AA) as compared to those who develop LAP (LAP/AA). DESIGN: H/AA subjects and healthy controls with no Aa (H) were enrolled in a longitudinal cohort study to investigate initiation of bone loss (LAP) over 3 years. After detection of LAP, stored saliva from 10 H, 10 H/AA, and 10 LAP/AA subjects was thawed, processed, and tested for (1) lactoferrin (Lf) concentration and iron levels; (2) agglutination of Aa; (3) killing of Gram-positive bacteria. RESULTS: LAP/AA saliva levels of Lf iron were low prior to and after bone loss (3.6+1.7ngFe/µg) (LAP/AA vs. H and H/AA p≤0.01). Saliva from H/AA subjects caused Aa to agglutinate significantly more than H or LAP/AA saliva (p≤0.01). LAP/AA saliva killed Streptococcus mutans, Streptococcus sanguis and Lactobacillus in vitro by >83%. Saliva from H individuals killed these bacteria by <3.3% (LAP/AA vs. H; p≤0.01). H/AA killing was intermediate. CONCLUSION: LAP/AA saliva showed: low levels of Lf iron, minimal Aa agglutinating activity, and high killing activity against Gram-positive bacteria. Aa-positive healthy saliva (H/AA) showed: higher levels of Lf iron, maximal Aa agglutinating activity, and moderate killing of Gram-positive bacteria. A salivary activity profile can distinguish between subjects who are Aa-positive and remain healthy from those who develop LAP.