Lactobacillus rhamnosus GR-1-induced IL-10 production in human placental trophoblast cells involves activation of JAK/STAT and MAPK pathways

The novel role of activating receptor KIR2DS5 in preeclampsia

Preeclampsia (PE) is a serious complication of pregnancy. Decidual natural killer (dNK) cells were reported to participate in the remodeling of spiral arteries through producing a group of cytokines, including granulocyte-macrophage colony stimulating factor (GM-CSF). KIR2DS5 is an activating receptor of NK cells that specifically recognizes HLA-C2 on trophoblasts. Currently, there are no reports regarding the precise mechanism of KIR2DS5 in PE. This study included 30 PE patients and 30 healthy pregnant women. We found that the expressions of KIR2DS5 were significantly lower in PE deciduae compared to those of healthy pregnancies. By transfecting knockdown and overexpression lentivirus vectors of KIR2DS5 into dNK cells isolated from deciduae of early pregnancy, we altered the KIR2DS5 expression level in dNK cells. Then, these dNK cells and trophoblast cell lines were co-cultured as trophoblast-dNK cells. In the trophoblast-dNK cells, we examined the influence of KIR2DS5 on the biological manifestations of trophoblasts. As anticipated, overexpression of KIR2DS5 could facilitate cell proliferation, migration, and invasion. Furthermore, increased expression of KIR2DS5 inhibited cell apoptosis and enhanced the progression of cells from theG1 to theS stage. Further mechanistic study demonstrated a positive relationship between KIR2DS5 and GM-CSF in trophoblast-dNK cells. Accordingly, our observations indicated that a decrease in KIR2DS5 could reduce the expression of GM-CSF via the JAK2/STAT5 pathway, resulting in the failure of the activated signal to be transmitted to dNK cells and ultimately leading to the occurrence of PE. KIR2DS5 may be a new contributor for the prediction and diagnosis of PE.

Cell autonomous expression of BCL6 is required to maintain lineage identity of mouse CCR6+ ILC3s

Innate lymphoid cells (ILC) are similar to T helper (Th) cells in expression of cytokines and transcription factors. For example, RORγt is the lineage-specific transcription factor for both ILC3 and Th17 cells. However, the ILC counterpart for BCL6-expressing T follicular helper (Tfh) cells has not been defined. Here, we report that in the ILC compartment, BCL6 is selectively co-expressed with not only CXCR5 but also RORγt and CCR6 in ILC3 from multiple tissues. BCL6-deficient ILC3 produces enhanced levels of IL-17A and IL-22. More importantly, phenotypic and single-cell ATAC-seq analysis show that absence of BCL6 in mature ILC3 increases the numbers of ILC1 and transitional cells co-expressing ILC3 and ILC1 marker genes. A lineage-tracing experiment further reveals BCL6+ ILC3 to ILC1 trans-differentiation under steady state. Finally, microbiota promote BCL6 expression in colonic CCR6+ ILC3 and thus reinforce their stability. Collectively, our data have demonstrated that CCR6+ ILC3 have both Th17 and Tfh programs and that BCL6 expression in these cells functions to maintain their lineage identity.

Substance P promotes immunotherapy efficacy for airway allergy

Background

Allergen-specific immunotherapy (AIT) has been employed in the treatment of allergic diseases for many years. However, the effectiveness of AIT requires improvement. Substance P (SP) can interact with immune cells, modulate immune cell activity, and regulate immune reaction. The purpose of this study is to use SP as an immune regulator to enhance the therapeutic efficacy of AIT.

Methods

An established mouse model of the airway allergy disorder (AAD) was employed with ovalbumin as a specific antigen. The AAD response was evaluated through established procedures. AAD mice were treated with AIT employing SP as an immune regulator. Dendritic cells were isolated from the airway tissues by magnetic cell sorting, and were analyzed by RNA sequencing (RNAseq).

Results

We observed that after sensitization with ovalbumin, mice exhibited AAD-like symptoms, serum specific IgE, and Th2 polarization. The presence of SP in the course of sensitization prevented the development of AAD. Treating mice with SP by nasal instillations induced IL-10, but not TGF-β, in dendritic cells of the airway tissues. The most differentially expressed genes (DEG) in the dendritic cells were those related to the IL-10 expression, including Il10, Tac1r, and Mtor. The gene ontology analysis showed that these DEGs mainly mapped to the tachykinin-PI3K-AKT-mTOR pathway. The addition of SP substantially enhanced the therapeutic efficacy of AIT for AAD by inducing antigen specific type 1 regulatory T cells (Tr1 cells).

Conclusion

Acting as an immune regulator, SP promotes the therapeutic efficacy for AAD by inducing antigen specific Tr1 cells in the airway tissues.

Melatonin ameliorates lipopolysaccharide induced brain inflammation through modulation of oxidative status and diminution of cytokine rush in Danio rerio

Lipopolysaccharide (LPS) is known to induce inflammation and immunonomodulation in a piscine model of Danio rerio. Present study aimed to explore the ability of melatonin in attenuating LPS-induced oxidative damages using this model. In LPS-exposed fish, activation of stress marker MDA was observed in brain with corresponding augmentation of multiple pro-inflammatory cytokines (IL1β, IL6, IL10 and TNFα). In addition, it also showed marked increase in the levels of heat shock factor (HSF) and heat shock proteins (HSPs) in association with transcription factors (NF-kB and NRF2) and mitogen-activated protein kinases (MAPKs). The changes in the levels of these mediators are highly correlated with the induction of pro-inflammatory cytokines. In melatonin-treated fishes, significant amelioration of oxidative stress was observed with reduced levels of MDA and pro-inflammatory cytokines. Melatonin also modulated expression of HSPs that facilitated the brain to overcome inflammation-induced stress by directly initiating NFkB/NRF2 translocation. In summary, melatonin effectively functions to reduce stress induced inflammatory signalling through modulation of oxidative stress and protects the brain from the neuropathological insult.

Leukotriene Receptor Antagonist, Montelukast Ameliorates L-NAME-Induced Pre-eclampsia in Rats through Suppressing the IL-6/Jak2/STAT3 Signaling Pathway

Aims: To investigate the potential protective role of montelukast (Mont) in the pre-eclampsia rat model induced by L-NG-Nitro arginine methyl ester (L-NAME). Methods and materials: Thirty-two pregnant female albino Wistar rats were assigned to four groups: the control group: pregnant rats received vehicles; the Mont group: pregnant rats received Mont (10 mg/kg/day, p.o.) from the 6th to the 18th day of gestation; the L-NAME group: pregnant rats received L-NAME (50 mg/kg/day, i.p.) from the 9th to the 18th day of gestation; the Mont/L-NAME group: pregnant rats received Mont (10 mg/kg/day, p.o.) from the 6th to the 18th day of gestation and L-NAME (50 mg/kg/day, i.p.) from the 9th to the 18th day of gestation. Placental, hepatic, and renal malondialdehyde (MDA), total nitrites (NOx), interleukin 6 (IL-6), and tumor necrosis factor (TNF)-α were determined. Serum alanine transaminase (ALT), aspartate transaminase (AST), creatinine, urea, 24-h urinary protein, and the placental growth factor (PGF) were measured. Histopathological examinations of the placental, hepatic, and renal tissues were also performed. In addition, placental, hepatic, and renal Janus kinase 2 (Jak2) and signal transducer and activator of transcription 3 (STAT3) immunoblotting were performed. Key findings: Mont improves oxidative stress, IL-6, TNF-α, ALT, AST, creatinine, urea, 24-h urinary protein, PGF, Jak2, and STAT3 which were all affected by L-NAME. Moreover, the histopathological assessment indicated that Mont restored the normal architecture that was markedly disturbed by L-NAME. Significance: Mont exerted the biochemical and histopathological amelioration of L-NAME-caused pre-eclampsia through its anti-inflammatory, anti-oxidant function and suppression of the IL-6/Jak2/STAT3 signaling pathway.

Mir-27a-3p attenuates bronchiolitis obliterans in vivo via the regulation of dendritic cells' maturation and the suppression of myofibroblasts' differentiation

Bronchiolitis obliterans (BO), is a chronic rejection phenotype characterized by chronic small airway fibrous obliteration, hinders the patients who suffer from lung transplanting for surviving longer. Cell-based therapies using dendritic cells (DCs) and T regulatory cells (Tregs) have been developed to regulate allograft rejection, and to induce and maintain immune tolerance. In the present study, the effects of mir-27a-3p on regulating DCs as well as resulting effects on BO attenuation have been investigated. According to our reporter assays, the potential targets of mir-27a-3p were Smad2, sprouty2, and Smad4, respectively. Furthermore, sprouty2 inhibition by mir-27-3p indirectly activated extracellular regulated protein kinases (ERK) and increased IL-10 production in DCs. This led to a positive feedback loop that maintained the immature state of DCs via IL-10/JAK/STAT3 pathway, and caused an increase in Foxp3⁺ CD4⁺ T cells amount as well as TGF-β level. Furthermore, mir-27a-3p regulated TGF-β function, inhibited TGF-β/Smad pathway, and suppressed myofibroblast differentiation through influencing the function of Smad2 and Smad4. In short, the study indicated the effect of mir-27a-3p on suppressing DC maturation, which implicated the potential clinical application in treating postlung transplant BO.

Ribosomal protein L4 of Lactobacillus rhamnosus LRB alters resistance to macrolides and other antibiotics

Lactobacillus rhamnosus is an important lactic acid bacterium that is predominantly used as a probiotic supplement. This bacterium secretes immunomodulatory and antibacterial peptides that are necessary for the probiotic trait. This organism also occupies diverse ecological niches, such as gastrointestinal tracts and the oral cavity. Several studies have shown that L. rhamnosus is prone to spontaneous genome rearrangement irrespective of the ecological origins. We previously characterized an oral isolate of L. rhamnosus, LRB, which is genetically closely related to the widely used probiotic strain L. rhamnosus LGG. In this study, we isolated a nontargeted mutant that was particularly sensitive to acid stress. Using next generation sequencing, we further mapped the putative mutations in the genome and found that the mutant had acquired a deletion of 75 base pairs in the rplD gene that encodes the large ribosomal subunit L4. The mutant had a growth defect at 37°C and at ambient temperature. Further antibiotic sensitivity analyses indicated that the mutant is relatively more resistant to erythromycin and chloramphenicol; two antibiotics that target the 50S subunit. In contrast, the mutant was more sensitive to tetracycline, which targets the 30S subunit. Thus, it appears that nontargeted mutations could significantly alter the antibiotic resistance profile of L. rhamnosus. Our study raises concern that probiotic use of L. rhamnosus should be carefully monitored to avoid unintended consequences.

Neurocognitive and social-communicative function of children born very preterm at 10 years of age: Associations with microorganisms recovered from the placenta parenchyma

OBJECTIVE

Infection of the placenta has been associated with preterm birth as well as neurocognitive impairment. This study aimed to determine whether specific bacterial species in the placenta of extremely preterm pregnancies are associated with neurological deficits later in life.

STUDY DESIGN

Using data from 807 children in the ELGAN study the risks of a low score on six neurological assessments in relation to 15 different microbes were quantified with odds ratios.

RESULTS

The presence of certain microbial species in the placenta was associated with lower scores on numerical and oral language assessments. Lactobacillus sp. was associated with decreased risk of a low oral language score and a composite measure of IQ and executive function.

CONCLUSION

Placental microorganisms were associated with neurocognitive, but not social-communicative, outcomes at age 10. In contrast, the presence of the anti-inflammatory Lactobacillus sp. in the placenta was associated with a lower risk of impaired neurocognitive functions.

Microorganisms in the Placenta: Links to Early-Life Inflammation and Neurodevelopment in Children

Prenatal exposure to various stressors can influence both early and later life childhood health. Microbial infection of the intrauterine environment, specifically within the placenta, has been associated with deleterious birth outcomes, such as preterm birth, as well as adverse neurological outcomes later in life. The relationships among microorganisms in the placenta, placental function, and fetal development are not well understood. Microorganisms have been associated with perinatal inflammatory responses that have the potential for disrupting fetal brain development. Microbial presence has also been associated with epigenetic modifications in the placenta, as well other tissues. Here we review research detailing the presence of microorganisms in the placenta and associations among such microorganisms, placental DNA methylation, perinatal inflammation, and neurodevelopmental outcomes.

Protective Effect of Methane-Rich Saline on Acetic Acid-Induced Ulcerative Colitis via Blocking the TLR4/NF-κB/MAPK Pathway and Promoting IL-10/JAK1/STAT3-Mediated Anti-inflammatory Response

Ulcerative colitis (UC) is an inflammation-related disease involved in uncontrolled inflammation and oxidative stress and is characterized by high recurrence and relapse risk. As a rising star in gas medicine, methane owns the properties of anti-inflammation, antioxidation, and antiapoptosis. Based on the possible mechanism, we aimed to investigate the effect of methane on UC. Methane-rich saline (MRS) was introduced here, and UC was induced by acetic acid. All the C57BL/6 mice were allocated into groups as follows: control group, colitis model group, colitis treated with salazosulfapyridine (SASP) group, and colitis treated with MRS (1 or 10 ml/kg) groups. Tissue damage, the degree of inflammation, oxidative stress, and apoptosis were evaluated in the study, as well as the TLR4/NF-κB/MAPK and IL-10/JAK1/STAT3 signaling pathways for further exploration of the potential mechanism. The results showed that MRS (1) alleviated tissue damage caused by acetic acid, (2) controlled acetic acid-induced inflammation, (3) inhibited acetic acid-caused oxidative stress, (4) reduced colonic cell apoptosis due to acetic acid, (5) suppressed the TLR-4/NF-κB/MAPK signaling pathway, and (6) activated IL-10/JAK1/STAT3 anti-inflammatory response to improve the injury induced by acetic acid. We conclude that MRS has a protective effect on acetic acid-induced ulcerative colitis in mice via blocking the TLR4/NF-κB/MAPK signaling pathway and promoting the IL-10/JAK1/STAT3-mediated anti-inflammatory response.

Probiotic Lactobacillus rhamnosus GR-1 is a unique prophylactic agent that suppresses infection-induced myometrial cell responses

Preterm birth (PTB) is a multifactorial syndrome affecting millions of neonates worldwide. Intrauterine infection can induce PTB through the secretion of pro-inflammatory cytokines and untimely activation of uterine contractions. In pregnant mice, prophylactic administration of probiotic Lactobacillus rhamnosus GR-1 supernatant (GR1SN) prevented lipopolysaccharide (LPS)-induced PTB and reduced cytokine expression in the uterine muscle (myometrium). In this study we sought to delineate the mechanisms by which GR1SN suppressed cytokine secretion in the myometrium. We observed that L. rhamnosus GR-1 uniquely secretes heat-resistant but trypsin-sensitive factors, which significantly suppressed LPS-induced secretion of pro-inflammatory cytokines IL-6, IL-8, and MCP-1 in the human myometrial cell line, hTERT-HM. This effect was unique to GR1SN and could not be replicated using supernatant derived from non-GR-1 commensal lactobacilli species: L. rhamnosus GG, L. lactis, L. casei, or L. reuteri RC-14. Furthermore, pre-incubation of hTERT-HM cells with low-dose Pam3CSK (a TLR1/2 synthetic agonist which mimics LPS action) prior to LPS administration also significantly decreased LPS-induced cytokine secretion. This study highlights the distinct capacity of protein-like moieties secreted by L. rhamnosus GR-1 to inhibit pro-inflammatory cytokine production by human myometrial cells, potentially through a TLR1/2-mediated mechanism.

MicroRNA let-7i regulates dendritic cells maturation targeting interleukin-10 via the Janus kinase 1-signal transducer and activator of transcription 3 signal pathway subsequently induces prolonged cardiac allograft survival in rats

BACKGROUND

In this study, we investig1ated whether microRNA let-7i regulates dendric cell maturation targeting interleukin-10 (IL-10) via the Janus kinase 1-signal transducer and activator of transcription 3 (JAK1-STAT3) signal pathway subsequently prolongs rat cardiac allograft survival.

METHODS

Quantitative real-time reverse transcriptase polymerase chain reaction, enzyme linked immunosorbent assay, and dual-luciferase assay were performed to verify whether IL-10 was the target of let-7i, and regulatory T cells were assessed by flow cytometry and immunohistochemical study. Western blot was performed to detect JAK1, STAT3, and phosphorylated STAT3 expression. Lewis recipients of Dark Agouti hearts were transfused with phosphate-buffered saline, lipopolysaccharide (LPS)-mature dendritic cells (mDCs), or let-7i-inhibitor-mDCs. Allograft survival times were recorded, and histologic studies were performed.

RESULTS

Expression of IL-10 messenger RNA level and production of IL-10 were increased in let-7i-inhibitor-mDCs compared with LPS-mDCs. Luciferase activity showed that the translational level of the IL-10 luciferase reporter was decreased by let-7i mimic but increased by let-7i-inhibitor. MicroRNA let-7i inhibitor suppressed DC maturation; however, pretreatment of IL-10 small interfering RNA attenuated the suppression. Expression of JAK1, STAT3, and phosphorylated STAT3 in mDCs were suppressed by let-7i mimic, and pre-treatment of IL-10 small interfering RNA, however, were upregulated by let-7i inhibitor. Lewis recipients transfused with let-7i-inhibitor-mDCs significantly prolonged Dark Agouti cardiac allograft survival. The allografts transfused with let-7i-inhibitor-mDCs showed slight cell infiltration and significantly preserved graft structure. Inhibition of let-7i increased CD4(+)CD25(+)forkhead box P3(+) regulatory T cells and modulated cytokine profiles in vivo and in vitro.

CONCLUSIONS

MicroRNA let-7i regulated DC maturation and function targeting IL-10 through the JAK1-STAT3 pathway. Moreover, transfusion of LPS-induced mDCs transfected with let-7i inhibitor induced prolonged cardiac allograft survival and generated regulatory T cells.

Preferential production of G-CSF by a protein-like Lactobacillus rhamnosus GR-1 secretory factor through activating TLR2-dependent signaling events without activation of JNKs

Background

Different species and strains of probiotic bacteria confer distinct immunological responses on immune cells. Lactobacillus rhamnosus GR-1 (GR-1) is a probiotic bacterial strain found in both the intestinal and urogenital tracts, and has immunomodulatory effects on several cell types including macrophages. However, detailed immunological responses and the signaling mechanism involved in the response are largely unknown.

Results

We examined the production of GR-1-induced cytokines/chemokines and signaling events in macrophages. Among 84 cytokines and chemokines examined, GR-1 discretely induced granulocyte colony-stimulating factor (G-CSF) mRNA at highest levels (>60-fold) without inducing other cytokines such as IL-1α, IL-1β, IL-6 and TNF-α (<5-fold). The toll-like receptor (TLR) 2/6-agonist PAM₂CSK₄, TLR2/1-agonist PAM₃CSK₄ and TLR4-agonist lipopolysaccharide induced all of these inflammatory cytokines at high levels (>50-fold). The TLR2 ligand lipoteichoic acid activated all mitogen-activated kinases, Akt and NF-κB; whereas, GR-1 selectively activated extracellular regulated kinases and p38, NF-κB and Akt, but not c-Jun N-terminal kinases (JNKs) in a TLR2-dependent manner. Using specific inhibitors, we demonstrated that lack of JNKs activation by GR-1 caused inefficient production of pro-inflammatory cytokines but not G-CSF production. A secreted heat-labile protein-like molecule, 30–100 kDa in size, induced the preferential production of G-CSF.

Conclusion

This study elucidated unique signaling events triggered by GR-1, resulting in selective production of the immunomodulatory cytokine G-CSF in macrophages.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-015-0578-2) contains supplementary material, which is available to authorized users.

Evaluation of serum interleukin-10 levels as a predictor of glycemic alteration in chronic periodontitis and type 2 diabetes mellitus

Aim:

Chronic periodontal disease (CPD) and type 2 diabetes mellitus (T2DM) share common pathogenic pathways. This study aimed to estimate levels of serum interleukin (IL-10), an anti-inflammatory cytokine also associated with T2DM and evaluate its association with hyperglycemia.

Materials and Methods:

This investigation involved sixty participants divided into four groups comprising 15 participants each: Group 1 (healthy controls), Group 2 (CPD patients), Group 3 (T2DM patients with CPD) and Group 4 (T2DM patients). Plaque index, gingival index, probing pocket depths (PPD), clinical attachment loss, bleeding on probing, random blood sugar, glycosylated hemoglobin (HbA1c), and serum IL-10 was measured.

Results:

Interleukin-10 was detected in all four groups. Statistically significant (P < 0.05) differences were observed in most of the variables in all groups. IL-10 correlated significantly with PPD in Group 1 and with HbA1c in Group 4. IL-10 regressed with PPD in Group 1 and with HbA1c in Group 4. IL-10 levels were lower in Group 3 when compared with Group 4 and was lowest in Group 2.

Conclusion:

Low IL-10 levels associated with high HbA1c. Pathogenic mechanisms of CPD seem to regulate IL-10. Serum IL-10 levels may be one of the predictors of glycemia.

Profiles and technological requirements of urogenital probiotics

Probiotics, defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, are considered a valid and novel alternative for the prevention and treatment of female urogenital tract infections. Lactobacilli, the predominant microorganisms of the healthy human vaginal microbiome, can be included as active pharmaceutical ingredients in probiotics products. Several requirements must be considered or criteria fulfilled during the development of a probiotic product or formula for the female urogenital tract. This review deals with the main selection criteria for urogenital probiotic microorganisms: host specificity, potential beneficial properties, functional specifications, technological characteristics and clinical trials used to test their effect on certain physiological and pathological conditions. Further studies are required to complement the current knowledge and support the clinical applications of probiotics in the urogenital tract. This therapy will allow the restoration of the ecological equilibrium of the urogenital tract microbiome as well as the recovery of the sexual and reproductive health of women.

Is there a role for probiotics in the prevention of preterm birth?

Preterm birth (PTB) continues to be a global health challenge. An over-production of inflammatory cytokines and chemokines, as well as an altered maternal vaginal microbiome has been implicated in the pathogenesis of inflammation/infection-associated PTB. Lactobacillus represents the dominant species in the vagina of most healthy pregnant women. The depletion of Lactobacillus in women with bacterial vaginosis (BV) has been associated with an increased risk of PTB. It remains unknown at what point an aberrant vaginal microbiome composition specifically induces the cascade leading to PTB. The ability of oral or vaginal lactobacilli probiotics to reduce BV occurrence and/or dampen inflammation is being considered as a means to prevent PTB. Certain anti-inflammatory properties of lactobacilli suggest potential mechanisms. To date, clinical studies have not been powered with sufficiently high rates of PTB, but overall, there is merit in examining this promising area of clinical science.

IL10, TGF beta1, and IFN gamma modulate intracellular signaling pathways and cytokine production to control Toxoplasma gondii infection in BeWo trophoblast cells

Considering that interleukin 10 (IL10), transforming growth factor beta1 (TGFB1), and interferon gamma (IFNG) are involved in the susceptibility of BeWo trophoblast cells to Toxoplasma gondii infection, the aim of the present study was to investigate the effector mechanisms triggered by these cytokines in the control of T. gondii in BeWo cells. For this purpose, infected/uninfected BeWo cells were treated with IL10, TGFB1 (50 ng/ml), and IFNG (20 or 100 ng/ml) in order to verify the phosphorylation of signal transducers and activators of transcription 1 (STAT1), STAT3, and Smad2, parasite intracellular proliferation, as well as the Th1/Th2/IL17A cytokine production. The treatment of BeWo cells with IL10 and TGFB1 favored T. gondii proliferation, and these findings were associated with STAT3 and Smad2 phosphorylation, respectively (P < 0.05). Also, these cytokine treatments were able to down-modulate TNF alpha (TNFA) and IL6 production (P < 0.05). Low concentration of IFNG was unable to control T. gondii infection but was able to trigger STAT1 phosphorylation and up-regulate IL6 and IL17A production; whereas a high concentration of IFNG was unable to activate STAT1 but down-modulated IL6 and TNFA and increased T. gondii proliferation (P < 0.05). IL10, TGFB1, and IFNG regulate a differential T. gondii proliferation in BeWo cells because they distinctly trigger intracellular signaling pathways and cytokine production, especially IL6 and TNFA. Our data open new windows to understand the mechanisms triggered by IL10, TGFB1, and IFNG at the maternal-fetal interface in the presence of T. gondii, contributing to recognizing the importance of these effector mechanisms involved in the vertical transmission of this parasite.

Probiotic Lactobacillus rhamnosus GR-1 supernatant prevents lipopolysaccharide-induced preterm birth and reduces inflammation in pregnant CD-1 mice

OBJECTIVE

The objective of this study was to determine the effect of probiotic Lactobacillus rhamnosus GR-1 supernatant (GR-1 SN) on lipopolysaccharide-induced preterm birth (PTB) and outputs of cytokines, chemokines, and progesterone in pregnant CD-1 mice.

STUDY DESIGN

We compared PTB rates after intrauterine injection of lipopolysaccharide with and without previous GR-1 SN treatment. Cytokines and chemokines in the maternal plasma, myometrium, placenta, and amniotic fluid were examined with multiplex assay, and circulating maternal progesterone was measured with enzyme-linked immunoassay. Statistical significance was assessed with 2-tailed 1-way analysis of variance or analysis of variance on ranks. Fetal sex ratios in mice that delivered preterm were compared with those that delivered at term after lipopolysaccharide and GR-1 SN treatments.

RESULTS

GR-1 SN reduced lipopolysaccharide-induced PTB by 43%. GR-1 SN significantly decreased the lipopolysaccharide-induced production of interleukin (IL)-1β, -6, and -12p40, tumor necrosis factor-α, CCL4, and CCL5 in maternal plasma; IL-6, -12p70, -17, and -13 and tumor necrosis factor-α in myometrium; IL-6, -12p70, and -17 in placenta; and IL-6, tumor necrosis factor-α, CCL3, and CCL4 in amniotic fluid. Maternal plasma progesterone was reduced significantly after lipopolysaccharide injection with and without GR-1 SN pretreatment. There was no difference in fetal sex ratios between mice that delivered preterm and those that did not after lipopolysaccharide and GR-1 SN treatments.

CONCLUSION

The supernatant of probiotic L rhamnosus GR-1 attenuated lipopolysaccharide-induced inflammation and PTB in vivo. GR-1 SN may confer therapeutic benefits in the prevention of infection-associated PTB by controlling systemic and intrauterine inflammation.

Infection-induced IL-10 and JAK-STAT: A review of the molecular circuitry controlling immune hyperactivity in response to pathogenic microbes

Generation of effective immune responses against pathogenic microbes depends on a fine balance between pro- and anti-inflammatory responses. Interleukin-10 (IL-10) is essential in regulating this balance and has garnered renewed interest recently as a modulator of the response to infection at the JAK-STAT signaling axis of host responses. Here, we examine how IL-10 functions as the “master regulator” of immune responses through JAK-STAT, and provide a perspective from recent insights on bacterial, protozoan, and viral infection model systems. Pattern recognition and subsequent molecular events that drive activation of IL-10-associated JAK-STAT circuitry are reviewed and the implications for microbial pathogenesis are discussed.

Probiotics and nutrients for the first 1000 days of life in the developing world

Clinically proven probiotics are, for the most part, not available in the developing world and certainly not affordable for the majority of people. This is unconscionable considering these products can alleviate diarrhoea and various infections, which are by far the major cause of death in children and in adults who are HIV positive. Indeed, some of these products have been proven in developing world settings. Distribution networks exist along with pharmacies and clinics that dispense drugs and products that require refrigeration. So, are lack of profit or company resources the problem? Our university has shown that alternative community based kitchen models that produce probiotics can be established. These empower local people, are socially responsible, produce affordable products and deliver benefits to over 3,000 children and adults daily. Surely, other institutions and corporations can multiply this effect and develop social business models across the developing world that are supported by clinical and basic science studies? In this review, we will discuss the application of probiotics and selected nutrients in the first 1000 days of life, a critical timepoint which is particularly challenging in resource disadvantaged countries.

Lactobacillus rhamnosus GR-1 enhances NF-kappaB activation in Escherichia coli-stimulated urinary bladder cells through TLR4

Background

Epithelial cells of the urinary tract recognize pathogenic bacteria through pattern recognition receptors on their surface, such as toll-like receptors (TLRs), and mount an immune response through the activation of the NF-kappaB pathway. Some uropathogenic bacteria can subvert these cellular responses, creating problems with how the host eliminates pathogens. Lactobacillus is a genus of lactic acid bacteria that are part of the microbiota and consist of many probiotic strains, some specifically for urogenital infections. Immunomodulation has emerged as an important mode of action of probiotic and commensal lactobacilli and given the importance of epithelial cells, we evaluated the effect of the urogenital probiotic Lactobacillus rhamnosus GR-1 on epithelial immune activation.

Results

Immune activation through the NF-kappaB pathway was initiated by stimulation of T24 urothelial cells with heat-killed Escherichia coli and this was further potentiated when cells were co-cultured with live L. rhamnosus GR-1. Heat-killed lactobacilli were poor activators of NF-kappaB. Concomitant stimulation of bladder cells with E. coli and L. rhamnosus GR-1 increased the levels of the pro-inflammatory cytokine TNF, whereas IL-6 and CXCL8 levels were reduced. Another probiotic, L. rhamnosus GG, was also able to potentiate NF-kappaB in these cells although at a significantly reduced level compared to the GR-1 strain. The transcript numbers and protein levels of the lipopolysaccharide receptor TLR4 were significantly increased after co-stimulation with E. coli and lactobacilli compared to controls. Furthermore, inhibition of TLR4 activation by polymixin B completely blocked the lactobacilli potentiation of NF-kappaB.

Conclusions

The immunological outcome of E. coli challenge of bladder cells was influenced by probiotic L. rhamnosus GR-1, by enhancing the activation of NF-kappaB and TNF release. Thus the urogenital probiotic L. rhamnosus GR-1 modulated the activation of the NF-kappaB through increased levels of TLR4 on the bladder cells and altered subsequent release of cytokines from urothelial cells. By influencing immunological factors such as TLR4, important in the process of fighting pathogens, lactobacilli could facilitate pathogen recognition and infection clearance.

Probiotics, nuclear receptor signaling, and anti-inflammatory pathways

There is increased investigation of the human microbiome as it relates to health and disease. Dysbiosis is implicated in various clinical conditions including inflammatory bowel disease (IBD). Probiotics have been explored as a potential treatment for IBD and other diseases. The mechanism of action for probiotics has yet to be fully elucidated. This paper discusses novel mechanisms of action for probiotics involving anti-inflammatory signaling pathways. We highlight recent progress in probiotics and nuclear receptor signaling, such as peroxisome-proliferator-activated receptor gamma (PPARγ) and vitamin D receptor (VDR). We also discuss future areas of investigation.