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T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy that is still fatal in many cases. T cell blasts are characterized by hyperactivation and strong proliferative and migratory capacities. The chemokine receptor CXCR4 is involved in mediating malignant T cell properties and cortactin has been shown to control CXCR4 surface localization in T-ALL cells. We have previously shown that cortactin overexpression is correlated with organ infiltration and relapse in B-ALL. However, the role of cortactin in T cell biology and T-ALL remains elusive. Here, we analyzed the functional relevance of cortactin for T cell activation and migration and the implications for T-ALL development. We found that cortactin is upregulated in response to TCR engagement and recruited to the immune synapse in normal T cells. Loss of cortactin caused reduced IL-2 production and proliferation. Cortactin-depleted T cells showed defects in immune synapse formation and migrated less due to impaired actin polymerization in response to TCR and CXCR4 stimulation. Leukemic T cells expressed much higher levels of cortactin compared to normal T cells that correlated with greater migratory capacity. Xenotransplantation assays in NSG mice revealed that cortactin-depleted human leukemic T cells colonized the bone marrow significantly less and failed to infiltrate the central nervous system suggesting that cortactin overexpression drives organ infiltration, which is a major complication of T-ALL relapse. Thus, cortactin could serve as a potential therapeutic target for T-ALL and other pathologies involving aberrant T cell responses.

Hypertension (HTN) causes end-organ damage and is a major cause of morbidity and mortality globally. Recent studies suggested blood cells participate in the maintenance of HTN. Platelets-anucleated cell fragments derived from megakaryocytes-exert diverse functions, including their well-characterized role in the formation of hemostatic clots. However, platelets from patients with HTN exhibit altered membrane lipid and protein compositions that impact platelet function and lead to formation of aggregates and vascular obstructions. Here, for the first time, we have identified, by proteomic analyses, the most relevant 11 proteins that show the greatest difference in their expression in platelets derived from patients with HTN, in comparison with those from normotensive individuals. These proteins are involved in cytoskeletal organization and the coagulation cascade that contributes to platelet activation, release of granule contents, and aggregation, which culminate in thrombus formation. These results have important implications in our understanding of the molecular mechanisms associated with the development of HTN, and in consequence, the development of new strategies to counteract the cardiovascular disorders associated with constitutive activation of platelets in HTN.

Enteropathogenic bacterial infections are a global health issue associated with high mortality, particularly in developing countries. Efficient host protection against enteropathogenic bacterial infection is characterized by coordinated responses between immune and nonimmune cells. In response to infection in mice, innate immune cells are activated to produce interleukin (IL)-23 and IL-22, which promote antimicrobial peptide (AMP) production and bacterial clearance. IL-36 cytokines are proinflammatory IL-1 superfamily members, yet their role in enteropathogenic bacterial infection remains poorly defined. Using the enteric mouse pathogen, C. rodentium, we demonstrate that signaling via IL-36 receptor (IL-36R) orchestrates a crucial innate-adaptive immune link to control bacterial infection. IL-36R-deficient mice (Il1rl2(−/−)) exhibited significant impairment in expression of IL-22 and AMPs, increased intestinal damage, and failed to contain C. rodentium compared to controls. These defects were associated with failure to induce IL-23 and IL-6, two key IL-22 inducers in the early and late phases of infection, respectively. Treatment of Il1rl2(−/−) mice with IL-23 during the early phase of C. rodentium infection rescued IL-22 production from group 3 innate lymphoid cells (ILCs), whereas IL-6 administration during the late phase rescued IL-22-mediated production from CD4(+) T cell, and both treatments protected Il1rl2(−/−) mice from uncontained infection. Furthermore, IL-36R-mediated IL-22 production by CD4(+) T cells was dependent upon NFκB-p65 and IL-6 expression in dendritic cells (DCs), as well as aryl hydrocarbon receptor (AhR) expression by CD4(+) T cells. Collectively, these data demonstrate that the IL-36 signaling pathway integrates innate and adaptive immunity leading to host defense against enteropathogenic bacterial infection.

The process by which blood cells are generated has been widely studied in homeostasis and during pathogen-triggered inflammatory response. Recently, murine lungs have been shown to be a significant source of hematopoietic progenitors in a process known as extramedullary hematopoiesis. Using multiparametric flow cytometry, we have identified mesenchymal, endothelial, and hematopoietic progenitor cells that express the secreted small protein Isthmin 1 (ISM1). Further characterization of hematopoietic progenitor cells indicated that ISM1

Manganese is considered essential for animal growth. Manganese ions serve as cofactors to three mitochondrial enzymes: superoxide dismutase (Sod2), arginase and glutamine synthase, and to glycosyltransferases residing in the Golgi. In Drosophila melanogaster, manganese has also been implicated in the formation of ceramide phosphoethanolamine, the insect's sphingomyelin analogue, a structural component of cellular membranes. Manganese overload leads to neurodegeneration and toxicity in both humans and Drosophila. Here, we report specific absorption and accumulation of manganese during the first week of adulthood in flies, which correlates with an increase in Sod2 activity during the same period. To test the requirement of dietary manganese for this accumulation, we generated a Drosophila model of manganese deficiency. Due to the lack of manganese-specific chelators, we used chemically defined media to grow the flies and deplete them of the metal. Dietary manganese depletion reduced Sod2 activity. We then examined gene and protein expression changes in the intestines of manganese depleted flies. We found adaptive responses to the presumed loss of known manganese-dependent enzymatic activities: less glutamine synthase activity (amination of glutamate to glutamine) was compensated by 50% reduction in glutaminase (deamination of glutamine to glutamate); less glycosyltransferase activity, predicted to reduce protein glycosylation, was compensated by 30% reduction in lysosomal mannosidases (protein deglycosylating enzymes); less ceramide phosphoethanolamine synthase activity was compensated by 30% reduction in the Drosophila sphingomyeline phospodiesterase, which could catabolize ceramide phosphoethanolamine in flies. Reduced Sod2 activity, predicted to cause superoxide-dependent iron–sulphur cluster damage, resulted in cellular iron misregulation.

The high prevalence of childhood obesity in Mexico is alarming in the health-science field. We propose to investigate the contribution of adipokines and cytokines polymorphisms and common BMI/obesity-associated loci, revealed in genome-wide association studies in Caucasian adult cohorts, with childhood obesity. This study included 773 Mexican-Mestizo children (5-15 years old) in a case-control study. The polymorphisms included were ADIPOQ (rs6444174), TNF-α (rs1800750), IL-1β (rs1143643), IL-6 (rs1524107; rs2069845), NEGR1 (rs34305371), SEC16B-RASAL2 (rs10913469), TMEM18 (rs6548238; rs7561317), GNPDA2 (rs16857402), LEP (rs2167270), MTCH2 (rs10838738), LGR4-LIN7C-BDNF (rs925946), BCDIN3D-FAIM2 (rs7138803), FTO (rs62033400), MC4R (rs11872992), MC4R (rs17782313), and KCTD15 (rs29942). No significant contribution was found with adipokines and cytokines polymorphisms in this study. Only both TMEM18 (rs6548238; rs7561317) polymorphisms were found associated with obesity (OR=0.5, P=0.008) and were in linkage disequilibrium (r2=0.87). The linear regression showed that the rs7561317 polymorphism of TMEM18 is negatively associated with obesity. This report highlights the influence of TMEM18 in Mexican-Mestizo children obesity, while adipokine and cytokine polymorphisms were not associated with it.

Overfishing of sea cucumber Isostichopus badionotus from Yucatan has led to a major population decline. They are being captured as an alternative to traditional species despite a paucity of information about their health-promoting properties. The transcriptome of the body wall of wild and farmed I. badionotus has now been studied for the first time by an RNA-Seq approach. The functional profile of wild I. badionotus was comparable with data in the literature for other regularly captured species. In contrast, the metabolism of first generation farmed I. badionotus was impaired. This had multiple possible causes including a sub-optimal growth environment and impaired nutrient utilization. Several key metabolic pathways that are important in effective handling and accretion of nutrients and energy, or clearance of harmful cellular metabolites, were disrupted or dysregulated. For instance, collagen mRNAs were greatly reduced and deposition of collagen proteins impaired. Wild I. badionotus is, therefore, a suitable alternative to other widely used species but, at present, the potential of farmed I. badionotus is unclear. The environmental or nutritional factors responsible for their impaired function in culture remain unknown, but the present data gives useful pointers to the underlying problems associated with their aquaculture.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Alphainfluenzavirus are RNA viruses that cause coronavirus disease-19 and influenza, respectively. Both viruses infect the respiratory tract, show similar symptoms, and use surface proteins to infect the host. Influenza requires hemagglutinin and neuraminidase to infect, whereas SARS-CoV-2 uses protein S. Both viruses depend on a viral RNA polymerase to express their proteins, but only SARS-CoV-2 has a proofreading mechanism, which results in a low mutation rate compared to influenza. E1KC4 and camostat mesylate are potential inhibitors of SARS-CoV-2 S protein, achieving an effect similar to oseltamivir. Due to the SARS-CoV-2 low mutation rate, nucleoside analogs have been developed (such as EIDD-2801), which insert lethal mutations in the viral RNA. Furthermore, the SARS-CoV-2 low mutation rate suggests that a vaccine, as well as the immunity developed in recovered patients, could provide long-lasting protection compared to vaccines against influenza, which are rendered obsolete as the virus mutates.La enfermedad por coronavirus de 2019 y la influenza son causadas por virus ARN: coronavirus tipo 2 del síndrome respiratorio agudo grave (SARS-CoV-2) y Alphainfluenzavirus, respectivamente. Ambos virus infectan el tracto respiratorio, presentan síntomas similares y emplean proteínas de superficie para infectar al huésped. El virus de la influenza requiere de hemaglutinina y neuraminidasa para infectar, mientras que el SARS-CoV-2 utiliza la proteína S. Ambos virus dependen de la ARN polimerasa viral para expresar sus proteínas, pero solo el SARS-CoV-2 cuenta con un mecanismo de corrección de errores, por lo que presenta una baja tasa de mutaciones en comparación con el virus de la influenza. E1KC4 y el mesilato de camostat son inhibidores potenciales de la proteína S del SARS-CoV-2, obteniendo un efecto similar al de oseltamivir. Aprovechando la baja tasa de mutación del SARS-CoV-2, se han desarrollado análogos de nucleósidos (como el fármaco EIDD-2801) que insertan mutaciones letales en el ARN viral. Además, la baja tasa de mutación del SARS-CoV-2, obteniendo un efecto similar al de oseltamivir sugiere que las vacunas desarrolladas, así como la inmunidad generada en pacientes recuperados, podrían brindar protección prolongada, en comparación con las vacunas desarrolladas contra la influenza, que resultan obsoletas frente a una cepa mutada.

In the development of cervical cancer (CC), the immune response plays an essential role, from the elimination of human papillomavirus (HPV) infection to the response against the tumor. For optimal function of the immune response, various factors are required, one of the most important being an adequate nutrition. The complex interaction between nutrients and microbiota maintains the immune system in homeostasis and in case of infection, it provides the ability to fight against pathogen invasion, as occurs in HPV infection. The purpose of this article is to describe the role of diet, food, and specific nutrients in the immune response from the onset of infection to progression to precancerous lesions and CC, as well as the role of diet and nutrition during oncological treatment. The immunomodulatory role of microbiota is also discussed. A detailed analysis of the evidence leads us to recommend a nutritional pattern very similar to the Mediterranean diet or the prudent diet for an optimal immune response. Moreover, pre- and probiotics favorably modulate the microbiota and induce preventive and therapeutic effects against cancer.

Sea cucumber body wall contains several naturally occurring bioactive components that possess health-promoting properties. Isostichopus badionotus from Yucatan, Mexico is heavily fished, but little is known about its bioactive constituents. We previously established that I. badionotus meal had potent anti-inflammatory properties in vivo. We have now screened some of its constituents for anti-inflammatory activity in vitro. Glycosaminoglycan and soluble protein preparations reduced 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammatory responses in HaCaT cells while an ethanol extract had a limited effect. The primary glycosaminoglycan (fucosylated chondroitin sulfate, FCS) was purified and tested for anti-inflammatory activity in vivo. FCS modulated the expression of critical genes, including NF-ĸB, TNF&alpha, iNOS, and COX-2, and attenuated inflammation and tissue damage caused by TPA in a mouse ear inflammation model. It also mitigated colonic colitis caused in mice by dextran sodium sulfate. FCS from I. badionotus of the Yucatan Peninsula thus had strong anti-inflammatory properties in vivo.

Background: Cronobacter sakazakii is an opportunistic foodborne pathogen associated with necrotizing enterocolitis, bacteraemia, and meningitis in infants. A comparative proteomic study of C . sakazakii ATCC BAA-894 (CS WT) and isogenic mutant of flagella were performed; including the ability of both strains to adhere and invade to N1E-115 cells. Results: To achieve this goal, a non-motile C. sakazakii ATCC BAA-894 fliF ::Tn5 (CS fliF ::Tn5) strain was generated using an EZ-Tn5Tnp Transposome kit. Analysis of differential protein expression showed that 81.49% (361/443) of the proteins were identified in both strains, 8.35% (37/443) were exclusively expressed in the CS WT strain and 10.16% (45/443) in the CS fliF ::Tn5 strain. The main exclusive proteins from the CS WT strain were classified into the following subcategories: “cell motility” and “signal transduction mechanisms”. In contrast, the exclusive proteins from the CS fliF ::Tn5 strain were classified into the following subcategories: “intracellular trafficking, secretion, and vesicular transport”, “replication, recombination, and repair”, “nucleotide transport and metabolism”, “carbohydrate transport and metabolism”, “coenzyme transport and metabolism”, and “lipid transport and metabolism”. Expression of the Cpa protein was shared by both strains but was more abundant in the CS WT strain than in the CS fliF ::Tn5 strain. Significant increases (p=0.0001) in adherence to N1E-115 cells were observed for the non-motile CS fliF ::Tn5 strain, with 31.3×10 6 CFU/mL, relative to the CS WT strain, with 14.5×10 6 CFU/mL. Additionally, for infection of N1E-115 cells, the CS WT strain showed a 0.17% invasion frequency, which was significantly increased (p=0.01) compared to that of the non-motile CS fliF ::Tn5 strain. Conclusion : The proteins involved in motility were mainly identified by proteomic analysis in CS WT strain when compare to CS fliF ::Tn5 strain. Our data showed that flagella are required to promote invasion to N1E-115 cells and absence of flagella significantly increases the adherence to N1E-115 cells when compare to CS WT strain.

Background and objectives: Type 2 diabetes (T2D) is a major problem of public health in Mexico. We investigated the influence of five polymorphisms, previously associated with obesity and cardiovascular disease in Europeans and Asians, on T2D in Mexican Mestizos. Materials and Methods: A total of 1358 subjects from 30 to 85 years old were genotyped for five loci: CXCL12 rs501120; CDNK2A/B rs1333049; HNF-1α rs2259816; FTO rs9939609; and LEP rs7799039. We used logistic regressions to test the effect of each locus on T2D in two case⁻control groups with obesity and without obesity. Also, linear regression models on glucose and glycated hemoglobin (HbA1c) were carried out on the whole sample, adjusted by age, gender, and body mass index. Results: The CXCL12 rs501120 C allele (OR = 1.96, p = 0.02), the FTO rs9939609 A allele (OR = 2.20, p = 0.04) and the LEP rs7799039 A allele (OR = 0.6, p = 0.03) were significantly associated with T2D in obesity case⁻control group. No significant association was found in the non-obesity case⁻control group. The linear regression model showed that CDNK2A/B rs1333049 C allele (β = 0.4, p = 0.03) and FTO rs9939609 A allele (β = 0.5, p = 0.03), were significantly associated with HbA1c, but no association was found among the loci with the glucose levels. Conclusions: Polymorphisms previously linked with obesity and cardiovascular events were also associated with T2D and high levels of HbA1c. Furthermore, we must point at the fact that this is the first report where polymorphisms CXCL12 rs501120 and LEP rs7799039 are associated with T2D in subjects with obesity.

Intestinal macrophages are highly mobile cells with extraordinary plasticity and actively contribute to cytokine-mediated epithelial cell damage. The mechanisms triggering macrophage polarization into a proinflammatory phenotype are unknown. Here, we report that during inflammation macrophages enhance its intercellular adhesion properties in order to acquire a M1-phenotype. Using in vitro and in vivo models we demonstrate that intercellular adhesion is mediated by integrin-alphaVbeta3 and relies in the presence of the unconventional class I myosin 1F (Myo1F). Intercellular adhesion mediated by alphaVbeta3 stimulates M1-like phenotype in macrophages through hyperactivation of STAT1 and STAT3 downstream of ILK/Akt/mTOR signaling. Inhibition of integrin-alphaVbeta3, Akt/mTOR or lack of Myo1F attenuated the commitment of macrophages into a pro-inflammatory phenotype. In a model of colitis, Myo1F deficiency strongly reduces the secretion of proinflammatory cytokines, decreases epithelial damage, ameliorates disease activity and enhances tissue repair. Together our findings uncover an unknown role for Myo1F as part of the machinery that regulates intercellular adhesion and polarization in macrophages.

The study of cancer has allowed researchers to describe some biological characteristics that tumor cells acquire during their development, known as the “hallmarks of cancer” but more research is needed to expand our knowledge about cancer biology and to generate new strategies of treatment. The role that RabGTPases might play in some hallmarks of cancer represents interesting areas of study since these proteins are frequently altered in cancer. However, their participation is not well known. Recently, Rab35was recognized as an oncogenic RabGTPase and and because of its association with different cellular functions, distinctly important in immune cells, a possible role of Rab35 in leukemia can be suggested. Nevertheless, the involvement of Rab35 in cancer remains poorly understood and its possible specific role in leukemia remains unknown. In this review, we analyze general aspects of the participation of RabGTPases in cancer, and especially, the plausible role of Rab35 in leukemia.

The gut epithelium acts to separate host immune cells from unrestricted interactions with the microbiota and other environmental stimuli. In response to epithelial damage or dysfunction, immune cells are activated to produce interleukin (IL)-22, which is involved in repair and protection of barrier surfaces. However, the specific pathways leading to IL-22 and associated antimicrobial peptide (AMP) production in response to intestinal tissue damage remain incompletely understood. Here, we define a critical IL-36/IL-23/IL-22 cytokine network that is instrumental for AMP production and host defense. Using a murine model of intestinal damage and repair, we show that IL-36γ is a potent inducer of IL-23 both in vitro and in vivo. IL-36γ–induced IL-23 required Notch2-dependent (CD11b+CD103+) dendritic cells (DCs), but not Batf3-dependent (CD11b−CD103+) DCs or CSF1R-dependent macrophages. The intracellular signaling cascade linking IL-36 receptor (IL-36R) to IL-23 production by DCs involved MyD88 and the NF-κB subunits c-Rel and p50. Consistent with in vitro observations, IL-36R– and IL-36γ–deficient mice exhibited dramatically reduced IL-23, IL-22, and AMP levels, and consequently failed to recover from acute intestinal damage. Interestingly, impaired recovery of mice deficient in IL-36R or IL-36γ could be rescued by treatment with exogenous IL-23. This recovery was accompanied by a restoration of IL-22 and AMP expression in the colon. Collectively, these data define a cytokine network involving IL-36γ, IL-23, and IL-22 that is activated in response to intestinal barrier damage and involved in providing critical host defense.

Neutrophil transepithelial migration (TEM) during acute inflammation is associated with mucosal injury. Using models of acute mucosal injury in vitro and in vivo, we describe a new mechanism by which neutrophils infiltrating the intestinal mucosa disrupt epithelial homeostasis. We report that junctional adhesion molecule-like protein (JAML) is cleaved from neutrophil surface by zinc metalloproteases during TEM. Neutrophil-derived soluble JAML binds to the epithelial tight junction protein coxsackie-adenovirus receptor (CAR) resulting in compromised barrier and inhibition of wound repair, through decreased epithelial proliferation. The deleterious effects of JAML on barrier and wound repair are reversed with an anti-JAML monoclonal antibody that inhibits JAML-CAR binding. JAML released from transmigrating neutrophils across inflamed epithelia may thus promote recruitment of leukocytes and aid in clearance of invading microorganisms. However, sustained release of JAML under pathologic conditions associated with persistence of large numbers of infiltrated neutrophils would compromise intestinal barrier and inhibit mucosal healing. Thus, targeting JAML-CAR interactions may improve mucosal healing responses under conditions of dysregulated neutrophil recruitment.

IL-17–expressing CD4+ T lymphocytes (Th17 cells) naturally reside in the intestine where specific cytokines and microbiota, such as segmented filamentous bacteria (SFB), promote their differentiation. Intestinal Th17 cells are thought to initially differentiate in the GALT and/or mesenteric lymph nodes upon Ag encounter and subsequently home to the lamina propria (LP) where they mediate effector functions. However, whether GALT and/or mesenteric lymph nodes are required for intestinal Th17 differentiation as well as how microbiota containing SFB regulate Ag-specific intestinal Th17 cells remain poorly defined. In this study, we observed that naive CD4+ T cells were abundant in the intestinal LP prior to weaning and that the accumulation of Th17 cells in response to microbiota containing SFB occurred in the absence of lymphotoxin-dependent lymphoid structures and the spleen. Furthermore, the differentiation of intestinal Th17 cells in the presence of microbiota containing SFB was dependent on MHC class II expression by CD11c+ cells. Lastly, the differentiation of Ag-specific Th17 cells required both the presence of cognate Ag and microbiota containing SFB. These findings suggest that microbiota containing SFB create an intestinal milieu that may induce Ag-specific Th17 differentiation against food and/or bacterial Ags directly in the intestinal LP.

Nuclear Akt1 phosphorylates 14.3.3ζ at serine 58 to inhibit β-catenin transactivation. The results outline a dual function of Akt1, which suppresses intestinal epithelial cell proliferation during intestinal inflammation., The proinflammatory cytokine interferon γ (IFNγ ) influences intestinal epithelial cell (IEC) homeostasis in a biphasic manner by acutely stimulating proliferation that is followed by sustained inhibition of proliferation despite continued mucosal injury. β-Catenin activation has been classically associated with increased IEC proliferation. However, we observed that IFNγ inhibits IEC proliferation despite sustained activation of Akt/β-catenin signaling. Here we show that inhibition of Akt/β-catenin–mediated cell proliferation by IFNγ is associated with the formation of a protein complex containing phosphorylated β-catenin 552 (pβ-cat552) and 14.3.3ζ. Akt1 served as a bimodal switch that promotes or inhibits β-catenin transactivation in response to IFNγ stimulation. IFNγ initially promotes β-catenin transactivation through Akt-dependent C-terminal phosphorylation of β-catenin to promote its association with 14.3.3ζ. Augmented β-catenin transactivation leads to increased Akt1 protein levels, and active Akt1 accumulates in the nucleus, where it phosphorylates 14.3.3ζ to translocate 14.3.3ζ/β-catenin from the nucleus, thereby inhibiting β-catenin transactivation and IEC proliferation. These results outline a dual function of Akt1 that suppresses IEC proliferation during intestinal inflammation.

Background Chemical pesticides, widely used in agriculture and vector-borne disease control, have shown toxic effects on the environment and the people in contact with them. Bacillus thuringiensis is a widely used bacterium for alternative and safer control of insect pests. Its toxins are specific for insects but innocuous for mammals and may be used as powerful adjuvants when applied with vaccines. The objective of this work was to characterize some autochthonous B. thuringiensis strains, which could be used for the control of a local pest ( Diatraea considerata Heinrich) that affects sugar cane crops in Sinaloa, Mexico. Also, to evaluate these strains as a source of Cry toxins, which may be used in the future as adjuvants for some vaccines. Methods Eight strains from field-collected dead insects were isolated. These were microbiologically identified as B. thuringiensis and confirmed by amplification and sequencing of 16S rDNA. Bioassays were performed to evaluate their pathogenicity against D. considerata , and Cry toxins were identified by proteomic analyses. Results An increased mortality among larvae infected with strain Bt-D was observed, and its toxin was identified as Cry1Ac. Conclusions The observed data showed that the selected strain was pathogenic to D. considerata and seemed to produce Cry1Ac protein, which has been reported as an adjuvant in different types of immunization.

IL-1 family members are central mediators of host defense. In this article, we show that the novel IL-1 family member IL-36γ was expressed during experimental colitis and human inflammatory bowel disease. Germ-free mice failed to induce IL-36γ in response to dextran sodium sulfate (DSS)-induced damage, suggesting that gut microbiota are involved in its induction. Surprisingly, IL-36R–deficient (Il1rl2−/−) mice exhibited defective recovery following DSS-induced damage and impaired closure of colonic mucosal biopsy wounds, which coincided with impaired neutrophil accumulation in the wound bed. Failure of Il1rl2−/− mice to recover from DSS-induced damage was associated with a profound reduction in IL-22 expression, particularly by colonic neutrophils. Defective recovery of Il1rl2−/− mice could be rescued by an aryl hydrocarbon receptor agonist, which was sufficient to restore IL-22 expression and promote full recovery from DSS-induced damage. These findings implicate the IL-36/IL-36R axis in the resolution of intestinal mucosal wounds.

Akt activation has been associated with proliferation, differentiation, survival and death of epithelial cells. Phosphorylation of Thr308 of Akt by phosphoinositide-dependent kinase 1 (PDK1) is critical for optimal stimulation of its kinase activity. However, the mechanism(s) regulating this process remain elusive. Here, we report that 14-3-3 proteins control Akt Thr308 phosphorylation during intestinal inflammation. Mechanistically, we found that IFNγ and TNFα treatment induce degradation of the PDK1 inhibitor, 14-3-3η, in intestinal epithelial cells. This mechanism requires association of 14-3-3ζ with raptor in a process that triggers autophagy and leads to 14-3-3η degradation. Notably, inhibition of 14-3-3 function by the chemical inhibitor BV02 induces uncontrolled Akt activation, nuclear Akt accumulation and ultimately intestinal epithelial cell death. Our results suggest that 14-3-3 proteins control Akt activation and regulate its biological functions, thereby providing a new mechanistic link between cell survival and apoptosis of intestinal epithelial cells during inflammation.

Summary Mice lacking junctional adhesion molecule A (JAM-A, encoded by F11r ) exhibit enhanced intestinal epithelial permeability, bacterial translocation, and elevated colonic lymphocyte numbers, yet do not develop colitis. To investigate the contribution of adaptive immune compensation in response to increased intestinal epithelial permeability, we examined the susceptibility of F11r −/− Rag1 −/− mice to acute colitis. Although negligible contributions of adaptive immunity in F11r +/+ Rag1 −/− mice were observed, F11r −/− Rag1 −/− mice exhibited increased microflora-dependent colitis. Elimination of T cell subsets and cytokine analyses revealed a protective role for TGF-β-producing CD4 + T cells in F11r −/− mice. Additionally, loss of JAM-A resulted in elevated mucosal and serum IgA that was dependent upon CD4 + T cells and TGF-β. Absence of IgA in F11r +/+ Igha −/− mice did not affect disease, whereas F11r −/− Igha −/− mice displayed markedly increased susceptibility to acute injury-induced colitis. These data establish a role for adaptive immune-mediated protection from acute colitis under conditions of intestinal epithelial barrier compromise.

Within the intestine reside unique populations of innate and adaptive immune cells that are involved in promoting tolerance towards commensal flora and food antigens while concomitantly remaining poised to mount inflammatory responses toward invasive pathogens1,2. Antigen presenting cells, particularly DCs and macrophages, play critical roles in maintaining intestinal immune homeostasis via their ability to sense and appropriately respond to the microbiota3-14. Efficient isolation of intestinal DCs and macrophages is a critical step in characterizing the phenotype and function of these cells. While many effective methods of isolating intestinal immune cells, including DCs and macrophages, have been described6,10,15-24, many rely upon long digestions times that may negatively influence cell surface antigen expression, cell viability, and/or cell yield. Here, we detail a methodology for the rapid isolation of large numbers of viable, intestinal DCs and macrophages. Phenotypic characterization of intestinal DCs and macrophages is carried out by directly staining isolated intestinal cells with specific fluorescence-labeled monoclonal antibodies for multi-color flow cytometric analysis. Furthermore, highly pure DC and macrophage populations are isolated for functional studies utilizing CD11c and CD11b magnetic-activated cell sorting beads followed by cell sorting.

Although several subsets of intestinal APCs have been described, there has been no systematic evaluation of their phenotypes, functions, and regional localization to date. In this article, we used 10-color flow cytometry to define the major APC subsets in the small and large intestine lamina propria. Lamina propria APCs could be subdivided into CD11c+CD11b−, CD11c+CD11b+, and CD11cdullCD11b+ subsets. CD11c+CD11b− cells were largely CD103+F4/80− dendritic cells (DCs), whereas the CD11c+CD11b+ subset comprised CD11c+CD11b+CD103+F4/80− DCs and CD11c+CD11b+CD103−F4/80+ macrophage-like cells. The majority of CD11cdullCD11b+ cells were CD103−F4/80+ macrophages. Although macrophages were more efficient at inducing Foxp3+ regulatory T (Treg) cells than DCs, at higher T cell/APC ratios, all of the DC subsets efficiently induced Foxp3+ Treg cells. In contrast, only CD11c+CD11b+CD103+ DCs efficiently induced Th17 cells. Consistent with this, the regional distribution of CD11c+CD11b+CD103+ DCs correlated with that of Th17 cells, with duodenum > jejunum > ileum > colon. Conversely, CD11c+CD11b−CD103+ DCs, macrophages, and Foxp3+ Treg cells were most abundant in the colon and scarce in the duodenum. Importantly, however, the ability of DC and macrophage subsets to induce Foxp3+ Treg cells versus Th17 cells was strikingly dependent on the source of the mouse strain. Thus, DCs from C57BL/6 mice from Charles River Laboratories (that have segmented filamentous bacteria, which induce robust levels of Th17 cells in situ) were more efficient at inducing Th17 cells and less efficient at inducing Foxp3+ Treg cells than DCs from B6 mice from The Jackson Laboratory. Thus, the functional specializations of APC subsets in the intestine are dependent on the T cell/APC ratio, regional localization, and source of the mouse strain.

The two most common forms of inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis, affect approximately 1 million people in the United States. Uncontrolled APC reactivity toward commensal bacteria is implicated in the pathogenesis of the disease. A number of functionally distinct APC populations exist in the mucosal lamina propria (LP) below the intestinal epithelium, but their relative contributions to inflammation remain unclear. Here, we demonstrate in mice important roles for the chemokine receptor CX3CR1 in maintaining LP macrophage populations, preventing translocation of commensal bacteria to mesenteric lymph nodes (mLNs), and limiting colitogenic Th17 responses. CX3CR1 was found to be expressed in resident LP macrophages (defined as CD11b(+)F4/80(+)) but not DCs (defined as CD11c(+)CD103(+)). LP macrophage frequency and number were decreased in two strains of CX3CR1-knockout mice and in mice deficient in the CX3CR1 ligand CX3CL1. All these knockout strains displayed markedly increased translocation of commensal bacteria to mLNs. Additionally, the severity of DSS-induced colitis was dramatically enhanced in the knockout mice as compared with controls. Disease severity could be limited by either administration of neutralizing IL-17A antibodies or transfer of CX3CR1-sufficient macrophages. Our data thus suggest key roles for the CX3CR1/CX3CL1 axis in the intestinal mucosa; further clarification of CX3CR1 function will likely direct efforts toward therapeutic intervention for mucosal inflammatory disorders such as IBD.