Novel therapies for immune-mediated inflammatory diseases: What can we learn from their use in rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus, psoriasis, Crohn's disease and ulcerative colitis?

The past three decades have witnessed remarkable advances in our ability to target specific elements of the immune and inflammatory response, fuelled by advances in both biotechnology and disease knowledge. As well as providing superior treatments for immune-mediated inflammatory diseases (IMIDs), such therapies also offer unrivalled opportunities to study the underlying immunopathological basis of these conditions.In this review, we explore recent approaches to the treatment of IMIDs and the insights to pathobiology that they provide. We review novel biologic agents targeting the T-helper 17 axis, including therapies directed towards interleukin (IL)-17 (secukinumab, ixekizumab, bimekizumab), IL-17R (brodalumab), IL-12/23p40 (ustekinumab, briakinumab) and IL-23p19 (guselkumab, tildrakizumab, brazikumab, risankizumab, mirikizumab). We also present an overview of biologics active against type I and II interferons, including sifalumumab, rontalizumab, anifrolumab and fontolizumab. Emerging strategies to interfere with cellular adhesion processes involved in lymphocyte recruitment are discussed, including both integrin blockade (natalizumab, vedolizumab, etrolizumab) and sphingosine-1-phosphate receptor inhibition (fingolimod, ozanimod). We summarise the development and recent application of Janus kinase (JAK) inhibitors in the treatment of IMIDs, including first-generation pan-JAK inhibitors (tofacitinib, baricitinib, ruxolitinib, peficitinib) and second-generation selective JAK inhibitors (decernotinib, filgotinib, upadacitinib). New biologics targeting B-cells (including ocrelizumab, veltuzumab, tabalumab and atacicept) and the development of novel strategies for regulatory T-cell modulation (including low-dose IL-2 therapy and Tregitopes) are also discussed. Finally, we explore recent biotechnological advances such as the development of bispecific antibodies (ABT-122, COVA322), and their application to the treatment of IMIDs.

Myeloid-derived cells in prostate cancer progression: phenotype and prospective therapies

Prostate cancer is the second most common cause of cancer mortality in men in the United States. As is the case for other tumor types, accumulating evidence suggests an important role for myeloid-derived cells in the promotion and progression of prostate cancer. Here, we briefly describe myeloid-derived cells that interact with tumor cells and what is known about their immune suppressive function. We next discuss new evidence for tumor cell-mediated myeloid infiltration via the PI3K/PTEN/AKT signaling pathway and an alternative mechanism for immune evasion that may be regulated by an endoplasmic reticulum stress response. Finally, we discuss several interventions that target myeloid-derived cells to treat prostate cancer.

STAT1 Is Required for Suppression of Type 17 Immunity during Influenza and Bacterial Superinfection

Influenza is an annual, global health care concern. Secondary bacterial pneumonia is a severe complication associated with primary influenza virus infection, often resulting in critical morbidity and mortality. Our laboratory has identified influenza-induced suppression of anti-bacterial Type 17 immunity as a mechanism for enhanced susceptibility to bacterial super-infection. We have shown that influenza-induced type I interferon impairs Type 17 activation. STAT1 is a transcription factor involved in interferon signaling, shared by type I, II, and III interferon. In this work, we investigated the role of STAT1 signaling during influenza, methicillin-resistant Staphylococcus aureus (MRSA) super-infection. STAT1-/- mice had increased morbidity and airway inflammation compared to control mice during influenza mono-infection. Despite this worsened anti-viral response, STAT1-/- mice were protected from super-infection bacterial burden and mortality compared to controls. Type 17 immune activation was increased in lymphocytes in STAT1-/- mice during super-infection. The elevation in Type 17 immunity was not related to increased IL-23 production, as type I interferon could inhibit IL-23 expression in a STAT1 independent manner. STAT1-/- antigen presenting cells were inherently biased towards Type 17 polarization compared to control cells. Further, STAT1-/- dendritic cells produced attenuated IL-6 and TNFα upon heat-killed S. aureus stimulation compared to control. Overall, these data indicate that STAT1 signaling plays a detrimental role in influenza, MRSA super-infection by controlling the magnitude of Type 17 immune activation.

Association of ESAT-6/CFP-10-induced IFN-γ, TNF-α and IL-10 with clinical tuberculosis: evidence from cohorts of pulmonary tuberculosis patients, household contacts and community controls in an endemic setting

Mycobacterium tuberculosis (Mtb) early secreted protein antigen 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) are among candidate vaccines against tuberculosis (TB). Results of experimental animal models show that these antigens are associated with induction of strong T cell immunity [interferon (IFN)-γ production], while others report that these proteins as virulent factors involved in pathogenicity of Mtb infection. However, the role of ESAT-6/CFP-10 during natural Mtb infections in humans has not been established. In this paper we present results of a longitudinal study from an Mtb-infected human population from an endemic setting. Whole blood assay was used to determine levels of IFN-γ, tumour necrosis factor (TNF)-α and interleukin (IL)-10 against rESAT-6/CFP-10 in TB patients, household contacts and community controls. The levels of IFN-γ, TNF-α and IL-10 against rESAT-6/CFP-10 at baseline were significantly higher in patients and community controls than in household contacts. In patients, no significant difference was observed in the level of these cytokines before and after chemotherapy whereas, in contacts, the level of these cytokines increased significantly and progressively over time. The study shows that the levels of IFN-γ, TNF-α and IL-10 against rESAT-6/CFP-10 are depressed during Mtb infection or exposure but are elevated during clinical TB. Our findings from a study of naturally infected human population suggest that IFN-γ, TNF-α and IL-10 against rESAT-6/CFP-10 are markers for clinical TB but not for protective immunity.

LTX-315: a first-in-class oncolytic peptide that reprograms the tumor microenvironment

The oncolytic peptide LTX-315, which has been de novo designed based on structure–activity relationship studies of host defense peptides, has the ability to kill human cancer cells and induce specific anticancer immune response when injected locally into tumors established in immunocompetent mice. The oncolytic effect of LTX-315 involves perturbation of plasma membrane and the mitochondria with subsequent release of danger-associated molecular pattern molecules, which highlights the ability of LTX-315 to induce complete regression and protective immune responses. Treatment with LTX-315 reprograms the tumor microenvironment by decreasing the local abundance of immunosuppressive cells and by increasing the frequency of effector T cells.

Lymphotoxin β receptor signalling executes Helicobacter pylori-driven gastric inflammation in a T4SS-dependent manner

OBJECTIVE

Lymphotoxin β receptor (LTβR) signalling has been implicated in inflammation-associated tumour development in different tissues. We have analysed the role of LTβR and alternative NF-κB signalling in Helicobacter pylori-mediated gastric inflammation and pathology.

DESIGN

We analysed several ligands and receptors of the alternative NF-κB pathway, RelB, p52 nuclear translocation and target genes in tissue samples of H. pylori-infected patients with different degrees of gastritis or early gastric tumours by in situ hybridisation, immunohistochemistry, Western blot and real-time PCR analyses. Molecular mechanisms involved in LTβR activation by H. pylori were assessed in vitro using human gastric cancer cell lines and distinct H. pylori isolates. The effects of blocking or agonistically activating LTβR on gastric pathology during challenge with a human pathogenic H. pylori strain were studied in a mouse model.

RESULTS

Among the tested candidates, LT was significantly increased and activated alternative NF-κB signalling was observed in the gastric mucosa of H. pylori-infected patients. H. pyloriinduced LTβR-ligand expression in a type IV secretion system-dependent but CagA-independent manner, resulting in activation of the alternative NF-κB pathway, which was further enhanced by blocking canonical NF-κB during infection. Blocking LTβR signalling in vivo suppressed H. pylori-driven gastritis, whereas LTβR activation in gastric epithelial cells of infected mice induced a broadened pro-inflammatory chemokine milieu, resulting in exacerbated pathology.

CONCLUSIONS

LTβR-triggered activation of alternative NF-κB signalling in gastric epithelial cells executes H. pylori-induced chronic gastritis, representing a novel target to restrict gastric inflammation and pathology elicited by H. pylori, while exclusively targeting canonical NF-κB may aggravate pathology by enhancing the alternative pathway.

Lipopolysaccharide induced Interleukin-6 production is mediated through activation of ERK 1/2, p38 MAPK, MEK, and NFκB in chicken thrombocytes

Thrombocytes express Toll-like receptor 4 and apparently use both mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB) pathways for nuclear signaling. However, it is not well known if the same enzyme systems found in mammalian cells are fully functional in chickens. Therefore, kinase inhibitors were used with thrombocytes to block kinases in lipopolysaccharide (LPS) stimulated cells to determine if interleukin (IL)-6 expression and production would be diminished. Results demonstrated that extracellular-signal-regulated kinase (ERK)1/2 and p38 MAPK pathways influence gene expression of IL-6 through treatment with either ERK or p38 MAPK inhibitor. In addition, thrombocyte lysates from cells treated with ERK, p38, mitogen-activated protein kinase kinase (MEK)1/2 and inhibitor of nuclear factor kappa-B kinase (IKK) inhibitor showed different levels of the phosphorylated form of ERK1/2, p38 and NFκB. Furthermore, IL-6 gene expression and production were significantly upregulated in LPS stimulated thrombocytes relative to all inhibitor-treated cells.

What Happens in the Thymus Does Not Stay in the Thymus: How T Cells Recycle the CD4+-CD8+ Lineage Commitment Transcriptional Circuitry To Control Their Function

MHC-restricted CD4(+) and CD8(+) T cells are at the core of most adaptive immune responses. Although these cells carry distinct functions, they arise from a common precursor during thymic differentiation, in a developmental sequence that matches CD4 and CD8 expression and functional potential with MHC restriction. Although the transcriptional control of CD4(+)-CD8(+) lineage choice in the thymus is now better understood, less was known about what maintains the CD4(+) and CD8(+) lineage integrity of mature T cells. In this review, we discuss the mechanisms that establish in the thymus, and maintain in postthymic cells, the separation of these lineages. We focus on recent studies that address the mechanisms of epigenetic control of Cd4 expression and emphasize how maintaining a transcriptional circuitry nucleated around Thpok and Runx proteins, the key architects of CD4(+)-CD8(+) lineage commitment in the thymus, is critical for CD4(+) T cell helper functions.

Endometrial transcription of microbial molecular patterns receptors in Gyr and F1 Holstein x Gyr postpartum cows

ABSTRACT Zebu and Holstein x Zebu crossbred have low incidence of uterine infection when compared to Holstein cows. Resistance to uterine infections may be associated with the ability to recognize invading microorganisms. Endometrial transcription of microbial molecular patterns receptors has been investigated in the postpartum period of Holstein cows, but it is completely unknown in Zebu or Holstein x Zebu cows. In this study, 9 Gyr and 12 F1 Holstein x Gyr cows were submitted to endometrial biopsies at the first and seventh days postpartum, with the objective to measure transcription levels of toll-like receptors (TLRs) 1/6, 2, 4, 5, and 9; nucleotide-binding oligomerization domain (NOD)-like receptors 1 and 2; and coreceptors cluster of differentiation 14 (CD14) and myeloid differentiation protein-2 (MD-2). There was a significant (P<0.05) decrease in transcription of TLR5 in Gyr, and an increase in transcription of TLR9 in F1 cows, between the first and seventh day postpartum. Both groups had low incidences of uterine infections up to 42 days postpartum. Uterine involution completed at 27.7 ± 10.1 and 25.1 ± 4.7 days postpartum for Gyr and F1 cows, respectively. In Gyr cows, higher transcription levels of TLR1/6 and NOD1 correlated to a longer period required for uterine involution. In F1 cows, lower levels of TLR1/6, TLR2 and NOD2 correlated to a longer period required for uterine involution. In conclusion, some pathogen recognition receptors associated significantly with the time required for uterine involution in Gyr and F1 cows.

Immunomodulatory effects of current cancer treatment and the consequences for follow-up immunotherapeutics

Recent advances in the use of immunotherapy have led to historic advancements in the field of oncology. Checkpoint inhibitors have demonstrated significant effectiveness against a broadening range of cancers. However, despite the success of antibodies against the immune regulators, CTLA4 and PD-L1/PD-1, only a subset of patients will have a durable response to these therapies, which implies that a broader view of cancer immunity is required. It is becoming increasingly apparent that combination therapy to target multiple events in the cancer-immunity cycle is needed and could potentially extend the benefit of immunotherapy to a larger population. In this review, we discuss the current status of immunotherapy and highlight the use of combination therapy to prime the tumor microenvironment and thereby improve treatment effect.

Diet-induced obesity causes visceral, but not subcutaneous, lymph node hyperplasia via increases in specific immune cell populations

OBJECTIVES

The spatial proximity of adipose depots to secondary lymph nodes allows a unique relation between the two systems. Obesity, predominately visceral adiposity, links to numerous diseases; hence, we postulate that secondary lymphatics within this region contributes to disease risk.

MATERIAL AND METHODS

Male C57BL/6 mice were fed standard CHOW (18% kcal fat) or Western diet (45% kcal fat) for 7 weeks. Visceral and subcutaneous lymph nodes and associated adipose depots they occupy were excised. Lymph node morphology and resident immune cell populations were characterized via histopathology, immunofluorescence and flow cytometry. Adipose tissue immune cell populations were also characterized.

RESULTS

Obesity caused lymph node expansion, increased viable cell number and deviations in immune cell populations. These alterations were exclusive to visceral lymph nodes. Notably, pro-inflammatory antigen presenting cells and regulatory T cells increased in number in the visceral lymph node. Obesity, however, reduced T regulatory cells in visceral lymph nodes. The visceral adipose depot also had greater reactivity towards HFD than subcutaneous, with a greater percent of macrophages, dendritic and CD8⁺ T cells. Immune cell number, in both the visceral and subcutaneous, however decreased as adipose depots enlarged.

CONCLUSION

Overall, HFD has a greater influence on visceral cavity than the subcutaneous. In the visceral lymph node, but not subcutaneous, HFD-induced obesity decreased cell populations that suppressed immune function while increasing those that regulate/activate immune response.

Haematopoietic stem cell transplantation for severe combined immunodeficiency: Long-term health outcomes and patient perspectives

AIM

To examine the long-term follow-up and health outcomes of patients who have undergone haematopoietic stem cell transplant (HSCT) for severe combined immunodeficiency (SCID).

METHODS

Through a structured questionnaire, we examined follow-up arrangements and long-term health outcomes in 22 children who have had a successful HSCT for SCID during the period of 1984-2012 at the Sydney Children's Hospital, Sydney, Australia.

RESULTS

Most children considered themselves healthy and 'cured' from SCID. Whilst many children enjoy relatively good bio-social health outcomes, specific negative health outcomes and absenteeism from school were perceived negatively. Two-thirds of children see their general practitioner or specialist regularly; however, there did not appear to be consistency with the nature of this follow-up.

CONCLUSION

The findings from our study highlight the complex bio-psychosocial health needs of post-HSCT SCID children and encourage SCID centres to consider a multidisciplinary approach to their follow-up. Further studies into the determinants of patients' perceptions of their health are needed.

Identification, characterization and modulation of ferritin-H in the sub-Antarctic Notothenioid Eleginops maclovinus challenged with Piscirickettsia salmonis

Ferritin is a major iron storage protein essential not only in the infectious process, but also in any circumstance generating oxidative stress. In this study, the cDNA coding sequence of ferritin-H was obtained from the sub-Antarctic Notothenioid fish Eleginops maclovinus through transcriptomic analysis of the head kidney. This sequence contained a 534 bp open reading frame that coded for a 177 amino acid protein with a molecular weight of 20,786.2 Da and a theoretical pI of 5.56. The protein displayed a region of iron putative response elements in the 5'UTR, two putative ferritin iron-binding region signatures, and seven characteristic amino acids with ferroxidase functions. Phylogenetic analysis related this sequence to ferritin-H sequences of other Antarctic Notothenioid fish, sharing 96.61% similarity. Constitutive gene expression analysis in different organs revealed increased ferritin-H gene expression in the gills, spleen, muscle, and liver. After infection with two bacterial strains of Piscirickettsia salmonis (LF-89 and Austral-005), ferritin-H was differentially expressed depending on bacterial strain and tissue. This study provides relevant information towards understanding the iron metabolism of a sub-Antarctic Notothenioid fish.

Inhibition of inflammasome activation improves lung acute injury induced by carrageenan in a mouse model of pleurisy

The inflammasome NLRP3 is a molecular pathway activated by a wide range of cellular insults to elicit innate immune defenses through the activation of caspase-1 and the maturation of proinflammatory cytokines, such as IL-1β and IL-18. The expression of NRLP3 is abnormally elevated in numerous human inflammatory diseases, including pulmonary diseases. An injection of carrageenan (CAR) into the pleural cavity triggered an acute inflammatory response, leading to tissue damage, inflammatory exudates, leukocyte infiltration, and increased myeloperoxidase activity. The aim of this study was to assess the effect of the inflammasome blocking agents BAY 11-7082 (30 mg/kg, i.p.) and Brilliant Blue G (BBG) (45.5 mg/kg, i.p.) in a mouse model of CAR-induced pleurisy. Treatment with BAY 11-7082 or BBG 1 h after CAR injection attenuated pulmonary membrane thickening and polymorphonuclear leukocyte infiltration, reduced NF-κB translocation in the nucleus, and inhibited the assembly of the NRLP3/ASC/caspase-1 complex. Treatment with BAY 11-7082 or BBG also down-regulated iNOS, nitrotyrosine, and poly-ADP-ribosyl polymerase expression and inhibited CAR-induced apoptosis. Our results demonstrate that treatment with inflammasome-blocking agents can significantly reduce the development of acute CAR-induced lung injury.-Fusco, R. Gugliandolo, E., Biundo, F., Campolo, M., Di Paola, R., Cuzzocrea, S. Inhibition of inflammasome activation improves lung acute injury induced by carrageenan in a mouse model of pleurisy.

γδ T cells represent a major spontaneously cytotoxic cell population in the chicken

Natural killer cells in the chicken are mainly confined to the intestine, while only small frequencies are detectable in spleen, lung and blood. Here, we compared the spontaneous cytotoxicity of lymphocytes isolated from blood, spleen and intestine using a flow cytometric based cytotoxicity assay. There was no spontaneous cytotoxicity detected in chicken blood preparations. In contrast, freshly prepared splenocytes exhibited a spontaneous cytotoxicity of up to 50% and intestinal epithelial lymphocytes of up to 85%. This cytotoxicity was observed against the RP9 but not against the chicken CU24 target cell line. The observed cytotoxicity was MHC unrestricted since B²B² derived effector cells killed RP9 target cells (B²B¹⁵) equally well compared to MHC mismatched 2D8 targets (B¹⁹B¹⁹). The cytotoxicity of splenocytes was enhanced by preincubation with IL-2 or strongly increased with IL-2 plus IL-12. By cell sorting, we identified the CD8⁺γδ T cell subset as the major effectors, whereas both CD8^-γδ T cells and CD8⁺αβ T cells had only low cytolytic potential. Within intestinal lymphocyte CD45⁺cells displayed cytotoxicity as well as sorted γδ T cells and NK cell. In conclusion, the chicken γδ T cells represent a major cytotoxic lymphocyte subset that can lyse target cells in a MHC unrestricted manner.

Ctenopharyngodon idella IKKβ interacts with PKR and IκBα

Inhibitor of nuclear factor kappa-B kinase β (IKKβ) is a subunit of the IKK complex. It can activate the NF-κB pathway through phosphorylating IκB in response to a wide range of stimuli. In the present study, an IKKβ gene from grass carp (Ctenopharyngodon idella; KT282114) was cloned and identified by homologous cloning and rapid-amplification of cDNA ends (RACE) technique. The complete CiIKKβ cDNA is 3428 bp in length, with the longest open reading frame (ORF) of 2337 bp encoding a polypeptide of 778 amino acids. The deduced amino acid sequence of CiIKKβ has similar domain distribution to those of mammalian. For example, CiIKKβ consists of a serine/threonine kinase domain at the N-terminal, a basic region leucin zipper (BRLZ) domain in the middle, a homeobox associated leucin zipper (HALZ) domain and an IKKβ NEMO (NF-κB essential modulator) binding domain at the C-terminal. Phylogenetic tree analysis also showed that CiIKKβ is highly homologous to zebrafish IKKβ (DrIKKβ) and clearly distinct from the mammalian and amphibian counterparts. The expression of CiIKKβ was ubiquitously found in the liver, intestine, kidney, gill, spleen, heart, and brain tissues of grass carp and significantly up-regulated in CIK cells under the stimulation with Poly I:C and UV-inactivated grass carp hemorrhagic virus. To investigate the activation mechanism of NF-κB pathway in fish and the role of CiIKKβ in the pathway, we explored the protein interactions of protein kinase R (PKR) with IKKβ and IKKβ with IκBα by co-immunoprecipitation and GST-pull down assays. The interaction between each pair was confirmed. The results suggest that CiIKKβ may be a primary member in the activation of NF-κB pathway in fish.

Leishmania donovani inhibits inflammasome-dependent macrophage activation by exploiting the negative regulatory proteins A20 and UCP2

In visceral leishmaniasis, we found that the antileishmanial drug Amp B produces a higher level of IL-1β over the infected control. Moreover, administering anti-IL-1β antibody to infected Amp B-treated mice showed significantly less parasite clearance. Investigation revealed that Leishmania inhibits stimuli-induced expression of a multiprotein signaling platform, NLRP3 inflammasome, which in turn inhibits caspase-1 activation mediated maturation of IL-1β from its pro form. Attenuation of NLRP3 and pro-IL-1β in infection was found to result from decreased NF-κB activity. Transfecting infected cells with constitutively active NF-κB plasmid increased NLRP3 and pro-IL-1β expression but did not increase mature IL-1β, suggesting that IL-1β maturation requires a second signal, which was found to be reactive oxygen species (ROS). Decreased NF-κB was attributed to increased expression of A20, a negative regulator of NF-κB signaling. Silencing A20 in infected cells restored NLRP3 and pro-IL-1β expression, but also increased matured IL-1β, implying an NF-κB-independent A20-modulated IL-1β maturation. Macrophage ROS is primarily regulated by mitochondrial uncoupling protein 2 (UCP2), and UCP2-silenced infected cells showed an increased IL-1β level. Short hairpin RNA-mediated knockdown of A20 and UCP2 in infected mice independently documented decreased liver and spleen parasite burden and increased IL-1β production. These results suggest that Leishmania exploits A20 and UCP2 to impair inflammasome activation for disease propagation.-Gupta, A. K., Ghosh, K., Palit, S., Barua, J., Das, P. K., Ukil, A. Leishmania donovani inhibits inflammasome-dependent macrophage activation by exploiting the negative regulatory proteins A20 and UCP2.

Card9-dependent IL-1β regulates IL-22 production from group 3 innate lymphoid cells and promotes colitis-associated cancer

Inflammatory bowel diseases (IBD) are key risk factors for the development of colorectal cancer, but the mechanisms that link intestinal inflammation with carcinogenesis are insufficiently understood. Card9 is a myeloid cell-specific signaling protein that regulates inflammatory responses downstream of various pattern recognition receptors and which cooperates with the inflammasomes for IL-1β production. Because polymorphisms in Card9 were recurrently associated with human IBD, we investigated the function of Card9 in a colitis-associated cancer (CAC) model. Card9-/- mice develop smaller, less proliferative and less dysplastic tumors compared to their littermates and in the regenerating mucosa we detected dramatically impaired IL-1β generation and defective IL-1β controlled IL-22 production from group 3 innate lymphoid cells. Consistent with the key role of immune-derived IL-22 in activating STAT3 signaling during normal and pathological intestinal epithelial cell (IEC) proliferation, Card9-/- mice also exhibit impaired tumor cell intrinsic STAT3 activation. Our results imply a Card9-controlled, ILC3-mediated mechanism regulating healthy and malignant IEC proliferation and demonstrates a role of Card9-mediated innate immunity in inflammation-associated carcinogenesis.

Synergistic Modulation of Inflammatory but not Metabolic Effects of High-Fat Feeding by CCR2 and CX3CR1

OBJECTIVE

The purpose of the study was to explore the impact of dual targeting of C-C motif chemokine receptor-2 (CCR2) and fractalkine receptor (CX3CR1) on the metabolic and inflammatory consequences of obesity induced by a high-fat diet (HFD).

METHODS

C57BL/6J wild-type, Cx3cr1^-/- , Ccr2^-/- , and Cx3cr1^-/- Ccr2^-/- double-knockout male and female mice were fed a 45% HFD for up to 25 weeks starting at 12 weeks of age.

RESULTS

All groups gained weight at a similar rate and developed a similar degree of adiposity, hyperglycemia, glucose intolerance, and impairment of insulin sensitivity in response to HFD. As expected, the circulating monocyte count was decreased in Ccr2^-/- and Cx3cr1^-/- Ccr2^-/- mice but not in Cx3cr1^-/- mice. Flow cytometric analysis of perigonadal adipose tissue of male, but not female, mice revealed trends to lower CD11c+MGL1- M1-like macrophages and higher CD11c-MGL1+ M2-like macrophages as a percentage of CD45+F4/80+CD11b+ macrophages in Cx3cr1^-/- Ccr2^-/- mice versus wild-type mice, suggesting reduced adipose tissue macrophage activation. In contrast, single knockout of Ccr2 or Cx3cr1 did not differ in their adipose macrophage phenotypes.

CONCLUSIONS

Although CCR2 and CX3CR1 may synergistically impact inflammatory phenotypes, their joint deficiency did not influence the metabolic effects of a 45% HFD-induced obesity in these model conditions.

Expression and Enzyme Activity of Catalase in Chilo suppressalis (Lepidoptera: Crambidae) Is Responsive to Environmental Stresses

Catalase (CAT) is an important antioxidant enzyme that protects organisms against oxidative stresses by eliminating hydrogen peroxide. In this study, we cloned and characterized a full-length cDNA of CAT from Chilo suppressalis (CsCAT) and examined the influence of environmental stresses on CsCAT expression and enzyme activity. The cDNA contains a 1659-bp open reading frame encoding a polypeptide of 553 amino acids most closely related (90.14%) to Papilio polytes catalases. The CsCAT was expressed in all developmental stages with the highest expression in the fat body, and the CsCAT enzyme activity closely mirrored its observed mRNA expression patterns. The CsCAT mRNA was up-regulated when the larvae were exposed to high temperature (≥30 °C), insecticides (abamectin and chlorantraniliprole), chemicals (H2O2, CHP, CdCl2, and CuSO4), and a dead-end trap plant (vetiver grass), and the CsCAT enzyme activity again mirrored the observed CsCAT expression patterns. These results suggest that up-regulation of CsCAT may enhance the defense response of C. suppressalis by weakening the effects of environmental stresses, and provide insight into the role of CsCAT during development of C. suppressalis.

Cell cycle-dependent control of homologous recombination

DNA double-strand breaks (DSBs) are among the most deleterious type of DNA lesions threatening genome integrity. Homologous recombination (HR) and non-homologous end joining (NHEJ) are two major pathways to repair DSBs. HR requires a homologous template to direct DNA repair, and is generally recognized as a high-fidelity pathway. In contrast, NHEJ directly seals broken ends, but the repair product is often accompanied by sequence alterations. The choice of repair pathways is strictly controlled by the cell cycle. The occurrence of HR is restricted to late S to G2 phases while NHEJ operates predominantly in G1 phase, although it can act throughout most of the cell cycle. Deregulation of repair pathway choice can result in genotoxic consequences associated with cancers. How the cell cycle regulates the choice of HR and NHEJ has been extensively studied in the past decade. In this review, we will focus on the current progresses on how HR is controlled by the cell cycle in both Saccharomyces cerevisiae and mammals. Particular attention will be given to how cyclin-dependent kinases modulate DSB end resection, DNA damage checkpoint signaling, repair and processing of recombination intermediates. In addition, we will discuss recent findings on how HR is repressed in G1 and M phases by the cell cycle.

Large numbers of interleukins-22- and -17A-producing T helper cells in cholangiocarcinoma related to liver fluke infection

Cholangiocarcinoma (CCA) associated with liver fluke infection involves inflammatory and immune processes; however, whether these involve the proinflammatory cytokine IL-17A and proliferative cytokine IL-22 remains unclear. Here, numbers of IL-22- and IL-17A-producing Th cells and cytokine concentrations in 30 patients with CCA and long-term liver fluke infection, 40 patients with liver-fluke infection but not CCA, and 16 healthy controls were compared. Analyses were performed using immunohistochemistry, flow cytometry, ELISA and RT-PCR. Immunohistochemical staining showed weaker expression of IL-22 and IL-17A in patients with CCA with than in those without liver fluke infection (P < 0.01). Flow cytometry revealed significantly greater median proportions of IL-22-producing T helper cells in patients with CCA (2.2%) than in those without it (0.69%) or controls (0.4%, P < 0.001). Similar results were obtained for IL-17A-producing T helper cells. ELISA revealed plasma concentrations of IL-22 were 1.3-fold higher in patients with CCA than in those without it and 4.6-fold higher than in controls (P < 0.001). Plasma concentrations of IL-17A were 2.5-fold higher in patients with CCA than in those without it, and 21-fold higher than in controls (P < 0.001). Amounts of IL-22 and IL-17A mRNAs in blood were significantly higher in patients with CCA than in the other two groups. Proportions of CD4+ CD45RO+ T cells producing IL-22 correlated with proportions producing IL-17A (r = 0.759; P < 0.001), and plasma concentrations of IL-22 correlated with those of IL-17A (r = 0.726; P < 0.001). These results suggest that both IL-17A and IL-22 affect development of CCA related to liver fluke infection.

Host regulation by the ectophagous parasitoid wasp Bracon nigricans

The host regulation process has been widely investigated in endophagous parasitoid wasps, which in most cases finely interact with living hosts (i.e. koinobiont parasitoids). In contrast, only very limited information is available for ectophagous parasitoids that permanently paralyze and rapidly suppress their victims (i.e. idiobiont parasitoids). Here we try to fill this research gap by investigating the host regulation by Bracon nigricans, an ectophagous idiobiont wasp species. Parasitism, mainly by venom action, is able to redirect host metabolism in order to enhance its nutritional suitability for the developing parasitoid larvae and to provide the required metabolic support to host tissues. The observed alterations of the host titers of haemolymph proteins, carbohydrates and acylglycerols are associated with a parasitoid-induced mobilization of nutrients stored in the fat body. This tissue undergoes a controlled degradation mediated by a close surface interaction with haemocytes, where a cathepsin L activity is localized, as demonstrated by immunolocalization, biochemical and transcriptional data. B. nigricans parasitism does not markedly influence the survival of haemocytes, even though a persistent suppression of the immune competence is observed in parasitized hosts, which show a reduced capacity to encapsulate and melanize non-self objects. These immune alterations likely allow a more efficient food uptake and use by the ectophagous larvae. The obtained results indicate that the host regulation process in basal lineages of parasitic Hymenoptera is more complex than expected and shares functional similarities with adaptive strategies occurring in derived koinobiont species.

Roles of IL-4 genetic polymorphisms and haplotypes in the risk of gastric cancer and their interaction with environmental factors

Gastric cancer (GC) is the fifth most common cancer and imposes a global cancer burden. IL-4 is a typical cytokine of Th2 cells. IL-4 genetic polymorphisms have multiple functions in many cancers. We performed a case-control study in the Chinese population, and evaluated the association between rs2243250 (590 C/T), rs2227284 (107 T/C), rs2070874 (166 T/C) and rs1801275 (576 Q/R) and gastric cancer risk. A total of 340 gastric cancer patients and 364 controls were enrolled into our study. SNP genotyping of IL-4 rs2243250, rs2227284, rs2070874 and rs1801275 was done in a 384-well plate format on the sequenom MassARRAY platform (Sequenom, San Diego, USA). We observed the CC genotype of IL-4 rs2243250 was associated with risk of gastric cancer when compared with the TT genotype (OR=2.36, 95% CI=1.49-3.75). Moreover, individuals harboring the CT+CC genotype exposed a higher risk of gastric cancer in comparison with the TT genotype (OR=1.66, 95% CI=1.17-2.35). However, there was no significant association between IL-4 rs2227284, rs2070874 and rs1801275 and gastric cancer risk. The TT+CT genotype of IL-4 rs2243250 showed a significant increased risk of gastric cancer in males (OR=2.48, 95% CI=1.67-3.68) and those without a family history of cancer (OR=1.97, 95% CI=1.44-2.70). In ever drinkers (OR=2.04, 95% CI=1.24-3.37) and H. pylori infected patients (OR=2.31, 95% CI=1.38-3.86), the TT+CT genotype of IL-4 rs2243250 had a higher risk of gastric cancer than non-drinkers (OR=1.77, 95% CI=1.20-2.61) and non-H. pylori infected ones (OR=1.76, 95% CI=1.19-2.62). The CTCA (OR=1.54, 95% CI=1.06-2.24), CTCG (OR=1.83, 95% CI=1.16-2.86) and CTTG (OR=1.89, 95% CI=1.16-3.07) haplotypes showed an increased risk in gastric cancer, while the TCTG (OR=0.22, 95% CI=0.09-0.52), TTCG (OR=0.47, 95% CI=0.32-0.69) and TTTA (OR=0.58, 95% CI=0.42-30.79) haplotypes were associated with an reduction risk of gastric cancer. In conclusion, our study indicated that the IL-4 rs2243250 CC genotype and CT+CC genotype were associated with gastric cancer risk in the Chinese population, and IL-4 haplotypes plays an important role in the development of gastric cancer.

The drug transporter OAT3 (SLC22A8) and endogenous metabolite communication via the gut-liver-kidney axis

The organic anion transporters OAT1 (SLC22A6) and OAT3 (SLC22A8) have similar substrate specificity for drugs, but it is far from clear whether this holds for endogenous substrates. By analysis of more than 600 metabolites in the Oat3KO (Oat3 knockout) by LC/MS, we demonstrate OAT3 involvement in the movement of gut microbiome products, key metabolites, and signaling molecules, including those flowing through the gut-liver-kidney axis. Major pathways affected included those involved in metabolism of bile acids, flavonoids, nutrients, amino acids (including tryptophan-derivatives that are uremic toxins), and lipids. OAT3 is also critical in elimination of liver-derived phase II metabolites, particularly those undergoing glucuronidation. Analysis of physicochemical features revealed nine distinct metabolite groups; at least one member of most clusters has been previously validated in transport assays. In contrast to drugs interacting with the OATs, endogenous metabolites accumulating in the Oat1KO (Oat1 knockout) versus Oat3KO have distinct differences in their physicochemical properties; they are very different in size, number of rings, hydrophobicity, and molecular complexity. Consistent with the Remote Sensing and Signaling Hypothesis, the data support the importance of the OAT transporters in inter-organ and inter-organismal remote communication via transporter-mediated movement of key metabolites and signaling molecules (e.g. gut microbiome-to-intestine-to-blood-to-liver-to-kidney-to-urine). We discuss the possibility of an intimate connection between OATs and metabolite sensing and signaling pathways (e.g. bile acids). Furthermore, the metabolomics and pathway analysis support the view that OAT1 plays a greater role in kidney proximal tubule metabolism and OAT3 appears relatively more important in systemic metabolism, modulating levels of metabolites flowing through intestine, liver, and kidney.

Autoreactive T cells in type 1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease that causes severe loss of pancreatic β cells. Autoreactive T cells are key mediators of β cell destruction. Studies of organ donors with T1D that have examined T cells in pancreas, the diabetogenic insulitis lesion, and lymphoid tissues have revealed a broad repertoire of target antigens and T cell receptor (TCR) usage, with initial evidence of public TCR sequences that are shared by individuals with T1D. Neoepitopes derived from post-translational modifications of native antigens are emerging as novel targets that are more likely to evade self-tolerance. Further studies will determine whether T cell responses to neoepitopes are major disease drivers that could impact prediction, prevention, and therapy. This Review provides an overview of recent progress in our knowledge of autoreactive T cells that has emerged from experimental and clinical research as well as pathology investigations.

Endoplasmic reticulum proteostasis impairment in aging

Perturbed neuronal proteostasis is a salient feature shared by both aging and protein misfolding disorders. The proteostasis network controls the health of the proteome by integrating pathways involved in protein synthesis, folding, trafficking, secretion, and their degradation. A reduction in the buffering capacity of the proteostasis network during aging may increase the risk to undergo neurodegeneration by enhancing the accumulation of misfolded proteins. As almost one-third of the proteome is synthetized at the endoplasmic reticulum (ER), maintenance of its proper function is fundamental to sustain neuronal function. In fact, ER stress is a common feature of most neurodegenerative diseases. The unfolded protein response (UPR) operates as central player to maintain ER homeostasis or the induction of cell death of chronically damaged cells. Here, we discuss recent evidence placing ER stress as a driver of brain aging, and the emerging impact of neuronal UPR in controlling global proteostasis at the whole organismal level. Finally, we discuss possible therapeutic interventions to improve proteostasis and prevent pathological brain aging.

Neutrophil Extracellular Traps in the Amniotic Cavity of Women with Intra-Amniotic Infection: A New Mechanism of Host Defense

OBJECTIVE

Neutrophil extracellular traps (NETs) control microbial infections through their antimicrobial activities attributed to DNA, histones, granules, and cytoplasmic proteins (eg, elastase). Intra-amniotic infection is characterized by the influx of neutrophils into the amniotic cavity; therefore, the aim of this study was to determine whether amniotic fluid neutrophils form NETs in this inflammatory process.

METHODS

Amniotic fluid samples from women with intra-amniotic infection (n = 15) were stained for bacteria detection using fluorescent dyes. Amniotic fluid neutrophils were purified by filtration. As controls, neutrophils from maternal blood samples (n = 3) were isolated by density gradients. Isolated neutrophils were plated onto glass cover slips for culture with and without 100 nM of phorbol-12-myristate-13-acetate (PMA). NET formation was assessed by 4',6-diamidino-2-phenylindole (DAPI) staining and scanning electron microscopy. Different stages of NET formation were visualized using antibodies against elastase and histone H3, in combination with DAPI staining, by confocal microscopy. Finally, maternal or neonatal neutrophils were added to amniotic fluid samples from women without intra-amniotic infection (n = 4), and NET formation was evaluated by DAPI staining.

RESULTS

(1) NETs were present in the amniotic fluid of women with intra-amniotic infection; (2) all of the amniotic fluid samples had detectable live and dead bacteria associated with the presence of NETs; (3) in contrast to neutrophils from the maternal circulation, amniotic fluid neutrophils did not require PMA stimulation to form NETs; (4) different stages of NET formation were observed by co-localizing elastase, histone H3, and DNA in amniotic fluid neutrophils; and (5) neither maternal nor neonatal neutrophils form NETs in the amniotic fluid of women without intra-amniotic infection.

CONCLUSION

NETs are detectable in the amniotic fluid of women with intra-amniotic infection.

Contribution of Human Lung Parenchyma and Leukocyte Influx to Oxidative Stress and Immune System-Mediated Pathology following Nipah Virus Infection

Nipah virus (NiV) is a zoonotic emerging paramyxovirus that can cause fatal respiratory illness or encephalitis in humans. Despite many efforts, the molecular mechanisms of NiV-induced acute lung injury (ALI) remain unclear. We previously showed that NiV replicates to high titers in human lung grafts in NOD-SCID/γ mice, resulting in a robust inflammatory response. Interestingly, these mice can undergo human immune system reconstitution by the bone marrow, liver, and thymus (BLT) reconstitution method, in addition to lung tissue engraftment, giving altogether a realistic model to study human respiratory viral infections. Here, we characterized NiV Bangladesh strain (NiV-B) infection of human lung grafts from human immune system-reconstituted mice in order to identify the overall effect of immune cells on NiV pathogenesis of the lung. We show that NiV-B replicated to high titers in human lung grafts and caused similar cytopathic effects irrespective of the presence of human leukocytes in mice. However, the human immune system interfered with virus spread across lung grafts, responded to infection by leukocyte migration to small airways and alveoli of the lung grafts, and accelerated oxidative stress in lung grafts. In addition, the presence of human leukocytes increased the expression of cytokines and chemokines that regulate inflammatory influx to sites of infection and tissue damage. These results advance our understanding of how the immune system limits NiV dissemination and contributes to ALI and inform efforts to identify therapeutic targets.IMPORTANCE Nipah virus (NiV) is an emerging paramyxovirus that can cause a lethal respiratory and neurological disease in humans. Only limited data are available on NiV pathogenesis in the human lung, and the relative contribution of the innate immune response and NiV to acute lung injury (ALI) is still unknown. Using human lung grafts in a human immune system-reconstituted mouse model, we showed that the NiV Bangladesh strain induced cytopathic lesions in lung grafts similar to those described in patients irrespective of the donor origin or the presence of leukocytes. However, the human immune system interfered with virus spread, responded to infection by leukocyte infiltration in the small airways and alveolar area, induced oxidative stress, and triggered the production of cytokines and chemokines that regulate inflammatory influx by leukocytes in response to infection. Understanding how leukocytes interact with NiV and cause ALI in human lung xenografts is crucial for identifying therapeutic targets.

Early apoptosis of monocytes induced by Helicobacter pylori infection through multiple pathways

Only a small percentage of people infected with Helicobacter pylori (H. pylori) will develop overt chronic gastric diseases. To understand the pathological mechanism, the action of H. pylori on monocyte apoptosis was detected. H. pylori co-culturing with peripheral blood monocytes, THP-1 or U937 cells result in early apoptosis at 6, 12, and 24 h after infection. The phosphorylated Bad and JNK were increased, and Bcl-2 was declined at 6, 12, and 24 h in peripheral blood monocytes after H. pylori infection. The phosphorylated Akt was augmented at 6 and 12 h post-infection. A slow apoptotic response was induced by H. pylori via Bad and Bcl-2 regulators, activated caspase-8 and caspase-9, and JNK at 24 h in THP-1 cells. Meanwhile, only Bad and JNK were involved in regulating U937 cells apoptosis at 24 h after infection. These results supported a novel mechanism of H. pylori escaping from monocytes by upregulation of early apoptosis and inhibition of late apoptosis. The differences among the three cells may reveal why H. pylori-derived disease occurs in relatively few people and provide a pathological mechanism whereby a treatment for H. pylori-derived disease may be developed.

Alterations of expression of inflammation/immune-related genes in the dorsal and ventral striatum of adult C57BL/6J mice following chronic oxycodone self-administration: a RNA sequencing study

INTRODUCTION

Non-medical use of prescription opioids such as the mu opioid receptor (MOP-r) agonist oxycodone is a growing problem in the USA and elsewhere. There is limited information about oxycodone's impact on diverse gene systems in the brain.

OBJECTIVES

The current study was designed to examine how chronic oxycodone self-administration (SA) affects gene expression in the terminal areas of the nigrostriatal and mesolimbic dopaminergic pathways in mice.

METHOD

Adult male C57BL/6J mice underwent a 14-day oxycodone self-administration procedure (4 h/day, 0.25 mg/kg/infusion, FR1) and were euthanized 1 h after the last session. The dorsal and ventral striata were dissected, and total RNAs were extracted. Gene expressions were examined using RNA sequencing.

RESULT

We found that oxycodone self-administration exposure led to alterations of expression in numerous genes related to inflammation/immune functions in the dorsal striatum (54 upregulated genes and 1 downregulated gene) and ventral striatum (126 upregulated genes and 15 downregulated genes), with 38 upregulated genes identified in both brain regions.

CONCLUSION

This study reveals novel neurobiological mechanisms underlying some of the effects of a commonly abused prescription opioid. We propose that inflammation/immune gene systems may undergo a major change during chronic self-administration of oxycodone.

A C-type lectin, Nattectin-like protein (CaNTC) in Qihe crucian carp Carassius auratus: Binding ability with LPS, PGN and various bacteria, and agglutinating activity against bacteria

C-type lectins (CTLs), as the members of pattern-recognition receptors (PRRs), play the significant roles in innate immunity through binding with pathogen-associated molecular patterns (PAMPs) on the surface of microbe. In the present study, a novel CTL, Nattectin-like protein (named as CaNTC), was investigated in Qihe crucian carp Carassius auratus. The full-length cDNA of CaNTC was composed of 776 bp, with a 152 bp 5'-untranslated region (UTR), a 492 bp ORF encoding a 163-aa protein, and a 132 bp 3'-UTR with a polyadenylation signal sequence AATAAA and a poly(A) tail. The deduced amino acid sequence of CaNTC contained a signal peptide, a single carbohydrate recognition domain (CRD) which had four conserved disulfide-bonded cysteine residues (Cys⁵⁷-Cys¹⁵⁰, Cys¹²⁶-Cys¹⁴²), and an EPN/WND motif required for carbohydrate-binding specificity. With regard to the mRNA transcript of CaNTC, it was predominately expressed in liver. The temporal expressions of CaNTC were obviously up-regulated in liver, spleen and head-kidney after challenged by Aeromonas hydrophila and poly I: C, respectively, and the change pattern was in the time-depended manner. The recombinant CaNTC (rCaNTC) purified from Escherichia coli BL21 (DE3), exhibited strong binding ability with LPS and PGN, as well as all tested bacteria in a Ca²⁺-independent manner. With regard to the agglutinating activity of rCaNTC, rCaNTC was able to agglutinate rabbit erythrocytes and three kinds of bacteria (Gram-negative bacteria, Escherichia coli and A. hydrophila, and Gram-positive bacteria Staphylococcus aureus) in a Ca²⁺-dependent manner. These findings collectively demonstrated that CaNTC, as a PRR, could be involved in the innate immunity and play an important role in immune defense of C. auratus.

The RNA-Binding Protein HuR Posttranscriptionally Regulates IL-2 Homeostasis and CD4+ Th2 Differentiation

Posttranscriptional gene regulation by RNA-binding proteins, such as HuR (elavl1), fine-tune gene expression in T cells, leading to powerful effects on immune responses. HuR can stabilize target mRNAs and/or promote translation by interacting with their 3' untranslated region adenylate and uridylate-rich elements. It was previously demonstrated that HuR facilitates Th2 cytokine expression by mRNA stabilization. However, its effects upon IL-2 homeostasis and CD4+ Th2 differentiation are not as well understood. We found that optimal translation of Il2ra (CD25) required interaction of its mRNA with HuR. Conditional HuR knockout in CD4+ T cells resulted in loss of IL-2 homeostasis and defects in JAK-STAT signaling, Th2 differentiation, and cytokine production. HuR-knockout CD4+ T cells from OVA-immunized mice also failed to proliferate in response to Ag. These results demonstrate that HuR plays a pivotal role in maintaining normal IL-2 homeostasis and initiating CD4+ Th2 differentiation.

Memory T Cells in Type 1 Diabetes: the Devil is in the Detail

PURPOSE OF REVIEW

Therapies that target beta-cell antigen-specific T cells subsets have not been as successful in patients with type 1 diabetes as in mice. This might be explained by complexities in the repertoire of beta-cell antigen-specific T cells and the variety of T cell subsets involved in type 1 diabetes development in human.

RECENT FINDINGS

T cells that infiltrate islets of people with type 1 diabetes (i) react towards known islet cell antigens but also unknown antigens, (ii) differ from one patient to another, and (iii) are also present in the circulation, but not in the islets, of healthy people. Moreover, several circulating memory T cell subsets not recognized as relevant in mouse are significantly associated with clinical outcome. A more detailed understanding of the specificity, phenotype, and function of T cells that are associated with defined clinical outcomes might identify new pathways for therapeutic intervention.

Perpetual change: autophagy, the endothelium, and response to vascular injury

Current studies of vascular health, aging, and autophagy emphasize how the endothelium adapts to stress and contributes to disease. The endothelium is far from an inert barrier to blood-borne cells, pathogens, and chemical signals; rather, it actively translates circulating mediators into tissue responses, changing rapidly in response to physiologic stressors. Macroautophagy-the cellular ingestion of effete organelles and protein aggregates to provide anabolic substrates to fuel bioenergetics in times of stress-plays an important role in endothelial cell homeostasis, vascular remodeling, and disease. These roles include regulating vascular tone, sustaining or limiting cell survival, and contributing to the development of atherosclerosis secondary to infection, inflammation, and angiogenesis. Autophagy modulates these critical functions of the endothelium in a dynamic and perpetual response to tissue and intravascular cues.

IL-4-secreting eosinophils promote endometrial stromal cell proliferation and prevent Chlamydia-induced upper genital tract damage

Genital Chlamydia trachomatis infections in women typically are asymptomatic and do not cause permanent upper genital tract (UGT) damage. Consistent with this presentation, type 2 innate and T_H2 adaptive immune responses associated with dampened inflammation and tissue repair are elicited in the UGT of Chlamydia-infected women. Primary C. trachomatis infection of mice also causes no genital pathology, but unlike women, does not generate Chlamydia-specific T_H2 immunity. Herein, we explored the significance of type 2 innate immunity for restricting UGT tissue damage in Chlamydia-infected mice, and in initial studies intravaginally infected wild-type, IL-10^-/-, IL-4^-/-, and IL-4Rα^-/- mice with low-dose C. trachomatis inoculums. Whereas Chlamydia was comparably cleared in all groups, IL-4^-/- and IL-4Rα^-/- mice displayed endometrial damage not seen in wild-type or IL-10^-/- mice. Congruent with the aberrant tissue repair in mice with deficient IL-4 signaling, we found that IL-4Rα and STAT6 signaling mediated IL-4-induced endometrial stromal cell (ESC) proliferation ex vivo, and that genital administration of an IL-4-expressing adenoviral vector greatly increased in vivo ESC proliferation. Studies with IL-4-IRES-eGFP (4get) reporter mice showed eosinophils were the main IL-4-producing endometrial leukocyte (constitutively and during Chlamydia infection), whereas studies with eosinophil-deficient mice identified this innate immune cell as essential for endometrial repair during Chlamydia infection. Together, our studies reveal IL-4-producing eosinophils stimulate ESC proliferation and prevent Chlamydia-induced endometrial damage. Based on these results, it seems possible that the robust type 2 immunity elicited by Chlamydia infection of human genital tissue may analogously promote repair processes that reduce phenotypic disease expression.

The Role of p38 MAPK, JNK, and ERK in Antibacterial Responses of Chilo suppressalis (Lepidoptera: Crambidae)

The mitogen-activated protein kinases (MAPKs) are conserved signal transduction pathways and broadly responsible for bacterial infection from yeast to mammals, and virus, fungi, and bacteria, specifically Bacillus thuringiensis, to insects. But little is known about the MAPK pathways in antibacterial responses in Chilo suppressalis (Walker), an important lepidopteran pest of rice. In this study, we used the bacteria of Bacillus thuringiensis, Escherichia coli, and Staphyloccocus aureus to infect C. suppressalis larvae, and the responses of MAPK pathways were analyzed. The results showed that E. coli infection induced the up-regulated expression of Csp38 and CsERK1 at 24 h postinfection (pi). Meanwhile, injection of B. thuringiensis and S. aureus resulted in strong activation of CsJNK phosphorylation at 3 h pi. These results suggest that MAPK signaling pathways play important functional roles in antibacterial responses in C. suppressalis larvae.

Overexpression of B-cell lymphoma 6 alters gene expression profile in a myeloma cell line and is associated with decreased DNA damage response

B-cell lymphoma 6 (BCL6) attenuates DNA damage response (DDR) through gene repression and facilitates tolerance to genomic instability during immunoglobulin affinity maturation in germinal center (GC) B cells. Although BCL6 expression is repressed through normal differentiation of GC B cells into plasma cells, a recent study showed the ectopic expression of BCL6 in primary multiple myeloma (MM) cells. However, the functional roles of BCL6 in MM cells are largely unknown. Here, we report that overexpression of BCL6 in a MM cell line, KMS12PE, induced transcriptional repression of ataxia telangiectasia mutated (ATM), a DDR signaling kinase, which was associated with a reduction in γH2AX formation after DNA damage. In contrast, transcription of known targets of BCL6 in GC B cells was not affected, suggesting a cell type-specific function of BCL6. To further investigate the effects of BCL6 overexpression on the MM cell line, we undertook mRNA sequence analysis and found an upregulation in the genomic mutator activation-induced cytidine deaminase (AID) with alteration in the gene expression profile, which is suggestive of de-differentiation from plasma cells. Moreover, interleukin-6 exposure to KMS12PE led to upregulation of BCL6 and AID, downregulation of ATM, and attenuation of DDR, which were consistent with the effects of BCL6 overexpression in this MM cell line. Taken together, these results indicated that overexpression of BCL6 alters gene expression profile and confers decreased DDR in MM cells. This phenotypic change could be reproduced by interleukin-6 stimulation, suggesting an important role of external stimuli in inducing genomic instability, which is a hallmark of MM cells.

Indigo Naturalis ameliorates murine dextran sodium sulfate-induced colitis via aryl hydrocarbon receptor activation

BACKGROUND

Indigo Naturalis (IN) is used as a traditional herbal medicine for ulcerative colitis (UC). However, the mechanisms of action of IN have not been clarified. We aimed to evaluate the efficacy of IN for ameliorating colonic inflammation. We further investigated the mechanisms of action of IN.

METHODS

Colitis severity was assessed in dextran sodium sulfate-induced colitis and trinitrobenzene sulfonic acid-induced colitis models with or without the oral administration of IN or indigo, which is a known major component of IN. Colonic lamina propria (LP) mononuclear cells isolated from IN-treated mice were analyzed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and flow cytometry. LP and splenic mononuclear cells cultured in vitro with IN or indigo were also analyzed. The role of the candidate receptor for indigo, the aryl hydrocarbon receptor (AhR), was analyzed using Ahr-deficient mice.

RESULTS

Colitis severity was significantly ameliorated in the IN and indigo treatment groups compared with the control group. The mRNA expression levels of interleukin (Il)-10 and Il-22 in the LP lymphocytes were increased by IN treatment. The treatment of splenocytes with IN or indigo increased the expression of anti-inflammatory cytokines and resulted in the expansion of IL-10-producing CD4+ T cells and IL-22-producing CD3-RORγt+ cells, but not CD4+Foxp3+ regulatory T cells. The amelioration of colitis by IN or indigo was abrogated in Ahr-deficient mice, in association with diminished regulatory cytokine production.

CONCLUSIONS

IN and indigo ameliorated murine colitis through AhR signaling activation, suggesting that AhR could be a promising therapeutic target for UC.