High IL-10 Production Research Articles

Irradiation at a young age induces immune-modulation through NF-κB pathway on spleen cells in old age mice (P3044)

Abstract It is reported that irradiation induces shortened lifespan in mice with dose-dependent. We also previously reported that young-age irradiated mice induces shorten lifespan compared to non-irradiated mice. In addition, the number of lymphocytes in the S- and G2/M- phases was significantly increased in the irradiated mice. However, the detail mechanism is still not fully understood. In the present study, we demonstrated that irradiation at young age induces immune-modulation of splenocytes in old age mice. The p53+/- mice were exposed to 3 Gy at 8 weeks of whole-body irradiation and were sacrificed at about 54 weeks of age. The expression of CDK2 was increased in the splenocytes of the mice irradiated at 8 weeks. Electrophoretic mobility shift assay demonstrated increased activated-NF-κB in the splenocytes of the mice irradiated at 8 weeks but not at 17 and 30 weeks mice. Cell viability assay shows constant activation of splenocytes in the mice irradiated at 8 weeks both female and male mice compared to non-irradiated mice. In contrast to this, splenocytes of the mice irradiated at 17 and 30 weeks were similar activities to non-irradiated mice. Finally, IL-6 production from splenocytes was measured by ELISA and irradiated mice have high production of IL-6. Taken together, these results suggest that young age irradiation induced immune-modulated response in the second lymphoid organ, which may relate to be activation of NF-κB.

The Response of Human Macrophages to β-Glucans Depends on the Inflammatory Milieu

Backgroundβ-glucans are fungal cell wall components that bind to the C-type lectin-like receptor dectin-1. Polymorphisms of dectin-1 gene are associated with susceptibility to invasive fungal infection and medically refractory ulcerative colitis. The purpose of this study has been addressing the response of human macrophages to β-glucans under different conditions mimicking the composition of the inflammatory milieu in view of the wide plasticity and large range of phenotypical changes showed by these cells, and the relevant role of dectin-1 in several pathophysiological conditions.Principal FindingsSerum-differentiated macrophages stimulated with β-glucans showed a low production of TNFα and IL-1β, a high production of IL-6 and IL-23, and a delayed induction of cyclooxygenase-2 and PGE2 biosynthesis that resembled the responses elicited by crystals and those produced when phagosomal degradation of the phagocytic cargo increases ligand access to intracellular pattern recognition receptors. Priming with a low concentration of LPS produced a rapid induction of cyclooxygenase-2 and a synergistic release of PGE2. When the differentiation of the macrophages was carried out in the presence of M-CSF, an increased expression of dectin-1 B isoform was observed. In addition, this treatment made the cells capable to release arachidonic acid in response to β-glucan.ConclusionsThese results indicate that the macrophage response to fungal β-glucans is strongly influenced by cytokines and microbial-derived factors that are usual components of the inflammatory milieu. These responses can be sorted into three main patterns i) an elementary response dependent on phagosomal processing of pathogen-associated molecular patterns and/or receptor-independent, direct membrane binding linked to the immunoreceptor tyrosine-based activation motif-bearing transmembrane adaptor DNAX-activating protein 12, ii) a response primed by TLR4-dependent signals, and iii) a response dependent on M-CSF and dectin-1 B isoform expression that mainly signals through the dectin-1 B/spleen tyrosine kinase/cytosolic phospholipase A2 route.

Impact of the magnitude of sensitization dose on the incidence and intensity of CHS to dinitrochlorobenzene (DNCB): Insight from ear swelling and challenged-skin draining lymph node response in rats

Allergic contact dermatitis (ACD) is a common skin inflammatory disease that develops in hosts sensitized with contact allergens. Elucidation of dose–response relationships represents one of the approaches in studying the type of ACD in humans/animal models, termed as contact hyper-sensitivity reaction (CHS). Such studies have demonstrated that the intensity of sensitization determines the response to elicitation with a contact allergen, but underlying mechanisms are unclear. The aim of this study is to explore the impact of the sensitization on contact hypersensitivity to dinitrochlorobenzene (DNCB) in rats by measuring the incidence and intensity of a challenge response in hosts sensitized with two different doses (i.e. low and high) of this hapten. Assumptions concerning the contribution from the magnitude of sensitization doses were drawn on the basis of effects from the two doses on the measured reaction parameters. Ear swelling and activity of lymph nodes that drain challenged skin (cdLN), including cellularity, proliferation, and effector cytokine IFNγ and IL-17 production was measured in rats sensitized with 0.4% or 4% DNCB and challenged with a non-irritant (0.13%) dose. Sensitization with 4% DNCB resulted in a greater proportion of rats who responded more intensely (than unsensitized challenged rats) to challenge in terms of ear swelling and increases in cdLN activity (except for IFNγ). The intensity of cdLN responses was higher in these hosts as well. Among the high-dose-sensitized rats, greater cellularity/proliferation of cells from lymph nodes (sdLN) that drain the high-dose-sensitized skin, as well as higher IL-17 production, was noted compared to what was seen in rats that received low-dose sensitization. In contrast, unchanged spontaneous and even decreased hapten-stimulated IFNγ production after the high DNCB dose was observed. Based on the data, it seems the impact of magnitude of sensitization dose on CHS might be related to the rise in the proportion of rats that responded to challenge with an increase of dLN activity. Coincidental higher production of IL-17 by dLN cells from the high-dose-sensitized rats and following challenge of these hosts underscored the significance of IL-17 for a CHS to DNCB.

Influence of Intron II microsatellite polymorphism in human toll-like receptor 2 gene in leprosy

Leprosy is a chronic granulomatous infection caused by the obligate intracellular organism Mycobacterium leprae. TLR2 plays a key role when activated by M. leprae lipoproteins initiating protective responses which induce bacterial killing and therefore control of disease spread. Microsatellite polymorphisms in intron2 of TLR2 gene have been reported to be associated with development of clinical features of several infectious diseases. The study aims to evaluate the influence of GT microsatellite on the expression of TLR2 which could make humans prone to M. leprae infections. A total of 279 individuals were enrolled in the study, 88 were leprosy patients, 95 were house hold contacts (HHC) and 96 were healthy controls (HC). Genotyping was done using PCR-Sequencing method. TLR2 mRNA expression was analyzed by RT-PCR. IL-10 and IFN-γ levels were measured using ELISA in MLSA stimulated cell culture supernatants. Statistical analysis was performed using Chi-Square (χ(2)) test and t-tests. Allele/genotype of TLR2 microsatellite which includes longer GT repeats was associated with low TLR2 mRNA expression and high IL-10 production while that including shorter GT repeats was associated with high TLR2 mRNA expression and low IL-10 production. High IL10 producing allele of TLR2 microsatellite might predispose house hold contacts to leprosy.

TNF-α, IL6, and IL10 polymorphisms and the effect of physical exercise on inflammatory parameters and physical performance in elderly women

High levels of inflammatory mediators are associated with reduced physical capabilities and muscle function in the elderly. Single nucleotide polymorphisms (SNPs) may affect the expression and synthesis of these molecules, thus influencing the intensity of the inflammatory response and susceptibility to certain diseases. Physical exercise may attenuate age-related chronic inflammation and improve physical performance. This study evaluated the interaction between the SNP rs1800629 in TNF-α, rs1800795 in IL6, and rs1800896 in IL10 and the effect of physical exercise on physical performance and inflammation in elderly women. There was a significant interaction between rs1800629 and the effect of exercise on physical performance and between the combined 3-SNP genotype and changes in physical performance in response to exercise. These SNPs did not influence the effect of exercise on inflammatory parameters. Elderly women with a combination of genotypes associated with an anti-inflammatory profile (low TNF-α and IL-6 production, high IL-10 production) showed better physical performance independent of exercise modality, evidence of an interactive influence of genetic and environmental factors on improving physical performance in elderly women.

The protective effect of aDNAvaccine encoding theToxoplasma gondiicyclophilin gene inBALB/cmice

Toxoplasmosis is a world-wide zoonosis that causes significant public health and veterinary problems. The study of vaccines remains the most promising method for the future prevention and control of toxoplasmosis. Recombinant Toxoplasma gondii cyclophilin has been shown to have potent PPIase and IL-12-inducing activities, thus promoting the stabilization of T. gondii's life cycle and maintaining the survival of its host during evolution. In this study, the T. gondii cyclophilin gene was used to construct a DNA vaccine (pVAX1-TgCyP). The immune response and protective efficacy of the vaccine against T. gondii infection in BALB/c mice were evaluated. All BALB/c mice that were vaccinated with pVAX1-TgCyP developed a high response with TgCyP-specific antibodies, and significant splenocyte proliferation (P < 0·05) compared with pVAX1 vector and PBS groups. pVAX1-TgCyP also induced a significant Th1 type immune response, indicated by the higher production of IL-2 and IFN-γ (P < 0·05). The survival rate of BALB/c mice increased significantly after vaccination with pVAX1-TgCyP (37·5%) (P < 0·05). These results indicate that TgCyP is a highly efficacious vaccine candidate that can generate protective immunity against T. gondii infection in BALB/c mice.

Mycobacterium avium subspecies impair dendritic cell maturation

Mycobacterium avium ssp. paratuberculosis (MAP) causes Johne's disease, a chronic, granulomatous enteritis of ruminants. Dendritic cells (DC) of the gut are ideally placed to combat invading mycobacteria; however, little is known about their interaction with MAP. Here, we investigated the interaction of MAP and the closely related M. avium ssp. avium (MAA) with murine DC and the effect of infected macrophages on DC maturation. The infection of DC with MAP or MAA induced DC maturation, which differed to that of LPS as maturation was accompanied by higher production of IL-10 and lower production of IL-12. Treatment of maturing DC with supernatants from mycobacteria-infected macrophages resulted in impaired DC maturation, leading to a semi-mature, tolerogenic DC phenotype expressing low levels of MHCII, CD86 and TNF-α after LPS stimulation. Though the cells were not completely differentiated they responded with an increased IL-10 and a decreased IL-12 production. Using recombinant cytokines we provide evidence that the semi-mature DC phenotype results from a combination of secreted cytokines and released antigenic mycobacterial components of the infected macrophage. Our results indicate that MAP and MAA are able to subvert DC function directly by infecting and indirectly via the milieu created by infected macrophages.

1646 – Genetic risk factors for interferon-induced anxiety

Interferon-alpha (IFN-α) and Ribavirin is the recommended treatment for chronic hepatitis C (CHC). Common treatment side-effects include neuropsychiatric symptoms such as anxiety, which impairs patient's quality of life and treatment adherence. Inflammation and neurotransmission systems may play a role in the pathogenesis of IFN-α-induced anxiety. The GC/GG genotype at a polymorphism located in the interleukin-6 synthesizer gene (IL6 gene) has been related with a higher production of IL-6 and “higher inflammation response”. A polymorphism in the serotonin transporter gene (SERT) has been related with anxiety and antidepressant response. The aim of the study was to assess the role of IL6 and SERT polymorphisms as predictive variables of IFN- induced anxiety. A cohort of 385 Caucasian outpatients with CHC initiating antiviral treatment. Patients were euthymic and without current anxiety disorder (SCID) at baseline. Anxiety evaluation: Hospital anxiety and depression scale. Assesment: Baseline, 4, 12, 24, and 48 weeks after antiviral treatment initiation. DNA was extracted and polymorphisms genotyped. Hardy- Weinberg equilibrium: IL-6 (p=0.72) and SERT (p=0.41). Statistical analysis: linear mixed-effects. Patients carrying the G allele (GC/GG genotype) of IL6 polymorphism (G vs. CC) had more anxiety symptoms (p=0.004) during antiviral treatment. We did not find a significant effect of SERT (S vs. LL) on anxiety (p=0.15). No significant interaction between both genes was reported. GC/GG genotype, that implies higher seric concentrations of IL6, predicts interferon-α-induced anxiety supporting a role of inflammatory pathway on pathophysiology of anxiety. PSICOCIT-VHC-P110/01827, and PSIGEN-VHC-EC08/00201. ERDF, European Union “One way to make Europe”.

High IL-4 production related to granuloma development in high-tolerogenic mice infected with Schistosoma mansoni.

Frontiers Events is a rapidly growing calendar management system dedicated to the scheduling of academic events. This includes announcements and invitations, participant listings and search functionality, abstract handling and publication, related events and post-event exchanges. Whether an organizer or participant, make your event a Frontiers Event!

Burn Injury Triggered Dysfunction in Dendritic Cell Response to TLR9 Activation and Resulted in Skewed T Cell Functions

Severe trauma such as burn injury is often associated with a systemic inflammatory syndrome characterized by a hyperactive innate immune response and suppressed adaptive immune function. Dendritic cells (DCs), which sense pathogens via their Toll-like receptors (TLRs), play a pivotal role in protecting the host against infections. The effect of burn injury on TLR-mediated DC function is a debated topic and the mechanism controlling the purported immunosuppressive response remains to be elucidated. Here we examined the effects of burn injury on splenic conventional DC (cDC) and plasmacytoid DC (pDC) responses to TLR9 activation. We demonstrate that, following burn trauma, splenic cDCs’ cytokine production profile in response to TLR9 activation became anti-inflammatory dominant, with high production of IL-10 (>50% increase) and low production of IL-6, TNF-α and IL-12p70 (∼25–60% reduction). CD4+ T cells activated by these cDCs were defective in producing Th1 and Th17 cytokines. Furthermore, burn injury had a more accentuated effect on pDCs than on cDCs. Following TLR9 activation, pDCs displayed an immature phenotype with an impaired ability to secrete pro-inflammatory cytokines (IFN-α, IL-6 and TNF-α) and to activate T cell proliferation. Moreover, cDCs and pDCs from burn-injured mice had low transcript levels of TLR9 and several key molecules of the TLR signaling pathway. Although hyperactive innate immune response has been associated with severe injury, our data show to the contrary that DCs, as a key player in the innate immune system, had impaired TLR9 reactivity, an anti-inflammatory phenotype, and a dysfunctional T cell-priming ability. We conclude that burn injury induced impairments in DC immunobiology resulting in suppression of adaptive immune response. Targeted DC immunotherapies to promote their ability in triggering T cell immunity may represent a strategy to improve immune defenses against infection following burn injury.

Sodium arsenite exposure inhibits AKT and Stat3 activation, suppresses self-renewal and induces apoptotic death of embryonic stem cells

Sodium arsenite exposure at concentration >5 μM may induce embryotoxic and teratogenic effects in animal models. Long-term health effects of sodium arsenite from contaminated drinking water may result in different forms of cancer and neurological abnormalities. As cancer development processes seem to be originated in stem cells, we have chosen to examine the effects of sodium arsenite on signaling pathways and the corresponding transcription factors that regulate cell viability and self-renewal in mouse embryonic stem cells (ESC) and mouse neural stem/precursor cells. We demonstrated that the crucial signaling pathway, which was substantially suppressed by sodium arsenite exposure (4 μM) in ESC, was the PI3K-AKT pathway linked with numerous downstream targets that control cell survival and apoptosis. Furthermore, the whole core transcription factor circuitry that control self-renewal of mouse ESC (Stat3-P-Tyr705, Oct4, Sox2 and Nanog) was strongly down-regulated by sodium arsenite (4 μM) exposure. This was followed by G2/M arrest and induction of the mitochondrial apoptotic pathway that might be suppressed by caspase-9 and caspase-3 inhibitors. In contrast to mouse ESC with very low endogenous IL6, mouse neural stem/precursor cells (C17.2 clone immortalized by v-myc) with high endogenous production of IL6 exhibited a strong resistance to cytotoxic effects of sodium arsenite that could be decreased by inhibitory anti-IL6 antibody or Stat3 inhibition. In summary, our data demonstrated suppression of self-renewal and induction of apoptosis in mouse ESC by sodium arsenite exposure, which was further accelerated due to simultaneous inhibition of the protective PI3K-AKT and Stat3-dependent pathways.

Higher IL10 Production by Transitional B Cells in Tolerant Kidney Transplant Recipients

Background: Induction of transplantation tolerance would reduce the risk of infection, malignancy and cardiovascular disease caused by immunosupresive drugs in renal transplant recipients. Indices of Tolerance Project, one of the largest studies identifying biomarkers of tolerance, revealed that tolerant kidney transplant recipients, had an expansion of B cells in peripheral blood. In parallel, a B cell subset with regulatory properties has been described in humans as a transitional B cell, characterised by high expression of CD38, CD24 and IL10 production. We set out to test the hypothesis that the expansion of this B cell subset was central in the process of spontaneous tolerance observed in these rare recipients and to test the ability of these cells to present alloantigens. Methods: Peripheral Blood Mononuclear Cells (PBMCs) samples from <tolerant: functionally stable recipients without immunosuppressive drugs, <stable: functionally stable recipients on standard immunosuppression, <chronic rejector: immunosuppressed recipients that presented signs of chronic rejection and <healthy controls were used in the study. B cell subsets from patients were identified by flow cytometry with anti-CD20, anti-CD19, anti-CD27, anti-IgM, anti-IgG, anti-CD24 and anti-CD38. PBMCs were cultured for 3 days alone, with CD40L and CpG in RPMI 10% FCS. After 3 days, activation markers (CD25, CD86 and CD40) were measured by surface staining and IL10, IFN-g and TNF-a were measured by intracellular staining and ELISA. Results: B cells were identified as CD20+CD19+ and memory B cells as CD20+CD19+CD27+. Within the CD27- non-memory B cells we selected the IgD+IgM+ population to study the non-class-switching B cells and then we identified Transitional B cells (regulatory B cells or Bregs) as CD24hiCD38hi. Within the C27- population, transitional B cells were more prevalent in tolerant patients (12,1%), in comparison with stable patients (4,5%), chronic rejectors (2,1%) and healthy controls (7,8%). B cells from all groups of patients increased activation markers and TLR-9 after CD40L and CpG activation, respectively. Tolerant patients displayed a higher percentage of IL10+Bcells in comparison with the rest of the groups in response to CD40L, however the response to CpG was similar in all patient groups. IFN-g-producing Bcells were not identified after any activation and levels of TNF-a were higher after activation with CD40L but not CpG in all of the tested patients. Discussion: CD40L interaction with B cells occurs after encounter with activated T cells. Only in this context B cells from tolerant recipients were producing higher amounts of IL-10. This is a first step towards a firm link between an expansion of transitional B cells and transplantation tolerance. Further studies are under way, to establish alloantigen specificity in this interaction.

The impact of pregnancy on the HIV-1-specific T cell function in infected pregnant women

Evidences indicate that pregnancy can alter the Ag-specific T-cell responses. This work aims to evaluate the impact of pregnancy on the in vitro HIV-1-specific immune response. As compared with non-pregnant patients, lower T-cell proliferation and higher IL-10 production were observed in T-cell cultures from pregnant patients following addition of either mitogens or HIV-1 antigens. In our system, the main T lymphocyte subset involved in producing IL-10 was CD4(+)FoxP3(-). Depletion of CD4(+) cells elevated TNF-α and IFN-γ production. Interestingly, the in vitro HIV-1 replication was lower in cell cultures from pregnant patients, and it was inversely related to IL-10 production. In these cultures, the neutralization of IL-10 by anti-IL-10 mAb elevated TNF-α release and HIV-1 replication. In conclusion, our results reveal that pregnancy-related events should favor the expansion of HIV-1-specific IL-10-secreting CD4(+) T-cells in HIV-1-infected women, which should, in the scenario of pregnancy, help to reduce the risk of vertical HIV-1 transmission.

Engagement of Siglec-7 Receptor Induces a Pro-Inflammatory Response Selectively in Monocytes

Sialic acid binding immunoglobulin-like lectin-7 (Siglec-7) is a trans-membrane receptor carrying immunoreceptor tyrosine based inhibitory motifs (ITIMs) and delivering inhibitory signals upon ligation with sialylated glycans. This inhibitory function can be also targeted by several pathogens that have evolved to express sialic acids on their surface to escape host immune responses. Here, we demonstrate that cross-linking of Siglec-7 by a specific monoclonal antibody (mAb) induces a remarkably high production of IL-6, IL-1α, CCL4/MIP-1β, IL-8 and TNF-α. Among the three immune cell subsets known to constitutively express Siglec-7, the production of these pro-inflammatory cytokines and chemokines selectively occurs in monocytes and not in Natural Killer or T lymphocytes. This Siglec-7-mediated activating function is associated with the phosphorylation of the extracellular signal-regulated kinase (ERK) pathway. The present study also shows that sialic acid-free Zymosan yeast particles are able to bind Siglec-7 on monocytes and that this interaction mimics the ability of the anti Siglec-7 mAb to induce the production of pro-inflammatory mediators. Indeed, blocking or silencing Siglec-7 in primary monocytes greatly reduced the production of inflammatory cytokines and chemokines in response to Zymosan, thus confirming that Siglec-7 participates in generating a monocyte-mediated inflammatory outcome following pathogen recognition. The presence of an activating form of Siglec-7 in monocytes provides the host with a new and alternative mechanism to encounter pathogens not expressing sialylated glycans.

High IL-10 production by aged AIDS patients is related to high frequency of Tr-1 phenotype and low in vitro viral replication

This work aims to elucidate the effects of age and HIV-1 infection on the frequency and function of T cell subsets in response to HIV-specific and non-specific stimuli. As compared with the younger AIDS group, the frequencies of naive and central memory T cells were significantly lower in aged AIDS patients. Although there was also a dramatic loss of classical CD4(+)FoxP3(+)CD25(+)Treg cells in this patient group, high frequencies of IL-10-producing CD4(+)FoxP3(-) T cells were observed. In our system, the increased production of IL-10 in aged AIDS patients was mainly derived from Env-specific CD4(+)FoxP3(-)CD152(+) T cells. Interestingly, while the blockade of IL-10 activity by monoclonal antibody clearly enhanced the release of IL-6 and IL-1β by Env-stimulated PBMC cultures from aged AIDS patients, this monoclonal antibody enhanced in vitro HIV-1-replication. In conclusion, HIV infection and aging undoubtedly contribute synergistically to a complex immune dysfunction in T cell compartment of HAART-treated older HIV-infected individuals.

Comparative Transcriptomics of H. pylori Strains AM5, SS1 and Their hpyAVIBM Deletion Mutants: Possible Roles of Cytosine Methylation

Helicobacter pylori is an important human pathogen and one of the most successful chronic colonizers of the human body. H. pylori uses diverse mechanisms to modulate its interaction with the host in order to promote chronic infection and overcome host immune response. Restriction-modification genes are a major part of strain-specific genes present in H. pylori. The role of N6 - adenine methylation in bacterial gene regulation and virulence is well established but not much is known about the effect of C5 -cytosine methylation on gene expression in prokaryotes. In this study, it was observed by microarray analysis and RT-PCR, that deletion of an orphan C5 -cytosine methyltransferase, hpyAVIBM in H. pylori strains AM5and SS1 has a significant effect on the expression of number of genes belonging to motility, adhesion and virulence. AM5ΔhpyAVIBM mutant strain has a different LPS profile and is able to induce high IL-8 production compared to wild-type. hpyAVIBM from strain 26695 is able to complement mutant SS1 and AM5 strains. This study highlights a possible significance of cytosine methylation in the physiology of H. pylori.

Cell Recruitment and Cytokines in Skin Mice Sensitized with the Vaccine Adjuvants: Saponin, Incomplete Freund’s Adjuvant, and Monophosphoryl Lipid A

Vaccine adjuvants are substances associated with antigens that are fundamental to the formation of an intense, durable, and fast immune response. In this context, the use of vaccine adjuvants to generate an effective cellular immune response is crucial for the design and development of vaccines against visceral leishmaniasis. The objective of this study was to evaluate innate inflammatory response induced by the vaccine adjuvants saponin (SAP), incomplete Freund’s adjuvant (IFA), and monophosphoryl lipid A (MPL). After a single dose of adjuvant was injected into the skin of mice, we analyzed inflammatory reaction, selective cell migration, and cytokine production at the injection site, and inflammatory cell influx in the peripheral blood. We found that all vaccine adjuvants were able to promote cell recruitment to the site without tissue damage. In addition, they induced selective migration of neutrophils, macrophages, and lymphocytes. The influx of neutrophils was notable at 12 h in all groups, but at other time points it was most evident after inoculation with SAP. With regard to cytokines, the SAP led to production of interleukin (IL)-2, IL-6, and IL-4. IFA promoted production of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-6, IL-17, IL-4, and IL-10. We also observed that MPL induced high production of IL-2, TNF-α, and IFN-γ, in addition to IL-6, IL-17, and IL-10. In peripheral blood, values of certain cell populations in the local response changed after stimulation. Our data demonstrate that the three vaccine adjuvants stimulate the early events of innate immune response at the injection site, suggesting their ability to increase the immunogenicity of co-administered antigens. Moreover, this work provides relevant information about elements of innate and acquired immune response induced by vaccine adjuvants administered alone.

Sex Differences in Inflammatory Cytokines and CD99 Expression Following In Vitro Lipopolysaccharide Stimulation

Sex influences the severity and evolution of various inflammatory conditions. Although many studies have demonstrated the role of sex hormones in immune response modulation, recent clinical data revealed significant sex differences in inflammatory markers in prepubertal children, suggesting a genetic contribution. We studied several immune functions depending on X-linked genes in healthy adults of both sexes: the respiratory burst of purified neutrophils, the CD99 and CD11b expression of stimulated leukocytes as markers of adhesion and diapedesis, and the production of inflammatory cytokines in whole blood after incubation with lipopolysaccharide for 24 h. The percentage of monocytes expressing CD99 was higher in men than in women, thus confirming the higher CD99 expression reported in males using reverse transcription-polymerase chain reaction. In addition, we observed a higher tumor necrosis factor α and tendency toward higher interleukin (IL) 6 production in men after lipopolysaccharide stimulation. These differences may contribute to the higher mortality reported in men with septic shock. Tumor necrosis factor α production significantly correlated with monocyte count, with men having a higher monocyte count than women. When cytokine levels were normalized to monocyte counts, a higher IL-8 production was found in women, which may explain the higher neutrophil count observed in girls with acute inflammatory diseases, because IL-8 is a major neutrophil chemoattractant. These sex differences regarding the activation of certain X-linked genes involved in innate immunity confirm our clinical observations, thus supporting the role of sex chromosomes in inflammatory response.

Immune regulatory gene polymorphisms as predisposing risk factors for the development of factor VIII inhibitors in Indian severe haemophilia A patients

Development of inhibitors to factor VIII, a serious complication of replacement therapy in haemophilia A patients, leads to increased bleeding, morbidity and mortality. There is no data on the risk factors for inhibitor development in Indian patients with severe haemophilia A. Our aim was to study the role of immune regulatory gene polymorphisms in the development of inhibitors. Fourteen immune regulatory gene polymorphisms (IL1β, IL4, IL10, TNFA and CTLA4) were analysed in 120 patients with severe haemophilia A, i.e. 50 inhibitor positive patients, and 70 inhibitor negative control patients, by PCR-RFLP, DNA sequencing and allele-specific PCRs. The IL10 promoter 'GCC' haplotypes overall (P: 0.002, OR: 3.452, 95% CI: 1.607-7.416), and 'GCC/ATA' (P: 0.011, OR: 3.492, 95% CI: 1.402-8.696) haplotype, associated with high and intermediate IL10 production, respectively, were significantly higher in inhibitor positive patients, whereas the 'non-GCC' haplotypes overall (P: 0.002,OR: 0.290, 95% CI 0.135-0.622) and 'ATA/ATA' haplotype (P: 0.025, OR: 0.278, 95% CI: 0.096-0.802), associated with low IL10 synthesis, were significantly higher among inhibitor negative patients. The TNFA rs1799724 C/T heterozygote prevalence was significantly higher in the inhibitor positive group (P: 0.021, OR: 3.190, 95% CI: 1.273-7.990), whereas the other polymorphisms showed no statistically significant association with the presence of inhibitors. Different immune regulatory gene polymorphisms play a significant role as possible risk factors for the development of inhibitors in severe haemophilia A patients.

Suppressive effect of berberine on experimental dextran sulfate sodium-induced colitis

The anti-inflammatory effect of berberine was evaluated in murine model of acute experimental colitis induced by dextran sulfate sodium (DSS). Berberine, given orally at 40, 20, 10 mg/kg for 10 days, ameliorated all the supposed inflammatory symptoms of the induced colitis, such as body weightloss, blood hemoglobin reduction, high myeloperoxidase levels, and malondialdehyde content-inflamed mucosa. Furthermore, the cytokine production of splenic lymphocytes was analyzed. The results showed the IFN-γ and IL-12 were increased, but IL-4 and IL-10 were decreased in DSS-induced colitis,when those were compared with the normal control. But the administration of berberine to DSS-induced colitis mice showed lower production of IFN-γ and IL-12 and higher production of IL-4 and IL-10 than the DSS-induced colitis mice. The results suggest that the protective effects of berberine against the DSS-induced colitis may be associated with the regulation of cytokine production.