Effect of Papaya Leaves (<i>Carica papaya</i> L.) Extract on Immune Response (TLR-7, TLR-9) and Inflammation (COX-2) in Rats Induces DMBA (7,12-Dimethylbenz[a]antrasen)

BACKGROUND AND OBJECTIVE

TLR is known to regulate the immune system in cancer. TLR-7 and TLR-9 can enhance the antitumor immune system in many types of solid tumors. Cyclooxygenase-2 (COX-2) is a biomarker of inflammation. This study aimed to investigate the effect of papaya leaves extract on immune response (TLR 7, TLR 9) and inflammation (COX-2) in rats induced DMBA.

MATERIALS AND METHODS

This experimental study used Sprague dawley female rats of age more less 50 days. Rats were divided into 4 groups: Negative Control (NC), Positive Control (PC), Cancer Drug Doxorubicin (DOXO) and Papaya Leaves Extract (PLE). The study was conducted for 13 weeks. DMBA induction performed for 5 weeks with administration of 2 times per week.

RESULTS

the expression of TLR-7 of PLE and DOXO was higher than PC groups significantly different (p<0.05). The expression of TLR-9 of PLE was higher than NC, PC and DOXO groups but not significantly different (p>0.05) while the expression of COX-2 of PLE and DOXO groups was lower than NC and PC groups but not significantly different (p>0.05).

CONCLUSION

It can be concluded that papaya leaves extract can improve the immune system and reduce inflammation. It shows that papaya leaves extract has potent as anti-cancer.

TLR7 in B cells promotes renal inflammation and Gd-IgA1 synthesis in IgA nephropathy

TLR7 has been linked to the pathogenesis of glomerulonephritis, but its precise roles are not clear. In this study, we evaluated the roles of TLR7 in IgA nephropathy (IgAN). TLR7 proteins were abundant in CD19+ B cells infiltrated in the kidneys of patients with IgAN. The intensities of both intrarenal TLR7 and CD19 proteins were closely associated with kidney function (estimated glomerular filtration rate [eGFR] and serum creatinine concentration) and renal histopathology (tubular atrophy, leukocyte infiltration, tubulointerstitial fibrosis, and global glomerulosclerosis) in patients with IgAN. Meanwhile, TLR7 mRNA levels were significantly increased in peripheral blood B cells of patients with IgAN. TLR7+CD19+ B cells expressed inflammatory cytokines (IL-6 and IL-12) in kidneys and produced high levels of IgA1 and galactose deficient-IgA1 (Gd-IgA1) in peripheral blood of patients with IgAN. Mechanistically, TLR7 activated B cells to produce high levels of Gd-IgA1 via the TLR7-GALNT2 axis in IgAN. Protein levels of GALNT2 were increased by overexpression of TLR7, while they were reduced by TLR7 knockdown in B cells. GALNT2 overexpression augmented Gd-IgA1 production in B cells derived from patients with IgAN. Taken together, high TLR7 expression in B cells has dual roles in the development and progression of IgAN, by facilitating renal inflammation and Gd-IgA1 antibody synthesis.

Circulating plasmablasts contribute to antiphospholipid antibody production, associated with type I interferon upregulation

Essentials The mechanism of antiphospholipid antibodies (aPL) production remains unclear. We investigated lymphocyte subset, single nucleotide polymorphisms (SNP), and aPL-producing cells. The increase of circulating plasmablasts was associated with type I interferon upregulation. Our novel ex vivo assay revealed circulating plasmablasts as a major source of aPL. SUMMARY: Background/objective Antiphospholipid antibodies (aPL) are pathogenic autoantibodies in antiphospholipid syndrome (APS). This study aimed to clarify the mechanism of aPL production. Methods T cell and B cell subsets were evaluated in peripheral blood mononuclear cells (PBMCs) of 26 primary APS (PAPS), 19 systemic lupus erythematosus-associated APS (SLE/APS) patients and 10 healthy controls. The SLE-related or APS-related single nucleotide polymorphisms (SNP) were analyzed in those patients. Interferon (IFN) score was calculated based on the mRNA expression of Ly6e, Mx1, IFIT1, and IFIT3 in PBMCs. The PBMCs obtained from APS patients were cultured ex vivo following depletion of CD20 positive or negative B cells and the culture supernatants were applied to aPL measurements. Results In PAPS and SLE/APS patients, Th2, Th17, and plasmablasts were increased while regulatory T, memory B, and regulatory B cells were decreased compared to healthy controls. Genetic analysis revealed that the increase of plasmablasts was more pronounced in patients carrying a risk allele of toll like receptor (TLR) 7 SNP rs3853839. The IFN score was significantly higher in the risk allele carriers. Ex vivo experiments showed that aPL were present in the culture supernatant of PBMCs lacking CD20+CD19+ subset, but not in that of cells lacking CD20-CD19+ subset. Conclusions Our data indicate an important role of plasmablasts in the production of aPL. Furthermore, the increase of plasmablasts was associated with TLR 7 and type I IFN, suggesting a common pathophysiology in SLE and APS. Targeting plasmablasts might be a novel immunological therapeutic approach in the treatment of APS.

Peripheral blood and hepatic Toll-like receptor 7 expression and interferon lambda 1 levels in chronic hepatitis C: Relation to virus replication and liver injury

BACKGROUND AND AIM

Toll-like receptor 7 (TLR7) can recognize single-stranded RNA viruses like hepatitis C virus (HCV) with subsequent induction of different interferon (IFN) types including IFN lambda (IFNL), which activate an immediate anti-viral response. However, the role of TLR7 in inflammation and fibrosis, characteristics of HCV-induced liver injury, is still controversial. The present work was designed to investigate the potential role of TLR7 and IFNL1 in chronic hepatitis C (CHC) in relation to viral replication and liver injury.

METHODS

Forty two treatment-naïve patients with CHC and 20 healthy subjects were enrolled in the study. TLR7 expression on peripheral blood CD14+ monocytes was studied by color flow cytometry and the frequency of TLR7+CD14+ cells was expressed as percentage of total monocyte count. Quantification of IFNL1 levels in serum was determined using enzyme-linked immunosorbant assay. Liver biopsies were examined for assessment of histological activity grade (A0-A3) and fibrosis stage (F0-F4) according to METAVIR scoring system as well as steatosis grade. Immunohistochemical staining was performed using human antibodies against TLR7 and IFNL1 and was scored semi-quantitatively (score 0-3). Hepatic expression of TLR7 and IFNL1 was further classified using a two-grade scale as low expression (score 0 or 1) and high expression (score 2 or 3).

RESULTS

Percentages of circulating TLR7+CD14+ monocytes and serum IFNL1 levels were significantly higher in patients with CHC than in healthy controls (P = 0.025 and P < 0.001 respectively) and were positively correlated with corresponding hepatic TLR7 and IFNL1 expression (P < 0.001 and P = 0.010 respectively). Significantly lower peripheral blood and hepatic TLR7 expression and IFNL1 levels were found in patients with viral loads between 200,000-600,000 IU/ml and >600,000 IU/ml than in those with viral load <200,000 IU/ml (P < 0.05), in patients with severe necroinflammation than in those with mild-to-moderate necroinflammation (P < 0.05) and in patients with advanced fibrosis than in those with early fibrosis (P < 0.01). Also, changes in TLR7 expression and IFNL1 production in peripheral blood and the liver were inversely correlated with serum levels of aspartate and alanine aminotransferases (P < 0.05) and HCV RNA (P < 0.01), histological activity grade (P < 0.01) and fibrosis stage (P < 0.01). By plotting receiver operating characteristics (ROC) curve, serum IFNL1 showed higher sensitivity and specificity than percentages of circulating TLR7+CD14+ monocytes in discriminating patients with CHC according to the severity of hepatic necroinflammation (area under the curve (AUC) = 0.901 vs. 0.816 respectively) and fibrosis (AUC = 0.971 vs. 0.825 respectively) at a cut-off value of 44.75 pg/ml and 10.25% respectively.

CONCLUSIONS

TLR7 activation and IFNL1 production in CHC may play an important role in controlling viral replication and limiting hepatic inflammation and fibrosis and their downregulation may result in viral persistence and disease progression. The immunoregulatory role of TLR7-IFNL1 pathway in the pathogenesis of chronic HCV infection should be further studied. Clinical trials with a large number of patients are needed to assess the usefulness of serum IFNL1 as a potential biomarker for severity of liver injury in chronic HCV infection and other liver diseases.

Increased Expression of TLR4 and TLR7 but Not Prolactin mRNA by Peripheral Blood Monocytes in Active Celiac Disease

BACKGROUND

Celiac disease (CD) is an organ-specific autoimmune disease, and both adaptive and innate immunity are involved in its development.

OBJECTIVES

The aim of the study was to determine whether the markers of intestinal mucosal inflammation in CD can be detected in peripheral blood monocytes (PBMs), and whether the immune properties of PBMs change as the clinical signs and symptoms of CD improve after the introduction of a gluten-free diet (GFD). The focus was on changes in mRNA expression of selected toll-like receptors (TLR2, TLR4, TLR7), stress cytokine prolactin (PRL), and proand anti-inflammatory cytokines (TNF-α, IL-6, IL-12, IL-10) in PBMs.

MATERIAL AND METHODS

The study involved 20 CD patients diagnosed according to the European Society for Pediatric Gastroenterology, Hepatology and Nutrition criteria and Marsh criteria: 10 recently-diagnosed cases (rCD) and 10 on a GFD for a minimum of one year. The control group comprised 10 ageand sex-matched healthy volunteers. PBMs from peripheral blood specimens were separated using immunomagnetic CD14+ beads. Total RNA was isolated using a standard commercial kit. Cytokine and TLR mRNA levels were quantified by relative qPCR with PGK1 as a reference gene.

RESULTS

Significantly higher expression of TLR4 and TLR7 mRNA was observed in PBMs from rCD patients compared to the healthy controls (1.63 times higher; p < 0.05). TLR7 mRNA levels in rCDs were also significantly elevated in comparison to the CD-GFD patients (2.11 times higher; p < 0.01). TNF-α mRNA expression tended to be higher in both groups of patients; by contrast, in IL-6 mRNA, a trend to a fourfold decrease was detected in PBMs from the CD-GFD subjects. IL-10, IL-12 and PRL levels did not differ among the groups.

CONCLUSIONS

The data suggest that the inflammatory process in rCD intestinal mucosa and submucosa reflecting enterocyte damage can be detected in PBMs in peripheral blood. Further, the cytokine and TLR expression profile in PBMs alters after one year of GFD treatment.

Expression of Toll like receptors 3 & 7 in peripheral blood from patients with chronic hepatitis C virus infection and their correlation with interferon-alpha

Toll-like receptor 3 (TLR3) and Toll-like receptor 7 (TLR7) are pathogen- recognition receptors that are expressed on innate immune cells. They recognize viral RNA which induces their activation with subsequent increase in IFN-alpha transcription. It has been postulated that HCV may cause down regulation of these receptors as one of immune evading mechanisms that participate in viral persistence. The aim of this work is to investigate the expression of Toll-like receptors 3 (TLR3) and 7 (TLR7) in peripheral blood from patients with chronic hepatitis C infection and correlate their expression to the peripheral blood expression of interferon-alpha (IFN-alpha), viral load and histopathology of the liver. IFN-alpha, TLR3 and TLR7 expression in peripheral blood from patients with chronic hepatitis C infection (n = 30) and from healthy controls (n = 20) were measured by real time polymerase chain reaction. Viral load and Liver biopsy were done for all patients. The results showed lower expression of TLR3 and TLR7 in patients than controls, and levels of expression correlated positively with IFN-alpha expression. No correlation was found between TLR3 and TLR7 and viral load or histopathological staging and grading of the liver tissue. In conclusion, HCV may induce down regulation of TLRs (TLR3 and TLR7) expression on innate immune cells with subsequent decrease in INF-alpha production suggesting that new therapies that aim to increase the expression level of TLRs may help in treatment of HCV infection.

Transcriptional profiling of TLR-4/7/8-stimulated guinea pig splenocytes and whole blood by bDNA assay

Toll-like receptor (TLR) agonists are currently being examined as adjuvants for vaccines, with several lead candidates now in licensed products or in late-stage clinical development. Guinea pigs are widely used for preclinical testing of drugs and vaccines; however, evaluation of TLR agonists in this model is hindered by the limited availability of immunological tools and reagents. In this study, we validated the use of a branched-chain DNA (bDNA) assay known as the QuantiGene Plex 2.0 Reagent System for measuring innate cytokine and chemokine mRNA levels following TLR stimulation of guinea pig cells. Gene expression for T-helper-1 (Th1) polarizing cytokines (TNF-α, IL-1β, IL-12) and chemokines (CXCL1, CCL2) was upregulated following ex vivo stimulation of guinea pig splenocytes and whole blood with TLR-4 or TLR-7/8 agonists. These data confirm the utility of the QuantiGene system both as an alternative to RT-PCR for measuring transcript levels and as a high-throughput screening tool for dissecting the immunological response to TLR stimulation in guinea pigs. Overall, the QuantiGene platform is reliable, reproducible, and sensitive. These agonists have the potential to be used as adjuvant components in vaccines against various pathogens.