Interleukin-17: a revisited study

Effects of Interferon Beta, Cyclophosphamide and Azathioprine on Cytokine Profile in Patients with Multiple Sclerosis

We assessed the in vitro effects of interferon beta-1b (IFNβ-1b), cyclophosphamide (CY), and azathioprine (AZA) alone and of the combination of IFNβ-1b with CY or AZA on the production of Th1 and Th2 cytokines in 10 patients with multiple sclerosis. Cytokine levels were determined at baseline and after stimulation with IFNβ-1b, CY, and AZA alone or with the combination of IFNβ-1b with CY or AZA. The combination of IFNβ-1b with CY resulted in a statistically significant decrease in the production of interleukin-2 (IL-2) (P=0.003) and tumor necrosis factor alfa (TNF-α) (P=0.03). An additive effect on the production of interferon gamma (IFN-γ) (P=0.2) and interleukin-10 (IL-10) (P=0.6), and a positive interaction on the production of interleukin-4 (IL-4) (P=0.08) were observed although the findings were not statistically significant. The combination of IFNβ-1b with AZA resulted in a significant negative effect on the production of IL-2 (P=0.006), whereas TNF-α (P=0.02), IFN-γ (P=0.03), IL-4 (P=0.2), and IL-10 (P=0.3) were not statistically impacted. Our data show that CY was able to improve the effects of IFNβ-1b on the ratio of Th1/Th2 cytokines.

Mesenteric Traction Syndrome or Gut in Distress

The mesenteric traction syndrome (MTS) remains, seventeen years after its first designation as a distinct pathologic entity, an aspect of surgical practice that has received limited attention. Apart from its symptomatology, there is mostly speculation about its exact causes and pathophysiologic mechanisms.

Even though full-blown MTS is rather rare, the advent of laparoscopic surgery has indicated that there are different stages of stress associated with open abdominal surgery. Some evidence points to the involvement of mast cell derived vasoactive mediators and suggests possible pharmacologic management.

Distinct immunoregulatory cytokine pattern in Egyptian patients with occult Hepatitis C infection and unexplained persistently elevated liver transaminases

Background/Aim:

The immunopathogenesis of occult Hepatitis C virus (HCV) infection is a matter of great controversy and has been suggested to involve a complex balance between cytokines with pro- and anti-inflammatory activity. This work aimed at studying the serum Th1 and Th2 cytokine production in patients with occult HCV infection.

Materials and Methods:

Serum levels of cytokines of Th1 (interleukin [IL]-2, INF-γ) and Th2 (IL-4) were measured in 27 patients with occult HCV infection and 28 patients with chronic hepatitis C infection.

Results:

The levels of IL-2 and interferon-γ were highly significantly increased in patients with chronic HCV infection (P<0.001). IL-4 was highly significantly increased in occult HCV infection (P<0.001). Significant increases were noted in chronic HCV infection regarding bilirubin (P<0.001), ALT (P = 0.009), AST (P = 0.013), AFP (P<0.001), while serum albumin was significantly higher in occult HCV infection (P<0.001). Necroinflammation (P<0.001), fibrosis (P<0.001), and cirrhosis (P = 0.03) were significantly increased in chronic HCV infection.

Conclusion:

Our data revealed a high prevalence of occult HCV infection (25%) in patients with unexplained persistently abnormal liver function test results. Those patients exhibited a distinct immunoregulatory cytokine pattern, favoring viral persistence and explaining the less aggressive course of this disease entity than chronic HCV infection.

T helper type 1/T helper type 17-related cytokines in chronic hepatitis C patients before and after interferon and ribavirin therapy

OBJECTIVE

This study examined the T helper (Th) 1/Th17-related cytokines, interferon (IFN)-γ and interleukin (IL)-17 in the serum of biopsy-proven chronic hepatitis C patients before and after IFN and ribavirin therapy to address whether or not viral clearance is related to Th1/Th17 cytokines.

SUBJECTS AND METHODS

The serum levels of IFN-γ and IL-17 were assayed by ELISA on 26 patients with chronic hepatitic C virus (HCV) infection before the start and 3 months after treatment with pegylated IFN-α plus ribavirin and compared with sera from 15 normal control subjects.

RESULTS

IFN-γ and IL-17 levels are higher in the serum of patients with chronic hepatitis than in normal controls and these elevated levels were not directly correlated (r = -0.01, p = 0.96 for IFN-γ and r = -0.08, p = 0.66 for IL-17) to the viremic state of the HCV infection. In contrast to IL-17, IFN-γ showed significant reduction after 12 weeks of treatment with pegylated IFN plus ribavirin. However, IFN-γ and IL-17 serum levels were not significantly (p = 0.19 and = 0.70, respectively) different among responders and nonresponders for pegylated IFN plus ribavirin therapy.

CONCLUSION

Our findings suggest that the combined treatment with pegylated IFN-α and ribavirin downmodulates the secretion of key cytokine IFN-γ as early as 12 weeks after treatment in infected patients. These findings could encourage new exciting possibilities for immune-based interventions with the aim of restoring functional antiviral T cell responses combined with improved viral clearance.

Resveratrol inhibits high glucose-induced PI3K/Akt/ERK-dependent interleukin-17 expression in primary mouse cardiac fibroblasts

We investigated the expression of the proinflammatory cytokine interleukin (IL)-17 in cardiac fibroblasts and its induction by high glucose (HG). Our results show that primary mouse cardiac fibroblasts (mCFs) secrete low basal levels of IL-17 and that HG (25 mM D-glucose) as opposed to low glucose (5 mM D-glucose + 20 mM mannitol) significantly enhances its secretion. HG induces IL-17 mRNA expression by both transcriptional and posttranscriptional mechanisms. HG induces phosphoinositide 3- kinase [PI3K; inhibited by adenoviral (Ad).dominant negative (dn)PI3Kp85], Akt (inhibited by Ad.dnAkt1), and ERK (inhibited by PD-98059) activation and induces IL-17 expression via PI3K-->Akt-->ERK-dependent signaling. Moreover, mCFs express both IL-17 receptors A and C, and although IL-17RA is upregulated, HG fails to modulate IL-17RC expression. Furthermore, IL-17 stimulates net collagen production by mCFs. Pretreatment with the phytoalexin resveratrol blocks HG-induced PI3K-, Akt-, and ERK-dependent IL-17 expression. These results demonstrate that 1) cardiac fibroblasts express IL-17 and its receptors; 2) HG upregulates IL-17 and IL-17RA, suggesting a positive amplification loop in IL-17 signaling in hyperglycemia; 3) IL-17 enhances net collagen production; and 4) resveratrol can inhibit these HG-induced changes. Thus, in hyperglycemic conditions, IL-17 may potentiate myocardial inflammation, injury, and remodeling through autocrine and paracrine mechanisms, and resveratrol has therapeutic potential in ameliorating this effect.

Chemokines as markers for parasite-induced inflammation and tumors

Chemokines are a group of small secreted proteins (8-10 kDa) produced and released by a wide variety of cell types. They were originally described as mediators of leukocyte recruitment, which is essential in acute and chronic inflammation. They also play a critical role in many pathophysiological processes such as allergic responses, infections and autoimmune diseases, tumor growth and hematopoietic development. This review introduces the three supergene families of chemokines (CXC, CC and C) with emphasis on their important role in different states in humans and in animal models with parasitic diseases. The concentration of transcription and translation of the cytokines and chemokines in the parasitic diseases may be an important marker for evaluation of the inflammatory state.

Expression of Interleukin-17 in Ischemic Brain Tissue

Ischemic brain injury is acute local inflammation, leading to accumulation of pro-inflammatory cytokines. Cytokines influence the recruitment of leucocytes and play a key role in the inflammatory injury processes. Recently, a number of studies have demonstrated a close relationship between brain ischemia and cytokines. Interleukin-17 (IL-17) is a newly identified T-cell-specific cytokine. In this study, we evaluated the source and the action of IL-17 over the course of cerebral ischemia in rats (Sprague-Dawley) and humans. The levels of IL-17 in the ischemic hemisphere of the human brain, which was removed at necropsy, were assayed immunohistochemically. In rats, permanent middle cerebral artery occlusion (pMCAO) was obtained by inserting nylon monofilament into the right external carotid artery, occluding the right middle cerebral artery. The expression of IL-17 mRNA in rat was assayed using oligoprobe in situ hybridization. IL-17 production by neuroglial cells was assayed by double-staining using antibody glial fibrillary acidic protein (GFAP) and antibody IL-17. Levels of IL-17 were elevated in the ischemic hemispheres of human brain compared with the opposite normal hemispheres and peaked at days 3-5 after brain ischemia. The IL-17-positive cells were found in the ischemic lesion region. IL-17 mRNA was also elevated in ischemic hemispheres of pMCAO-operated rats, which were slightly elevated after 1 h and peaked at 6 days. IL-17 and GFAP double-stained were extensive in rat ischemic hemisphere. The ischemia-induced IL-17 expression in human brain reported here for the first time was very similar to that in rat model except that the peak was slightly earlier. We found for the first time that IL-17 was involved in an intense inflammatory reaction of brain ischemic injury in human. In pMCAO-operated rats, our findings suggest that IL-17 is produced by the neuroglial cells in the brain region undergoing ischemic insult. We suggest that in additional to T cells the neuroglial cell may be another cellular origin of IL-17 in later progression of brain ischemia.

Alzheimer patients treated with an AchE inhibitor show higher IL-4 and lower IL-1 beta levels and expression in peripheral blood mononuclear cells

The study evaluates the expression and production of cytokines in peripheral blood mononuclear cells of patients with Alzheimer disease treated or not treated with acetylcholinesterase inhibitor, which enhances neuronal transmission. Cytokines associated with brain inflammation such as interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha have been implicated in the regulation of amyloid peptide protein synthesis. The anti-inflammatory cytokine, IL-4, may suppress the activity of IL-1beta. Patients were assessed for clinical and immunologic features at baseline and after 1 month of treatment with Donepezil, an acetylcholinesterase inhibitor. Peripheral blood mononuclear cells were cultured with and without phytohemagglutinin stimulation. IL-1beta and IL-4 levels were measured by enzyme-linked immunosorbent assay. Reverse transcriptase-polymerase chain reaction was used to determine the expression of cytokines in peripheral mononuclear cells. Compared with untreated patients and healthy control subjects, IL-1beta levels and expression decreased in Alzheimer disease patients treated with Donepezil (P < 0.001). In contrast, IL-4 levels and expression were significantly higher in Alzheimer patients treated with the acetylcholinesterase inhibitor. This increment was observed in both unstimulated and phytohemagglutinin-stimulated peripheral blood mononuclear cells.