A comparison of multiplex suspension array large-panel kits for profiling cytokines and chemokines in rheumatoid arthritis patients

Type I IFN signaling constrains IL-17A/F secretion by gammadelta T cells during bacterial infections

Recognition of intracellular bacteria by macrophages leads to secretion of type I IFNs. However, the role of type I IFN during bacterial infection is still poorly understood. Francisella tularensis, the causative agent of tularemia, is a pathogenic bacterium that replicates in the cytosol of macrophages leading to secretion of type I IFN. In this study, we investigated the role of type I IFNs in a mouse model of tularemia. Mice deficient for type I IFN receptor (IFNAR1(-/-)) are more resistant to intradermal infection with F. tularensis subspecies novicida (F. novicida). Increased resistance to infection was associated with a specific increase in IL-17A/F and a corresponding expansion of an IL-17A(+) gammadelta T cell population, indicating that type I IFNs negatively regulate the number of IL-17A(+) gammadelta T cells during infection. Furthermore, IL-17A-deficient mice contained fewer neutrophils compared with wild-type mice during infection, indicating that IL-17A contributes to neutrophil expansion during F. novicida infection. Accordingly, an increase in IL-17A in IFNAR1(-/-) mice correlated with an increase in splenic neutrophil numbers. Similar results were obtained in a mouse model of pneumonic tularemia using the highly virulent F. tularensis subspecies tularensis SchuS4 strain and in a mouse model of systemic Listeria monocytogenes infection. Our results indicate that the type I IFN-mediated negative regulation of IL-17A(+) gammadelta T cell expansion is conserved during bacterial infections. We propose that this newly described activity of type I IFN signaling might participate in the resistance of the IFNAR1(-/-) mice to infection with F. novicida and other intracellular bacteria.

Escalating weekly doses of cetuximab and correlation with skin toxicity: a phase I study

BACKGROUND

Cetuximab is a chimeric monoclonal antibody targeting the epidermal growth factor receptor (EGFR). The recommended dosage is an initial load of 400 mg/m² intravenously (IV) followed by a weekly maintenance dose of 250 mg/m². It has been reported retrospectively that cetuximab efficacy was correlated with dose-related severity of skin rash. This study was prospectively designed to examine the safety and feasibility of escalating weekly doses of cetuximab, testing the hypothesis of the relationship of dose-dependent skin toxicity and efficacy. Methods Four dose levels were tested: Cetuximab 400 mg/m² IV loading dose and 250, 300, 350, 400 mg/m² weekly IV maintenance. There was no intra-patient dose escalation. Standard dose limiting toxicity criteria were used. Rash was evaluated using two additional validated dermatology methods: global acne grading scale (GAGS) and acne lesion counting (ALC). Tumor specimens and blood samples were obtained for correlative analyses.

RESULTS

Twenty seven patients with solid tumors were enrolled: five head and neck, three pancreas, four gall bladder, two each of prostate, breast, colorectal, lung, and esophagus, and five others. Planned dose escalation was completed without reaching dose-limiting toxicity (DLT) or the maximum tolerated dose (MTD). The highest dose level was expanded to a total of 17 patients. Gr 3/4 toxicities included: lymphopenia (2), fatigue (2), and hypomagnesemia (2). One patient experienced a grade 3 rash (350 mg/m²). Sixty five percent of pts had a ≥ Gr 2 rash that was not dose dependent. In 22 evaluable patients, there was one partial response (PR) in a patient with cholangiocarcinoma (400 mg/m²) and seven patients had stable disease (SD). ALC and GAGS demonstrated no correlation with dose or response. Correlative studies evaluating k-ras, EGFR FISH status and immunologic correlatives were conducted on available tumor samples.

CONCLUSIONS

Cetuximab administered at 400 mg/m² IV as a loading dose with weekly maintenance dose of 400 mg/m² is feasible and well tolerated. There was no direct correlation of the grade of rash with dose in this group of patients with heterogenous solid tumors.

Circulating levels of interleukin-1 family cytokines in overweight adolescents

Objectives. Obesity and related diseases are dramatically increasing problems, particularly in children and adolescents. We determined circulating levels of different interleukin (IL)-1 family members in normal weight and overweight adolescents. Methods. Seventy male, Caucasian adolescents (13–17 years) were recruited. Thirty-five had a body-mass index (BMI) above the 90th age-specific percentile. IL-1α, IL-1β, IL-1 receptor antagonist (IL-1ra), and IL-18 were determined using multiplex-technology. Results. IL-18 concentrations were higher in the overweight group compared to normal weight (161.6 ± 40.7 pg/ml versus 134.7 ± 43.4 pg/ml, P = .009). Concentrations of circulating IL-1β levels were below the detection threshold. IL-18 (R²:0.355, P < .01) and IL-1ra (R²:0.287, P < .05) correlated with BMI, whereas IL-1α did not. Conclusions. Accumulating data indicate the importance of the endocrine function of adipose tissue for the pathophysiological consequences of obesity-related co-morbidities. Since IL-18 is involved in the pathogenesis of different cardiovascular diseases, we conclude that IL-18 may represent a link between obesity and related co-morbidities in children and adolescents.

Serum chemokine levels in major depressive disorder

OBJECTIVE

To examine the role of chemokines of two major chemokine families, CC and CXC, in major depressive disorder (MDD) in a population-based sample.

METHOD

The serum levels of CC chemokines MCP-1 and MIP-1beta, and CXC chemokine IL-8 were measured from 122 participants (MDD group, n=61; controls, n=61). Depression severity was assessed with the 29-item Hamilton Depression Rating Scale.

RESULTS

The MDD group had lower levels of MCP-1, MIP-1beta and IL-8 than the healthy controls. The likelihood of major depressive disorder for participants with chemokine levels below the median (MCP-1: < 26.26 pg/mL; MIP-1beta: < 42.57 pg/mL; IL-8: < 2.86 pg/mL) was 3.6 (p=0.002) for MIP-1beta and 2.4 (p=0.037) for IL-8 in regression models adjusted for age, gender, body mass index, smoking, and alcohol consumption. MCP-1 did not associate with the presence of MDD after adjustments for potential confounders. Further adjustments for somatic illnesses or medications did not affect these findings.

CONCLUSION

Our findings suggest that depression-related alterations of inflammatory markers may be more complex than previously assumed, and that at least some of the chemokines may be down-regulated.

IL-9: basic biology, signaling pathways in CD4+ T cells and implications for autoimmunity

CD4(+) T cell subsets play an important role in the adaptive immune response in human autoimmune diseases and in animal models of autoimmunity. In recent years, our knowledge of CD4(+) T cell differentiation has increased significantly, and new subsets continue to be recognized. Of significant importance is the recent discovery of Th9 cells, the CD4 + T cell subset that produces Interleukin-9. IL-9 has largely been regarded as a Th2 cytokine; however, it is now known that under specific conditions, Tregs, Th1, Th17 and the Th9 subset of T cells also produce IL-9. The STAT family of proteins plays a major role in the signaling pathways of these CD4(+)T subsets. Biological actions of IL-9 and the STATs signaling pathways in autoimmune diseases are continuing to be clarified. Investigation of IL-9-producing CD4(+)T cells, and elucidation of the mechanisms of IL-9-induced STATs signaling, in concert with other transcription factors, will provide a better understanding of the pathogenesis of various autoimmune diseases.

Unemployment and ill health: a connection through inflammation?

Background

Unemployment is a source of acute and long-term psychosocial stress. Acute and chronic psychosocial stress can induce pronounced changes in human immune responses. In this study we tested our hypothesis that stress-induced low-grade tissue inflammation is more prevalent among the unemployed.

Methods

We determined the inflammatory status of 225 general population subjects below the general retirement age (65 years in Finland). Those who had levels of both interleukin-6 (≥ 0.97 pg/mL) and high-sensitivity C-reactive protein (≥ 1.49 mg/L) above the median were assessed to have an elevated inflammatory status (n = 72).

Results

An elevated inflammatory status was more common among the unemployed than among other study participants (59% versus 30%, p = 0.011). In the final multivariate model, those who were unemployed had over five-fold greater odds for having an elevated inflammatory status (OR 5.20, 95% CI 1.55-17.43, p = 0.008).

Conclusion

This preliminary finding suggests that stress-induced low-grade inflammation might be a link between unemployment and ill health.