Imbalance between IL-1 and IL-1 receptor antagonist in the cerebrospinal fluid of HIV-infected patients

Proteomic analysis of saliva in HIV-positive heroin addicts reveals proteins correlated with cognition

The prevalence of HIV-associated neurocognitive disorders (HAND) remains high despite effective antiretroviral therapies. Multiple etiologies have been proposed over the last several years to account for this phenomenon, including the neurotoxic effects of antiretrovirals and co-morbid substance abuse; however, no underlying molecular mechanism has been identified. Emerging evidence in several fields has linked the gut to brain diseases, but the effect of the gut on the brain during HIV infection has not been explored. Saliva is the most accessible gut biofluid, and is therefore of great scientific interest for diagnostic and prognostic purposes. This study presents a longitudinal, liquid chromatography-mass spectrometry-based quantitative proteomics study investigating saliva samples taken from 8 HIV-positive (HIV⁺), 11 −negative (HIV⁻) heroin addicts. In addition, saliva samples were investigated from 11 HIV⁻, non-heroin addicted healthy controls. In the HIV⁺ group, 58 proteins were identified that show significant correlations with cognitive scores, implicating disruption of protein quality control pathways by HIV. Notably, only one protein from the HIV⁻ heroin addict cohort showed a significant correlation with cognitive scores, and no proteins correlated with cognitive scores in the healthy control group. In addition, the majority of correlated proteins have been shown to be associated with exosomes, allowing us to propose that the salivary glands and/or oral epithelium may modulate brain function during HIV infection through the release of discrete packets of proteins in the form of exosomes.

Decreased interleukin-1 receptor antagonist response following moderate exercise in patients with colorectal carcinoma after primary treatment

Clinical and experimental studies have shown that a moderately increased physical activity level may have beneficial effects in terms of exercise conditioning, resistance to infection and decreased relative risk of cancer. Modulation of the innate and adaptive components of the immune system with a shift of cytokines and their antagonists to a more pro- and less anti-inflammatory response was found to be a prominent feature in non-tumor patients and healthy volunteers. As quantitative data concerning the cytokine/antagonist response following exercise are not available for tumor patients, we compared the effects of a post-operative rehabilitation program with moderate exercise (ME) intensity (0.55-0.65 x maximal aerobic power) with a program with low exercise (LE) intensity (0.30-0.40 x maximal aerobic power) in patients with curatively treated colorectal carcinoma (UICC II and III) measuring pro- (IL-1beta, IL-6, tumour necrosis factor (TNF)) and anti-inflammatory cytokines (IL-1 receptor antagonist, sTNF receptors I and II). Twenty-three patients participated in this prospective trial, N = 13 in the ME group, N = 10 in the LE group. Exercise was performed daily 30-40 min for 2 weeks. Basal (circulating) and LPS-stimulated (phasic) cytokine and antagonist response was determined before exercise and after 1 and 2 weeks using appropriate ELISA tests. The LPS-stimulated interleukin-1 receptor antagonist (IL-1ra) response in the ME group gradually decreased from 31,532.6 (160.0-70,028.0) to 18,033.0 pg/ml (5040.0-52,570.0) after one and to 22,892.0 pg/ml (6376.0-34,726.0) after 2 weeks (P < 0.05) with a concomitant decrease of the corresponding IL-1ra/IL-6 and IL-1ra/IL-1beta ratio: 2.51-1.41 and 4.1-3.1, respectively. In contrast, in the LE group LPS-stimulated cytokines and antagonists did not significantly change during exercise. Circulating cytokines and antagonists remained unchanged in both groups. In providing quantitative data in patients with curatively-treated colorectal cancer, we demonstrated that a short-term rehabilitation program with moderate exercise leads to a decreased LPS-induced antagonist response with a shift to a more pro-inflammatory state (decreased antagonist/cytokine ratio). Whether this change of the phasic immune response to moderate exercise may be clinically beneficial (decreased rates of infection, relapses and/or second tumours) is possible, but has to be investigated in long-term studies.

Intra-tumoral interleukin-6 down-regulation system and genetic mutations of tumor suppressor genes in colorectal carcinoma

BACKGROUND

The interleukin (IL)-1-IL-6 network, the most potent cascade of pro-inflammatory cytokines, plays an autocrine role in tumor growth. The IL-1-IL-6 network is down-regulated by a phased cytokine inhibitor IL-1 receptor antagonist (ra) and an anti-inflammatory cytokine IL-10. The current study evaluated this down-regulation system in colorectal carcinoma and its relation to the genetic alteration of tumor suppressor genes.

METHODS

Seventy-four specimens of primary colorectal carcinoma and normal mucosa were collected to measure tissue concentrations of cytokines. Polymerase chain reaction amplification was performed to investigate the loss of heterozygosity of the microsatellite markers on chromosomes 17p and 18q.

RESULTS

The IL-1ra/IL-6 ratio in the carcinoma specimens was lower than ratios in adenomas and normal mucosae and decreased with disease progression. The IL-1ra/IL-6 ratio in early cancers tended to be lower than that in adenomas and normal mucosae. However, the tissue concentrations of IL-1beta and IL-10 were not associated with any clinicopathologic parameters. The tissue IL-1ra concentration correlated with that of IL-6 only in adenomas and early cancers. Immunohistochemically, IL-1ra and IL-6 were localized in the tumor cytoplasm. A reduced tissue IL-1ra/IL-6 ratio in the carcinomas correlated with poor prognosis and was associated with the loss of heterozygosity of the microsatellite markers on chromosomes 18q.

CONCLUSIONS

There is an IL-6-IL-1ra network system in colorectal tumors, but this system deteriorates with carcinogenesis and tumor growth. The deterioration of this network system was associated with the allelic loss of a portion of chromosome 18q, reflecting the genetic alteration of tumor suppressor genes.

Nutritional status and postoperative cytokine response in colorectal cancer patients

The present study was designed to investigate the relationship between pre-operative nutritional status and peri-operative regulation of the cytokine network, and to clarify its relation to clinical outcome in colorectal cancer patients. Protein-energy malnutrition was assessed using the creatinine height index. Peripheral venous blood samples were obtained peri-operatively, and the serum concentrations of interleukin (IL-)6, IL-1 receptor antagonist (ra), IL-6 soluble receptor (sR) C-reactive protein (CRP) and the percentage of peripheral neutrophils were determined. Excessive operative blood loss was associated with postoperative morbidity. Pre-operative malnutrition was associated with postoperative mortality when excessive bleeding occurred. Postoperative IL-6 response was exaggerated and postoperative IL-1ra response was suppressed in nutritionally depleted patients. The postoperative serum concentrations of IL-6sR in malnourished patients remained at the lowest levels when excessive bleeding occurred. In these patients, the percentage of peripheral neutrophils remained at high levels even after resolution of the postoperative cytokine storm. A marked activation of the pro-inflammatory cytokine network associated with a decreased antagonistic reaction and an increased consumption of IL-6sR became prominent in malnourished patients when they underwent intense surgical stress. These immunological disturbances may be relevant to neutrophil activation and subsequent clinical outcome.

Profile of circulating levels of interleukin-1 receptor antagonist and interleukin-6 in colorectal cancer patients

BACKGROUND

Circulating levels of pro-inflammatory cytokines are associated with the disease status of cancer patients. We investigated the profile of circulating levels of interleukin (IL)-6 and its antagonist in colorectal cancer patients.

METHODS

Serum concentrations of interkeukin-1 receptor antagonist (IL-1ra) and IL-6 in 80 colorectal cancer patients and tissue concentrations of IL-1ra and IL-6 in 60 primary colorectal cancers and normal colonic mucosas were determined. The serum concentration of immunosuppressive acidic protein (IAP) was also determined.

RESULTS

The serum concentrations of IL-1ra and IL-6 in the patients were significantly higher than those in the controls. The serum concentration of IL-1ra in the patients was associated with clinicopathologic factors including tumor size, liver metastasis, lymph node metastasis, vessel involvement, or serum level of carcinoembryonic antigen. Although the serum IL-1ra level increased in keeping with the increase of serum IL-6, the net balance between IL-1ra and IL-6 was significantly lower than that in the controls. The serum IL-1ra to IL-6 ratio decreased in association with the patient's age, the rate of loss of body weight and the serum level of IAP. Although the serum level of IL-6 correlated with the IL-6 concentration in the cancer tissue, the serum level of IL-1ra did not correlate with the IL-1ra concentration in this tissue.

CONCLUSIONS

Serum IL-1ra, induced systemically by a marked activation of the IL-6 network in cancer tissue, may be a potent index that evaluates disease progression of colorectal carcinoma. Decreased serum IL-1ra to IL-6 ratio may reflect the deterioration of the systemic anti-inflammatory response that is associated with aging, tumor-related malnutrition, or immunosuppression.