Involvement of tyrosine kinases and MAP kinases in the production of TNF-alpha and IL-1beta by macrophages in vitro on treatment with phytohemagglutinin

A dimeric Phaseolus coccineus lectin with anti-oxidative, anti-proliferative and cytokine-inducing activities

In the present study, a dimeric glucosamine binding lectin, designated as CHL, was purified from Phaseolus coccineus L. var. albonanus Bailey through three chromatographic steps. The molecular weight of CHL was approximately 66kDa. Its hemagglutinating activity toward rabbit erythrocytes was dependent on carbohydrates, especially glucosamine, and was stable at temperatures between 20 and 70°C, and at pH between 1 and 13. Intriguingly, further characterization showed that CHL served as a potent antioxidant to prevent erythrocytes from haemolysis induced by 2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in a dose-dependent manner. Moreover, it exerted antitumor activity against human nasopharyngeal carcinoma CNE1 cells, hepatoma HepG2 cells, and breast cancer MCF7 cells but was devoid of antifungal activity. In addition, the CHL could bring about a significant dose-dependent increase in the production of mRNAs of pro-inflammatory cytokines including interferon-gamma and interleukin-2. These results suggest the potential therapeutic utility of CHL.

Two interleukin-17C-like genes exist in rainbow trout Oncorhynchus mykiss that are differentially expressed and modulated

Interleukin (IL)-17 family members (IL-17A-F) are key players in adaptive immune responses and have a central role in coordinating innate and adaptive immunity. Here, we report on two novel IL-17 homologues in rainbow trout Oncorhynchus mykiss, trout (t) IL-17C1 and tIL-17C2, that share 73.7% amino acid identity. The two tIL-17C-like molecules have relatively higher sequence identities to IL-17Cs from fish and mammals and the fish IL-17C-like molecules phylogenetically form a specific clade that groups with the mammalian IL-17C and IL-17E clades. However, the gene organisation of the fish IL-17C-like molecules is closer to mammalian IL-17Es than to IL-17Cs, and this taken together with other factors suggest the fish IL-17C-like genes may have arisen from an ancestral gene that gave rise to mammalian IL-17C and IL-17E. The expression of tIL-17Cs was detectable in all the eight tissues examined, with the expression of tIL-17 mainly contributed by tIL-17C1 in gills and skin, and by tIL-17C2 in spleen, head kidney and brain. The expression of tIL-17Cs was modulated by inflammatory stimulants, including IL-1beta, interferon-gamma, LPS and PolyIC, in a trout macrophage cell line (RTS-11). IL-1beta was the most potent inducer of tIL-17C2 but only had a minor effect on the expression of tIL-17C1. LPS and PolyIC were also potent inducers of tIL-17C2. The expression of tIL-17Cs was also up-regulated by bacterial infection, with the extent and increase more dramatic for tIL-17C2. The broad distribution of expression and differential modulation of tIL-17Cs by inflammatory stimulants and infection suggest important roles of the two tIL-17Cs in the salmonid immune system.

Anti-inflammatory agents as cancer therapeutics

Cancer prevention sometimes referred to as tertiary prevention or chemoprevention makes use of specific xenobiotics or drugs to prevent, delay, or retard the development of cancer. Over the last two decades or so cancer prevention has made significant strides. For example, prevention of lung cancer through smoking cessation; cervical cancer prevention through regular Pap smear tests; colon cancer prevention through screening colonoscopy; and prostate cancer reductions by prostate-specific antigen measurements in conjunction with regular prostate examinations. The seminal epidemiological observation that nonsteroidal anti-inflammatory drugs (NSAIDs) prevent colon and other cancers has provided the impetus to develop novel chemoprevention approaches against cancer. To that end, a number of "designer drugs" have been synthesized that are in different stages of development, evaluation, and deployment. Some include the cyclooxygenase-2-specific inhibitors (coxibs), nitric oxide-releasing NSAIDs (NO-NSAIDs and NONO-NSAIDs), hydrogen sulfide-releasing NSAIDs, modulators of the lipoxygenase pathway, prostanoid receptor blockers, and chemokine receptor antagonists. In addition to these novel agents, there are also a host of naturally occurring compounds/micronutrients that have chemopreventive properties. This chapter reviews these classes of compounds, their utility and mechanism(s) of action against the background of mediators that link inflammation and cancer.

Curcumin, resveratrol and flavonoids as anti-inflammatory, cyto- and DNA-protective dietary compounds

Numerous dietary compounds, ubiquitous in fruits, vegetables and spices have been isolated and evaluated during recent years for their therapeutic potential. These compounds include flavonoid and non-flavonoid polyphenols, which describe beneficial effects against a variety of ailments. The notion that these plant products have health promoting effects emerged because their intake was related to a reduced incidence of cancer, cardiovascular, neurological, respiratory, and age-related diseases. Exposure of the body to a stressful environment challenges cell survival and increases the risk of chronic disease developing. The polyphenols afford protection against various stress-induced toxicities through modulating intercellular cascades which inhibit inflammatory molecule synthesis, the formation of free radicals, nuclear damage and induce antioxidant enzyme expression. These responses have the potential to increase life expectancy. The present review article focuses on curcumin, resveratrol, and flavonoids and seeks to summarize their anti-inflammatory, cytoprotective and DNA-protective properties.

Significance of immune cell function monitoring in renal transplantation after Thymoglobulin induction therapy

Monitoring of immune status in transplant recipients is essential for predicting the risk of rejection or infection. In this study, we assessed the significance of immune cell function in 76 renal allograft recipients after Thymoglobulin induction and initiation of maintenance immunosuppression. Using the Immuknow (Cylex Inc) assay, the amount of adenosine triphosphate (ATP) produced by CD4+ cells in response to phytohemagglutinin (PHA) was measured in patients whole blood. In parallel, the frequency and phenotype of CD4+ T cells were determined by flow cytometry. The Immuknow assay yielded paradoxically high ATP values during the first 3 months post-transplantation, despite very low CD4+ T cell counts. High ATP values were caused by peripheral blood myeloid cells, did not predict rejection, and occurred primarily in transplant recipients who received darbepoietin (p = 0.017). CD4+ T cells displayed predominantly an activated/memory phenotype and comprised a subpopulation of CD25+FOXP3+ cells. Over the first 5 months post-transplantation, mean ATP activity gradually decreased, whereas CD4+ T cell counts slowly increased. Low ATP values were predictive of infection (p = 0.002). Thus Immuknow results need to be interpreted with caution in patients receiving Thymoglobulin induction therapy. Although low ATP levels identify patients at increased risk for infection, high ATP values fail to correlate with rejection and do not justify increased immunosuppression.

Modulation of inflammatory genes by natural dietary bioactive compounds

Several epidemiologic studies have shown that chronic inflammation predisposes individuals to various types of cancer. Many cancers arise from sites of infection, chronic irritation, and inflammation. Conversely, an oncogenic change induces an inflammatory microenvironment that promotes the development of tumors. Natural bioactive compounds in dietary plant products including fruits, vegetables, grains, legumes, tea, and wine are claimed to help prevent cancer, degenerative diseases, and chronic and acute inflammation. Modern methods in cell and molecular biology allow us to understand the interactions of different natural bioactive compounds with basic mechanisms of inflammatory response. The molecular pathways of this cancer-related inflammation are now unraveled. Natural bioactive compounds exert anti-inflammatory activity by modulating pro-inflammatory gene expressions have shown promising chemopreventive activity. This review summarizes current knowledge on natural bioactive compounds that act through the signaling pathways and modulate inflammatory gene expressions, thus providing evidence for these substances in cancer chemopreventive action.

Posttranscriptional regulation of interleukin-10 expression by hsa-miR-106a

IL-10 is a key regulator of the immune system that critically determines health and disease. Its expression is finely tuned both at the transcriptional and posttranscriptional levels. Although the importance of posttranscriptional regulation of IL-10 has been previously shown, understanding the underlying mechanisms is still in its infancy. In this study, using a combination of bioinformatics and molecular approaches, we report that microRNA (hsa-miR-106a) regulates IL-10 expression. The hsa-miR-106a binding site in the 3' UTR of IL10 has been identified by site-directed mutagenesis studies. Also, the involvement of transcription factors, Sp1 and Egr1, in the regulation of hsa-miR-106a expression and concomitant decrease in the IL-10 expression, has also been demonstrated. In summary, our results showed that IL-10 expression may be regulated by miR-106a, which is in turn transcriptionally regulated by Egr1 and Sp1.