S. Frydas

IL-10 subfamily members: IL-19, IL-20, IL-22, IL-24 and IL-26

It has been reported that the CD4+ T cell is a very important source of interleukin 10 (IL-10), while CD8+ cells produce low amounts. IL-10 exerts several immune stimulating, as well as inhibitory effects. There are at least five novel human IL-10 family-related molecules: IL-19, IL-20, IL-22, IL-24, and IL-26. Activated T cells produce IL-19, IL-22 and IL-26, while IL-24 is produced by activated monocytes and T-cells. IL-20 induces cheratin proliferation and Stat-3 signal transduction pathway, while IL-22 induces acute-phase production by hepatocytes and neonatal lethality with skin abnormalities reminiscent of psoriasic lesions in humans. In addition, IL-22 mediates inflammation and binds class II cytokine receptor heterodimers IL-22 RA1/CRF2-4. This cytokine is also involved in immuno-regulatory responses. IL-26 (AK155) is a novel cytokine generated by memory cells and is involved in the transformed phenotype of human T cells after infection by herpes virus. All these new IL-10 subfamily member cytokines are strongly involved in immune regulation and inflammatory responses.

Nutrition and cancer prevention

Cancer cells invade surrounding tissues and metastasize to distant sites. Diet high in fat is a strong link to, and perhaps causes, a high incidence of tumours. Trans-fatty acid might impair the function and it could be involved in the development of cancer. Cholesterol is also strongly suspected to be involved in the development of tumours, therefore it is important for everyone to eat well, especially for people with cancer to prevent the body tissues from breaking down and helping to rebuild the normal tissue that may have been affected by the treatments. Factors secreted by adipocytes and macrophages such as TNF-alpha and other inflammatory proteins are involved in inflammation in cancer. In addition, MCSF which up-regulates adipocyte tissue is also important for the stimulation of fat cell proliferation and is expressed by human adipocytes. Many cytokines, such as IL-1, IL-6, IL-8, IL-32, IL-33 and MCP-1, are biomarkers for cancer and chronic diseases along with transcription factors NFkB and AP-1; these last two factors are important bioactive substances on the molecular mechanism of the control of genes which in turn affect cellular metabolism. In this paper we revisit the interrelationship between cancer and metabolism.

Inhibitory effect of quercetin on tryptase and interleukin-6 release, and histidine decarboxylase mRNA transcription by human mast cell-1 cell line.

Mast cells are involved in inflammatory processes and in allergic reactions where immunologic stimulation leads to degranulation and generation of numerous cytokines and inflammatory mediators. Mast cells have been proposed as an immune gate to the brain, as well as sensors of environmental and emotional stress, and are likely involved in neuropathologic processes such as multiple sclerosis. Among mast cell products, the protease tryptase could be associated with neurodegenerative processes through the activation of specific receptors (PARs) expressed in the brain, while interleukin (IL)-6 likely causes neurodegeneration and exacerbates dysfunction induced by other cytokines; or it could have a protective effect against demyelinisation. In this report we show that quercetin, a natural compound able to act as an inhibitor of mast cell secretion, causes a decrease in the release of tryptase and IL-6 and the down-regulation of histidine decarboxylase (HDC) mRNA from human mast cell (HMC)-1 cells. As quercetin dramatically inhibits mast cell tryptase and IL-6 release and HDC mRNA transcription by HMC-1 cell line, these results nominate quercetin as a therapeutical compound in association with other therapeutical molecules for neurological diseases mediated by mast cell degranulation.

Generation of TNF alpha, IFN gamma, IL-6, IL-4 and IL-10 in mouse serum from trichinellosis: effect of the anti-inflammatory compound 4-deoxypyridoxine (4-DPD)

Infections caused by the nematode Trichinella spiralis is characterized in the host by an inflammatory response with cytokine production. In these studies we have detected TNF alpha, IL-6, IFN gamma, IL-4 and IL-10 in the serum of 10 mice infected with T. spiralis. Moreover, we detected, for the first time, these cytokines in the serum of mice treated with 4-DPD, a potent antagonist of vitamin B6 coenzyme which has anti-inflammatory properties. 4-DPD was used at 100, 400, 800 micrograms/bolus for 20 days, starting one day before the infection. After 15 days of T. spiralis infection, TNF alpha reached a maximum level, while IL-6 was maximal after 7 days, IFN gamma at 20 days and IL-4 at 14 days. IL-10 was not affected by the T. spiralis infection. When the animals were treated with 4-DPD at the reported dosages and infected with T. spiralis the inhibition of TNF alpha and IL-6, were dose-dependent in the first 7 days while IL-4 was reduced only at 400-800 micrograms/bolus. 4-DPD-treated mice did not statistically (P > 0.05) affect the generation of IFN gamma. In healthy animals the production of cytokines were not measurable, just as it was in non-infected animals treated with 4-DPD. The increase of cytokines such as, TNF alpha and IL-6 may be related to the severity of the disease, boosting the hosts resistance to the pathogen and inhibiting parasite survival. In addition, the augmentation of IL-4 production enhances T and B cells and macrophage responses and may stimulate T-cell antibody-mediated response to the pathogen. 4-DPD, an inhibitor of IL-1 and inflammatory reactions, proved to be most effective on TNF alpha and IL-6, which are mainly produced by macrophages.

Effect of selenium and vitamin E on antibody production by dairy cows vaccinated against Escherichia coli

Sixty clinically healthy Holstein cows were randomly assigned to one of four groups according to their age and parity and vaccinated in late pregnancy (day 190) with a multivalent vaccine against Escherichia coli. The 15 cows in the first group (SeE) were injeded intramuscularly with a solution of sodium selenite (0.1 mg Se/kg bodyweight) and vitamin E (α-tocopherol acetate, 8 U/kg bodyweight), the cows in the second group (Se) received only selenium and the cows in the third group (E) received only vitamin E at the same doses and by the same route of administration; the cows in the fourth group were used as controls. The vaccination and the injections of selenium and vitamin E were repeated 42 days later. The concentration of selenium in whole blood and of vitamin E in serum was determined by fluorometric methods. Specific antibody titres against E coli were determined in serum samples by ELISA. The results showed that the injection of selenium either alone or in combination with vitamin E significantly improved the production of specific antibodies against E coli, and that the production of specific antibodies was greater after the administration of selenium alone.

Serum adenosine deaminase and procalcitonin concentrations in neutropenic febrile children with acute lymphoblastic leukaemia

Abstract Neutropenia as a state of immunosuppression is probably the major problem in patients suffering from acute lymphoblastic leukaemia undergoing intensive chemotherapy. Fever is frequent in neutropenic patients and often related to infection. Clinically, the presence of infection in patients with neutropenia may be difficult to establish, because there are usually few signs of infection. The aim of this work was to study sensitive markers for early diagnosis of microbial infection in neutropenic children undergoing intensive chemotherapy as a treatment for acute lymphoblastic leukaemia. The study included three groups (A, B and C) of children with acute lymphoblastic leukaemia and neutropenia. Group A consisted of 29 children with febrile neutropenia and microbial infection, aged 1–14 years (5.8±2.9), 11 boys and 18 girls; Group B of 38 children with febrile neutropenia without microbial infection, aged 2–14 years (6.8±3.1), 14 boys and 24 girls; and Group C of 53 children with neutropenia without fever and without infection, aged 1–14 years (5.9±2.1), 21 boys and 32 girls. Blood samples were collected upon admission and before the start of any antimicrobial treatment. The samples were used for blood culture, serological tests, leukocyte count and analysis of levels of C–reactive protein, procalcitonin, total adenosine deaminase (ADA) activity and its isoenzymes, ADA–1 and ADA–2. According to our results the procalcitonin levels and total ADA activity discriminated best between neutropenic febrile (Groups A and B) and neutropenic afebrile episodes (Group C). In conclusion, this study suggests procalcitonin and total ADA activity as two easily measurable and cost effective markers for the assessment of immune response in febrile neutropenic patients with acute lymphoblastic leukaemia.

Impact of mast cells on the skin.

When through the skin a foreign antigen enters it provokes an immune response and inflammatory reaction. Mast cells are located around small vessels that are involved in vasaldilation. They mature under the influence of local tissue to various cytokines. Human skin mast cells play an essential role in diverse physiological and pathological processes and mediate immediate hypersensitive reaction and allergic diseases. Injection of anti-IgE in the skin or other agents that directly activate mast cells may cause the decrease in vascular tone, leakage of plasma and may lead to a fall in blood pressure with fatal anaphylactic shock. Skin mast cells are also implicated as effector cells in response to multiple parasites such as Leishmania which is primarily characterized by its tissue cutaneous tropism. Activated macrophages by IFNγ, cytotoxic T cells, activated mast cells and several cytokines are involved in the elimination of the parasites and immunoprotection. IL-33 is one of the latest cytokines involved in IgE-induced anaphylaxis and in the pathogenesis of allergic skin disorders. IL-33 has been shown in epidermis of patients with psoriasis and its skin expression causes atopic dermatitis and it is crucial for the development of this disease. Here we review the impact of mast cells on the skin.

The proinflammatory interleukin-21 elicits anti-tumor response and mediates autoimmunity.

Interleukins (IL) are inflammatory proteins (except IL-4 and IL-10) that modulate the immune system (1-4). IL-2l induced inflammation in vivo, based on recruitment of neutrophil and monocyte populations (5-8). This cytokine is similar in primary sequence and structure to IL-2 and IL-15 and is a member of the type I cytokine superfamily which includes IL-2, IL-4, IL-7, IL-9, IL-ll, IL-12, IL-13, IL-15 and Colony Stimulating Factors (CSFs). IL-2l is a multifunctional cytokine having roles in both innate and adaptive immune responses of the Th 1 type (9-11) with an effect on proliferation, apoptosis and differentiation of T cells, NK cells, dendritic cells and B cells (12-15) and lymphocytes function (16-18) (Fig. 1). IL-21, like other members of this family, is a gamma-chain dependent cytokine playing a prominent role in promoting and maintaining T cell populations (19-21). Human and murine IL-2l are 57% identical at the amino acid level, display a 4helix-bundle-type with homology to IL-2, IL-4 and IL-15 and have a unique receptor, IL-21R. The exon and intron structure of the IL-2 and IL-2l genes are very similar and are related to each other. IL21R is a type I cytokine receptor that acts through the interaction with the common gamma chain and is expressed in lymphoid tissues: thymus, spleen, peripheral blood leukocytes such as T cells (CD4+ and CD8+), B cells, NK cells, dendritic cells and several cell lines (22-24). IL-2l R possesses alpha, beta and gamma chain heterotrimer. The beta and gamma chain are essential for signal transduction while the alpha subunit seems to be more involved in high-affinity binding conversion. An anti-gamma chain antibody inhibits cell proliferation induced by IL-2l, suggesting that the gamma chain plays an essential role in IL-2l signal transduction (2527). The generation of IL-21R-deficient mice with normal lymphoid cells revealed dysfunction in immunoglobulin IgG1 production and an increase in IgE responses in immunized animals (28-30). IL-2l needs the common gamma chain to mediate the intracellular survival and/or mitogenic signalling, which occurs through the essential transducermolecule JAK3 (5, 31); however, three major pathways are involved in IL-2l signalling ( JAKISTAT, MAPK and PI3K) to promote and maintain T lymphocyte populations (32-34). Survival and differentiation of B cells is mediated by IL-2l through down-regulation of anti-apoptotic proteins and up-regulation of proapoptotic proteins (35-38).

Impact of Capsaicin on Mast Cell Inflammation

Mast cells are inflammatory cells, and they are prominent in inflammatory diseases such as allergy and asthma. Mast cells possess high-affinity receptors for IgE (FCεRI) and the cross-linking of these receptors is essential to trigger the secretion of granules containing arachidonic acid metabolism [such as prostaglandin (PG) D2, leukotriene (LT) B4, and LTC4], histamine, cytokines, chemokines, and proteases, including mast cell-specific chymases and tryptases. Activation of mast cells provokes the secretion of cytokines and mediators that are responsible for the pathologic reaction of immediate hypersensitivity. Sensory nerve stimulation by irritants and other inflammatory mediators provokes the release of neuropeptides, causing an increase in vascular permeability, plasma extravasation and edema. Trigeminal nerve stimulation actives dura mast cells and increases vascular permeability, effects inhibited by capsaicin. Capsaicin causes release of sensory neuropeptide, catecholamines and vasodilation. Several studies have reported that capsaicin is effective in relief and prevention of migraine headaches, improves digestion, helps to prevent heart disease, and lowers blood cholesterol and blood pressure levels. The findings reported in these studies may have implications for the pathophysiology and possible therapy of neuroinflammatory disorders.

Distribution of Culicoides in Greece

Culicoides biting midges (Diptera: Ceratopogonidae) were trapped between 1999 and 2004 at 122 locations in mainland Greece and on most of the larger Aegean and Ionian islands, using OVI light traps, in order to determine the distribution and seasonal activity of bluetongue virus vectors and other Culicoides species. Thirty-nine Culicoides species were identified, six of which (C. furcillatus, C. impunctatus, C. paolae, C. pictipennis, C. riethi, and C. scoticus) were identified for the first time in Greece. Two of these (C. impunctatus and C. scoticus) may be of veterinary importance due to their role as vectors of bluetongue virus and related orbiviruses. In addition, C. imicola was detected for the first time in mainland Greece.