Volume 8 Issue 4

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Page 32 of 35 | # 44 | Page 33 B cells: (also called B lymphocytes) can turn into plasma cells that make antibodies, which help fight infec on and disease. B cells can also remember the types of infec on and disease the body has fought against in the past. If the same germ gets into the body, B cells can quickly make more an bodies to help fight it, so you don't get sick. Dendri c cells: (DCs), named for their probing, 'tree-like' or dendritic shapes, are responsible for the initiation of adaptive immune responses and hence function as the 'sentinels' of the immune system. Macrophages: are specialized cells involved in the detec on, phagocytosis and destruc on of bacteria and other harmful organisms. In addi on, they can also present an gens to T cells and ini ate inflamma on by releasing molecules (known as cytokines) that ac vate other cells. An bodies: (also called immunoglobulin) are proteins made by B cells that have turned into plasma cells. An bodies travel around in the blood. They fight infec on and defend the body against harmful foreign substances by recognizing and binding to a substance (like a germ) that is causing the body to have an immune response. The foreign substances or germs that an bodies bind to are called an gens. A specific an body is made by plasma cells to fight a specific an gen. An an body binds to an an gen like a lock and key. So only an an body made against a specific an gen can bind to it, much like a key can only open a specific lock. When this happens, white blood cells can find and destroy the substance that is causing an infec on or disease. PROTECTORS OF THE REALM: Immune Boosters An oxidants: A diet that is low in the consumption of fruits and vegetables has long been associated with increased suscep bility to infec ous disease. The increase in severity from and suscep bility to infec ous disease in malnourished hosts is thought to be the result of an impaired immune response. For example, malnutri on could influence the immune response by inducing a less effec ve ability to manage the challenge of an infec ous disease. Work in our laboratory has demonstrated that not only is the host affected by the nutri onal deficiency, but the invading pathogen is as well. Using a deficiency in selenium (Se) as a model system, mice deficient in Se were more suscep ble to infec on with coxsackievirus, as well as with influenza virus. Se-deficient mice develop myocardi s when infected with a normally benign strain of coxsackievirus. They also develop severe pneumoni s when infected with a mild strain of influenza virus. The immune system was altered in the Se-deficient animals, as was the viral pathogen itself. Sequencing of viral isolates recovered from Se-deficient mice demonstrated muta ons in the viral genome of both coxsackievirus and influenza virus. These changes in the viral genome are associated with the increased pathogenesis of the virus. The an oxidant selenoenzyme, glutathione peroxidase-1, was found to be cri cally important, as glutathione peroxidase knockout mice developed myocardi s, similar to the Se-deficient mice, when infected with the benign strain of myocardi s. This work points to the importance of host nutri on in not only op mizing the host immune response, but also in preven ng viral muta ons which could increase the viral pathogenicity. Beta-Glucans: The healing and immunostimulating properties of mushrooms have been known for thousands of years in the Eastern countries. These mushrooms contain biologically active polysaccharides that mostly belong to the group of beta-glucans. These substances increase host immune defense by activating complement system, enhancing macrophages and natural killer cell function. Beta-Glucans also show anticarcinogenic activity. They can prevent oncogenesis (the development of a tumor or tumors) due to the protective effect against potent genotoxic carcinogens. As an immunostimulating agent, which acts through the activation of macrophages and NK cell cytotoxicity, beta-glucan can inhibit tumor growth in the promotion stage too. Anti-angiogenesis can be one of the pathways through which beta- glucans can reduce tumor proliferation and prevent tumor metastasis. Beta-Glucan as adjuvant to cancer chemotherapy and radiotherapy demonstrated a positive role in the restoration of hematopoiesis following bone marrow injury. Immunotherapy using monoclonal antibodies is a novel strategy of cancer treatment. These antibodies activate complement system and opsonize tumor cells with iC3b fragment. In contrast to microorganisms, tumor cells, as well as other host cells, lack beta-glucan as a surface component and cannot trigger complement receptor 3-dependent cellular cytotoxicity and initiate tumor-killing activity. This mechanism could be induced in the presence of beta-glucans. Astragalus: has a long history of use in traditional Chinese medicine (TCM), and is often used along with other herbs as a tonic to increase stamina, strength, and vitality. Extracts of astragalus are sold as dietary supplements to improve immune function and to decrease fatigue. Beneficial effects of astragalus are attributed to its polysaccharides and triterpenoid saponin compounds. In vitro and animal studies indicate that astragalus and its constituents have antioxidant, anti-inflammatory, and antiviral activities, along with exerting protective effects on the heart, kidney, bones, and the nervous system. Preclinical studies showed the an cancer proper es of astragalus against gastric, colon, hepa c and ovarian cancers. Clinical data are limited but astragalus has been associated with prolonged survival mes in acute myeloid leukemia pa ents, and data suggest beneficial effects when used with chemotherapy. Also, injectable forms of astragalus may alleviate cancer symptoms and improve quality of life in pa ents with advanced and metasta c cancers, but whether orally administered astragalus exerts similar effects is not known. In another study, an astragalus extract helped to manage cancer-related fa gue. Meta- analyses suggest astragalus to be associated with reduc ons in chemotherapy-induced nausea and vomi ng, and to have benefits in pa ents with hepatocellular cancers.

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