Immune system immunostimulation

Retinoids and the Immune System Immunostimulation by Vitamin A Gunther Dennert... 

Immune system immunostimulating properties, role as super antigen change in the number and distribution of cells in the immime system (increase in the number of macrophages, decline in number of NK cells - natural killer cells) development of systemic autoimmune diseases, such as arthritis, hypothyroidism, fibromyalgia formation of antibodies against polymers [24, 31,45,48,60, 66-69]... 

The active immunotherapeutic approach is specific and based on the premise that tumor antigens are immunogenic and the host is sufficientiy immunocompetent to mount an effective immune response to an autologous tumor. Theoretically, a weak or suppressed host immune system that had allowed the formation of a tumor may be overridden by active immunization or immunostimulation. In practice, vaccines composed of so-called autologous tumor extracts have been used to treat patients with malignant melanoma (73), and purified melanoma tumor-associated antigens have been used to ehcit antibody responses in melanoma patients (74). 

Nonspecific immunostimulants (Table 9.5) can have widespread effects on the immune system similar to microbially-derived agents, including side effects akin to infection... 

Immunostimulation by Components of the Immune Systems Used as Therapeutics... 

Immunoglobulin. Immunoprotein glycoprotein of animal origin with known antibody activity, or protein related by chemical structure, which may or may not have antibody activity. Divided into five classes IgM, IgG, IgA, IgD, and IgE on the basis of structure and biological activity. Immunostimulant. Stimulating various functions or activities of the immune system. Immunosuppressant. An agent capable of suppressing immune responses. 

The effect of echinacea on the immune system is controversial. In vivo human studies using commercially marketed formulations of E purpurea have shown increased phagocytosis, total circulating white blood cells, monocytes, neutrophils, and natural killer cells but not immunostimulation. In vitro, Epurpurea juice increased production of interleukins-1, -6, and -10, and tumor necrosis factor- by human macrophages. Enhanced natural killer cell activity and antibody-dependent cellular toxicity was also observed with E purpurea extract in cell lines from both healthy and immunocompromised patients. Studies using the isolated purified polysaccharides from Epurpurea have also shown cytokine activation. Polysaccharides by themselves, however, are unlikely to accurately reproduce the activity of the entire extract. 

A number of agents can suppress the immune system. However, there has been considerable interest in developing pharmacologic methods to modify or even stimulate immune function in specific situations. In particular, agents that have a positive immunomodulating effect could be beneficial to patients with compromised immune function (such as AIDS or certain cancers) or chronic infections.19,41 Development of immunostimulants, however, is understandably a complex and potentially dangerous proposition. Excessive or incorrect immune activation could trigger myriad problems that resemble autoimmune diseases. Likewise, it may be difficult to selectively stimulate certain aspects of the immune system to treat a specific... 

Influence of Food Antigens (Immunostimulators) on the Immune System... 

Immunomodulators—substances (nutrients, allergens, some food components, herbs, and drugs) that can affect the immune system function. There are two types of such substances depending on their effects immunosuppressants and immunostimulators. 

The direct effects opioid and opioidlike peptides exhibit on cells of the immune system is both varied and, in some instances, contradictory, depending on which receptor subtype is being studied. Mu and kappa receptors generally affect immunofunction in a suppressive manner, where delta receptors tend to express immunostimulation [82-85]. However, selected delta antagonists have shown to elicit suppressive effects on B-cell proliferation, NK cell activity, and T-helper cell cytokine production [86]. The alteration of leukocyte function via opioid receptors will be discussed highlighting specific cell subtype immunomodulation. Endorphin shows a inhibitory effect on splenocyte proliferation through central and peripheral autocrine/paracrine pathways [87]. 

Echinacea has been used for centuries as a medicinal plant and has been promoted recently as an immunostimulant. Research from the last two decades has shown that Echinacea can enhance the immune system using in vitro and in vivo indicators. Jager et al. (2002) reported that dodeca-2E,4 , 8Z,10 yZ-tetraenoic acid isobutylamides could cross biological barriers via passive diffusion, suggesting that the alkamides may contribute to the in vivo effects noted by researchers. In contrast, conflicting results have... 

This section provides a discussion of the pharmacology of the various agents that directly affect the immune system. It emphasizes their mechanism of action with a brief description of their therapeutic uses. More detailed information on their pharmacology can be found in Goodman and Gilman s The Pharmacological Basis of Therapeutics (Brunton et al, 2006). Immunopharmacologics can be divided into two major areas, the immunostimulants and the immunosuppressives. 

Since many diseases are associated with cellular immunodeficiency there is an important need for immunostimulants. They have potential use as vaccine adjuvants and for the treatment of cancer, human immunodeficiency viral infections and in certain other infections. The immunostimulating agents are probably best known at this time for their use in the treatment of cancer. When used for this purpose these drugs often act through more than one mechanism. For example, in addition to their ability to augment the immune system, they may have direct cytotoxic effects as well as being able to induce differentiation of the cancer cells. 

Immunotoxicological impacts include molecular and structural effects in immune tissues and organs, cellular pathology, reductions in immune cell numbers, retarded maturation of immune system cells, and altered immune system antibody production. These adverse effects are manifest by two types of reaction immunosuppression and immunostimulation. 

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