Natural killer cell immune function

The sterols and sterolins in rice bran are potent immunomodulators. The best response was obtained with a 100 1 sterol/sterolin mixture that demonstrated T-cell proliferation from 20% to 920% and active cell antigens after four weeks in human subjects (Bouic et al, 1996). Another in vitro experimental study with sterol/sterolins, demonstrated a significant increase in cytokinines, interleukin-2 and y-interferon between 17% and 41 % in addition to an increase in natural killer cell activity. These experiments (Bouic et al, 1996) prove that sterol/sterolins are potent immunomodulators with important implications for the treatment of immune dysfunction. Rice bran products are excellent dietary supplements for the improvement of immune function. It is probable that the effects of rice bran on diabetes, CVD and cancer all result from improved immune function. 

Other investigators have been unable to demonstrate lead-induced effects on various components of the immune system in laboratory animals. The effects of lead exposure of varying duration on natural killer cell and T-lymphocytc function were investigated in rats. Male Alderly Park rats received lead as lead acetate in the drinking water at lead concentrations equivalent to 14.3 and 143 mg lead/kg/day for... 

Immunotoxicity. The data in humans are limited to a few studies of immune function in lead workers and a study of firearm instructors. In both type of studies, inhalation is assumed to be the primary route of exposure. One study reported significant suppression of IgA levels (Ewers et al. 1982). Another study indicated that serum immunoglobulin levels were not significantly altered (Alomran and Shleamoon 1988). Another large study examined several parameters of immune function (serum immunoglobulins, PHA response, and natural killer cell activity) and found no differences in exposed workers and controls (Kimber et al. 1986b). The study of firearm instructors found functional impairment of cell-mediated immunity in subjects with PbB levels >25 pg/dL (Fischbein et al. 1993). A recent study that evaluated a... 

Follow-on studies are also recommended as needed. These include determination of potential test article effects on blood or tissue immunophenotypes (by flow cytometry or immunohistochemistry), natural killer cell, macrophage, or neutrophil function, host resistance to infection or tumors, and cell-mediated immunity. The important issue in all of these guidelines is this do not ignore signs of immunotoxicity, and assess these findings when observed. 

De Guise, S. et al., Immune functions in beluga whales (Delphinapterus leucas) evaluation of natural killer cell activity, Vet. Immunol. Immunopathol., 58, 345, 1997. 

Other Cells with a Possible Regulatory Function It has been clearly demonstrated that natural killer cells, epithelial cells, macrophages, glial cells, etc., express suppressor cytokines such as IL-10 and TGF-(3. Although their role has not been coined as professional regulatory cells, these cells may efficiently contribute to the generation and maintenance of a regulatory/suppressor type immune response [121-126]. The expression of suppressor cytokines in resident tissue cells may additionally contribute to this process (table 1). 

The names helper cells, cytotoxic cells and natural killer cells indicate the function of the cells and are, therefore, useful. The more formal , nomenclature is the CD classification (e.g. CD4-tve cells and CD8-tve cells). CD stands for the cluster of differentiation, which is a technique for distinguishing between different protein molecules attached to different cells its value is that it can identify very precisely the type of immune cell (Appendix 17.3). Thus the helper cells express CD4 molecules on their surface, whereas cytotoxic cells express CDS molecules on their surface. 

Hoskin DW, Mader JS, Furlong SJ, Conrad DM, Blay J (2008) Inhibition of T cell and natural killer cell function by adenosine and its contribution to immune evasion by tumor cells (review). Int J Oncol 32(3) 527-535... 

In addition to its antiviral actions, interferon has an antiproliferative effect and modifies the functions of macrophages and natural killer cells. Thymosin, a protein synthesized by the epithelioid component of the thymus, may be potentially valuable in patients with DiGeorge s syndrome or other T cell deficiency states. Levamisole augments T cell-mediated immunity and may be of value in the immunodeficiency associated with Hodgkin s disease. 

Surprisingly, no difference in immune function as measured by spleen cell counts, in vitro lymphocyte proliferation responses to mitogens, and in vitro and in vivo plaque-forming cell responses to antigens was observed (30). However, human studies have shown changes in natural killer cell activity after TSD and during RS (31,32). 

The opioids may modulate the actions of the immune system by effects on lymphocyte proliferation, antibody production, and chemotaxis. Natural killer cell cytolytic activity and lymphocyte proliferative responses to mitogens are usually inhibited by opioids. Although the mechanisms involved are complex, activation of central opioid receptors could mediate a significant component of the changes observed in peripheral immune function. In general, these effects are mediated by the sympathetic nervous system in the case of acute administration and by the hypothalamic-pituitary-adrenal system in the case of prolonged administration of opioids. 

The potential association between the immune system and mood disorders has become a major topic of interest in biological psychiatry in the past decade. In general, three immune measures have been examined, namely white blood cell counts, functional measures of cellular immunity such as natural killer cell activity and immune cell markers as exemplified by human lymphoctye antigen (HLA). The cumulative data from these studies suggests that depressed patients have a decreased number of lymphocytes, reduced mitogen-induced lymphocyte proliferation and a reduction in the number of natural killer cells. However, this does not apply to all depressed patients. Furthermore, not all aspects of immune function... 

The most relevant bioassays measure specific activities on immune function, either as effector or regulatory, for example, assay of cytokine IL-12 by the augmentation of the cytolytic function of natural killer cells (B9), IL-10 by the inhibition of the production of TNF-o from stimulated monocytes (B13), and IL-8 and eotaxin by the chemotaxis of neutrophils and eosinophils, respectively (C2). 

Conneely, 2001). LF has the ability to bind to the surface of several types of immune cells, which suggests that it can modulate immune functions. Both stimulatory and inhibitory effects of LF on lymphocyte proliferation have been described in the literature. LF has been reported to induce in vitro maturation of T- and B-lymphocytes, to modulate the activity of natural killer cells and to enhance the phagocytic activity of neutrophils. In mice, bovine LF has been shown to induce both mucosal and systemic immune responses (Debbabi et al., 1998). Cell-culture studies have demonstrated that LF and peptides derived from LF influence the production of various cytokines which regulate the immune and inflammatory responses of the body (Crouch et al., 1992 Shinoda et al., 1996). 

The effects of marijuana on immune function have been reviewed (122). The studies suggest that marijuana affects immune cell function of T and B lymphocytes, natural killer cells, and macrophages. In addition, cannabis appears to modulate host resistance, especially the secondary immune response to various infectious agents, both viral and bacterial. Lastly, marijuana may also affect the cytokine network, influencing the production and function of acute-phase and immune cytokines and modulating network cells, such as macrophages and T helper cells. Under some conditions, marijuana may be immunomodulatory and promote disease. 

---