Immune response neutrophils

White blood cells or leukocytes are components of blood that play a vital role in the immune response. Neutrophils, for example, are responsible for rapid and unspecific immune defense by digesting invading bacte-... 

Several cytokines are in clinical use that support immune responses, such as IL-2, DFNs, or colony-stimulating factors. IL-2 supports the proliferation and effector ftmction of T-lymphocytes in immune compromised patients such as after prolonged dialysis or HIV infection. IFNs support antiviral responses or antitumoral activities of phagocytes, NK cells, and cytotoxic T-lymphocytes. Colony-stimulatory factors enforce the formation of mature blood cells from progenitor cells, e.g., after chemo- or radiotherapy (G-CSF to generate neutrophils, TPO to generate platelets, EPO to generate erythrocytes). 

The intermediate-duration oral MRL was derived based on the observation of decreases in humoral and cell-mediated immune responses in rats consuming 0.9 mg/kg/day for 22 weeks (Banerjee and Hussain 1986). Choice of this end point is supported by the observation of similar effects in rats at higher doses following ingestion for shorter periods (Banerjee and Hussain 1986, 1987) and decreased neutrophils and... 

Although controversial, findings as to how chronically administered morphine modulates neutrophil chemotaxis and function, a growing consensus believes that morphine is suppressive in the recruitment and functional aspects of these cells during an innate immune response. When peripheral human blood neutrophils were pretreated with exogenous opioids, lL-8-induced chemotaxis was inhibited (Grimm et al. 1998). Conversely, Simpkins et al. reported an increase in neutrophil chemotaxis... 

Neutrophils are the most abundant leukocytes in humans, comprising about two thirds of peripheral blood leukocytes. Upon tissue injury, they rapidly infiltrate injury sites and play an important role in innate immune responses. In addition, they also contribute to the development of adaptive immune responses by producing an array of cytokines and chemokines. Tissue infiltration of neutrophils is initiated by signals generated by the interaction between chemoattractants produced at sites of injury and their corresponding cell surface receptors. Classical chemoattractants, such as C5a, N-formyl-methionyl-leucyl-... 

L. inocua ferritin site however, is the first described so far that has ligands belonging to two different subunits, and is not contained within a four-helix bundle. Recently it has been suggested that the neutrophil-activating protein of Helicobacter pylori, the major antigen of the immune response in infected individuals, is also a dodecameric ferritin, capable of binding up to 500 iron atoms per oligomer (Tonello et ah, 1999). 

Stress-related immune dysregulation also involves the synthesis of hormones including ACTH, growth hormone, and prolactin.14-17 Interestingly, it has also been demonstrated that various aspects of the immune response, for example., proliferation of B- and T-cells, cytokine production, antibody production, chemotaxis of monocytes and neutrophils, and natural killer (NK) cell cytotoxicity, can be affected by glucocorticoids (including cortisol) as well as peptides such as ACTH, CRH, endorphins, substance P, and somatostatin.1218... 

Myeloperoxidase (MPO) is a heme containing protein that catalyzes the two electron oxidation of halides (Cl-, Br- and I-) and pseudohalide (SCN-) to the corresponding hypohalous acid (Eq. (51)) in a process that is dependent upon [X-], [H202] and [H+] (135). MPO is found in high concentrations in neutrophiles and plays important roles in immune response and inflammation (136). 

Lloyd, A. R., Oppenheim, J. J. (1992). Poly s lament The neglected role of the polymorphonuclear neutrophil in the afferent limb of the immune response. Immunol. Today 13,169-72. 

Immune responses are mediated through the lymphocytes called B cells and T cells. Lymphocytes are a particular type of white blood cell. White blood cells (leukocytes) are divided into granulocytes (neutrophils, 55-70% eosinophils, 1-3% and basophils, 0.5-1%) and agranulocytes (lymphocytes [B and T cells], 20-40% and monocytes, 1-6%). There are 5000-10,000 white blood cells per milliliter of blood, compared with five million red blood cells in the same volume. 

Endogenous histamine has a modulating role in a variety of inflammatory and immune responses. Upon injury to a tissue, released histamine causes local vasodilation and leakage of plasma-containing mediators of acute inflammation (complement, C-reactive protein) and antibodies. Histamine has an active chemotactic attraction for inflammatory cells (neutrophils, eosinophils, basophils, monocytes, and lymphocytes). Histamine inhibits the release of lysosome contents and several T- and B-lymphocyte functions. Most of these actions are mediated by H2 or H4 receptors. Release of peptides from nerves in response to inflammation is also probably modulated by histamine, in this case acting through presynaptic H3 receptors. 

IgG or IgM antibodies direct the immune response toward the antigen located on a cell (e.g., a red blood cell or thrombocyte). Macrophages, NK cells, and neutrophils are recruited by the antibodies to the site of the antigen on the cell surface and destroy the cell by phagocytosis or lysis. Additionally, complement activation will damage the cell (Fig. 6.32). The result, for example, where red cells are the targets is hemolytic anemia. 

This type of immune response is unlike the other three in that antibodies are not involved, the response being initiated by sensitized TH1 cells. These are activated by contact with APCs. This stimulates them to secrete cytokines, which recruit macrophages, neutrophils, and eosinophils causing inflammation at the site of exposure. The cytokines also recruit and activate cytotoxic T cells, which can destroy the cell such as when an altered cell membrane is the antigen (Fig. 6.34). 

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