Phagocytic function

Rojavin M, Szabo I, Bussiere JL, Rogers TJ, Adler MW, Eisenstein TK (1993) Morphine treatment in vitro or in vivo decreases phagocytic functions of murine macrophages. Life Sci 53(12) 997-1006... 

Karl, MO, Valtink, M, Bednarz, J, and Engelmann, K, 2007. Cell culture conditions affect RPE phagocytic function. Graefes Arch Clin Exp Ophthalmol 245, 981-991. 

Thiem, P.A., Halper, L.K. and Bloom, J.C. (1988). Techniques for assessing canine mononuclear phagocyte function as part of an immunotoxicologic evaluation. Int. J. Immuno-pharm. 10 765-771. 

Volkman, A. (1984). Mononuclear Phagocyte Function. Marcel Dekker, New York. 

Ezekowitz, R. A. B., Sieff, C. A., Dinauer, M. C., Nathan, D. G., Orkin, S. H., Newburger, P. E. (1990). Restoration of phagocyte function by interferon-yin X-linked chronic granulomatous disease occurs at the level of a progenitor cell. Blood 76,2443-8. 

Holmes, B., Page, A. R., Good, R. A. (1967). Studies of the metabolic activity of leukocytes from patients with a genetic abnormality of phagocytic function. J. Clin. Invest. 46,1422-32. 

Primary defects in neutrophils expose individuals to recurring infections. These defects may be due to a variety of causes such as neutrophil adhesion defects, defects in phagocyte function, and other causes. 

Defective phagocytosis by neutrophils in CGD can be demonstrated by the classical nitroblue terazolium test by the absence of dark-blue staining of the cytoplasm, in contrast, normal neutrophils with efficient phagocytic function exhibit dark-blue cytoplasmic staining (84). Flow cytometry is also a powerful tool for the study of CGD (85). 

Phagocyte function defects Neutrophils deficient in H2O2... 

Thus a variety of biochemical defects can compromise the phagocytic function of neutrophils (see Table 8). 

B) An increased susceptibility to respiratory infection due to impairment in phagocyte function... 

Mechanism of Action A biologic response modifier that induces activation of macrophages in blood monocytes to phagocytes, which is necessary in the body s cellular immune response to intracellular and extracellular pathogens. Enhances phagocytic function and antimicrobial activity of monocytes Therapeutic Effect Decreases signs and symptoms of serious infections in chronic granulomatous disease. Pharmacokinetics Slowly absorbed after subcutaneous administration. Half-life 0.5-1 hr. 

Greenhalgh D. The role of monocytes/macrophages in wound healing. In Robinson JP, Babcock GF (Eds), Phagocyte Function A Guide for Research and Clinical Evaluation. Wiley-Liss Inc., 1998, pp. 349-357. 

L6. Landry, M., Phagocyte function and cell-mediated immunity in systemic lupus erythematosus. Arch. Dermatol. 113, 147-154 (1997). 

V7. Vazquez Doval, J., and Sanchez Ibarrola, A., Defective mononuclear phagocyte function in systemic lupus erythematosus Relationship of FcRII (CD32) with intermediate cytoskeletal filaments. J. Inv. Allergol. Clin. Immunol. 3, 86-91 (1993). 

The presence of edema and increased skin fragility (often the site of entrance of bacteria) are among the causes of increased risk of infections in nephrotic syndrome. Losses of immunoglobulin G and factor B (from the alternative pathway of the activation of complement) into the urine weaken the ability of the defense system to respond mainly to encapsulated microbes like pneumococci. The function of lymphocytes can be further weakened as a consequence of losses of zinc and transferrin into the urine. Weakening of the phagocytic function of macrophages has been described as well. 

Sometimes PD properties are common across species, thus allowing for pertinent toxicity data to be collected from a variety of species. An example of this is granulocyte colony stimulating factor (G-CSF), a cytokine produced by various cells including monocytes, fibroblasts, and endothelial cells that regulates the production of neutrophils within the bone marrow, influences neutrophil proliferation and differentiation, and contributes to increased phagocytic function, respiratory burst, and antibody-dependent killing. Keller... 

A macrophage is a cell type that is involved in the engulfing of foreign material, such as bacteria and damaged host cells. In view of this specialized phagocytic function, draw what you think an electron microscopist would see in a cross section of the cell. 

Edema toxin does not produce major tissue damage. In fact, its major role is to impair phagocyte function (Leppla, 2000). This is consistent with other toxins which fimction to elevate cAMP concentrations. Edema toxin inhibits phagocytosis of spores by human PMNs (O Brien et al, 1985) similar to LF this is in contrast to spores which promote immune cell uptake (see Table 31.1). Increased intracellular cAMP induced by EF inhibits neutrophil chemotaxis, phagocytosis, superoxide production, and microbicidal activity (Crawford et al, 2006 Turk, 2007 O Brien et al, 1985 Friedman et al, 1987 O Dowd et al, 2004 Ahmed et al, 1995). EF has been shown to inhibit TNFa and increase IL-6 production (Hoover et al, 1994). Increased cAMP levels also block LPS-induced activation... 

Hydroxychloroquine (and also chloroquine, see Ch. 14) in addition to their antimalarial actions exert anti-inflammatory and immunomodulating effects that are useful in rheumatoid disease. Hydroxychloroquine accumulates within lymphocytes, macrophages, polymorphs and fibroblasts, and inhibits phagocyte function but its exact mode of action is unknown. Its action is terminated both by metabolism and renal elimination (t/ 18 days). 

Nakamura, L, Ochiai, K., Imawari, M. Phagocytic function of neutrophils of patients with decompensated cirrhosis is restored by oral supplementation of branched-chain amino acids. Hepatol. Res. 2004 29 207-211... 

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