Human milk immunoglobulins

G. Harzer, J. G. Bindels, Changes in human milk immunoglobulin A and lactoferrin during early lactation, in J. Schaub (ed.), Composition and Physiological Properties of Human Milk, Elsevier Science, Amsterdam, 1985, pp. 285-295. 

Welsh, J. K., Skurrie, 1. J., and May, J. T. (1978). Use of Semliki forest virus to identify lipid-mediated antiviral activity and anti-alphavirus immunoglobulin A in human milk. Infect. Immun. 19, 395 01. 

Stephens, S., Dolby, J.M., Montreuil, J., and Spik, G. 1980. Differences in inhibition of the growth of commensal and enteropathogenic strains of Escherichia coli by lactotransferrin and secretory immunoglobulin A isolated from human milk. Immunology 41, 597-603. 

It is interesting to note that /3-lactoglobulin is the major protein in cow s milk whey, but it is absent from human milk whey. However, the content of a-lactoalbumin and immunoglobulins (Ig) is higher in human than in cow s milk whey. Serum albumin and lactoferrins are found in similar concentrations in human and cow s milk whey, and the amount of lactoferrin is higher in colostrum than in mature milk. In any case, lactoferrin is present in milk throughout the lactation period. 

Van Cott K, Lubon H, Gwazdauskas F, et al. Recombinant human protein C expression in the milk of transgenic pigs and the effect on endogenous milk immunoglobulin and transferrin levels. Transgenic Res., 2001 10(1) 43-51. 

Human milk has multiple components that likely mediate this anti-infectious, immuno-logically enhancing effect. These include secretory immunoglobulin A, lactoferrin, lysozymes, intact cellular components, and oligosaccharides. A comprehensive list of compounds found in human milk by class of ingredient is shown in Table 3-2. 

Cravioto, A., Tello, A., Villafan, H., Ruiz, J., del Vedovo, S., and Neeser, J.-R. (1991). Inhibition of localized adhesion of enteropathogenic Escherichia coli to HEp-2 cells by immunoglobulin and oligosaccharide fractions of human colostrum and breast milk. /. Infect. Dis. 163,1247-1255. 

Manjarrez-Hernandez, H. A., Gavilanes-Parra, S., Chavez-Berrocal, E., Navarro-Ocana, A., and Cravioto, A. (2000). Antigen detection in enteropathogenic Escherichia coli using secretory immunoglobulin A antibodies isolated from human breast milk. Infect. Immun. 68, 5030-5036. 

Several centers have been collecting human samples, including urine, breast milk, peripheral blood, cord blood, meconium, vernix, saliva, hair, and placental tissue (Eskenazi et al. 2005). The samples have been analyzed for the presence of numerous substances, such as mercury, lead, cotinine, pesticides, phthalates, PAHs, PAH-DNA adducts, allergens, endotoxin, antioxidant micronutrients, cytokines, immunoglobulin E, cholinesterase, and thyroid hormones. The centers have also been storing samples for future research purposes (Eskenazi et al. 2005). 

BSA monomer, ovalbumin (chicken), P-lactoglobulin (bovine milk), serum albumin (human), carbonic anhydrase (bovine), L-glutamic dehydrogenase (bovine liver), a-chymotrypsin (bovine), a-chymotrypsinogen A (bovine), immunoglobulin (bovine milk), pepsin, trypsin (bovine), and heparin were from Sigma. RNase and lysozyme (egg white) were from Calbiochem. The recombinant human basic fibroblast... 

Maternal Immunoglobulins (antibodies) contained in ingested breast milk are transported across the intestinal epithelial cells of the newborn mouse and human by transcytosis (Figure 17-34). The F receptor that mediates this movement binds antibodies at the acidic pH of 6 found in the intestinal lumen but not at the neutral pH of the extracellular fluid on the basal side of the Intestinal epithelium. This difference in the pH of the extracellular media on the two sides of intes-... 

Pearse and Bretscher (1981) have discussed the role of coated vesicles in membrane synthesis and function. Eukaryotic cells are able to specifically take up macromolecules by absorptive endocytosis. The macromolecules are usually transferred to lyso-somes where they may be degraded. The first stage of the process involves the binding of macromolecules to receptors which are localized in coated pits. The latter are indented sites on the plasma membrane and the coated pit buds into the cytoplasm to form a coated vesicle in which lie the endocytosed macromolecules. The coated vesicle sheds its coat rapidly and the endocytic vesicles fuse with each other. This allows receptors to be returned to the plasma membrane while the contents are transferred to the lyso-somes. In order to explain how lysosomal and plasma membranes remain different, it was suggested that the coated pits are able to accept certain macromolecules while excluding others. The accepted proteins enter the coated pit and were presumed to bind directly or indirectly to clathrin. Clathrin, a 180000-dalton protein on the cytoplasmic face of coated pits, provides the polyhedron skeleton for the coated vesicles. Examples of the use of coated vesicles for mediated endocytosis are in the uptake of low-density lipoprotein from the blood and in humans for the transport of immunoglobulins from the mother to the child. For other mammals such as the rat the antibodies are selectively absorbed from the mother s milk by the intestinal epithelium. Coated vesicles also provide a mechanism for virus transport into cells. 

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