Milk protein foreign proteins

It is unclear why certain foreign proteins can also stimulate the B-cells to secrete IgE antibodies, to result in allergy or hypersensitivity. The terms are used interchangeably, although the latter is usually restricted to milder forms of the response. The term anaphylaxis is used to describe the severe response (Box 17.4). Both reactions arise in genetically susceptible individuals and they are precipitated by exposure to environmental antigens such as pollen, some organic compounds, tobacco smoke, animal hairs or even components of some common foods such as milk and cereals. 

Hennighausen, L., Ruis, L., and Wall, R. (1990). Transgenic animals - Production of foreign proteins in milk. Curr. Opin. Biotechnol. 1, 74—78. 

Exclusive breast feeding may prevent hypersensitivity to allergens during the first months of life when the infant s immune system is immature. Foreign protein is related to atopic diseases such as asthma, eczema and allergies such as cows milk protein intolerance. The mechanism is probably related to transient IgA deficiency due to immaturity of the body s immune system allowing intact protein to permeate the gut wall. There is no proof that any alternative to breast feeding, such as soya rather than cows milk formula, will prevent atopic disease. 

To complete the picture of the protein complement of milk, one should include the numerous enzymes that have been demonstrated to be present in milk (Table 3.2). Only those enzymes normally present in milk are listed, including those that are constituents of the leukocytes and those that are transferred from the blood of the animal to its milk. Those that result from microbial contamination or other foreign sources are not listed. Some additional enzymes have been detected in milk, but insufficient work has been done to demonstrate conclusively their presence in milk as it comes from the cow. The distribution of the various enzymes in the milk system is rather specific for the particular... 

The transport of foreign chemicals from maternal blood into breast milk can proceed by a number of different mechanisms. Uncharged lipid-soluble molecules may diffuse passively through membranes, whereas small water-soluble and small charged molecules may cross membranes through minute pores or water channels. In addition, lactating cells may secrete nutrients like proteins and fat droplets both can carry foreign chemicals, either bound to proteins or dissolved into fat droplets. 

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