Here's a study that shows what a useful tool IgA is in breastmilk for detection of bacteria and viruses. Probably the why of this component's use in various test kits such as ELISE or Western Blot. While this study represents the wonders of breastmilk, notice that the end result is to make a vaccine for use in young infants. I assume those young infants won't be the breastfed ones. http://www.asmusa.org/pcsrc/gm2001/34752.htm "Human breast milk contains immune molecules called IgA antibodies, which allow us to detect components of dangerous microorganisms to humans (pathogen bacteria and virus). By using these antibodies we have detected virulent proteins that were injected by the bacteria into the cells after these microorganisms attach to the intestinal mucosa. The bacteria called Enteropathogenic Escherichia coli (EPEC) is a bacterial pathogen that adheres to human intestinal cells, resulting in persistent diarrhea in infants and young children. We have shown that IgA antibodies isolated from breast milk from Mexican women block the adherence of the bacteria to human cells and reacted with several virulent proteins that have been transferred by the bacteria into the intestinal cells.Our results indicate that IgA antibodies from human milk may be one of the main factors by which human milk protect newborns against enteric bacterial pathogens. The information obtained in the present study is useful in the development of a future vaccine to protect young infant against these pathogens." This study also shows that IgA inhibited the adherence of E-coli strains to cells. But, of course, this knowledge will help us make a wonderful vaccine. I would think that one would want to put more energy/funds into promoting breastfeeding. But I guess that is silly of me to think that this would be done. Instead we will make a vaccine and some company will make alot of money. Valerie W. McClain, IBCLC More quotes from this study... "Human milk has been found to be an important protective factor against infectious diseases. Several studies have shown that colostrum and human milk protect newborn children against gastrointestinal infections. We have previously shown that human secretory IgA from breast milk inhibited the adherence of EPEC strains to human cells. The IgA antibodies from breast milk can be used as a tool to detect virulent proteins from pathogenic microorganisms since the hard work (selection of the virulent proteins and production of the specific antibodies) has already done by the immune system of the mother. The aim of the present study was to search for virulence antigens transferred from EPEC to human cells using IgA antibodies. Detection of the EPEC-infected cells by IgA antibodies showed several virulent proteins that were transferred into the human cells. Preliminary experiments suggested the identity of three of these proteins; 1) Tir (Translocated intimin receptor) which is injected by the bacteria into the intestinal cell and functions as a receptor for its binding partner, intimin, resulting in a pedestal-like structure upon which the bacteria resides; 2) EspB a secreted protein that participates in the production of lesions to the intestinal cell; 3) EspC, a secreted protein that has an unclear role in the pathogenesis of EPEC-associated intestinal damage. This reaction to EPEC is due to exposure of woman donors to EPEC strains that have induced an antibody response in their milk. This explanation is supported by a preliminary study that showed that milk samples from women living in poor sanitary conditions have a stronger IgA response to EPEC than milk samples from women living in good sanitary conditions. Our results suggest that the virulent proteins injected by EPEC into the intestinal cells stimulate an immune response and may elicit protective immunity against EPEC disease." *********************************************** The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(TM) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html