Consuming Transgenic Goats' Milk Containing the Antimicrobial Protein Lysozyme Helps Resolve Diarrhea in Young Pigs

Abstract

Childhood diarrhea is a significant problem in many developing countries and E. coli is a main causative agent of diarrhea in young children. Lysozyme is an antimicrobial protein highly expressed in human milk, but not ruminant milk, and is thought to help protect breastfeeding children against diarrheal diseases. We hypothesized that consumption of milk from transgenic goats which produce human lysozyme (hLZ-milk) in their milk would accelerate recovery from bacterial-induced diarrhea. Young pigs were used as a model for children and infected with enterotoxigenic E. coli. Once clinical signs of diarrhea developed, pigs were fed hLZ-milk or non-transgenic control goat milk three times a day for two days. Clinical observations and complete blood counts (CBC) were performed. Animals were euthanized and samples collected to assess differences in histology, cytokine expression and bacterial translocation into the mesenteric lymph node. Pigs consuming hLZ-milk recovered from clinical signs of infection faster than pigs consuming control milk, with significantly improved fecal consistency (p = 0.0190) and activity level (p = 0.0350). The CBC analysis showed circulating monocytes (p = 0.0413), neutrophils (p = 0.0219), and lymphocytes (p = 0.0222) returned faster to pre-infection proportions in hLZ-milk fed pigs, while control-fed pigs had significantly higher hematocrit (p = 0.027), indicating continuing dehydration. In the ileum, pigs fed hLZ-milk had significantly lower expression of pro-inflammatory cytokine IL-8 (p = 0.0271), longer intestinal villi (p<0.0001), deeper crypts (p = 0.0053), and a thinner lamina propria (p = 0.0004). These data demonstrate that consumption of hLZ-milk helped pigs recover from infection faster, making hLZ-milk an effective treatment of E. coli-induced diarrhea.

Production of human lactoferrin and lysozyme in the milk of transgenic dairy animals: past, present, and future

“…While normal goat milk is able to repair intestinal barrier function damage induced by EAEC the hLZ transgenic goat milk provides further protection (Carvalho et al 2012). In an in vivo model of diarrhea using young pigs infected with enterotoxigenic E. coli (ETEC), pigs consuming hLZ-milk recovered from clinical signs of infection faster than pigs consuming control milk, with significantly improved fecal consistency and activity level (Cooper et al 2013). Circulating monocytes, neutrophils, and lymphocytes returned faster to pre-infection proportions in hLZ-milk fed pigs, while control-fed pigs had significantly higher hematocrit, indicating continuing dehydration.…”

“…In the ileum, pigs fed hLZ-milk had significantly lower expression of pro-inflammatory cytokine IL-8, longer intestinal villi, deeper crypts, and a thinner lamina propria. Thus consumption of hLZ-milk helped pigs recover from infection faster, making hLZ-milk an effective treatment of E. coli-induced diarrhea (Cooper et al 2013). …”

“…Additionally investigations into the effects of long term consumption as well as monitoring how long after the cessation of consumption the effects on parameters such as intestinal architecture, immune response, and microbiota persist. Knowledge about these factors will be vital in enabling the design of future studies, as more research teams transition from testing the general effects of lactoferrin or lysozyme milk, to testing the efficacy of these milks against specific diseases such as E.coli infections (Cooper et al 2013), and other GI tract disturbances.…”

“…A great deal of research has been performed to characterize the fitness of these different lines of transgenic animals (Yang et al 2008;Jackson et al 2010), as well as the recombinant proteins they produce (Yang et al 2011;Thomassen et al 2005;Yu et al 2011). Recently, many reports have emerged reporting the effects of consumption of milk containing these recombinant proteins in both healthy animal models (Brundige et al 2010;Zhou et al 2011;Cooper et al 2012) and as a treatment in animal models of disease Cooper et al 2013).…”

The use of genetic engineering techniques to improve the lipid composition in meat, milk and fish products: a review

“…The most frequent objective of genetic modification of the mammary glands of farm animals is to express foreign, biologically important proteins, for instance human lysozyme in milk (Maga and Murray, 1995;Cooper et al, 2013;Lu et al, 2014). However, for some time there has also been increasing interest in using transgenic techniques to modify the composition of the lipid fractions of milk, as well as to reduce milk's overall fat content through inactivation of the genes responsible for the synthesis of lipids in the mammary gland.…”