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Updated: Jun 15, 2026

Development of an in vitro model system for studying the interaction of Equus caballus IgE with its high-affinity receptor FcεRI
Published on: November 1, 2014
Selective transport of IgE into ovine mammary secretions
B C Hine1, P W Hunt, A M Beasley
1CSIRO Livestock Industries, F.D. McMaster Laboratory, Armidale, NSW 2350, Australia. brad.hine@agresearch.co.nz
Immunoglobulin (Ig) E is actively transported into ovine colostrum. Here we examine the degree of selectivity and the mechanism by which this transfer occurs in sheep. Results indicate that during colostrogenesis in sheep, transfer of immunoglobulins was most selective for IgG1 and IgA followed by IgE, IgM and IgG2. In milk, selectivity was greatest for IgA, followed by IgM, IgE, IgG1 and IgG2. The neonatal Fc receptor (FcRn) and poly immunoglobulin receptor (pIgR) mediate the transport of IgG1 and IgA across the ovine mammary epithelium respectively. In primates and rodents, the low-affinity IgE receptor, Fc epsilonRII, functions to transport IgE across the intestinal epithelium. We therefore investigated the expression of the low-affinity IgE receptor (CD23), pIgR and FcRn transcripts in the ovine mammary gland. The expression profiles of FcRn, pIgR and CD23 mRNA reflected concentrations of their Ig ligands in mammary secretions. These findings suggest a role for CD23 in transport of IgE across the mammary epithelium of sheep.
Immunoglobulin (Ig) E is actively transported into ovine colostrum. Here we examine the degree of selectivity and the mechanism by which this transfer occurs in sheep. Results indicate that during colostrogenesis in sheep, transfer of immunoglobulins was most selective for IgG1 and IgA followed by IgE, IgM and IgG2. In milk, selectivity was greatest for IgA, followed by IgM, IgE, IgG1 and IgG2. The neonatal Fc receptor (FcRn) and poly immunoglobulin receptor (pIgR) mediate the transport of IgG1 and IgA across the ovine mammary epithelium respectively. In primates and rodents, the low-affinity IgE receptor, Fc epsilonRII, functions to transport IgE across the intestinal epithelium. We therefore investigated the expression of the low-affinity IgE receptor (CD23), pIgR and FcRn transcripts in the ovine mammary gland. The expression profiles of FcRn, pIgR and CD23 mRNA reflected concentrations of their Ig ligands in mammary secretions. These findings suggest a role for CD23 in transport of IgE across the mammary epithelium of sheep.
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