In @entity19 the majority of the immunoglobulins (Ig) in milk belongs to the IgA class. Prior to its transepithelial transportation into the milk, dimeric IgA (dIgA) is bound to the transmembrane form of the secretory component or polymeric Ig receptor (SC/ @entity40262 ). The latter is synthesized in the epithelial cells lining the ducts and alveoli of the mammary gland. A candidate for playing the role of adhesion molecule to primed lymphocytes present in the @entity19 mammary gland might be the @entity37196 ( @entity37196 ). We studied the correlation between the levels of IgA in colostrum and milk, the number of IgA producing plasma cells in the mammary gland and the expression of @entity37196 in mammary gland endothelial cells during pregnancy and lactation. The relation between the IgA levels in the milk and the expression levels of @entity40262 in mammary gland epithelial cells was also investigated. We found that the expression of @entity37196 and @entity40262 starts in early-mid pregnancy; the number of IgA-producing plasma cells and the IgA concentration in milk increase from early lactation onwards. The @entity37196 expression declines during lactation whereas the @entity40262 levels and IgA-producing plasma cell numbers rise until the end of lactation. Because the @entity37196 level starts to rise several days before the rise of the IgA-producing plasma cell level, @entity37196 cannot be the rate determining factor governing extravasation of primed B cells to the mammary gland. We also conclude that the @entity40262 is present in sufficient amounts to enable increasing S-IgA secretion into the milk during lactation.

Lymphocyte homing and Ig secretion in the XXXX mammary gland.

@entity19 :: ('10090', 'Species') :: ['mice', 'murine'] @entity40262 :: ('18703(Tax:10090)', 'Gene') :: ['pIgR'] @entity37196 :: ('17123(Tax:10090)', 'Gene') :: ['MAdCAM-1', 'mucosal addressin cell adhesion molecule-1']
@entity19 :: (10090,Species) :: ['murine']
