Intestinal Secretion of IgA and IgM: A Hypothetical Model

The Normal Tear Film

“…Lysozyme is well known for its muramidase activity in the outer cell wall of Gram-positive bacteria, while both lactoferrin and lipocalin have iron-sequestering properties which inhibit siderophilic bacteria [40,41]. Secretory IgA exerts immunological protection after priming of the plasma cells against specific microorganisms and viruses; priming can be via mucosa-associated lymphoid tissue in the conjunctiva or elsewhere [42,43]. Recently a group of small protective peptides known as defensins have been identified in the tears by immunochemical means.…”

Role of the colonic lymphoglandular complex in mucosal immunity in swine

“…Secretion of IgA is the dominant mucosal immune defense mechanism (101), though IgM is also actively secreted (25) where it would likely be of more harm than benefit (13,113). One notable exception to the preeminence of IgA in mucosal secretions is the active transport of IgGl into ruminant colostrum and milk; it represents the major Ig constituent throughout lactation (162).…”

“…In disease, these numbers and ratios of cells may be altered. Epithelial cells contain no intracellular IgG, though small amounts may be present between cells (interstitially) or in goblet cells (25).…”

“…IgG is more prevalent than either IgA or IgM in the interstitium of the lamina propria (25). Interdependency of lymphocytes and epithelium in both the afferent and effector limbs of mucosal immunity is emphasized (19,27).…”

Immunological and pathological alterations in the intestine of cattle following intraluminal inoculation with bovine viral diarrhea virus

“…IgG (Hanson and Brandtzaeg 1973;Lee and Lascelles 1970); IgM, (Lascelles and McDowell 1970;Brandtzaeg and Baklien 1977); IgD, or IgD-like ; and IgE, (Ishizaka et al 1969; Mayrhofer 1977) have been demonstrated in the intestine. Ontological studies of antibody producing cells have been reported in several species including porcine (Chapman et al 1974), bovine (Schultz et al 1973) and murine (Friedberg and Weissman 1974).…”