Macrophage function in milk and the fate of transferred phagocytes in the neonatal gut

Hughes, Anne (1987) Macrophage function in milk and the fate of transferred phagocytes in the neonatal gut. PhD thesis, University of Glasgow.

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Abstract

To investigate the effect of infant feeding regimes on macrophage function, interaction of infant formula and human breast milk supernatant with macrophages was studied. Phagocytosis and degradation of radiolabel1ed transferrin-antitransferrin immune complexes by resident and stimulated mouse peritoneal in macrophages was inhibited by liquid infant formula, particularly in the case by resident cells. Ingestion and killing of Staghylococcus aureus NCTC 8532 by resident macrophages was also reduced following pre-incubation with formula. In contrast, human milk had little or no effect on either function. Human milk supernatant and liquid infant formula inhibited phagocytosis but not degradation of radiolabelled immune complexes by human peritoneal macrophages, whereas human breast-milk macrophages appeared to be unaffected by either milk or formula. Immunofluorescence studies showed that both murine and human macrophages exposed to formula bound casein (CAS) and beta-lactoglobulin (BLG) but little, if any, alpha-lactalbumin (ALA). Comparison of the effect of various artificial milks, cow's milk and purified CAS on the activity of mouse macrophages indicated that both the concentration and the degree of denaturation of CAS may be important in the impairment of macrophage function by milk. Human peritoneal macrophages and breast-milk macrophagess showed a positive correlation between binding of milk proteins in the liquid formula and expression of HLA-DER antigen. Thus,, it is proposed that formula milk might impair macrophage function in the small intestine, and binding of milk proteins by HLA-DR +-ve macrophages may be important in sensitisation of infants to cow's milk., Furthermore, in infants on a mixed-feeding regime,, ingested mi1k macrophages might also act to present cow's milk proteins. To investigate survival of milk macrophages in the gastrointestinal tract, of the neonate, newborn mice were fed peritoneal macrophages labelled with fluorescent beads. Intact cells survived in the stomach for at least 4h after feeding. In addition, transferred cells were recovered in the gut and spleen sections from a small number of mice. Thus, milk macrophages may be able to persist in the neonate and may thus contribute toward the immunological development of the infant. The consequences of infant feeding on the immunological status of the neonate are discussed in the context of the presented work.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Additional Information: Adviser: Jeremy H Brock
Keywords: Immunology
Date of Award: 1987
Depositing User: Enlighten Team
Unique ID: glathesis:1987-72285
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 24 May 2019 15:12
Last Modified: 24 May 2019 15:12
URI: http://theses.gla.ac.uk/id/eprint/72285

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