Presence of macrophage migration inhibitory factor in human milk: evidence in the aqueous phase and milk fat globules.
Human milk is a source of bioactive substances regulating the development and activity of the newborn immune system. Human milk has been found to contain a number of cytokines, including interleukins, growth factors, and colony stimulating factors. In the present study, we assessed 10 specimens of human milk for the presence of macrophage migration inhibitory factor (MIF), a cytokine recently described in several human reproductive organs and tissues. Using biochemical as well as immunologic techniques, we showed that MIF is abundantly present in human milk, mostly distributed in the lipid layer and in the aqueous phase. Fractionation of the lipid layer showed that MIF is highly concentrated inside milk fat globules. In view of its proinflammatory features, we speculate that milk MIF may protect the newborn against infection and play a role in preserving the functionality of the lactating mammary gland. Furthermore, the localization of MIF in lipid globules suggests a possible strategy for the protection of milk cytokines from the gastric barrier.
Magi
Barbara
B
Department of Molecular Biology, University of Siena, Italy.
Ietta
Francesca
F
Romagnoli
Roberta
R
Liberatori
Sabrina
S
Pallini
Vitaliano
V
Bini
Luca
L
Tripodi
Sergio A
SA
Cintorino
Marcella
M
Chellini
Francesca
F
Arcuri
Felice
F
De Felice
Claudio
C
Paulesu
Luana
L
D000328:Adult; D005591:Chemical Fractionation; D005260:Female; D006017:Glycolipids / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006801:Humans; D007774:Lactation; D066292:Lipid Droplets; D008055:Lipids; D008263:Macrophage Migration-Inhibitory Factors / Q000032:analysis* / Q000097:blood; D008894:Milk Proteins / Q000032:analysis*; D008895:Milk, Human / Q000737:chemistry*; D049590:Postpartum Period; D012995:Solubility; D014867:Water
D006017:Glycolipids; D006023:Glycoproteins; D008055:Lipids; D008263:Macrophage Migration-Inhibitory Factors; D008894:Milk Proteins; C110367:milk fat globule; D014867:Water