Immune Components in Human Milk Are Associated with Early Infant Immunological Health Outcomes: A Prospective Three-Country Analysis.

The role of breastfeeding in improving allergy outcomes in early childhood is still unclear. Evidence suggests that immune mediators in human milk (HM) play a critical role in infant immune maturation as well as protection against atopy/allergy development. We investigated relationships between levels of immune mediators in colostrum and mature milk and infant outcomes in the first year of life. In a large prospective study of 398 pregnant/lactating women in the United Kingdom, Russia and Italy, colostrum and mature human milk (HM) samples were analysed for immune active molecules. Statistical analyses used models adjusting for the site of collection, colostrum collection time, parity and maternal atopic status. Preliminary univariate analysis showed detectable interleukin (IL) 2 and IL13 in HM to be associated with less eczema. This finding was further confirmed in multivariate analysis, with detectable HM IL13 showing protective effect OR 0.18 (95% CI 0.04-0.92). In contrast, a higher risk of eczema was associated with higher HM concentrations of transforming growth factor ß (TGFß) 2 OR 1.04 (95% CI 1.01-1.06) per ng/mL. Parental-reported food allergy was reported less often when IL13 was detectable in colostrum OR 0.10 (95% CI 0.01-0.83). HM hepatocyte growth factor (HGF) was protective for common cold incidence at 12 months OR 0.19 (95% CI 0.04-0.92) per ng/mL. Data from this study suggests that differences in the individual immune composition of HM may have an influence on early life infant health outcomes. Increased TGFß2 levels in HM are associated with a higher incidence of reported eczema, with detectable IL13 in colostrum showing protective effects for food allergy and sensitization. HGF shows some protective effect on common cold incidence at one year of age. Future studies should be focused on maternal genotype, human milk microbiome and diet influence on human milk immune composition and both short- and long-term health outcomes in the infant.

Hepatocyte growth factor attenuates collagen accumulation in a murine model of pulmonary fibrosis.

We investigated the in vivo effects of recombinant human hepatocyte growth factor (HGF) on epithelial cell proliferation in normal mouse lung and on the repair process that follows bleomycin-induced lung injury. Intratracheal administration of 100 micrograms of rhHGF to C57BL/6 mice led to proliferation of bronchial and alveolar epithelial cells as indicated by an increased number of cells staining for proliferating cell nuclear antigen (PCNA). The effect of HGF on the lung repair process was examined by administration of 100 micrograms of rhHGF on Day 3 and Day 6 after intratracheal injection of bleomycin to mice. We found that HGF significantly attenuated collagen accumulation induced by bleomycin as determined by quantitation of hydroxyproline content and by scoring of the extent of fibrosis. To explore the potential mechanisms involved in the beneficial effects of HGF, we performed in vitro studies with A549 pulmonary epithelial cells and found that HGF enhanced cell surface plasmin generation, expression of u-PA activity, and cell migration. In summary, HGF has potent in vivo and in vitro effects on epithelial cells, which suggests it may have a role in the therapy of pulmonary fibrosis.

Hepatocyte growth factor in human breast milk.

PROBLEM: The purposes of this study were to investigate the presence of hepatocyte growth factor (HGF) in human milk, to identify the cells that produce HGF in human milk, and to determine the contribution of HGF to the growth of neonates. METHOD OF STUDY: The HGF concentrations in serum and whey were determined with an enzyme-linked immunosorbent assay kit. The presence of HGF in whey was also examined by Western blot analysis. To determine which cells in human milk produce HGF, an immunohistochemical examination was conducted. The expression of HGF mRNA in the mononuclear cells in human milk was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). The effects of whey and of recombinant HGF (rHGF) on DNA synthesis by a rat small intestinal cell line, IEC-6, were examined by [3H]thymidine uptake. RESULTS: Human colostrum whey contained 2.22 +/- 1.02 ng of HGF/ml. Milk whey collected 1 month later contained 1.83 +/- 1.03 ng of HGF/ml. The presence of the heterodimeric form of HGF in colostrum whey was demonstrated by Western blot analysis. HGF was detected in the cytoplasm of human milk macrophages by an immunohistochemical examination, and the RT-PCR also revealed that HGF mRNA is expressed in the mononuclear cells of human milk. DNA synthesis by IEC-6 cells was increased by rHGF treatment and by whey treatment. The effect of whey on DNA synthesis by IEC-6 cells was partially, but significantly, decreased by anti-human HGF-neutralizing antibody treatment. CONCLUSIONS: Human milk contains a large amount of the active form of HGF, produced by macrophages, and HGF in human milk induces the growth of intestinal cells. Our data suggest that HGF in human milk is one of the important factors regulating the growth of intestinal cells in neonates after birth.

Expression of the met receptor tyrosine kinase in muscle progenitor cells in somites and limbs is absent in Splotch mice.

Hepatocyte growth factor/scatter factor (HGF/SF) stimulates proliferation, dissociation, migration and morphogenesis of cells in culture. To investigate a possible role for HGF/SF and its receptor, the Met tyrosine kinase, in embryonic development, we have analyzed their expression in mouse embryos from day 7.5 of gestation by whole-mount in situ hybridization. Met expression is first detected in the ventral portion of somites at day 9.25 of gestation (22 somite embryo) at the level of fore limb buds. As somites mature, met expression is detected in caudal somites, and is confined to the lateral and media] tips of the dermomyotome and dermomyotome/myotome respectively. In contrast, HGF/SF is expressed exclusively in the mesodermal core of the limb bud. As the dermomyotome elongates ventrolaterally, the met-expressing cells at the lateral tip appear to detach from the somite, invade the limb bud and localize at the dorsal and ventral limb sides in close proximity to HGF/SF-expressing cells. At later stages, both met- and HGF/SF-expressing cells appear to migrate distally and localize to the digit forming area of the developing hand plate. Met expression in the lateral dermomyotome and limb bud coincides with expression of Pax-3, a marker for migrating muscle precursor cells in the somite and limb. Splotch-2H and Splotch-delayed mice, which harbor mutations in Pax-3, show major disruptions in early limb muscle development. Significantly, no met-expressing cells were observed in the limbs of homozygous Splotch-2H and Splotch-delayed animals, whereas HGF/SF expression was not affected. The restricted expression of met to a sub-population of Pax-3-expressing cells in the lateral tip of the dermomyotome, demonstrates that met represents a unique molecular marker for this migratory cell population. From these observations, together with the biological activities of HGF/SF, we propose that in homozygous Splotch embryos the failure of muscle precursors to migrate into and populate the limb bud results from a loss of met expression in the cells at the ventrolateral edge of the somitic dermomyotome.