Recombinant Derp5 allergen with αS1-casein signal peptide secreted in murine milk protects against dust mite allergen-induced airway inflammation.

Recent advances in recombinant technology make transgenic animals that produce pharmaceutical proteins in their milk more feasible. The group 5 allergen isolated from Dermatophagoides pteronyssinus (Derp5) is one of the most important dust mite allergens in humans. The aims of this study were to develop transgenic mice that could secrete recombinant Derp5-containing milk and to demonstrate that ingesting recombinant milk protects against allergic airway inflammation. Two transgenes were constructed separately. The α-LA-Derp5f transgene consisted of the bovine α-lactalbumin (α-LA) promoter and full-length Derp5 cDNA. The α-LA-CN-Derp5t transgene included the α-LA promoter, a leader sequence of αS1-casein (CN), and signal peptide-truncated Derp5 cDNA. Both species of transgenic mice were confirmed to have successful transgene integration and stable germline transmission. Western blot analysis of the milk obtained from the offspring of transgenic mice demonstrated that recombinant Derp5 was secreted successfully in the milk of αLA-CN-Derp5t transgenic mice but not in that of αLA-Derp5f transgenic mice. This study provides new evidence that transgenic mice can secrete recombinant Derp5 efficiently in milk by adding a signal peptide of αS1-casein. The antigenic activity of recombinant Derp5 milk was demonstrated to have a protective effect against allergic airway inflammation in a murine model in which the ingestion of recombinant Derp5-containing milk was used as pretreatment.

Ingestion of milk containing the Dp2 peptide, a dust mite allergen, protects mice from allergic airway inflammation and hyper-responsiveness.

BACKGROUND: Allergen-specific immunotherapy has been demonstrated to have potential for the treatment of allergic diseases. Transgenic animals are currently the best available bioreactors to produce recombinant proteins, which can be secreted in milk. It has not been clearly demonstrated whether milk from transgenic animals expressing recombinant allergens has immunomodulatory effects on allergic asthma. METHODS: We aimed to determine whether the oral administration of milk containing a mite allergen can down-regulate allergen-specific airway inflammation. Transgenic CD-1 mice that express a recombinant group 2 allergen from Dermatophagoides pteronyssinus (Dp2) in their milk were generated using an embryonic gene-microinjection technique. Mouse pups were fed transgenic Dp2-containing milk or wild-type milk. Subsequently, these mice were sensitized and challenged with Dp2 to induce allergic airway inflammation. RESULTS: Upon sensitization and challenge, mice fed transgenic Dp2 milk had decreased T-helper 2 (Th2) and increased T-helper 1 (Th1) responses in the airway compared with mice fed wild-type milk. Moreover, pre-treatment with transgenic Dp2 milk attenuated airway inflammation and decreased airway hyper-responsiveness. CONCLUSIONS: This study provides new evidence that oral administration of transgenic milk containing the Dp2 allergen down-regulated and moderately protected against allergic airway inflammation. Milk from transgenic animals expressing allergens may have potential use in the prevention of allergic asthma.

Regulation of oocyte and cumulus cell interactions by intermedin/adrenomedullin 2.

Ovarian folliculogenesis has been studied as a model of hormonal regulation of development and differentiation, cell death, and cell-cell communication. In addition to gonadotropins from the pituitary and follicular paracrine factors, oocyte secreted factors have been shown to play critical roles in the regulation of follicular cell functions. Except for the well characterized BMP family proteins, including GDF9 and BMP15, oocytes are known to secrete oocyte secreted factors that are important for the regulation of cumulus cell survival and the maintenance of tertiary structure of cumulus cell-enclosed oocyte complexes (COCs). Based on genomic screening and studies of COCs cultured in vitro, we showed that intermedin (IMD)/adrenomedullin 2 (ADM2) is a novel oocyte-derived ligand important for the regulation of cell interactions in COCs that functions, in part, by suppressing cumulus cell apoptosis. Consistently, we showed that suppression of IMD/ADM2 signaling in growing rat ovaries in vivo leads to oocyte atresia and aberrant cell cycle progression in follicular cells. Together, our studies indicated that mammalian oocytes deploy a G protein-coupled receptor ligand to coordinate normal interactions of oocytes and cumulus cells and provided a better understanding of how the tertiary structure of a COC is maintained as follicles undergo exponential growth during the late stages of folliculogenesis.