Soya protein hydrolysates modify the expression of various pro-inflammatory genes induced by fatty acids in ovine phagocytes.

The objective of the present study was to test the hypothesis that fatty acids are the circulating mediators acting in a pro-inflammatory manner towards activated circulating ovine monocyte/macrophages and neutrophils. Furthermore, whether soya protein hydrolysates (SPH) inhibit the fatty acid-induced increase in the production of pro-inflammatory responses by ovine phagocytes was tested in vitro. All the fatty acids tested (myristic, palmitic, palmitoleic, stearic and oleic) increased (P<0·01; C18>C16>C14) membrane-bound urokinase plasminogen activator (u-PA) and u-PA free binding sites in cell membranes of activated ovine blood monocytes/macrophages, but only the C18 fatty acids (stearic, oleic) were effective towards blood neutrophils.

Acute mastitis induces upregulation of expression of plasminogen activator-related genes by blood monocytes and neutrophils in dairy ewes.

The main objective of the present study was to examine whether genes implicated in the plasminogen activating cascade: urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR) and plasminogen activator inhibitors type 1 (PAI-1) and type 2 (PAI-2) are expressed in a differential manner in ovine blood monocytes and neutrophils obtained from healthy and mastitic dairy ewes. A total of 48 blood samples were collected from 8 healthy and 8 mastitic dairy ewes over a period of 3 weeks. Streptococcus agalactiae was detected in milk samples isolated from mastitic animals.

Milk peptides and immune response in the neonate.

Bioactive peptides encrypted within the native milk proteins can be released by enzymatic proteolysis, food processing, or gastrointestinal digestion. These peptides possess a wide range of properties, including immunomodulatory properties. The first months of life represent a critical period for the maturation of the immune system because a tolerance for nutrient molecules should be developed while that for pathogen-derived antigens is avoided.

Biological effects of milk proteins and their peptides with emphasis on those related to the gastrointestinal ecosystem.

The protein fraction of milk contains several components with physiological significance for the development of the newborn. Among them, immunomodulatory peptides and lactoferrin exemplify the complexity of biologically active substances of milk. Immunomodulatory peptides have latent activity within the native protein and are generated after proteolysis during gastrointestinal transit.