Lina Zhang

Dynamics of inmune proteins due to individual, lactation stage and specie differences

Lina Zhang

lina.zhang@wur.nl

Supervisors:

Kasper Hettinga

Project term:

09.2011- 08.2015  

Introduction

Milk is the most important food for the growth and development of the neonate because of its unique nutrient composition combined with the presence of many bioactive proteins. One of the most interesting components, the immune proteins, plays a pivotal role in protecting the gut mucosa against pathogens and achieving many beneficial outcomes for the immunity status of the neonate. The two main functions of immune proteins are protecting the mammary gland against mastitis (Gapper, et al. 2007) and providing the neonate with an immunological defence against pathogen (Korhonen et al. 2000). Some, mainly qualitative, studies have already been done to describe the immune proteins in both human and bovine milk, but the knowledge on dynamics of the immune proteins is still very limited.

Aim

The objective of this project is to study the extent and causes of variation in immune proteins using an advanced proteomics approach.

Research

This research will be performed in four parts according to its variation causes, lactation stage, Healthy status, individuals and species difference.  The first part is the effect of mammary gland inflammation  

on immune proteins in bovine milk. I use milk of five groups with different SCC (somatic cell count) for this study. Every group has 20 cows. Milk serum will be analysed using 1D-gel. The samples will subsequently be analysed using nano-LC/orbitrap-MS. In the data-analysis step, the peptides will be identified based on their respective MS/MS-spectra. Database searches based on the human and bovine database will be used to identify the proteins. Peak intensity ratios between differentially peptides can be used to calculate relative amounts of the peptides.

Future research

I will study the profile of the immune protein of human and bovine milk over lactation and look the difference in immune proteome among individual cows and individual human using the combination of FASP, Dimethyl labeling and LC-MS/MS. For the difference in immune proteome between species (human and cow) Dimethyl labeling will be replaced by label free.

References

Gapper L. W., Copestake D. E. J.,  Otter D. E.,  Indyk H. E. 2007. Analysis of bovine immunoglobulin G in milk, colostrum and dietary supplements: a review. Anal Bioanal Chem, 389:93–109
Korhonen H., Marnila P. & Gill H.S. 2000. Milk immunoglobulins and complement factors. British Journal of Nutrition, 84: 75–80