Effect of Tannins on the Intestinal Immune System in of Poultry

Overview

The morphological and immunological changes, which can be caused by tannins on the epithelial cells in the small intestine, has not been studied enough. Several peculiarities of the intestinal epithelial cells make them unique: the function of the epithelial cells of the small intestine exists not only in digestion and absorption of the Nutrients, but they also serve as antigen-precursor cells (APC): both cells MHC class I as well as the MHC class II are expressed and they serve as antigen-precursor cells for T cells. Further, the epithelial cells of the small intestine produced immunoregulatory cytokines that enhance the activity of professional antigen presenting cells (PAPC) (macrophages, dendritic cells and B lymphocytes).

The intestinal epithelial cells can increase the activity of CD8 + T cells. The Transport of immunoglobulins IgA and IgG into the lumen of the intestine occurs exclusively by these cells: The transmembrane poly-Fc receptor (SC, secretory component) is located on the laminaproprial Surface of these cells, which act as receptors for IgA.

Morphological and Immunological Changes

Quebracho tannin had no significant effect on the size of cells except in the cecum. Unaltered cell size with the presence of relative villus atrophy means decrease in the number of epithelial cells and may indicate the induction of apoptosis, either by interaction of quebracho tannin with certain superficial receptors on the epithelial cells and induction of apoptosis Promoting genes, or by direct activation of T-CD8 cell, or by inhibiting the metabolism of enterocytes and disrupting mitochondrial performance. Further clarification is required.

Mucosal Immunological Changes

Goblet cells

The observed Increase of the goblet cells may emphasizes the role of activated T-cells.

Brush Border

No major effects on the thickness of the brush border of the poultry feed with high-tannin sorghum.

Epithelial Cells

A sub-acute crypten inflammation and loss of epithelial cells was observed in the lamina propria.