Project Number: 6406-32000-010-00
Project Type: Appropriated

Start Date: Feb 01, 2007
End Date: Jan 31, 2012

Objective:
Optimize current Mycoplasma gallisepticum (MG) vaccination protocols for layer hens and define virulence determinants and mechanisms of MG infection in poultry in order to optimize diagnostic methodologies and control strategies. Also, identify and characterize immunogens of MG and related host responses leading to the development of immunity in poultry.

Approach:
A secondary vaccination with the F strain Mycoplasma gallisepticum (MG) will be performed on layer chickens previously treated with the MG vaccines, ts-11 or 6/85. Efficacy of the secondary treatment will be determined and effects on layer hen productivity, physiology, and immunology will be quantitated. Effects of the secondary vaccination on eggs produced by treated layer hens will be investigated. Proteome analyses of MG varying in virulence/pathogenicity will be conducted via 2D-PAGE combined with protein identification via mass spectrometry. The function/roles of virulence-associated proteins in virulence/pathogenicity will be investigated. Also, cytokine levels will be monitored from the blood and tracheal tissue of layer chickens vaccinated with the three licensed MG vaccines or infected with a virulent strain of MG. Flow cytometry will be utilized to assess changes in specific sub-populations of cells from the peripheral blood. Changes in levels of specific cytohesins will be assessed by isolating the mRNA and quantitating expression levels by Real Time PCR. Alternately, tracheas will be removed for RNA isolation. Changes in gene expression will be profiled by cDNA microarray.