Microarray analysis of monocytes recruited in the peritoneum during experimental infection with Listeria monocytogenes

The immune system cellular response to tissue damage and infection requires the recruitment of blood leukocytes to the target tissue. This process is mediated through a classical multistep mechanism which involves transient rolling on the endothelium and recognition of inflammation followed by extravasation. We show here, by direct examination of blood monocyte functions in vivo, that resident monocytes monitor the endothelium of healthy tissues through patrolling, a new mechanism which allows extravasation in the absence of rolling.Patrolling depends on the integrin LFA1 and the chemokine receptor CX3CR1, and is required for rapid tissue invasion and initiation of an early immune response by monocytes that differentiate into macrophages at the site of tissue damage and infection. The main goal of the experiment was to compare expression levels of genes in Gr1- monocytes in the blood and after recruitment in the peritoneum during experimental infection with Listeria monocytogenes (time course analysis). Keywords: expression profiling; time course analysis; infection response