Strain and model dependent differences in inflammatory cell recruitment in mice

Objective and design: The objective of this study was to determine genetic differences in inflammation in these distinct inbred mouse strains. Methods: Peritoneal leukocyte recruitment, matrix metalloproteinases and cytokines were quantified in A/J, 129/svJ, C57BL/6J. using thioglycollate or biomaterial implants as inflammatory stimuli. Results: In response to thioglycollate, A/J had significant decreases compared to C57BL/6J in both neutrophil (86%) and macrophage (62%) recruitment, and 129/svJ had a significant (43%) decrease compared to C57BL/6J in macrophage recruitment. The reduced leukocyte recruitment corresponded to reduced matrix metalloproteinase-9. In the bioimplant model, 129/svJ had a 2-fold increase in neutrophil and macrophage recruitment compared to C57BL/6J, and the increased leukocyte recruitment corresponded to elevated cytok-ines, monocyte inhibitory protein-2 and monocyte chemoattractant protein-1, in the lavage compared to the values for C57BL/6J. Conclusion: Not only was leukocyte recruitment strain dependent, but the three strains had marked differences in metalloproteinases and cytokine response. In addition, there were model specific differences in the metalloproteinase and cytokine response to the two inflammatory stimuli. Thus, inflammatory cell recruitment is genetically determined and stimulus specific and may determine the susceptibility to complex diseases.