IL1B and inflammatory response: As has been shown by others the main cells involved in inflammationwere macrophages, as determined by F4/80 immunostaining (Figure 5F and G).By multiplex ligation-dependent probe amplification (MLPA), we detectedsignificantly increased levels of interleukin (IL)-1β, IL-1 ReceptorAssociated Kinase (IRAK)-3, and toll-like receptor (TLR)2 mRNA in hearts fromuPAR knock-out mice compared to WT littermate controls two weeks post infection(Figure 5H), consistent with the observed higher B. burgdorferinumbers and more severe cardiac inflammation in uPAR knock-out mice.