TLR2 and infection: Upon infection with Brucella or in response to Brucella lipoproteins, such as the lipidated outer membrane protein 19 (L-Omp19), macrophages release inflammatory mediators such as TNF-a, interleukin-6 (IL-6), and IL-1β in a toll-like receptor 2-dependent manner (TLR2) [46].