Toll-Like Receptor 2 Agonists Exacerbate Accelerated Nephrotoxic Nephritis

Glomerulonephritis can be exacerbated by infection. This study investigated the effect of N-palmitoyl-S-(2,3-bis(palmitoyloxy)-(2R,S)-propyl)-(R)-cysteinyl-seryl-(lysyl)3-lysine (Pam3CysSK4), a synthetic Toll-like receptor 2 (TLR2) ligand, that was given at immunization on disease severity in accelerated nephrotoxic nephritis. Stimulation of TLR by microbial constituents is known to influence the development of the adaptive immunity. It was hypothesized that the TLR2 ligand Pam3CysSK4 can modulate the development of disease in accelerated nephrotoxic nephritis by influencing the development of adaptive immunity. It is shown that Pam3CysSK4, when given at immunization, can increase profoundly the severity of disease, and with the use of TLR2-deficient mice, it is shown that this disease exacerbation depends on the presence of TLR2. Wild-type mice that were given Pam3CysSK4 at immunization and had more severe disease also had a greater amount of antigen-specific IgG1, IgG2b, and IgG3 in the serum and more IgG2b and IgG3 deposited within the glomerulus. They also had increased numbers of glomerular CD4-positive T cells. Therefore, the more severe disease that was seen in the group that was immunized with lipopeptide can be attributed to an influence on the adaptive immune response.