HKLM - TLR2 Agonist

Heat Killed Listeria monocytogenes

HKLM is a freeze-dried heat-killed preparation of Listeria monocytogenes (LM), a facultative intracellular Gram-positive bacterium. Infection with LM induces a strong nonspecific response characterized by the secretion of proinflammatory cytokines.

This response is mediated by the interaction between MyD88 and several TLRs, mainly TLR2 [1], a Toll-like receptor involved in the recognition of multiple products of Gram+ bacteria.

Stimulation with HKLM induces immediate activation of NF-κB and the production of proinflammatory cytokines [2,3].

References:

1. Flo TH. et al., 2000. Human toll-like receptor 2 mediates monocyte activation by Listeria monocytogenes, but not by group B streptococci or lipopolysaccharide. J Immunol, 164(4):2064-9.
2. Hauf N. et al., 1997. Listeria monocytogenes infection of P388D1 macrophages results in a biphasic NF-κB (RelA/p50) activation induced by lipoteichoic acid and phospholipases and mediated by IkBa and IkBb degradation. Proc. Natl. Acad. Sci. USA 94(17):9394-9.
3. Plevy SE. et al., 1998. Multiple control elements mediate activation of the murine and human interleukin 12 p40 promoters: evidence of functional synergy between C/EBP and Rel proteins. Mol Cell Biol. 17(8):4572-88.
4. Schindler U. & Baichwal Vr., 1994. Three NF-κB binding sites in the human Eselectin gene required for maximal tumor necrosis factor alpha-induced expression. Mol Cell Biol, 14(9):5820-5831.