Fig. 9.

Illustration of the putative components of D. immitis host pathogen interactions. A testable model for the ML in vivo mode of action can be constructed from the hypothetical interaction of ML, D. immitis, ES (variously colored circles), and the canine immune system (illustrated as various peripheral circulating morphonuclear cells). Microfilariae, and potentially L3 and L4 stages, broadcast a milieu of bioactive molecules that may specifically interact with host immune cells, abrogating a successful immune response that would clear the parasite. In the presence of MLs GluCls are engaged, neuronal signaling is silenced and the function of the ES apparatus (marked brown) shuts down. The resulting loss of ability to manipulate host immune signaling pathways results in clearance by a functional immune response.