Abstract
AbstractToxoplasma gondii(T.gondii) hijacks host immune cells as ‘Trojan Horse’, and the infected cells accelerated the parasites dissemination. During acute infection,T.gondiispecificity crosses the blood-brain-barrier to enter the brain. This selective mode of parasite transmission may be associated with the directed migration of infected immune cells. Immune cells follow various environmental cues for directional migration. However, the effect ofT.gondiiinfection on the recognition of mechanical cues by immune cells remains unknown. Here, we examined the adhesion and migration ofT.gondii-infected dendritic cells (DCs) on high and low stiffness substrates. We found thatT.gondiiinfection alters the durotaxis migration of DCs. Infected DC exhibited stronger adhesion and lower migration on low stiffness substrates. In contrast to uninfected DCs, infected DCs migrated towards the low stiffness environment. TgWIP and TgROP17 co-regulate the F-actin structure of DCs and are involved in the formation of abnormal F-actin filaments. Rearrangement of the F-actin structure resulting fromT.gondiiinfection regulates DCs’ abnormal recognition response to the mechanical cues. Recognition of DCs to the mechanical signals is independent of β2- integrin expression. Meanwhile, challenging DCs withT.gondiiincreased the phosphorylation of focal adhesion kinase (FAK). Treatment with a FAK inhibitor (VS- 6063) influences the recognition response of infected DCs. FAK inhibition in adoptively transferred infected DCs effectively prevents the dissemination ofT.gondiito the brain. The data reveal thatT.gondiiinfection inversely affects the durotaxis of DCs by altering the phosphorylation level of FAK and remodeling of F-actin structure.T.gondiiutilizes the change in DCs’ durotaxis migration to accelerate the parasites crossing the blood-brain-barrier.Author SummaryImmune cells travel through blood vessels and lymph vessels to various tissues, and respond to different types of environmental cues. Cells sense the cues and transmit these information to the cytoskeletal which induce directed cell migration towards or away from these signals.T.gondiiinfection remodeling the cytoskeletal of DCs which may cause abnormalities in these cues transduction. We found thatT.gondiiinfection induces the formation of abnormal F-actin filaments in DCs, TgWIP and TgROP17 co-regulate the DCs’ F-actin structure.T.gondiiinfection increased the phosphorylation of FAK in DCs and has no effect with DCs surface β2-integrin expression. These reasons lead to alter the original durotaxis migration of DCs, and makes infected-DCs tend to stay in the low stiffness environment. Meanwhile, the recognition response of infected DC to mechanical signal determines the parasite rapid crossing the blood-brain-barrier.
Publisher
Cold Spring Harbor Laboratory