Triatoma infestans relies on salivary lysophosphatidylcholine to enhance Trypanosoma cruzi transmission

Abstract

Triatoma infestans is a mandatory haematophagous vector of Chagas disease in Brazil. Despite a large number of studies on the anti-haemostatic molecules present in its saliva, the role of its salivary components on parasite transmission is poorly understood. Here, we show that the bioactive lipid molecule, lysophosphatidylcholine (LPC), is present in the salivary gland of T. infestans. We characterized the lipid profiles of each unit of the T. infestans salivary gland. We noticed that LPC is present in the three units of the salivary gland and that the insect feeding state does not influence its proportion. T. infestans saliva and LPC can enhance T. cruzi transmission to mice by dramatically altering the profile of inflammatory cells at the site of inoculation on mouse skin, facilitating the transmission of T. cruzi to the vertebrate host. Consequently, the mortality curves of either saliva- or LPC-injected mice display significant higher mortality rates than the control. Altogether, these results implicate LPC as one of key salivary molecule involved in Chagas disease transmission.

Lipid hijacking: A unifying theme in vector-borne diseases

“…T. cruzi parasites bind lipoproteins from the vertebrate blood meal on their surface, thus agglutinating parasites and enhancing infectivity in the insect vector ( Moreira et al, 2018 ). These parasites may benefit from the immunosuppressive properties of arthropod-derived lipids, where LPC in the salivary glands of Triatoma infestans and Rhodnius prolixus was shown to enhance T. cruzi transmission by altering the local inflammatory environment at the bite site ( Mesquita et al, 2008 ; Lima et al, 2018 ). Ultimately, the interactions between parasites, hosts, and lipids are critical for the establishment and dissemination of arthropod-borne infections.…”