Authors
M A Duque-Correa2; F Schreiber2; A Roustant2; T Mkandawire2; D A Goulding2; R K Grencis1; M Berriman2; 1 University of Manchester, UK; 2 Wellcome Sanger Institute, UK Discussion
Whipworms (Trichuris trichiura) are soil-transmitted helminths and the etiologic agent of the human disease, trichuriasis. Whipworms live preferentially in the caecum of their hosts where they tunnel through epithelial cells and cause inflammation potentially resulting in colitis. Despite extensive research, the early whipworm interactions with host intestinal epithelial cells (IECs) determining parasite establishment or expulsion remain unclear. Here, we investigate novel interactions of whipworms with the host IECs during the first events of infection. Imaging caecum of T. muris -infected mice (a mouse model of T. trichuira infection in humans) after three hours, one day and three days post infection has revealed whipworm larvae (L1) infecting the epithelium at the base of the crypts of the intestine of mice. These images suggest a close interaction between the L1 larvae and the host goblet cells. Based on these data, we hypothesize that targeted infection of goblet cells by L1 larvae can support parasite growth and establishment in the host, potentially by the degradation of mucus. To further understand this critical early colonisation event, we are using intestinal organoids as a replacement model of the murine infections that are currently used. Organoids are a novel in vitro system generated from human and mouse primary tissues and recapitulating their architecture and cellular composition. Intestinal organoids are three-dimensional cell clusters generated from gut tissue showing similar characteristics and function to the gut. Thus far, we have developed and established protocols for generating and differentiating intestinal organoids, derived from either mouse caecum or human inducible pluripotent stem cells; hatching T. muris and T. trichiura eggs; and microinjecting organoids with T. muris and T. trichuira L1 larvae. Using whipworm-infected organoids, we are performing microscopy studies to identify the intestinal epithelial cell type targeted by the whipworm and visualise active infection. Moreover, we are performing transcriptomic experiments and planning proteomic, flow cytometry and cytokine analysis to discover host IECs-whipworm interactions and evaluate IECs responses to whipworm larvae infection. 
