African trypanosome transmission: unraveling the molecular 'tripartite' between a protozoan parasite, a symbiotic bacterium and the tsetse fly innate immunity

  • Van Den Abbeele, Jan (Promotor)
  • De Vooght, Linda, (Copromotor)
  • Caljon, Guy, (Copromotor)
  • De Smet, Sieglinde, (Administrator)

Project Details


Many pathogens including protozoan parasites rely on blood feeding vectors for their transmission. In many cases this is a biological transmission which implies that the parasites have to go through an obligatory developmental cycle within different micro-environments of the vector before dissemination into the mammalian host population can occur. Optimization of a successful parasite transmission is a key evolutionary drive that has influenced many aspects of the parasite biology, including molecular interactions within the blood-feeding arthropod vector. Here, parasites are challenged by the immune defenses of the vector. These consist of innate humoral and cell-mediated immune responses, both of which affect the parasites as they establish and sustain in their vectors. In addition to this, many vectors harbour a symbiotic microbiome that affects the vector physiology/immune responsive status and that in turn can influence the pathogen transmission process.
The key of transmission of the major African trypanosomes - Trypanosoma brucei sp. and congolense - is a complex and obligatory developmental cycle of the parasite in the blood feeding tsetse fly. During this developmental cycle the parasite encounters a variety of ‘hostile’ micro-environments along the alimentary tract (i.e. midgut, proventriculus, mouthparts) and in the salivary glands. In these tissues, the tsetse fly also harbours an ‘evolutionary recently established’ symbiotic enterobacterium, Sodalis glossinidius. Successful development of the trypanosome in the tsetse fly is the outcome of the parasite molecular sensing and adaptive capabilities to these different micro-environments which are modulated by i) vertebrate blood factors, ii) the tsetse fly defense and/or tolerance reactions to trypanosomes and to the symbiotic Sodalis bacterium, iii) trypanosome derived/released molecules, and iv) Sodalis-derived/released molecules. Although some research on tsetse fly immune responses and factors that affect trypanosome development has been documented in literature, our knowledge on the molecular tripartite interactions between the protozoan trypanosome parasite, the bacterial symbiont Sodalis glossinidius and the tsetse fly innate immune system represents a genuine black box. Therefore, this SOFI project aims to gain novel insights in these interactions by focusing on i) the tsetse fly immune responses (antimicrobial peptides as well as reactive oxygen species) to the two key microorganisms: the trypanosome parasite as well as the ‘recent’ symbiotic Sodalis bacterium and ii) the influence of this ‘tripartite’ interaction on the efficiency of trypanosome development in the tsetse fly and on the tsetse fly biology.
Effective start/end date1/07/1331/12/18


  • Flemish Government - Department of Economy, Science & Innovation: €602,950.00

IWETO expertise domain

  • B361-physiology-of-invertebrates
  • Innate immunity
  • symbionts
  • Trypanosoma
  • tsetse fly