Dr Johannes Dessens
in Parasite Cell Biology
I studied Plant Pathology at the University of Wageningen, The Netherlands, before embarking on a PhD in molecular virology at the John Innes Institute in Norwich. After a couple of postdocs in virology in INRA Versailles and IVEM Oxford, respectively, I got involved with malaria research at Imperial College London. The recipient of a Wellcome Trust University Award I obtained a senior lecturer position at the LSHTM, which I started in the autumn of 2005.
I am Course Director of the MSc course "Molecular Biology of Infectious Diseases" (MBID) and chair the MBID MSc Course Committee. I am also a member of the MBID Exam Board and as such contribute to setting the exam questions and their marking. In addition I am the Module Organiser of "Molecular Biology" (3333) taught in Term 1.
Research of my group is focussed on the molecular genetics of malaria parasites using the rodent malaria parasite model Plasmodium berghei. Our aims are to better understand the parasite’s molecular and cell biology, particularly in the mosquito vector, and to use this to identify innovative ways of intervention. Central to this work is the generation of genetically modified parasite lines in which target genes are disrupted, tagged or mutated, providing important information on the expression, subcellular localization, function and redundancy of gene products. I was one of the first in the UK to successfully establish gene targeting technology in P. berghei and have since applied it to shed light on the function of many different Plasmodium genes, in particular those relevant to sporogonic development and mosquito transmission. Some of my most significant scientific contributions to date include:
(1) The identification of circumsporozoite and TRAP-related protein (CTRP) as an essential molecule for motility and infectivity of the ookinete (Dessens et al., 1999; EMBO J). This has become a highly cited paper, and CTRP has become a reference ookinete marker.
(2) The identification of the IMC1 family of membrane skeleton proteins (now known as alveolins) as being key molecules involved in Plasmodium zoite morphogenesis, motility, tensile strength and infectivity (Khater, Sinden & Dessens, 2004, J Cell Biol). We and other labs are now working on the alveolins as potential targets for parasite intervention (Al-Khattaf et al., 2015, Parasitol Res).
(3) The discoveries that a gametocyte-expressed family of LCCL-Lectin adhesive-like proteins (LAPs) are essential for Plasmodium sporozoite transmission (Claudianos et al., 2002, Mol Microbiol) and are physically and functionally linked to the crystalloid organelle (Carter et al., 2008, Mol Microbiol; Saeed et al., 2015, Int J Parasitol). This has shed important new light on the origins and functions of this enigmatic organelle that was first described in 1962.