title: Rhodnius prolixus: from physiology by Wigglesworth to recent studies of immune system modulation by Trypanosoma cruzi and Trypanosoma rangeli.
abstract: This review is dedicated to the memory of Professor Sir Vincent B. Wigglesworth (VW) in recognition of his many pioneering contributions to insect physiology which, even today, form the basis of modern-day research in this field. Insects not only make vital contributions to our everyday lives by their roles in pollination, balancing eco-systems and provision of honey and silk products, but they are also outstanding models for studying the pathogenicity of microorganisms and the functioning of innate immunity in humans. In this overview, the immune system of the triatomine bug, Rhodnius prolixus, is considered which is most appropriate to this dedication as this insect species was the favourite subject of VW's research. Herein are described recent developments in knowledge of the functioning of the R. prolixus immune system. Thus, the roles of the cellular defences, such as phagocytosis and nodule formation, as well as the role of eicosanoids, ecdysone, antimicrobial peptides, reactive oxygen and nitrogen radicals, and the gut microbiota in the immune response of R. prolixus are described. The details of many of these were unknown to VW although his work gives indications of his awareness of the importance to R. prolixus of cellular immunity, antibacterial activity, prophenoloxidase and the gut microbiota. This description of R. prolixus immunity forms a backdrop to studies on the interaction of the parasitic flagellates, Trypanosoma cruzi and Trypanosoma rangeli, with the host defences of this important insect vector. These parasites remarkably utilize different strategies to avoid/modulate the triatomine immune response in order to survive in the extremely hostile host environments present in the vector gut and haemocoel. Much recent information has also been gleaned on the remarkable diversity of the immune system in the R. prolixus gut and its interaction with trypanosome parasites. This new data is reviewed and gaps in our knowledge of R. prolixus immunity are identified as subjects for future endeavours. Finally, the publication of the T. cruzi, T. rangeli and R. prolixus genomes, together with the use of modern molecular techniques, should lead to the enhanced identification of the determinants of infection derived from both the vector and the parasites which, in turn, could form targets for new molecular-based control strategies.
authors.affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ, Brazil; Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, RJ, Brazil. Electronic address: azambuja.p@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Azambuja
authors.affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ, Brazil; Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, RJ, Brazil. Electronic address: garciaeloi@gmail.com.
authors.forename: E S
authors.initials: ES
authors.lastname: Garcia
authors.affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ, Brazil. Electronic address: peter.waniek@cityweb.de.
authors.forename: P J
authors.initials: PJ
authors.lastname: Waniek
authors.affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ, Brazil. Electronic address: ceciliastahl@gmail.com.
authors.forename: C S
authors.initials: CS
authors.lastname: Vieira
authors.affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ, Brazil. Electronic address: marcela.figueiredo@gmail.com.
authors.forename: M B
authors.initials: MB
authors.lastname: Figueiredo
authors.affiliation: Laboratório de Biologia de Insetos, Universidade Federal Fluminense, Niterói, RJ, Brazil. Electronic address: msgonzalez@id.uff.br.
authors.forename: M S
authors.initials: MS
authors.lastname: Gonzalez
authors.affiliation: Laboratório de Biologia de Insetos, Universidade Federal Fluminense, Niterói, RJ, Brazil. Electronic address: cicerobrasileiro@globo.com.
authors.forename: C B
authors.initials: CB
authors.lastname: Mello
authors.affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ, Brazil; Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, RJ, Brazil. Electronic address: didan.castro@gmail.com.
authors.forename: D P
authors.initials: DP
authors.lastname: Castro
authors.affiliation: Laboratório de Biologia de Insetos, Universidade Federal Fluminense, Niterói, RJ, Brazil; Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, Wales, United Kingdom. Electronic address: N.A.Ratcliffe@swansea.ac.uk.
authors.forename: N A
authors.initials: NA
authors.lastname: Ratcliffe
mesh_terms: D000818:Animals; D012239:Rhodnius / Q000276:immunology* / Q000469:parasitology*; D014349:Trypanosoma cruzi / Q000502:physiology*; D057509:Trypanosoma rangeli / Q000502:physiology*
keywords: Antimicrobial peptides; Haemocyte; Immune system; Prophenoloxidase; Rhodnius prolixus; Trypanosomes; Wigglesworth