Molecular characterization of a tsetse fly midgut proteolytic lectin that mediates differentiation of African trypanosomes

Dynamics of infection and competition between two strains of Trypanosoma brucei bruceiin the tsetse fly observed using fluorescent markers

“…Our observations are more consistent with the hypothesis that individual flies are either permissive (susceptible) or non-permissive (resistant) to infection, and that permissiveness operates at a series of gates that are encountered sequentially by invading trypanosomes as they progress in their developmental cycle through the fly. Firstly, the establishment of a midgut infection, with subsequent invasion of the ectoperitrophic space and proventriculus, relies on trypanosomes surviving the initial immune response of the fly [3,21-23]; in our experiment, about half of the infections foundered at this stage. Secondly, proventricular trypanosomes need to differentiate into migratory forms and invade the foregut by retraversing the peritrophic matrix; here, over two thirds of established midgut infections failed to progress beyond the proventriculus.…”

Immunity-related genes in Ixodes scapularis—perspectives from genome information

“…A group of carbohydrate-binding proteins called lectins (Grubhoffer et al, 1997, 2004), which are often produced in a tissue specific manner within arthropods, especially in the gut, hemocytes, or fat bodies, could be key mediators of the process (Grubhoffer et al, 2004, 2005). Agglutination of pathogens by lectins, which also function as host recognition receptors for pathogen-associated molecular patterns (Dam and Brewer, 2010), has been reported in many arthropod vectors, including mosquitoes and tsetse flies, where they play an important role in the pathogen-host relationship (Abubakar et al, 1995, 2006; Barreau et al, 1995; James, 2003). While lectins can function as signaling factors for the maturation of the African trypanosome or as lytic factors (Abubakar et al, 1995, 2006), in mosquitoes they act as agonists of the development of malarial parasites within the vector (Barreau et al, 1995; James, 2003) While tick lectins, particularly those in hard ticks ( Ixodidae ), have not been studied as extensively as other arthropod lectins, previous reviews summarized available information on lectins of I. ricinus (Grubhoffer and Jindrak, 1998; Grubhoffer et al, 2004).…”

“…Agglutination of pathogens by lectins, which also function as host recognition receptors for pathogen-associated molecular patterns (Dam and Brewer, 2010), has been reported in many arthropod vectors, including mosquitoes and tsetse flies, where they play an important role in the pathogen-host relationship (Abubakar et al, 1995, 2006; Barreau et al, 1995; James, 2003). While lectins can function as signaling factors for the maturation of the African trypanosome or as lytic factors (Abubakar et al, 1995, 2006), in mosquitoes they act as agonists of the development of malarial parasites within the vector (Barreau et al, 1995; James, 2003) While tick lectins, particularly those in hard ticks ( Ixodidae ), have not been studied as extensively as other arthropod lectins, previous reviews summarized available information on lectins of I. ricinus (Grubhoffer and Jindrak, 1998; Grubhoffer et al, 2004). Since most lectins isolated from arthropods are the ones from the hemocoel, studies have focused on their localization or hemagglutinating activity in the hemolymph (Sonenshine, 1993; Kuhn et al, 1996).…”

Nutritional stress of adult female tsetse flies (Diptera: Glossinidae) affects the susceptibility of their offspring to trypanosomal infections

“…Other factors that are induced by starvation and that may affect the development of a trypanosomal infection in tsetse can, however, not be excluded. They include midgut lectins, anti-oxidants and symbiotic associations in tsetse (Abubakar et al, 2006;Munks et al, 2005;Macleod et al, 2007;Roditi and Lehane, 2008). Although these observations are based entirely on laboratory experiments, the outcome may contribute to a better understanding of the seasonal dynamics of trypanosomal infection rates in field populations of tsetse flies.…”