Differential activity on trypanosomatid parasites of a novel recombinant defensin type 1 from the insect Triatoma (Meccus) pallidipennis

Antimicrobial Peptides (AMPs): Potential Therapeutic Strategy against Trypanosomiases?

“…They are encoded by specific genes and expressed constitutively or in response to specific environmental stimuli [ 19 ]. In some insects, AMPs are key for vector–microorganism interaction and are effective against both quiescent and actively proliferating pathogenic organisms [ 20 , 21 , 22 ].…”

“…The antiparasitic activity of AMPs has also been evaluated on T. cruzi , using some peptides obtained from a variety of natural sources and others synthetically prepared [ 17 , 22 , 103 , 106 , 178 , 184 , 185 ] ( Figure 4 ).…”

“…AMPs obtained from various triatomine species, including some T. cruzi -transmitting vectors, have been shown to possess activity against this parasite. Some of these are involved in the defense response against infection and control of parasitemia in the vector [ 20 , 22 , 186 , 187 ] ( Figure 4 A). From the saliva of Triatoma infestans , the trialysin peptide was isolated, which has a cytotoxic activity against the infective (metacyclic trypomastigote (Tryp) and replicative (epimastigote (Epi)) insect stage of the T. cruzi Y strain (a BZN-resistant strain), through the formation of pores in the membrane [ 20 ] ( Figure 4 A.1).…”

“…From the saliva of Triatoma infestans , the trialysin peptide was isolated, which has a cytotoxic activity against the infective (metacyclic trypomastigote (Tryp) and replicative (epimastigote (Epi)) insect stage of the T. cruzi Y strain (a BZN-resistant strain), through the formation of pores in the membrane [ 20 ] ( Figure 4 A.1). In Triatoma (Meccus) pallidipennis , defensins 1.3 (Def1.3) have trypanocidal activity against the parasitic kinetoplastids, including the T. cruzi TBAR/MX/0000/Querétaro strain (Qro) , inducing morphological alterations, reduced viability and inhibited growth [ 22 ] ( Figure 4 A.2). It should be noted that the Qro isolate is a highly virulent parasite that under experimental conditions causes 100% mortality in mice.…”

“…This paratransgenic strategy could represent a novel alternative for control of vectorial transmission of T. cruzi , especially relevant because of the increasing resistance of vectors to insecticides [ 191 , 192 , 193 ]. All these AMPs isolated from insect vectors and their symbionts such as R. rhodnii exert their trypanocidal effect at micromolar concentrations; however, some of them, such as trialysin, are cytotoxic to host cells [ 20 , 22 , 186 , 187 , 190 ].…”