Abstract
Chagas disease remains a serious health problem for countries where the most common mode of transmission is infection contracted from the feces of a Triatominae insect vector. In México, 32 species of Triatoma have been identified; amongst them, Triatoma (Meccus) pallidipennis is an endemic species reported to have high percentages of infection with T. cruzi. Defensins, cysteine-rich cationic peptides, are a family of antimicrobial peptides (AMPs); the synthesis of these molecules is crucial for insect’s immune defense. In the present study, the genes encoding defensins in T. pallidipennis were sequenced with the purpose of identifying the variability of these genes in a Mexican vector of T. cruzi. We found 12 different genes encoding three mature peptides, all of which had the typical folding of a functional insect defensin. In this work two Defensins type 1 and one type 4 were identified. The pro-peptide domain was highly variable and the mature peptide was not. This is the first report focus on variability of defensins from an epidemiologically important Triatoma in Mexico.
Highlights
Chagas disease, one of the neglected tropical diseases, is caused by the protozoan Trypanosoma cruzi, the main transmission is through the feces of hematophagous insects of the Triatominae subfamily (Hemiptera: Reduviidae)
Most antimicrobial peptide (AMP) are synthesized as inactive precursor proteins or propeptides, and active peptides or mature peptides are generated by proteolysis; these molecules have a broad spectrum of targetted organisms ranging from viruses to parasites and are produced by several species other than insects, including species of bacteria, plants, and vertebrates [5,6]
The sequences obtained from the amplicons generated with the Def3 oligos are more homogeneous; 3.1 and 3.4 have the same sequence, and in all the sequences, the intron begins at position 89 and ends at position 186
Summary
One of the neglected tropical diseases, is caused by the protozoan Trypanosoma cruzi, the main transmission is through the feces of hematophagous insects of the Triatominae subfamily (Hemiptera: Reduviidae). Ramsey et al (2015) [2] reported 31 different species in the country, including the endemic Triatoma (Meccus) pallidipennis (T. pallidipennis) that forms part of the Phyllosoma complex and colonizes extensive areas in the center of the country, living in domestic and peridomestic environments and more importantly with a natural infection index of 50% in some regions [3,4]. Humoral immunity consists of the generation of prophenoloxidase (PPO), hemolymph coagulation cascades, reactive oxygen species (ROS), reactive nitrogen species (RNS), and antimicrobial peptides (AMPs). Most AMPs are synthesized as inactive precursor proteins or propeptides, and active peptides or mature peptides are generated by proteolysis; these molecules have a broad spectrum of targetted organisms ranging from viruses to parasites and are produced by several species other than insects, including species of bacteria, plants, and vertebrates [5,6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
