Thioester‐containing proteins in the tsetse fly (Glossina) and their response to trypanosome infection

Abstract

Thioester‐containing proteins (TEPs) are conserved proteins with a role in innate immune immunity. In the current study, we characterized the TEP family in the genome of six tsetse fly species (Glossina spp.). Tsetse flies are the biological vectors of several African trypanosomes, which cause sleeping sickness in humans or nagana in livestock. The analysis of the tsetse TEP sequences revealed information about their structure, evolutionary relationships and expression profiles under both normal and trypanosome infection conditions. Phylogenetic analysis of the family showed that tsetse flies harbour a genomic expansion of specific TEPs that are not found in other dipterans. We found a general expression of all TEP genes in the alimentary tract, mouthparts and salivary glands. Glossina morsitans and Glossina palpalis TEP genes display a tissue‐specific expression pattern with some that are markedly up‐regulated when the fly is infected with the trypanosome parasite. A different TEP response was observed to infection with Trypanosoma brucei compared to Trypanosoma congolense, indicating that the tsetse TEP response is trypanosome‐specific. These findings are suggestive for the involvement of the TEP family in tsetse innate immunity, with a possible role in the control of the trypanosome parasite.

A New Assessment of Thioester-Containing Proteins Diversity of the Freshwater Snail Biomphalaria glabrata

“…BgTEP3 harbors a single nucleotide mutation in this site leading to the replacement of the cysteine residue to a serine residue, but the Gln-moiety of the thioester is preserved. Such replacement of the cysteine residue by a serine was also reported for tsetse fly TEP2, an iTEP of which the expression is particularly up-regulated in the salivary gland following Trypanosoma brucei infection [69]. The replacement of cysteine residue in the thioester site was also evidenced for chicken ovostatin [70], without alteration of its proteinase-inhibitor activity [71].…”

“…Genes 2020, 11, 69 6 of 16 transcripts corresponding to incomplete BgC3-2 cDNA was previously identified from the B. glabrata genome publication [49]. BgA2M also clustered with the A2M members from other mollusks.…”

Wolbachia‐induced expression of kenny gene in testes affects male fertility in Drosophila melanogaster

“…Some genes have been demonstrated to have functions in both immunity and reproduction in various animals (Li et al, 2001;Loongyai et al, 2007;Cao et al, 2010;Pompon & Levashina, 2015). For example, thioestercontaining protein 1 (TEP1) is a critical immune factor that mediates insect resistance to a wide range of pathogens (Oliveira et al, 2012;Matetovici & van Den Abbeele, 2018). However, it was reported that TEP1 had a new role in male fertility in the mosquito Anopheles gambiae through binding to, and removal of the aberrant sperm to preserve high fertility rates (Pompon & Levashina, 2015).…”

The immune and circulatory systems are functionally integrated across insect evolution

“…Thioester-containing complement-like proteins and Nimrod family proteins are immune factors that influence the migration of hemocytes to the heart of mosquitoes and fruit flies ( 11 , 12 , 16 , 30 ). Both of these protein families are encoded in the genomes of diverse insects ( 31 , 32 ), so their roles in heart-associated responses likely extend beyond Diptera. In addition, a collagen protein that is part of the cardiac extracellular matrix, called Pericardin, facilitates the aggregation of hemocytes on the heart of fruit flies ( 13 ).…”