The Exosome-like Vesicles of Giardia Assemblages A, B, and E Are Involved in the Delivering of Distinct Small RNA from Parasite to Parasite

Abstract

The genetically related assemblages of the intestinal protozoa parasite Giardia lamblia are morphologically indistinguishable and are often derived from specific hosts. The Giardia assemblages are separated by large genetic distances, which might account for their relevant biological and pathogenic differences. In this work, we analyzed the RNAs cargo released into exosomal-like vesicles (ElVs) by the assemblages A and B, which differentially infect humans, and the assemblage E, which infects hoofed animals. The RNA sequencing analysis revealed that the ElVs of each assemblage contained distinct small RNA (sRNA) biotypes, suggesting a preference for specific packaging in each assemblage. These sRNAs were classified into three categories, ribosomal-small RNAs (rsRNAs), messenger-small RNAs (msRNAs), and transfer-small RNAs (tsRNAs), which may play a regulatory role in parasite communication and contribute to host-specificity and pathogenesis. Uptake experiments showed, for the first time, that ElVs were successfully internalized by the parasite trophozoites. Furthermore, we observed that the sRNAs contained inside these ElVs were first located below the plasma membrane but then distributed along the cytoplasm. Overall, the study provides new insights into the molecular mechanisms underlying the host-specificity and pathogenesis of G. lamblia and highlights the potential role of sRNAs in parasite communication and regulation.

Starvation induces changes in abundance and small RNA cargo of extracellular vesicles released from Plasmodium falciparum infected red blood cells

“…This could suggest that the packing of these potentially gene regulatory tRNAs in EVs is a conserved mechanism among protozoans. In addition, our study revealed Gly GCC , His GTG , Glu CTC/TTC and Pro AGG to be the most dominant tRNA fragments, which is similar to the observations in other protozoans where Gly and Glu tRNA fragments were among the most abundant 62 – 64 . Transcriptomic studies of EVs from different protozoans also suggest that the RNA cargo of EVs is independent of the transcriptomic profiles of the cells from which the EVs originate 17 , 62 , 63 .…”

“…Studies on the transcriptomic cargo of EVs released from other protozoan parasites such as Leishmania spp. 62 , Trypanosoma cruzi 63 and Giardia intestinalis 64 have similarly demonstrated that tRNA fragments are a dominant biotype. This could suggest that the packing of these potentially gene regulatory tRNAs in EVs is a conserved mechanism among protozoans.…”

A thermo‐resistant and RNase‐sensitive cargo from Giardia duodenalis extracellular vesicles modifies the behaviour of enterobacteria

“…Using state-of-the-art methodologies, including nanoparticles track analysis (NTA) and transmission electron microscopy (TEM), our first goal was to characterize the morphology of Giardia EVs. Our findings suggest that G. duodenalis isolate NF trophozoites secrete lipid bilayer-coated large vesicles (200-270 nm; macrovesicles-like particles) which are slightly larger than previously observed EVs from other Giardia isolates (Gavinho et al, 2020;Moyano et al, 2019;Natali et al, 2023). We then assessed whether EV production is altered upon exposure to chemical stimuli.…”

“…The present studies examined whether extracellular vesicles (EVs) released by G. duodenalis may mediate pathogenic effects on commensal bacteria using E. coli and E. cloacae TW1 as target models, both well‐recognized opportunistic pathogens of the gut microbiota. Recent studies have examined the biogenesis of G. duodenalis EVs and their role in modulating various aspects of host‐parasite interactions (Evans‐Osses et al., 2017; Gavinho et al., 2020; Moyano et al., 2019; Natali et al., 2023; Zhao et al., 2021). However, the role of EVs in parasite‐microbiota interactions has yet to be explored.…”

Extracellular Vesicles and Their Impact on the Biology of Protozoan Parasites

“…A more recent study characterized the RNA content of the vesicles secreted by Giardia duodenalis [ 38 ]. The vesicles were found to be similar in size, shape, and protein and lipid composition to those described for exosomes from other eukaryotic cells and were therefore called “exosomal-like vesicles (ElVs)”.…”