Snakes of the Philodryadini tribe are included in the Dipsadidae family, which is a diverse group of rear-fanged snakes widespread in different ecological conditions, including habitats and diet. However, little is known about the composition and effects of their venoms despite their relevance for understanding the evolution of these snakes or even their impact on the occasional cases of human envenoming. In this study, we integrated venom gland transcriptomics, venom proteomics and functional assays to characterize the venoms from eight species of the Philodryadini tribe, which includes the genus Philodryas, Chlorosoma and Xenoxybelis. The most abundant components identified in the venoms were snake venom metalloproteinases (SVMPs), cysteine-rich secretory proteins (CRISPs), C-type lectins (CTLs), snake endogenous matrix metalloproteinases type 9 (seMMP-9) and snake venom serinoproteinases (SVSPs). These protein families showed a variable expression profile in each genus. SVMPs were the most abundant components in Philodryas, while seMMP-9 and CRISPs were the most expressed in Chlorosoma and Xenoxybelis, respectively. Lineage-specific differences in venom composition were also observed among Philodryas species, whereas P. olfersii presented the highest amount of SVSPs and P. agassizii was the only species to express significant amounts of 3FTx. The variability observed in venom composition was confirmed by the venom functional assays. Philodryas species presented the highest SVMP activity, whereas Chlorosoma species showed higher levels of gelatin activity, which may correlate to the seMMP-9 enzymes. The variability observed in the composition of these venoms may be related to the tribe phylogeny and influenced by their diets. In the presented study, we expanded the set of venomics studies of the Philodryadini tribe, which paves new roads for further studies on the evolution and ecology of Dipsadidae snakes.

Toxoplasmosis is an alarming public health problem that affects more than one-third of the world’s population. In our work, we investigated the antiparasitic effects of catalytically active [BpMP-I and Jararhagin (Jar)] and catalytically inactive [Jararhagin-C (Jar-C)] snake venom metalloproteinases (SVMPs) in human HeLa cells. These toxins impaired the parasite invasion and intracellular growth, and modulated IL-6, IL-8, and MIF cytokines that control the cell susceptibility and response against T. gondii. Furthermore, we verified that the antiprotozoal activities are not restricted to the presence of the proteolytic domain, and the adhesive domains participate in the control of T. gondii infection. Also, by analyzing the structures of Jar and Jar-C through molecular modeling and dynamics, we observed that the adhesive domains in Jar-C are more exposed due to the absence of the proteolytic domain, which could favor the interaction with different targets. Our investigation on the role of SVMP domains in combating T. gondii infection highlights their potential application as biotechnological tools for creating more effective treatments for toxoplasmosis.

Peptidases constitute at least 2% of genes in living organisms and participate in nearly all physiological processes across life forms. Conversely, peptidase inhibitors are essential for regulating proteolytic activity and have been widely applied. Combining high-throughput sequencing of novel peptidase inhibitor sources with molecular modeling and drug design currently represents an efficient strategy for developing new molecules. Venomous spiders harbor a wide array of peptidase inhibitors in both their venom and digestive system. However, biochemical and transcriptomic investigations of non-venomous spiders (Uloboridae) remain recent and scarce. Here, transcriptomic and biochemical analyses of the Uloboridae spider Zosis geniculata’s digestive midgut diverticula (MD) revealed that this species exhibited a digestive enzyme profile similar to that of other spiders. Furthermore, the MD transcriptome identified 19 peptidase inhibitors belonging to six inhibitor families. Serine peptidase inhibitors were the most abundant and diverse, while metallopeptidases represented the main proteolytic enzymes, suggesting that these inhibitors may have evolved to counteract prey-derived peptidases. Inhibitory assays using trypsin from potential insect prey confirmed this activity. The diversity and abundance of these molecules highlight Uloboridae spiders as promising novel sources of proteolytic inhibitors.

Brazil is the most hyperendemic country for dengue, with historically dominant circulation of DENV-1 and DENV-2. Bayesian phylodynamic analyses of 489 Brazilian DENV-3 genomes, including 84 newly generated sequences, reveal a recent and sustained increase in the effective population size of DENV-3 associated with the recent introduction and expansion of the 3III_B.3.2 lineage. This increase coincides with a sharp rise in the proportion of laboratory-confirmed dengue cases attributed to DENV-3 among records with available serotype information from 2024 onwards and a shift in serotype dynamics in 2025, suggesting a change in serotype distribution and a potential risk of renewed DENV-3 outbreaks, particularly in populations with limited prior exposure to this serotype.