Chikungunya virus entry is strongly inhibited by phospholipase A2 isolated from the venom of Crotalus durissus terrificus

Abstract

Chikungunya virus (CHIKV) is the etiologic agent of Chikungunya fever, a globally spreading mosquito-borne disease. There is no approved antiviral or vaccine against CHIKV, highlighting an urgent need for novel therapies. In this context, snake venom proteins have demonstrated antiviral activity against several viruses, including arboviruses which are relevant to public health. In particular, the phospholipase A2CB (PLA2CB), a protein isolated from the venom of Crotalus durissus terrificus was previously shown to possess anti-inflammatory, antiparasitic, antibacterial and antiviral activities. In this study, we investigated the multiple effects of PLA2CB on the CHIKV replicative cycle in BHK-21 cells using CHIKV-nanoluc, a marker virus carrying nanoluciferase reporter. The results demonstrated that PLA2CB possess a strong anti-CHIKV activity with a selectivity index of 128. We identified that PLA2CB treatment protected cells against CHIKV infection, strongly impairing virus entry by reducing adsorption and post-attachment stages. Moreover, PLA2CB presented a modest yet significant activity towards post-entry stages of CHIKV replicative cycle. Molecular docking calculations indicated that PLA2CB may interact with CHIKV glycoproteins, mainly with E1 through hydrophobic interactions. In addition, infrared spectroscopy measurements indicated interactions of PLA2CB and CHIKV glycoproteins, corroborating with data from in silico analyses. Collectively, this data demonstrated the multiple antiviral effects of PLA2CB on the CHIKV replicative cycle, and suggest that PLA2CB interacts with CHIKV glycoproteins and that this interaction blocks binding of CHIKV virions to the host cells.

Snake venom phospholipase A2s exhibit strong virucidal activity against SARS-CoV-2 and inhibit the viral spike glycoprotein interaction with ACE2

“…Thus, these data show that AA released upon membrane lipid hydrolysis has the potential to contribute to the inhibitory action of PLA 2 s. Investigation of the stage(s) of the replication cycle affected by PLA 2 showed that stages "full-time" and "postentry" were efficiently inhibited by HDP-2 and stage "entry" was less influenced (although it should be noted that a few snake venom PLA 2 s can be internalized and exert effects inside cells [69,70]). Moderate inhibition of post-entry steps of Chikungunya virus infection was observed for phospholipase A2 CB from the venom of Crotalus durissus terrificus [33]. Using pseudotyped virus labelled with GFP we observed that in a "post-entry" experiment, HDP-2 inhibited the expression of GFP.…”

“…The PLA 2 s from snake venoms are in groups I and II [27]. Previous studies have shown that PLA 2 s have antiviral activity against a number of viruses including Dengue and Yellow fever viruses [28], HIV [29] Rous virus [30], adenovirus [31], Newcastle virus [32] and Chikungunya virus [33]. We, therefore, tested several snake venom PLA 2 s for antiviral activity against SARS-CoV-2.…”

Overview on Chikungunya Virus Infection: From Epidemiology to State-of-the-Art Experimental Models

“…BHK-21 and Vero-E6 cells are widely used in plaque assays for analysis of viral replication, screening of antiviral compounds, and evaluation of neutralizing antibodies (Franco et al, 2018;Lee et al, 2019;Noval et al, 2019;Sharma et al, 2019;de Oliveira et al, 2020;Tumkosit et al, 2020;Pereira et al, 2021). Using a BHK-21 cell model, Santos and colleagues analyzed the potential antiviral properties of the snake venom phospholipase A2 CB (PLA2 CB ) on CHIKV replication cycle and demonstrated that this molecule inhibits CHIKV entry process (Santos et al, 2021). Likewise, Singh and colleagues characterized two peptidomimetic compounds as CHIKV protease inhibitors in a BHK-21 cell model and were able to propose their mechanism of action on the replicative process (Singh H. et al, 2018).…”

Antiviral Effects of Animal Toxins: Is There a Way to Drugs?

“…The investigation of two recombinant PLA2-CB isoforms showed that they exerted virucidal effect on ZIKV and CHIKV as well as on DENV and YFV [ 34 ]. A more detailed study of native PLA2-CB activity against CHIKV was carried out using BHK-21 cells [ 35 ]. It was found that PLA2-CB strongly hinder the virus entry into the cell by reducing adsorption and post-attachment stages.…”

“…In addition, PLA2-CB manifested a noticeable activity at the post-entry stages of CHIKV replicative cycle. Spectroscopy measurements and docking calculations suggested PLA2-CB interaction with CHIKV glycoproteins, and this interaction may block the binding of CHIKV virions to the host cells [ 35 ].…”