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Baudou FG, Gutiérrez JM, Rodríguez JP. Immune response to neurotoxic South American snake venoms. Toxicon 2023; 234:107300. [PMID: 37757959 DOI: 10.1016/j.toxicon.2023.107300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 09/29/2023]
Abstract
South American rattlesnakes (Crotalus durissus spp) and coral snakes (Micrurus sp) venoms are characterized by inducing a limited inflammatory innate immune response, in contrast to Bothrops sp snake venoms which exert a prominent inflammatory activity. Some Crotalus durissus spp venoms, in addition, exert immunosuppressive activities that hamper the development of neutralizing antibodies in animals immunized for antivenom production. Micrurus sp venoms are rich in low molecular mass neurotoxins that elicit a limited immune response. These characteristics make it difficult to generate antivenoms of high neutralizing activity. Therefore, the study of the mechanisms operating behind this limited immune response to venoms is relevant from both fundamental and practical perspectives. This review summarizes key aspects of the immune response to these venoms and discusses some pending challenges to further understand these phenomena and to improve antivenom production.
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Affiliation(s)
- Federico G Baudou
- Universidad Nacional de Luján (UNLu), Depto. de Ciencias Básicas, Luján, Buenos Aires, Argentina; Grupo de Investigaciones Básicas y Aplicadas en Inmunología y Bioactivos (GIBAIB), Instituto de Ecología y Desarrollo Sustentable (INEDES), UNLu-CONICET, Luján, Buenos Aires, Argentina.
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Juan Pablo Rodríguez
- Laboratorio de Investigaciones Bioquímicas de la Facultad de Medicina (LIBIM), Instituto de Química Básica y Aplicada del Nordeste Argentino (IQUIBA-NEA), Universidad Nacional del Nordeste, Consejo Nacional de Investigaciones Científicas y Técnicas (UNNE-CONICET), Corrientes, Argentina
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2
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Ratanabanangkoon K. Polyvalent Snake Antivenoms: Production Strategy and Their Therapeutic Benefits. Toxins (Basel) 2023; 15:517. [PMID: 37755943 PMCID: PMC10536913 DOI: 10.3390/toxins15090517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023] Open
Abstract
Snake envenomation remains an important yet neglected medical problem in many countries, with around five million people affected, and over a hundred thousand deaths annually. Plasma-derived antivenoms are the main therapeutic agent available. Monovalent antivenoms are produced via the immunization of large animals, e.g., horses, with one venom, after which the horse serum can neutralize the homologous venom, with minimal or no cross neutralization against other venoms. It is necessary, therefore, for the culprit snake to be identified, so that the appropriate specific antivenom can be selected. Polyvalent antivenoms (pAVs) are produced via immunization with a number of snake venoms, and the serum can neutralize all the venoms used in its production. Thus, pAVs can be used to treat several venoms from a country/region, and the identification of the culprit snake is not necessary. There are various parameters and processes involved in the production of pAVs, depending on the requirements and resources available. Most commercial pAVs use a mixture of both elapid and viperid venoms as immunogens, while some pAVs use either elapid or viperid venoms. Some pAVs are produced through the mixing of more than one monovalent or polyvalent antivenom. These various types of pAVs have their own characteristics, and have benefits and drawbacks. The major benefits of pAVs are the wide coverage of many medically important venoms, including many heterologous venoms. They also remove the need to identify the culprit snake, and they can be produced at a lower cost than several monovalent antivenoms. Interesting polyvalent antivenoms, termed 'syndromic pAVs' (s-pAVs), have recently gained attention. They are produced for use according to the syndromes manifested in snakebite patients. The venoms that produce these syndromes are used as immunogens in the production of 'syndromic antivenoms'. For example, 'neurotoxic polyvalent antivenom' and 'hematotoxic polyvalent antivenom' are produced using the neurotoxic elapid and hematotoxic viperid venoms as immunogens, respectively. They were first marketed by the Thai Red Cross in 2012, and have since gained attention as a possible therapeutic modality to help solve the problem of snakebite envenomation globally. The merits of these s-pAVs, including their efficacy and wide paraspecificities, are discussed.
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Affiliation(s)
- Kavi Ratanabanangkoon
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
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3
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Chan YW, Tan CH, Heh CH, Tan KY. An immunoinformatic approach to assessing the immunogenic capacity of alpha-neurotoxins in elapid snake venoms. Front Pharmacol 2023; 14:1143437. [PMID: 37153801 PMCID: PMC10155835 DOI: 10.3389/fphar.2023.1143437] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/27/2023] [Indexed: 05/10/2023] Open
Abstract
Introduction: Most elapid snakes produce venoms that contain alpha-neurotoxins (α-NTXs), which are proteins that cause post-synaptic blockade and paralysis in snakebite envenoming. However, existing elapid antivenoms are known for their low potency in neutralizing the neurotoxic activity of α-NTXs, while the immunological basis has not been elucidated. Methods: In this study, a structure-based major histocompatibility complex II (MHCII) epitope predictor of horse (Equus caballus), complemented with DM-editing determinant screening algorithm was adopted to assess the immunogenicity of α-NTXs in the venoms of major Asiatic elapids (Naja kaouthia, Ophiophagus hannah, Laticauda colubrina, Hydrophis schistosus, Hydrophis curtus). Results: The scoring metric M2R, representing the relative immunogenic performance of respective α-NTXs, showed all α-NTXs have an overall low M2R of <0.3, and most of the predicted binders feature non-optimal P1 anchor residues. The M2R scores correlate strongly (R2 = 0.82) with the potency scores (p-score) generated based on the relative abundances of α-NTXs and the neutralization potency of commercial antivenoms. Discussion: The immunoinformatic analysis indicates that the inferior antigenicity of α-NTXs is not only due to their small molecular size but also the subpar immunogenicity affected by their amino acid composition. Structural modification with conjugation and synthetic epitope as immunogen may potentially enhance the immunogenicity for improved antivenom potency against α-NTXs of elapid snakes.
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Affiliation(s)
- Yi Wei Chan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Choon Han Heh
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Malaya, Kuala Lumpur, Malaysia
| | - Kae Yi Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- *Correspondence: Kae Yi Tan,
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4
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Tan CH, Wong KY, Huang LK, Tan KY, Tan NH, Wu WG. Snake Venomics and Antivenomics of Cape Cobra ( Naja nivea) from South Africa: Insights into Venom Toxicity and Cross-Neutralization Activity. Toxins (Basel) 2022; 14:toxins14120860. [PMID: 36548757 PMCID: PMC9783313 DOI: 10.3390/toxins14120860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/24/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022] Open
Abstract
Naja nivea (Cape Cobra) is endemic to southern Africa. Envenoming by N. nivea is neurotoxic, resulting in fatal paralysis. Its venom composition, however, has not been studied in depth, and specific antivenoms against it remain limited in supply. Applying a protein decomplexation approach, this study unveiled the venom proteome of N. nivea from South Africa. The major components in the venom are cytotoxins/cardiotoxins (~75.6% of total venom proteins) and alpha-neurotoxins (~7.4%), which belong to the three-finger toxin family. Intriguingly, phospholipase A2 (PLA2) was undetected-this is a unique venom phenotype increasingly recognized in the African cobras of the Uraeus subgenus. The work further showed that VINS African Polyvalent Antivenom (VAPAV) exhibited cross-reactivity toward the venom and immunorecognized its toxin fractions. In mice, VAPAV was moderately efficacious in cross-neutralizing the venom lethality with a potency of 0.51 mg/mL (amount of venom completely neutralized per milliliter of antivenom). In the challenge-rescue model, VAPAV prevented death in 75% of experimentally envenomed mice, with slow recovery from neurotoxicity up to 24 h. The finding suggests the potential para-specific utility of VAPAV for N. nivea envenoming, although a higher dose or repeated administration of the antivenom may be required to fully reverse the neurotoxic effect of the venom.
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Affiliation(s)
- Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
- Institute of Bioinformatics and Structural Biology, Department of Life Science, National Tsing Hua University, Hsinchu 300044, Taiwan
- Correspondence: or
| | - Kin Ying Wong
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
- Institute of Bioinformatics and Structural Biology, Department of Life Science, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - Li-Kun Huang
- Institute of Bioinformatics and Structural Biology, Department of Life Science, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - Kae Yi Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Nget Hong Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Wen-Guey Wu
- Institute of Bioinformatics and Structural Biology, Department of Life Science, National Tsing Hua University, Hsinchu 300044, Taiwan
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Meléndez-Zempoalteca A, Juárez-González VR, Rudiño-Piñera E, Pastor N, Vargas-Jaimes L, Valcarcel-Gamiño JA, Vázquez-Vuelvas OF, Quintero-Hernández V, Valdez-Velázquez LL. Antivenom Derived from the Ct1a and Ct17 Recombinant Toxins of the Scorpion Centruroides tecomanus. Int J Pept Res Ther 2022. [DOI: 10.1007/s10989-022-10439-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Tan CH, Tan KY, Wong KY, Tan NH, Chong HP. Equatorial Spitting Cobra ( Naja sumatrana) from Malaysia (Negeri Sembilan and Penang), Southern Thailand, and Sumatra: Comparative Venom Proteomics, Immunoreactivity and Cross-Neutralization by Antivenom. Toxins (Basel) 2022; 14:toxins14080522. [PMID: 36006183 PMCID: PMC9414237 DOI: 10.3390/toxins14080522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 11/23/2022] Open
Abstract
The Equatorial Spitting Cobra (Naja sumatrana) is a medically important venomous snake species in Southeast Asia. Its wide geographical distribution implies potential intra-specific venom variation, while there is no species-specific antivenom available to treat its envenoming. Applying a protein-decomplexing proteomic approach, the study showed that three-finger toxins (3FTX), followed by phospholipases A2 (PLA2), were the major proteins well-conserved across N. sumatrana venoms of different locales. Variations were noted in the subtypes and relative abundances of venom proteins. Of note, alpha-neurotoxins (belonging to 3FTX) are the least in the Penang specimen (Ns-PG, 5.41% of total venom proteins), compared with geographical specimens from Negeri Sembilan (Ns-NS, 14.84%), southern Thailand (Ns-TH, 16.05%) and Sumatra (Ns-SU, 10.81%). The alpha-neurotoxin abundance, in general, correlates with the venom’s lethal potency. The Thai Naja kaouthia Monovalent Antivenom (NkMAV) was found to be immunoreactive toward the N. sumatrana venoms and is capable of cross-neutralizing N. sumatrana venom lethality to varying degrees (potency = 0.49–0.92 mg/mL, interpreted as the amount of venom completely neutralized per milliliter of antivenom). The potency was lowest against NS-SU venom, implying variable antigenicity of its lethal alpha-neurotoxins. Together, the findings suggest the para-specific and geographical utility of NkMAV as treatment for N. sumatrana envenoming in Southeast Asia.
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Affiliation(s)
- Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.W.); (H.P.C.)
- Correspondence: or
| | - Kae Yi Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.T.); (N.H.T.)
| | - Kin Ying Wong
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.W.); (H.P.C.)
| | - Nget Hong Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.T.); (N.H.T.)
| | - Ho Phin Chong
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.W.); (H.P.C.)
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7
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Virus-like particles displaying conserved toxin epitopes stimulate polyspecific, murine antibody responses capable of snake venom recognition. Sci Rep 2022; 12:11328. [PMID: 35790745 PMCID: PMC9256628 DOI: 10.1038/s41598-022-13376-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 05/24/2022] [Indexed: 11/14/2022] Open
Abstract
Antivenom is currently the first-choice treatment for snakebite envenoming. However, only a low proportion of antivenom immunoglobulins are specific to venom toxins, resulting in poor dose efficacy and potency. We sought to investigate whether linear venom epitopes displayed on virus like particles can stimulate an antibody response capable of recognising venom toxins from diverse medically important species. Bioinformatically-designed epitopes, corresponding to predicted conserved regions of group I phospholipase A2 and three finger toxins, were engineered for display on the surface of hepatitis B core antigen virus like particles and used to immunise female CD1 mice over a 14 weeks. Antibody responses to all venom epitope virus like particles were detectable by ELISA by the end of the immunisation period, although total antibody and epitope specific antibody titres were variable against the different epitope immunogens. Immunoblots using pooled sera demonstrated recognition of various venom components in a diverse panel of six elapid venoms, representing three continents and four genera. Insufficient antibody yields precluded a thorough assessment of the neutralising ability of the generated antibodies, however we were able to test polyclonal anti-PLA2 IgG from three animals against the PLA2 activity of Naja nigricollis venom, all of which showed no neutralising ability. This study demonstrates proof-of-principle that virus like particles engineered to display conserved toxin linear epitopes can elicit specific antibody responses in mice which are able to recognise a geographically broad range of elapid venoms.
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8
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Chong HP, Tan KY, Liu BS, Sung WC, Tan CH. Cytotoxicity of Venoms and Cytotoxins from Asiatic Cobras (Naja kaouthia, Naja sumatrana, Naja atra) and Neutralization by Antivenoms from Thailand, Vietnam, and Taiwan. Toxins (Basel) 2022; 14:toxins14050334. [PMID: 35622581 PMCID: PMC9144634 DOI: 10.3390/toxins14050334] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 02/04/2023] Open
Abstract
Envenoming by cobras (Naja spp.) often results in extensive local tissue necrosis when optimal treatment with antivenom is not available. This study investigated the cytotoxicity of venoms and purified cytotoxins from the Monocled Cobra (Naja kaouthia), Taiwan Cobra (Naja atra), and Equatorial Spitting Cobra (Naja sumatrana) in a mouse fibroblast cell line, followed by neutralization of the cytotoxicity by three regional antivenoms: the Thai Naja kaouthia monovalent antivenom (NkMAV), Vietnamese snake antivenom (SAV) and Taiwanese Neuro bivalent antivenom (NBAV). The cytotoxins of N. atra (NA-CTX) and N. sumatrana (NS-CTX) were identified as P-type cytotoxins, whereas that of N. kaouthia (NK-CTX) is S-type. All venoms and purified cytotoxins demonstrated varying concentration-dependent cytotoxicity in the following trend: highest for N. atra, followed by N. sumatrana and N. kaouthia. The antivenoms moderately neutralized the cytotoxicity of N. kaouthia venom but were weak against N. atra and N. sumatrana venom cytotoxicity. The neutralization potencies of the antivenoms against the cytotoxins were varied and generally low across NA-CTX, NS-CTX, and NK-CTX, possibly attributed to limited antigenicity of CTXs and/or different formulation of antivenom products. The study underscores the need for antivenom improvement and/or new therapies in treating local tissue toxicity caused by cobra envenomings.
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Affiliation(s)
- Ho Phin Chong
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | - Kae Yi Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | - Bing-Sin Liu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli 35053, Taiwan;
| | - Wang-Chou Sung
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli 35053, Taiwan;
- Correspondence: (W.-C.S.); (C.H.T.)
| | - Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
- Correspondence: (W.-C.S.); (C.H.T.)
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9
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Pruksaphon K, Yuvaniyama J, Ratanabanangkoon K. Immunogenicity of snake α-neurotoxins and the CD4 T cell epitopes. Toxicon 2022; 214:136-144. [DOI: 10.1016/j.toxicon.2022.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/22/2022] [Accepted: 05/17/2022] [Indexed: 11/26/2022]
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10
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Lian Q, Zhang D, Fu K, Liu C, Cao L, Xiong K, Huang C. The molecular basis of venom resistance in the non-venomous snake Sinonatrix annularis. J Chromatogr B Analyt Technol Biomed Life Sci 2022; 1195:123182. [DOI: 10.1016/j.jchromb.2022.123182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 02/12/2022] [Accepted: 02/15/2022] [Indexed: 12/22/2022]
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11
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Snake Venomics: Fundamentals, Recent Updates, and a Look to the Next Decade. Toxins (Basel) 2022; 14:toxins14040247. [PMID: 35448856 PMCID: PMC9028316 DOI: 10.3390/toxins14040247] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 01/11/2023] Open
Abstract
Venomic research, powered by techniques adapted from proteomics, transcriptomics, and genomics, seeks to unravel the diversity and complexity of venom through which knowledge can be applied in the treatment of envenoming, biodiscovery, and conservation. Snake venom proteomics is most extensively studied, but the methods varied widely, creating a massive amount of information which complicates data comparison and interpretation. Advancement in mass spectrometry technology, accompanied by growing databases and sophisticated bioinformatic tools, has overcome earlier limitations of protein identification. The progress, however, remains challenged by limited accessibility to samples, non-standardized quantitative methods, and biased interpretation of -omic data. Next-generation sequencing (NGS) technologies enable high-throughput venom-gland transcriptomics and genomics, complementing venom proteomics by providing deeper insights into the structural diversity, differential expression, regulation and functional interaction of the toxin genes. Venomic tissue sampling is, however, difficult due to strict regulations on wildlife use and transfer of biological materials in some countries. Limited resources for techniques and funding are among other pertinent issues that impede the progress of venomics, particularly in less developed regions and for neglected species. Genuine collaboration between international researchers, due recognition of regional experts by global organizations (e.g., WHO), and improved distribution of research support, should be embraced.
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12
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Varespladib (LY315920) rescued mice from fatal neurotoxicity caused by venoms of five major Asiatic kraits (Bungarus spp.) in an experimental envenoming and rescue model. Acta Trop 2022; 227:106289. [PMID: 34929179 DOI: 10.1016/j.actatropica.2021.106289] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 11/23/2022]
Abstract
The venoms of Asiatic kraits (Bungarus spp.) contain various neurotoxic phospholipases A2 (beta-bungarotoxins) which can irreversibly damage motor nerve terminals, resulting in rapidly fatal suffocation by respiratory muscle paralysis or oral airway obstruction. Hence, there is a need of adjunct therapy at the pre-hospital stage to prevent or delay the onset of neurotoxicity, so that antivenom can be given within golden hour before the envenoming becomes antivenom-resistant. This study investigated the efficacy of varespladib, a small molecule PLA2 (phospholipase A2) inhibitor, given as a bolus subcutaneously upon the onset of krait venom-induced paralysis in a mouse experimental envenoming and rescue model, where the severity of neurotoxicity was scored and the survival rate was monitored over 24 h. Varespladib at 10 mg/kg effectively alleviated the neurotoxicity of Bungarus sindanus, Bungarus multicinctus and Bungarus fasciatus venoms, and rescued all mice from venom-induced lethality (100% survival). Varespladib at this dose, however, only partially reduced the neurotoxicity of Bungarus caeruleus and Bungarus candidus venoms, while all challenged mice were dead by 23 h (B. caeruleus) and 12 h (B. candidus). An increased dose of varespladib at 20 mg/kg markedly abated the venom neurotoxicity past 8 h of envenoming, and protected the mice from venom lethality (B. caeruleus: 75% survival; B. candidus: 100% survival). The finding is consistent with previous studies which demonstrated varespladib's inhibitory effect against some snake venoms. The findings suggest varespladib could be repurposed as an emergency drug for prevention or rescue (if given early enough) from the acute, neurotoxic envenoming syndromes caused by various major krait species in Asia.
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13
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Palasuberniam P, Chan YW, Tan KY, Tan CH. Snake Venom Proteomics of Samar Cobra (Naja samarensis) from the Southern Philippines: Short Alpha-Neurotoxins as the Dominant Lethal Component Weakly Cross-Neutralized by the Philippine Cobra Antivenom. Front Pharmacol 2022; 12:727756. [PMID: 35002690 PMCID: PMC8740184 DOI: 10.3389/fphar.2021.727756] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 11/24/2021] [Indexed: 11/16/2022] Open
Abstract
The Samar Cobra, Naja samarensis, is endemic to the southern Philippines and is a WHO-listed Category 1 venomous snake species of medical importance. Envenomation caused by N. samarensis results in neurotoxicity, while there is no species-specific antivenom available for its treatment. The composition and neutralization of N. samarensis venom remain largely unknown to date. This study thus aimed to investigate the venom proteome of N. samarensis for a comprehensive profiling of the venom composition, and to examine the immunorecognition as well as neutralization of its toxins by a hetero-specific antivenom. Applying C18 reverse-phase high-performance liquid chromatography (RP-HPLC) and tandem mass spectrometry (LC-MS/MS), three-finger toxins (3FTx) were shown to dominate the venom proteome by 90.48% of total venom proteins. Other proteins in the venom comprised snake venom metalloproteinases, phospholipases A2, cysteine-rich secretory proteins, venom nerve growth factors, L-amino acid oxidases and vespryn, which were present at much lower abundances. Among all, short-chain alpha-neurotoxins (SαNTX) were the most highly expressed toxin within 3FTx family, constituting 65.87% of the total venom proteins. The SαNTX is the sole neurotoxic component of the venom and has an intravenous median lethal dose (LD50) of 0.18 μg/g in mice. The high abundance and low LD50 support the potent lethal activity of N. samarensis venom. The hetero-specific antivenom, Philippine Cobra Antivenom (PCAV, raised against Naja philippinensis) were immunoreactive toward the venom and its protein fractions, including the principal SαNTX. In efficacy study, PCAV was able to cross-neutralize the lethality of SαNTX albeit the effect was weak with a low potency of 0.20 mg/ml (defined as the amount of toxin completely neutralized per milliliter of the antivenom). With a volume of 5 ml, each vial of PCAV may cross-neutralize approximately 1 mg of the toxin in vivo. The findings support the potential para-specific use of PCAV in treating envenomation caused by N. samarensis while underscoring the need to improve the potency of its neutralization activity, especially against the highly lethal alpha-neurotoxins.
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Affiliation(s)
- Praneetha Palasuberniam
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Yi Wei Chan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kae Yi Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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14
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Malhotra A, Wüster W, Owens JB, Hodges CW, Jesudasan A, Ch G, Kartik A, Christopher P, Louies J, Naik H, Santra V, Kuttalam SR, Attre S, Sasa M, Bravo-Vega C, Murray KA. Promoting co-existence between humans and venomous snakes through increasing the herpetological knowledge base. Toxicon X 2021; 12:100081. [PMID: 34522881 PMCID: PMC8426276 DOI: 10.1016/j.toxcx.2021.100081] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 11/23/2022] Open
Abstract
Snakebite incidence at least partly depends on the biology of the snakes involved. However, studies of snake biology have been largely neglected in favour of anthropic factors, with the exception of taxonomy, which has been recognised for some decades to affect the design of antivenoms. Despite this, within-species venom variation and the unpredictability of the correlation with antivenom cross-reactivity has continued to be problematic. Meanwhile, other aspects of snake biology, including behaviour, spatial ecology and activity patterns, distribution, and population demography, which can contribute to snakebite mitigation and prevention, remain underfunded and understudied. Here, we review the literature relevant to these aspects of snakebite and illustrate how demographic, spatial, and behavioural studies can improve our understanding of why snakebites occur and provide evidence for prevention strategies. We identify the large gaps that remain to be filled and urge that, in the future, data and relevant metadata be shared openly via public data repositories so that studies can be properly replicated and data used in future meta-analyses.
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Affiliation(s)
- Anita Malhotra
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
| | - Wolfgang Wüster
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
| | - John Benjamin Owens
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
- Captive & Field Herpetology Ltd, Wales, 13 Hirfron, Holyhead, Llaingoch, Anglesey, LL65 1YU, UK
| | - Cameron Wesley Hodges
- School of Biology, Institute of Science, Suranaree University of Technology, Muang Nakhon Ratchasima, Thailand
| | - Allwin Jesudasan
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Gnaneswar Ch
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Ajay Kartik
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Peter Christopher
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | | | - Hiral Naik
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg. P. O. Wits, 2050, Gauteng, South Africa
- Save the Snakes, R527, Blyderus, Hoedspruit, 1380, South Africa
| | - Vishal Santra
- Captive & Field Herpetology Ltd, Wales, 13 Hirfron, Holyhead, Llaingoch, Anglesey, LL65 1YU, UK
- Society for Nature Conservation, Research and Community Engagement (CONCERN), Nalikul, Hooghly, West Bengal 712407, India
| | - Sourish Rajagopalan Kuttalam
- Society for Nature Conservation, Research and Community Engagement (CONCERN), Nalikul, Hooghly, West Bengal 712407, India
| | - Shaleen Attre
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, Marlowe Building, University of Kent, Canterbury, Kent, CT2 7NR, UK
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
| | - Carlos Bravo-Vega
- Research Group in Mathematical and Computational Biology (BIOMAC), Department of Biomedical Engineering, University of the Andes, Bogotá, Colombia
| | - Kris A. Murray
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, UK
- MRC Unit The Gambia at London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, Gambia
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15
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Chen F, Qin M, Liu W, Wang F, Ren W, Xu H, Li F. Snake Venom Identification via Fluorescent Discrimination. Anal Chem 2021; 93:14025-14030. [PMID: 34528790 DOI: 10.1021/acs.analchem.1c02804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The identification and discrimination of snake venom are highly desired for timely clinical treatment. However, the complex components in snake venom make it a great challenge to achieve rapid and accurate identification. Inspired by the organism's taste sensing system, a fluorescent sensor array that could differentiate snake venoms was fabricated. The interaction of snake venoms with different fluorescent dyes in the sensor array gave rich information, based on which efficient detection of complex snake venom was achieved. The main six proteins of snake venom in the same concentration, different concentrations, and their mixtures were identified with 100% accuracy. Furthermore, seven snake venoms belonging to different snake families were discriminated in PBS buffer and human plasma. Interferents of bovine serum albumin (BSA), thrombin, and transferrin (TRF) demonstrated the practicability of the fluorescent sensor array. This strategy of a multiresponse sensor array provides an effective method for accurate and rapid venom toxicology analysis, benefiting early and timely clinical diagnosis and treatment.
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Affiliation(s)
- Fei Chen
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Guangdong Engineering & Technology Research Centre of Graphene-like Materials and Products, Jinan University, Guangzhou 510632, China
| | - Meng Qin
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Wei Liu
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453000, China
| | - Fan Wang
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453000, China
| | - Wanjie Ren
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Guangdong Engineering & Technology Research Centre of Graphene-like Materials and Products, Jinan University, Guangzhou 510632, China
| | - Huihua Xu
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Guangdong Engineering & Technology Research Centre of Graphene-like Materials and Products, Jinan University, Guangzhou 510632, China
| | - Fengyu Li
- College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Guangdong Engineering & Technology Research Centre of Graphene-like Materials and Products, Jinan University, Guangzhou 510632, China
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16
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Wong KY, Tan KY, Tan NH, Gnanathasan CA, Tan CH. Elucidating the Venom Diversity in Sri Lankan Spectacled Cobra ( Naja naja) through De Novo Venom Gland Transcriptomics, Venom Proteomics and Toxicity Neutralization. Toxins (Basel) 2021; 13:558. [PMID: 34437429 PMCID: PMC8402536 DOI: 10.3390/toxins13080558] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/01/2021] [Accepted: 08/05/2021] [Indexed: 01/18/2023] Open
Abstract
Inadequate effectiveness of Indian antivenoms in treating envenomation caused by the Spectacled Cobra/Indian Cobra (Naja naja) in Sri Lanka has been attributed to geographical variations in the venom composition. This study investigated the de novo venom-gland transcriptomics and venom proteomics of the Sri Lankan N. naja (NN-SL) to elucidate its toxin gene diversity and venom variability. The neutralization efficacy of a commonly used Indian antivenom product in Sri Lanka was examined against the lethality induced by NN-SL venom in mice. The transcriptomic study revealed high expression of 22 toxin genes families in NN-SL, constituting 46.55% of total transcript abundance. Three-finger toxins (3FTX) were the most diversely and abundantly expressed (87.54% of toxin gene expression), consistent with the dominance of 3FTX in the venom proteome (72.19% of total venom proteins). The 3FTX were predominantly S-type cytotoxins/cardiotoxins (CTX) and α-neurotoxins of long-chain or short-chain subtypes (α-NTX). CTX and α-NTX are implicated in local tissue necrosis and fatal neuromuscular paralysis, respectively, in envenomation caused by NN-SL. Intra-species variations in the toxin gene sequences and expression levels were apparent between NN-SL and other geographical specimens of N. naja, suggesting potential antigenic diversity that impacts antivenom effectiveness. This was demonstrated by limited potency (0.74 mg venom/ml antivenom) of the Indian polyvalent antivenom (VPAV) in neutralizing the NN-SL venom. A pan-regional antivenom with improved efficacy to treat N. naja envenomation is needed.
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Affiliation(s)
- Kin Ying Wong
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | - Kae Yi Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | - Nget Hong Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | | | - Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
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Alomran N, Alsolaiss J, Albulescu LO, Crittenden E, Harrison RA, Ainsworth S, Casewell NR. Pathology-specific experimental antivenoms for haemotoxic snakebite: The impact of immunogen diversity on the in vitro cross-reactivity and in vivo neutralisation of geographically diverse snake venoms. PLoS Negl Trop Dis 2021; 15:e0009659. [PMID: 34407084 PMCID: PMC8423360 DOI: 10.1371/journal.pntd.0009659] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/07/2021] [Accepted: 07/18/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Snakebite is a neglected tropical disease that causes high global rates of mortality and morbidity. Although snakebite can cause a variety of pathologies in victims, haemotoxic effects are particularly common and are typically characterised by haemorrhage and/or venom-induced consumption coagulopathy. Antivenoms are the mainstay therapeutic for treating the toxic effects of snakebite, but despite saving thousands of lives annually, these therapies are associated with limited cross-snake species efficacy due to venom variation, which ultimately restricts their therapeutic utility to particular geographical regions. METHODOLOGY/PRINCIPAL FINDINGS In this study we explored the feasibility of generating globally effective pathology-specific antivenoms to counteract the haemotoxic signs of snakebite envenoming. Two different immunogen mixtures, consisting of seven and twelve haemotoxic venoms sourced from geographically diverse and/or medically important snakes, were used to raise ovine polyclonal antibodies, prior to characterisation of their immunological binding characteristics and in vitro neutralisation profiles against each of the venoms. Despite variability of the immunogen mixtures, both experimental antivenoms exhibited broadly comparable in vitro venom binding and neutralisation profiles against the individual venom immunogens in immunological and functional assays. However, in vivo assessments using a murine preclinical model of antivenom efficacy revealed substantial differences in venom neutralisation. The experimental antivenom generated from the seven venom immunogen mixture outperformed the comparator, by providing protective effects against venom lethality caused by seven of the eight geographically diverse venoms tested, including three distinct venoms that were not used as immunogens to generate this antivenom. These findings suggest that a core set of venom immunogens may be sufficient to stimulate antibodies capable of broadly neutralising a geographically diverse array of haemotoxic snake venoms, and that adding additional venom immunogens may impact negatively on the dose efficacy of the resulting antivenom. CONCLUSIONS/SIGNIFICANCE Although selection of appropriate immunogens that encapsulate venom toxin diversity without diluting antivenom potency remains challenging and further optimisation is required, the findings from this pilot study suggest that the generation of pathology-specific antivenoms with global utility is likely to feasible, thereby highlighting their promise as future modular treatments for the world's tropical snakebite victims.
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Affiliation(s)
- Nessrin Alomran
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Jaffer Alsolaiss
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Laura-Oana Albulescu
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Edouard Crittenden
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Robert A. Harrison
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Stuart Ainsworth
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
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18
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Remarkable intrapopulation venom variability in the monocellate cobra (Naja kaouthia) unveils neglected aspects of India's snakebite problem. J Proteomics 2021; 242:104256. [PMID: 33957314 DOI: 10.1016/j.jprot.2021.104256] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/29/2021] [Accepted: 05/01/2021] [Indexed: 11/20/2022]
Abstract
Interpopulation venom variation has been widely documented in snakes across large geographical distances. This variability is known to markedly influence the effectiveness of snakebite therapy, as antivenoms manufactured against one population may not be effective against others. In contrast, the extent of intrapopulation venom variability, especially at finer geographical scales, remains largely uninvestigated. Moreover, given the historical focus on the 'big four' Indian snakes, our understanding of venom variation in medically important yet neglected snakes, such as the monocellate cobra (Naja kaouthia), remains unclear. To address this shortcoming, we investigated N. kaouthia venoms sampled across a small spatial scale (<50 km) in Eastern India. An interdisciplinary approach employed in this study unveiled considerable intrapopulation differences in the venom proteomic composition, pharmacological and biochemical activities, and toxicity profiles. Documentation of stark differences in venoms at such a finer geographical scale, despite the influence of similar ecological and environmental conditions, is intriguing. Furthermore, evaluation of in vitro and in vivo venom recognition and neutralisation potential of Indian polyvalent 'big four' antivenoms and Thai monovalent N. kaouthia antivenom revealed concerning deficiencies. These results highlight the negative impact of phylogenetic divergence and intrapopulation snake venom variation on the effectiveness of conventional antivenom therapy. SIGNIFICANCE: In contrast to our understanding of snake venom variation across large distances, which is theorised to be shaped by disparities in ecology and environment, intrapopulation variation at finer geographic scales remains scarcely investigated. Assessment of intrapopulation venom variability in Naja kaouthia at a small spatial scale (<50 km) in Eastern India unravelled considerable differences in venom compositions, activities and potencies. While the influence of subtle differences in prey preference and local adaptations cannot be ruled out, these findings, perhaps, also emphasise the role of accelerated molecular evolutionary regimes that rapidly introduce variations in evolutionarily younger lineages, such as advanced snakes. The inability of 'big four' Indian antivenoms and Thai N. kaouthia monovalent antivenom in countering these variations highlights the importance of phylogenetic considerations for the development of efficacious snakebite therapy. Thus, we provide valuable insights into the venoms of one of the most medically important yet neglected Indian snakes.
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19
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Ratanabanangkoon K. A Quest for a Universal Plasma-Derived Antivenom Against All Elapid Neurotoxic Snake Venoms. Front Immunol 2021; 12:668328. [PMID: 33968072 PMCID: PMC8102826 DOI: 10.3389/fimmu.2021.668328] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/06/2021] [Indexed: 01/08/2023] Open
Abstract
This review describes the research aimed at the development of universal antivenom against elapid neurotoxic snake venoms. The antivenoms produced in Thailand in the 1980s were of low potency, especially against the elapid venoms. This was thought to be due to the low immunogenicity of the α-neurotoxins, which are the most lethal toxins in these venoms. Comparisons of various α-neurotoxin conjugates and polymers, and also different immunological adjuvants, showed that the adjuvant used is the major determinant in the antibody response in horses. The potent Freund's adjuvant was not used due to its severe local side-effect in horses. Therefore, a novel immunization protocol termed 'low dose, low volume multi-site' was developed for use in horses. This immunization protocol has led to the production of highly potent monospecific antivenoms against several elapid and viperid venoms, and two potent polyspecific antivenoms, one against 4 neurotoxic and another against 3 hematotoxic venoms. The immunization protocol has also led to other improvements in antivenom production including: several fold increases in antiserum potency, a reduction in the time required to reach therapeutically useful antibody titers, a 90% reduction in the amount of venom used, and 100% of the horses responding to the immunization program. This development is partly responsible for significant decrease in the Thailand's annual snakebite death toll from a few dozens to mostly nil in recent years. Finally, a simple and novel immunization strategy, using a 'diverse toxin repertoire' composed of numerous elapid toxin fractions as immunogen, was proposed and tested. This immunization procedure has resulted in the successful production of a widely paraspecific antiserum against at least 36 neurotoxic venoms of 28 species encompassing 10 genera and from 20 countries on four continents, and possibly against all elapid venoms with α-neurotoxins as the lethal toxins. These results indicate that, with optimizations of the composition of the 'diverse toxin repertoire', the immunization scheme and antibody fractionation to increase the antivenom neutralizing potency, an effective universal antivenom against the neurotoxic elapid snakes of the world can be produced.
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Affiliation(s)
- Kavi Ratanabanangkoon
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
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20
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Tan CH, Tan KY. De Novo Venom-Gland Transcriptomics of Spine-Bellied Sea Snake ( Hydrophis curtus) from Penang, Malaysia-Next-Generation Sequencing, Functional Annotation and Toxinological Correlation. Toxins (Basel) 2021; 13:toxins13020127. [PMID: 33572266 PMCID: PMC7915529 DOI: 10.3390/toxins13020127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/31/2021] [Accepted: 02/02/2021] [Indexed: 01/26/2023] Open
Abstract
Envenomation resulted from sea snake bite is a highly lethal health hazard in Southeast Asia. Although commonly caused by sea snakes of Hydrophiinae, each species is evolutionarily distinct and thus, unveiling the toxin gene diversity within individual species is important. Applying next-generation sequencing, this study investigated the venom-gland transcriptome of Hydrophis curtus (spine-bellied sea snake) from Penang, West Malaysia. The transcriptome was de novo assembled, followed by gene annotation and sequence analyses. Transcripts with toxin annotation were only 96 in number but highly expressed, constituting 48.18% of total FPKM in the overall transcriptome. Of the 21 toxin families, three-finger toxins (3FTX) were the most abundantly expressed and functionally diverse, followed by phospholipases A2. Lh_FTX001 (short neurotoxin) and Lh_FTX013 (long neurotoxin) were the most dominant 3FTXs expressed, consistent with the pathophysiology of envenomation. Lh_FTX001 and Lh_FTX013 were variable in amino acid compositions and predicted epitopes, while Lh_FTX001 showed high sequence similarity with the short neurotoxin from Hydrophis schistosus, supporting cross-neutralization effect of Sea Snake Antivenom. Other toxins of low gene expression, for example, snake venom metalloproteinases and L-amino acid oxidases not commonly studied in sea snake venom were also identified, enriching the knowledgebase of sea snake toxins for future study.
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Affiliation(s)
- Choo Hock Tan
- Venom Research and Toxicoogy Lab, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
- Correspondence:
| | - Kae Yi Tan
- Protein and Interactomics Lab, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
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21
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Wong KY, Tan KY, Tan NH, Tan CH. A Neurotoxic Snake Venom without Phospholipase A 2: Proteomics and Cross-Neutralization of the Venom from Senegalese Cobra, Naja senegalensis (Subgenus: Uraeus). Toxins (Basel) 2021; 13:toxins13010060. [PMID: 33466660 PMCID: PMC7828783 DOI: 10.3390/toxins13010060] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/22/2020] [Accepted: 01/07/2021] [Indexed: 11/16/2022] Open
Abstract
The Senegalese cobra, Naja senegalensis, is a non-spitting cobra species newly erected from the Naja haje complex. Naja senegalensis causes neurotoxic envenomation in Western Africa but its venom properties remain underexplored. Applying a protein decomplexation proteomic approach, this study unveiled the unique complexity of the venom composition. Three-finger toxins constituted the major component, accounting for 75.91% of total venom proteins. Of these, cardiotoxin/cytotoxin (~53%) and alpha-neurotoxins (~23%) predominated in the venom proteome. Phospholipase A2, however, was not present in the venom, suggesting a unique snake venom phenotype found in this species. The venom, despite the absence of PLA2, is highly lethal with an intravenous LD50 of 0.39 µg/g in mice, consistent with the high abundance of alpha-neurotoxins (predominating long neurotoxins) in the venom. The hetero-specific VINS African Polyvalent Antivenom (VAPAV) was immunoreactive to the venom, implying conserved protein antigenicity in the venoms of N. senegalensis and N. haje. Furthermore, VAPAV was able to cross-neutralize the lethal effect of N. senegalensis venom but the potency was limited (0.59 mg venom completely neutralized per mL antivenom, or ~82 LD50 per ml of antivenom). The efficacy of antivenom should be further improved to optimize the treatment of cobra bite envenomation in Africa.
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Affiliation(s)
- Kin Ying Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | - Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.T.); (N.H.T.)
| | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.T.); (N.H.T.)
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
- Correspondence: ; Tel.: +60-3-7967-6685
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Tan CH, Liew JL, Chong HP, Tan NH. Protein decomplexation and proteomics: A complementary assessment method of the physicochemical purity of antivenom. Biologicals 2021; 69:22-29. [PMID: 33431232 DOI: 10.1016/j.biologicals.2020.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 11/28/2020] [Accepted: 12/22/2020] [Indexed: 01/21/2023] Open
Abstract
The quality of antivenom is governed by its safety and efficacy profiles. These quality characteristics are much influenced by the purity of antivenom content. Rigorous assessment and meticulous monitoring of antivenom purity at the preclinical setting is hence crucial. This study aimed to explore an integrative proteomic method to assess the physicochemical purity of four commercially available antivenoms in the region. The antivenoms were subjected to Superdex 200 HR 10/30 size-exclusion fast-protein liquid chromatography (SE-FPLC). The proteins in each fraction were trypsin-digested and analyzed by nano-ESI-liquid chromatography-tandem mass spectrometry (LC-MS/MS). SE-FPLC resolved the antivenom proteins into three major protein components of very high (>200 kDa), high (100-120 kDa) and medium (<60 kDa) molecular weights. The major components (80-95% of total proteins) in the antivenoms were proteins of 100-120 kDa consisting of mainly the light and partially digested heavy immunoglobulin chains, consistent with F(ab')2 as the active principle of the antivenoms. However, LC-MS/MS also detected substantial quantity of large proteins (e.g. alpha-2-macroglobulins), immunoglobulin aggregates and impurities e.g. albumins in some products. The method is practical and able to unveil the quantitative and qualitative aspects of antivenom protein compositions. It is therefore a potentially useful preclinical assessment tool of antivenom purity.
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Affiliation(s)
- Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| | - Jia Lee Liew
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Ho Phin Chong
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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23
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Durso AM, Bolon I, Kleinhesselink AR, Mondardini MR, Fernandez-Marquez JL, Gutsche-Jones F, Gwilliams C, Tanner M, Smith CE, Wüster W, Grey F, Ruiz de Castañeda R. Crowdsourcing snake identification with online communities of professional herpetologists and avocational snake enthusiasts. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201273. [PMID: 33614073 PMCID: PMC7890515 DOI: 10.1098/rsos.201273] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
Species identification can be challenging for biologists, healthcare practitioners and members of the general public. Snakes are no exception, and the potential medical consequences of venomous snake misidentification can be significant. Here, we collected data on identification of 100 snake species by building a week-long online citizen science challenge which attracted more than 1000 participants from around the world. We show that a large community including both professional herpetologists and skilled avocational snake enthusiasts with the potential to quickly (less than 2 min) and accurately (69-90%; see text) identify snakes is active online around the clock, but that only a small fraction of community members are proficient at identifying snakes to the species level, even when provided with the snake's geographical origin. Nevertheless, participants showed great enthusiasm and engagement, and our study provides evidence that innovative citizen science/crowdsourcing approaches can play significant roles in training and building capacity. Although identification by an expert familiar with the local snake fauna will always be the gold standard, we suggest that healthcare workers, clinicians, epidemiologists and other parties interested in snakebite could become more connected to these communities, and that professional herpetologists and skilled avocational snake enthusiasts could organize ways to help connect medical professionals to crowdsourcing platforms. Involving skilled avocational snake enthusiasts in decision making could build the capacity of healthcare workers to identify snakes more quickly, specifically and accurately, and ultimately improve snakebite treatment data and outcomes.
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Affiliation(s)
- A. M. Durso
- Institute of Global Health, Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Department of Biological Sciences, Florida Gulf Coast University, Ft. Myers, FL, USA
| | - I. Bolon
- Institute of Global Health, Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - A. R. Kleinhesselink
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - M. R. Mondardini
- Citizen Science Center Zürich, ETHZ and University of Zürich, Zurich, Switzerland
| | | | - F. Gutsche-Jones
- Citizen Science Center Zürich, ETHZ and University of Zürich, Zurich, Switzerland
| | - C. Gwilliams
- Citizen Science Center Zürich, ETHZ and University of Zürich, Zurich, Switzerland
| | - M. Tanner
- Citizen Science Center Zürich, ETHZ and University of Zürich, Zurich, Switzerland
| | | | - W. Wüster
- Bangor University College of Natural Sciences, Bangor, UK
| | - F. Grey
- Citizen Cyberlab, University of Geneva, Geneva, Switzerland
| | - R. Ruiz de Castañeda
- Institute of Global Health, Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Tan CH, Bourges A, Tan KY. King Cobra and snakebite envenomation: on the natural history, human-snake relationship and medical importance of Ophiophagus hannah. J Venom Anim Toxins Incl Trop Dis 2021; 27:e20210051. [PMID: 35069710 PMCID: PMC8733962 DOI: 10.1590/1678-9199-jvatitd-2021-0051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/25/2021] [Indexed: 01/28/2023] Open
Abstract
King Cobra (Ophiophagus hannah) has a significant place in many
cultures, and is a medically important venomous snake in the world. Envenomation
by this snake is highly lethal, manifested mainly by neurotoxicity and local
tissue damage. King Cobra may be part of a larger species complex, and is widely
distributed across Southeast Asia, southern China, northern and eastern regions
as well as the Western Ghats of India, indicating potential geographical
variation in venom composition. There is, however, only one species-specific
King Cobra antivenom available worldwide that is produced in Thailand, using
venom from the snake of Thai origin. Issues relating to the management of King
Cobra envenomation (e.g., variation in the composition and
toxicity of the venom, limited availability and efficacy of antivenom), and
challenges faced in the research of venom (in particular proteomics), are rarely
addressed. This article reviews the natural history and sociocultural importance
of King Cobra, cases of snakebite envenomation caused by this species, current
practice of management (preclinical and clinical), and major toxinological
studies of the venom with a focus on venom proteomics, toxicity and
neutralization. Unfortunately, epidemiological data of King Cobra bite is
scarce, and venom proteomes reported in various studies revealed marked
discrepancies in details. Challenges, such as inconsistency in snake venom
sampling, varying methodology of proteomic analysis, lack of mechanistic and
antivenomic studies, and controversy surrounding antivenom use in treating King
Cobra envenomation are herein discussed. Future directions are proposed,
including the effort to establish a standard, comprehensive Pan-Asian proteomic
database of King Cobra venom, from which the venom variation can be determined.
Research should be undertaken to characterize the toxin antigenicity, and to
develop an antivenom with improved efficacy and wider geographical utility. The
endeavors are aligned with the WHO´s roadmap that aims to reduce the disease
burden of snakebite by 50% before 2030.
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Affiliation(s)
| | - Aymeric Bourges
- University of Malaya, Malaysia; Université Libre de Bruxelles, Belgium
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Pruksaphon K, Tan KY, Tan CH, Simsiriwong P, Gutiérrez JM, Ratanabanangkoon K. An in vitro α-neurotoxin-nAChR binding assay correlates with lethality and in vivo neutralization of a large number of elapid neurotoxic snake venoms from four continents. PLoS Negl Trop Dis 2020; 14:e0008581. [PMID: 32857757 PMCID: PMC7535858 DOI: 10.1371/journal.pntd.0008581] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/05/2020] [Accepted: 07/09/2020] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to develop an in vitro assay for use in place of in vivo assays of snake venom lethality and antivenom neutralizing potency. A novel in vitro assay has been developed based on the binding of post-synaptically acting α-neurotoxins to nicotinic acetylcholine receptor (nAChR), and the ability of antivenoms to prevent this binding. The assay gave high correlation in previous studies with the in vivo murine lethality tests (Median Lethal Dose, LD50), and the neutralization of lethality assays (Median Effective Dose, ED50) by antisera against Naja kaouthia, Naja naja and Bungarus candidus venoms. Here we show that, for the neurotoxic venoms of 20 elapid snake species from eight genera and four continents, the in vitro median inhibitory concentrations (IC50s) for α-neurotoxin binding to purified nAChR correlated well with the in vivo LD50s of the venoms (R2 = 0.8526, p < 0.001). Furthermore, using this assay, the in vitro ED50s of a horse pan-specific antiserum against these venoms correlated significantly with the corresponding in vivo murine ED50s, with R2 = 0.6896 (p < 0.01). In the case of four elapid venoms devoid or having a very low concentration of α-neurotoxins, no inhibition of nAChR binding was observed. Within the philosophy of 3Rs (Replacement, Reduction and Refinement) in animal testing, the in vitro α-neurotoxin-nAChR binding assay can effectively substitute the mouse lethality test for toxicity and antivenom potency evaluation for neurotoxic venoms in which α-neurotoxins predominate. This will greatly reduce the number of mice used in toxicological research and antivenom production laboratories. The simpler, faster, cheaper and less variable in vitro assay should also expedite the development of pan-specific antivenoms against various medically important snakes in many parts of the world.
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Affiliation(s)
- Kritsada Pruksaphon
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Kavi Ratanabanangkoon
- Laboratory of Immunology, Chulabhorn Research Institute, Bangkok, Thailand
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
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