Department of Cell Biology, Federal University of Paraná (UFPR), Curitiba, 81530-900, PR, Brazil.
Production and Research Center of Immunobiological Products (CPPI), State Department of Health, Piraquara, 83302-200, PR, Brazil.
Acta Trop. 2024 Oct;258:107354. doi: 10.1016/j.actatropica.2024.107354. Epub 2024 Aug 4.
Loxoscelism is the pathological condition triggered by a brown spider bite. The venom of these spiders is rich in phospholipases D (PLDs), which can induce virtually all local and systemic manifestations. Recombinant mutated PLDs from clinically relevant Loxosceles species in South America have been investigated as potential antigens to develop novel therapeutic strategies for loxoscelism. However, certain gaps need to be addressed before a clinical approach can be implemented. In this study, we examined the potential of these recombinant mutated PLDs as antigens by testing some variations in the immunization scheme. Furthermore, we evaluated the efficacy of the produced antibodies in neutralizing the nephrotoxicity and sphingomyelinase activity of brown spider venoms. Our findings indicate that the number of immunizations has a greater impact on the effectiveness of neutralization compared to the amount of antigen. Specifically, two or three doses were equally effective in reducing dermonecrosis and edema. Additionally, three immunizations proved to be more effective in neutralizing mice lethality than one or two. Moreover, immunizations mitigated the signs of kidney injury, a crucial aspect given that acute renal failure is a serious systemic complication. In vitro inhibition of the sphingomyelinase activity of Loxosceles venoms, a key factor in vivo toxicity, was nearly complete after incubation with antibodies raised against these antigens. These findings underscore the importance of implementing an effective immunization scheme with multiple immunizations, without the need for high antigen doses, and enhances the spectrum of neutralization exhibited by antibodies generated with these antigens. In summary, these results highlight the strong potential of these antigens for the development of new therapeutic strategies against cutaneous and systemic manifestations of loxoscelism.
类淋巴丝菌病是由棕色蜘蛛咬伤引起的病理状况。这些蜘蛛的毒液富含磷脂酶 D (PLD)，可引起几乎所有局部和全身表现。来自南美洲临床相关的 Loxosceles 物种的重组突变 PLD 已被研究作为开发新型类淋巴丝菌病治疗策略的潜在抗原。然而，在实施临床方法之前，需要解决某些差距。在这项研究中，我们通过测试免疫方案中的一些变化来研究这些重组突变 PLD 作为抗原的潜力。此外，我们评估了产生的抗体中和棕色蜘蛛毒液的肾毒性和神经鞘磷脂酶活性的功效。我们的研究结果表明，免疫次数对中和效果的影响大于抗原量。具体来说，两次或三次免疫与减少皮肤坏死和水肿的效果相同。此外，三次免疫在中和小鼠致死率方面比一次或两次免疫更有效。此外，免疫减轻了肾脏损伤的迹象，这是一个关键方面，因为急性肾衰竭是一种严重的全身并发症。用针对这些抗原产生的抗体孵育后，对 Loxosceles 毒液的神经鞘磷脂酶活性的体外抑制几乎完全。这些发现强调了实施多次免疫而无需高抗原剂量的有效免疫方案的重要性，并增强了这些抗原产生的抗体所表现出的中和谱。总之，这些结果突出了这些抗原在开发针对类淋巴丝菌病皮肤和全身表现的新型治疗策略方面的强大潜力。
