Desenvolvimento de uma formulação de um peptídeo baseado na Anexina-A1 para o tratamento de infecções graves por dengue

Abstract

Dengue affects approximately 400 million people in 130 countries annually. Severe dengue (GD) is characterized by exacerbated inflammation resulting from a “cytokine storm”, accompanied by vascular leakage, hemorrhage, and hypovolemic shock. These events are mediated by the participation of innate immunity cells, such as neutrophils, mast cells and macrophages as well as their products (eg: TNF, PAF, MCPT-1). Dengue management is symptomatic. There are no licensed antiviral drugs, nor drugs targeting host molecules. Therefore, the development/repositioning of drugs aimed at treating dengue fever is urgent. We recently demonstrated that GD is the result of failure to mount an adequate resolving response mediated by Annexin A1 (AnxA1), a protein that acts through its receptor FPR2/ALX, expressed by several cell types including leukocytes and endothelial cells. AnxA1KO mice are more susceptible to Dengue virus (DENV) infection and have a delayed resolution of the disease. On the other hand, treatment of WT mice with the AnxA1 mimetic peptide (AC2-26) resulted in improvement of the disease without altering the host's ability to control the infection. Peptides such as AC2-26 are unstable and rapidly cleaved when administered systemically. Faced with this problem, we sought to develop a cyclodextrin (CD) formulation carrying the AC2-26 peptide to improve its bioavailability and effects on the host. To do this, we initially identify the best CD for constructing the formulation of interest. We then evaluated and compared the effect of treatment with pure or formulated AC2-26 peptide and the associated potential antiinflammatory/ pro-resolving mechanisms. We observed the non-toxic effect of HP-BCD on Vero cells, with low antiviral effect. Therefore, HP-BCD was chosen as a candidate formulation to improve the stability and bioavailability of the peptide. Treatment with pure AC2-26 reversed clinical scores and thrombocytopenia induced by DENV, while formulated AC2-26 (CDX-AC2- 26) exhibited a potentiated effect in improving these parameters. CDX-AC2-26 decreased inflammatory markers in plasma (MCPT-1) and spleen (CXCL1, IFN-γ, CCL2 and CCL5). It also reduced mast cell degranulation and inflammatory infiltrate in the liver of DENV-infected mice. Administration of CDX-AC2-26 enhances its effects compared to the pure peptide. This improvement is probably due to greater stability and better absorption of the drug by the body, enhancing the improvement in the pro-resolving and clinical effects observed.