Menezes-Silva Luísa, Catarino Jonatas da Silva, de Faria Laura Caroline, Pizzolante Bárbara Cristina, Andrade-Silva Leonardo Eurípedes, da Silva Marcos Vinicius, Rodrigues Virmondes, Sales-Campos Helioswilton, Oliveira Carlo José Freire
Laboratory of Immunology and Bioinformatics, Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil.
Department of Immunology, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, SP, Brazil.
J Venom Anim Toxins Incl Trop Dis. 2022 Jul 18;28:e20210124. doi: 10.1590/1678-9199-JVATITD-2021-0124. eCollection 2022.
Triatomines are blood-feeding arthropods belonging to the subfamily Triatominae (Hemiptera; Reduviidae), capable of producing immunomodulatory and water-soluble molecules in their hemolymph, such as antimicrobial peptides (AMPs). In this work, we evaluated the antifungal and immunomodulatory activity of the hemolymph of (MPH) and (RPH) against .
We assessed the activity of the hemolymph of both insects on fungal growth by a minimum inhibitory concentration (MIC) assay. Further, RAW 264.7 macrophages were cultivated with hemolymph and challenged with . Then, their phagocytic and killing activities were assessed. The cytokines MCP-1, IFN-γ, TNF-α, IL-10, IL-12, and IL-6 were measured in culture supernatants 4- and 48-hours post-infection.
Both hemolymph samples directly affected the growth rate of the fungus in a dose-dependent manner. Either MPH or RPH was capable of inhibiting fungal growth by at least 70%, using the lowest dilution (1:20). Treatment of RAW 264.7 macrophages with hemolymph of both insects was capable of increasing the production of MCP-I and TNF-α. In addition, when these cells were stimulated with hemolymph in the presence of , a 2- and a 4-fold increase in phagocytic rate was observed with MPH and RPH, respectively, when compared to untreated cells. For the macrophage killing activity, MPH decreased in approximately 30% the number of viable yeasts inside the cells compared to untreated control; however, treatment with RPH could not reduce the total number of viable yeasts. MPH was also capable of increasing MHC-II expression on macrophages. Regarding the cytokine production, MCP-I and TNF-α, were increased in the supernatant of macrophages treated with both hemolymphs, 4 and 48 hours after stimulation.
These results suggested that hemolymph of triatomines may represent a source of molecules capable of presenting antifungal and immunomodulatory activity in macrophages during fungal infection.
锥蝽是吸血节肢动物，属于锥蝽亚科（半翅目；猎蝽科），能够在其血淋巴中产生免疫调节和水溶性分子，如抗菌肽（AMPs）。在本研究中，我们评估了美西锥蝽（MPH）和红带锥蝽（RPH）血淋巴对白色念珠菌的抗真菌和免疫调节活性。
我们通过最低抑菌浓度（MIC）测定评估了两种昆虫血淋巴对真菌生长的活性。此外，用RAW 264.7巨噬细胞与血淋巴共培养，并用白色念珠菌进行刺激。然后，评估它们的吞噬和杀伤活性。在感染后4小时和48小时，测量培养上清液中的细胞因子MCP-1、IFN-γ、TNF-α、IL-10、IL-12和IL-6。
两种血淋巴样品均以剂量依赖性方式直接影响真菌的生长速率。使用最低稀释度（1:20）时，MPH或RPH均能够抑制真菌生长至少70%。用两种昆虫的血淋巴处理RAW 264.7巨噬细胞能够增加MCP-1和TNF-α的产生。此外，当这些细胞在白色念珠菌存在的情况下用两种昆虫的血淋巴刺激时，与未处理的细胞相比，MPH和RPH分别使吞噬率提高了2倍和4倍。对于巨噬细胞杀伤活性，与未处理的对照相比，MPH使细胞内活酵母数量减少了约30%；然而，用RPH处理不能减少活酵母的总数。MPH还能够增加巨噬细胞上MHC-II的表达。关于细胞因子的产生，在刺激后4小时和48小时，两种血淋巴处理的巨噬细胞上清液中MCP-1和TNF-α均增加。
这些结果表明，锥蝽的血淋巴可能是在真菌感染期间能够在巨噬细胞中呈现抗真菌和免疫调节活性的分子来源。
