Department of Public Health and Pediatrics, University of Torino, 10125 Turin, Italy.
Int J Mol Sci. 2023 Jan 28;24(3):2541. doi: 10.3390/ijms24032541.
Polymorphonuclear leukocytes (PMNs) are the most important cell type involved in the early nonspecific host response to bacterial pathogens. has evolved mechanisms to evade immune responses that contribute to its persistence in PMNs, and acquired resistance to several antimicrobials. Additionally, methicillin-resistant (MRSA) is one of the most common causes of acute bacterial skin and skin-structure infections (ABSSSIs). Dalbavancin (DBV), a lipoglycopeptide, is indicated for the treatment of ABSSSIs, and has a broad spectrum of action against most microorganisms. Here, we sought to determine the effect of DBV on the neutrophil killing of MRSA and its potential immunomodulating activity. Our results revealed that DBV boosts MRSA killing by acting on both bacteria and PMNs. DBV pre-treatment of PMNs did not change the respiratory burst or degranulation, while an increased trend in neutrophil extracellular traps-associated elastase and in the production of TNFα and CXCL8 was revealed. In parallel, DBV caused a delay in the apoptosis of MRSA-infected neutrophils. In conclusion, we demonstrated a cooperative effect between the antimicrobial properties of PMNs and DBV, thus owing to their immunomodulatory activity. In the choice of the treatment management of serious infections, DBV should be considered as an outstanding option since it reinforces PMNs pathogen clearance capability by exerting its effect directly, not only on MRSA but also on neutrophils.
多形核白细胞(PMNs)是参与宿主对细菌病原体早期非特异性反应的最重要细胞类型。已经进化出逃避免疫反应的机制,这有助于其在 PMNs 中持续存在,并获得对几种抗菌药物的耐药性。此外,耐甲氧西林金黄色葡萄球菌(MRSA)是急性细菌性皮肤和皮肤结构感染(ABSSSIs)的最常见原因之一。达巴万星(DBV)是一种糖肽类抗生素,用于治疗 ABSSSIs,对大多数微生物具有广泛的作用。在这里,我们试图确定 DBV 对 MRSA 杀伤中性粒细胞的影响及其潜在的免疫调节活性。我们的结果表明,DBV 通过作用于细菌和 PMNs 来增强 MRSA 的杀伤作用。DBV 对 PMNs 的预处理不会改变呼吸爆发或脱颗粒,而揭示了中性粒细胞细胞外陷阱相关弹性蛋白酶和 TNFα和 CXCL8 的产生呈增加趋势。同时,DBV 导致感染 MRSA 的中性粒细胞凋亡延迟。总之,我们证明了 PMNs 的抗菌特性和 DBV 之间存在协同作用,因此由于其免疫调节活性。在严重感染治疗管理的选择中,DBV 应该被认为是一个杰出的选择,因为它通过直接发挥作用来增强 PMNs 清除病原体的能力,不仅对 MRSA 而且对中性粒细胞都有作用。