Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA.
Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, USA.
Infect Immun. 2024 Apr 9;92(4):e0050323. doi: 10.1128/iai.00503-23. Epub 2024 Mar 7.
Non-neutralizing functions of antibodies, including phagocytosis, may play a role in (CT) infection, but these functions have not been studied and assays are lacking. We utilized a flow-cytometry-based assay to determine whether serum samples from a well-characterized cohort of CT-infected and naïve control individuals enhanced phagocytosis via Fc-receptor-expressing THP-1 cells, and whether this activity correlated with antibody titers. Fc-receptor-mediated phagocytosis was detected only in CT+ donors. Phagocytosis generally did not correlate well with antibody titer. In addition, we found that complement from both CT+ and negative individuals enhanced phagocytosis of CT into primary neutrophils. These results suggest that anti-CT antibodies can have functions that are not reflected by titer. This method could be used to quantitively measure Fc-receptor-mediated function of anti-CT antibodies or complement activity and could reveal new immune correlates of protection.
抗体的非中和功能，包括吞噬作用，可能在沙眼衣原体（CT）感染中发挥作用，但这些功能尚未得到研究，也缺乏相关检测方法。我们利用基于流式细胞术的检测方法，确定来自一组特征明确的 CT 感染和未感染对照个体的血清样本是否通过表达 Fc 受体的 THP-1 细胞增强吞噬作用，以及这种活性是否与抗体滴度相关。仅在 CT+供体中检测到 Fc 受体介导的吞噬作用。吞噬作用通常与抗体滴度相关性不佳。此外，我们发现来自 CT+和阴性个体的补体均能增强 CT 进入原代中性粒细胞的吞噬作用。这些结果表明，抗 CT 抗体可能具有与其滴度无关的功能。这种方法可用于定量测量抗 CT 抗体或补体活性的 Fc 受体介导功能，并可能揭示新的保护性免疫相关因素。
