Smith Christiana, Curtis Kaili, Bonham Adrianne, Boyer Shea, Lenz Laurel, Weinberg Adriana
Section of Infectious Diseases and Epidemiology, Department of Pediatrics, University of Colorado, Aurora, CO, United States.
Departments of Immunology and Microbiology, University of Colorado, Aurora, CO, United States.
Immunohorizons. 2025 Jan 24;9(2). doi: 10.1093/immhor/vlae010.
Respiratory syncytial virus (RSV) is a major contributor to morbidity and mortality in infants. We developed an in vitro model of human respiratory infection to study cellular immune responses to RSV in infants, children, and adults. The model includes human lung epithelial A549 cells or human fetal lung fibroblasts infected with a clinical strain of RSV at a multiplicity of infection of 0.3, cocultured with human cord blood mononuclear cells (CBMCs) or peripheral blood mononuclear cells (PBMCs). Mononuclear cells were collected at multiple ages ranging from birth to adulthood. After 20 h of incubation, flow cytometry was used to measure CBMC/PBMC responses to RSV. A549s were more permissive to RSV and when infected produced more CCL5, CCL11, and CXCL9; less CSF-3, CXCL10, interleukin (IL)-1α, IL-1RA, and IL-6; and similar CCL2, CCL3, CCL4, CCL7, CXCL1, CXCL11, IL-1β, IL-7, IL-8, and tumor necrosis factor α compared with fibroblasts; A594s were used for subsequent experiments. CBMCs/PBMCs upregulated multiple markers of activation, maturation, and degranulation upon exposure to RSV-infected A549s. Interferon γ expression in natural killer, CD4, and CD8 cells and CD107a expression in natural killer cells showed a gradual increase from infancy to adulthood. IL-12 expression in dendritic cells and monocytes was highest in adult PBMCs. Our in vitro model of human RSV infection recapitulated the expected bias away from T helper 1 and effector responses to RSV infection in infancy and revealed changes in innate and adaptive RSV-specific cellular immune responses over time.
呼吸道合胞病毒（RSV）是导致婴儿发病和死亡的主要因素。我们建立了一种人类呼吸道感染的体外模型，以研究婴儿、儿童和成人对RSV的细胞免疫反应。该模型包括以感染复数0.3感染临床RSV毒株的人肺上皮A549细胞或人胎儿肺成纤维细胞，并与人脐血单个核细胞（CBMC）或外周血单个核细胞（PBMC）共培养。在从出生到成年的多个年龄段收集单个核细胞。孵育20小时后，使用流式细胞术测量CBMC/PBMC对RSV的反应。与成纤维细胞相比，A549细胞对RSV更敏感，感染后产生更多的CCL5、CCL11和CXCL9；更少的CSF-3、CXCL10、白细胞介素（IL）-1α、IL-1受体拮抗剂和IL-6；以及相似的CCL2、CCL3、CCL4、CCL7、CXCL1、CXCL11、IL-1β、IL-7、IL-8和肿瘤坏死因子α；后续实验使用A594细胞。暴露于RSV感染的A549细胞后，CBMC/PBMC上调了多种激活、成熟和脱颗粒标志物。自然杀伤细胞、CD4和CD8细胞中的干扰素γ表达以及自然杀伤细胞中的CD107a表达从婴儿期到成年期逐渐增加。树突状细胞和单核细胞中的IL-12表达在成人PBMC中最高。我们的人类RSV感染体外模型重现了婴儿期对RSV感染偏离T辅助1型和效应反应的预期偏差，并揭示了先天性和适应性RSV特异性细胞免疫反应随时间的变化。
