Duong Jonathan V, Motiwala Aqsa, Hotz William J, Gozashti Landen, Long Anthony D, Barbour Alan G
Department of Microbiology and Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, United States.
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States.
bioRxiv. 2025 Jul 18:2025.07.16.665222. doi: 10.1101/2025.07.16.665222.
The white-footed deermouse is a primary reservoir for the agents of Lyme disease and other zoonoses in North America and manifests infection tolerance for the bacteria, protozoa, and viruses it hosts. In previous in vivo studies and differed in the degree of sickness and profiles of biomarkers after exposure to bacterial lipopolysaccharide, a TLR4 agonist. As an approach for assessing immunity of mammals in nature and for longitudinal studies of colony animals in the laboratory, we evaluated using bulk and single cell RNA-seq primary dermal fibroblast cultures of and in their short-term responses to a TLR2 agonist lipopeptide. By single cell RNA-seq cultures of both species comprised at least two types of fibroblasts, which were further differentiated in their responses to TLR agonists. With continued passage the mouse cell population lost viability, while the deermouse cell population spontaneously transformed into a cell line stably maintained under standard conditions. Bulk RNA-seq revealed distinctive profiles for deermouse and mouse cells in arginine metabolism gene expression, high baseline transcription of the antioxidant transcription factor Nfe2l2 (Nrf2) in deermouse fibroblasts, and the transcription of the aging-associated cytokine interleukin-11 in agonist-treated mouse fibroblasts but not deermouse fibroblasts. In both species' cultures there was increased transcription of several types of endogenous retrovirus (ERV) and transposable elements (TE) after exposure to the agonist. The transcribed ERV/TE sequences in cells were generally longer in length and with greater potential for translation than sequences in treated cells. The results indicate feasibility of this in vitro model for both laboratory- and field-based studies and that inherent differences between deermice and mice in cell-autonomous innate immune responses and ERV/TE activation can be demonstrated in dermal fibroblasts as well as the animals themselves.
白足鹿鼠是北美莱姆病和其他人畜共患病病原体的主要宿主，对其所携带的细菌、原生动物和病毒表现出感染耐受性。在先前的体内研究中，暴露于TLR4激动剂细菌脂多糖后，[具体物种1]和[具体物种2]在疾病程度和生物标志物谱方面存在差异。作为评估自然环境中哺乳动物免疫力以及实验室中群居动物纵向研究的一种方法，我们使用批量和单细胞RNA测序评估了[具体物种1]和[具体物种2]原代表皮成纤维细胞培养物对TLR2激动剂脂肽的短期反应。通过单细胞RNA测序发现，两个物种的培养物都包含至少两种类型的成纤维细胞，它们对TLR激动剂的反应进一步分化。随着传代的继续，小鼠细胞群体失去活力，而鹿鼠细胞群体自发转化为在标准条件下稳定维持的细胞系。批量RNA测序揭示了鹿鼠和小鼠细胞在精氨酸代谢基因表达方面的独特谱型，鹿鼠成纤维细胞中抗氧化转录因子Nfe2l2（Nrf2）的高基线转录，以及激动剂处理的小鼠成纤维细胞而非鹿鼠成纤维细胞中与衰老相关的细胞因子白细胞介素-11的转录。在两个物种的培养物中，暴露于激动剂后几种内源性逆转录病毒（ERV）和转座元件（TE）的转录均增加。处理后的[具体物种1]细胞中转录的ERV/TE序列通常比处理后的[具体物种2]细胞中的序列长度更长，翻译潜力更大。结果表明，这种体外模型对于基于实验室和野外的研究都是可行的，并且在皮肤成纤维细胞以及动物自身中都可以证明鹿鼠和小鼠在细胞自主先天性免疫反应和ERV/TE激活方面的固有差异。
