Data from: Immune responses in hibernating little brown myotis (Myotis lucifugus) with white-nose syndrome

White-nose syndrome (WNS) is a fungal disease responsible for decimating many bat populations in North America. Pseudogymnoascus destructans (Pd), the psychrophilic fungus responsible for WNS, prospers in the winter habitat of many hibernating bat species. The immune response that Pd elicits in bats is not yet fully understood; antibodies are produced in response to infection by Pd, but they may not be protective and indeed may be harmful. To understand how bats respond to infection during hibernation, we studied the effect of Pd inoculation on the survival and gene expression of captive hibernating Myotis lucifugus with varying pre-hibernation antifungal antibody titres. We investigated gene expression through the transcription of selected cytokine genes (Il6, Il17a, Il1b, Il4 and Ifng) associated with inflammatory, Th1, Th2 and Th17 immune responses in wing tissue and lymph nodes. We found no difference in survival between bats with low and high anti-Pd titres, although anti-Pd antibody production during hibernation differed significantly between infected and uninfected bats. Transcription of Il6 and Il17a was higher in the lymph nodes of infected bats compared with uninfected bats. Increased transcription of these cytokines in the lymph node suggests that a pro-inflammatory immune response to WNS is not restricted to infected tissues and occurs during hibernation. The resulting Th17 response may be protective in euthermic bats, but because it may disrupt torpor, it could be detrimental during hibernation.

白鼻综合征（White-nose syndrome, WNS）是一种真菌性疾病，曾导致北美地区大量蝙蝠种群锐减。引发WNS的致病嗜冷真菌为德氏假裸囊菌（Pseudogymnoascus destructans, Pd），该真菌可在多种冬眠蝙蝠的冬季栖息环境中大量增殖。目前学界对蝙蝠针对Pd感染所引发的免疫应答尚未完全阐明：蝙蝠会在Pd感染后产生抗体，但此类抗体未必具备保护作用，甚至可能产生有害影响。
为阐明蝙蝠在冬眠期间对感染的应答机制，本研究针对不同冬眠前抗真菌抗体滴度的圈养冬眠小棕蝠（Myotis lucifugus），探究了Pd接种对其存活情况与基因表达的影响。研究通过检测选定的细胞因子基因——白细胞介素6（Interleukin 6, Il6）、白细胞介素17a（Interleukin 17a, Il17a）、白细胞介素1b（Interleukin 1b, Il1b）、白细胞介素4（Interleukin 4, Il4）以及干扰素γ（Interferon γ, Ifng）——的转录水平，分析了翼组织与淋巴结中与炎症、辅助性T细胞1（Th1）、辅助性T细胞2（Th2）及辅助性T细胞17（Th17）型免疫应答相关的基因表达情况。
研究结果显示，抗Pd抗体滴度高低不同的蝙蝠之间存活情况并无显著差异，但感染与未感染蝙蝠在冬眠期间的抗Pd抗体生成水平存在显著差异。与未感染蝙蝠相比，感染蝙蝠淋巴结内Il6与Il17a的转录水平更高。
上述细胞因子在淋巴结中的转录水平升高表明，针对WNS的促炎性免疫应答并非仅局限于感染组织，且可在冬眠期间发生。由此产生的Th17型免疫应答在恒温蝙蝠中或可发挥保护作用，但由于其可能扰乱冬眠蛰伏状态，因此在冬眠期间或会产生不利影响。