Data from: Immunocompetence in a long-lived ectothermic vertebrate is temperature dependent but shows no decline in older adults

1. Temperature affects nearly all aspects of the physiology of ectotherms, including their ability to mount an immune response. Typically, the ectothermic vertebrate immune system can respond over a wide range of temperatures, but there is a species-specific temperature at which responses are strongest, with impaired responses above and below this threshold. In long-lived ectotherms, aging could also influence the ability to respond to temperature changes as immunosenecence, the functional decrease in immune function with age, is widely reported. 2. This study examined the effects of the interaction between temperature and age on B cell function in a long-lived reptile, the red-eared slider turtle, Trachemys scripta. B cells in this species have previously been shown to have two main functions, phagocytosis and antibody production. 3. Adult turtles were trapped and blood samples taken. Because sliders grow throughout their lifetime, plastron length was used as a proxy for age. Leukocytes were isolated and used in either an ELISpot assay to examine their ability to produce antibodies spontaneously or when stimulated, or used in a phagocytic assay. The ELISpot and phagocytic assays were conducted over a range of biologically relevant temperatures. 4. We found no interaction between age and temperature on any measure of B cell function. In all cases there was a significant effect of temperature, with impaired function at temperatures below 29°C, but no impairment of function at higher temperatures. We also found little evidence of immunosenesce in any response. 5. This study provides insight into the thermal biology of B cell function in sliders and provides an interesting connection between immunology, behavior, and ecology in this long-lived turtle.

1. 温度几乎会影响变温动物（ectotherms）生理机能的方方面面，包括其产生免疫应答（immune response）的能力。通常而言，变温脊椎动物的免疫系统可在较宽温度范围内发挥应答功能，但存在一个物种特异性的最佳温度，在此温度下免疫应答最强，高于或低于该阈值时应答功能均会受损。对于长寿变温动物而言，衰老也可能影响其应对温度变化的能力，因为免疫衰老（immunosenescence）——即免疫功能随年龄增长出现的功能性衰退——已有广泛报道。
2. 本研究针对一种长寿爬行动物——红耳滑龟（Trachemys scripta），探究了温度与年龄的交互作用对其B细胞（B cell）功能的影响。此前已有研究表明，该物种的B细胞主要具备两项功能：吞噬作用（phagocytosis）与抗体产生（antibody production）。
3. 研究人员捕获成年龟并采集血液样本。由于红耳滑龟终生均可生长，因此以腹甲（plastron）长度作为年龄的替代指标。研究人员分离出白细胞（leukocytes），分别用于酶联免疫斑点试验（ELISpot）以检测其自发或受刺激时的抗体产生能力，或用于吞噬功能检测试验。上述ELISpot试验与吞噬功能试验均在一系列生物学相关温度条件下开展。
4. 研究结果显示，年龄与温度的交互作用对B细胞功能的各项测量指标均无显著影响。所有测试中均观察到温度的显著效应：在29℃以下的温度环境中B细胞功能受损，而更高温度下则无功能受损现象。此外，本研究未发现任何免疫衰老相关的显著证据。
5. 本研究为红耳滑龟B细胞功能的热生物学特性提供了新的见解，同时也为该长寿龟类的免疫学、行为学与生态学之间的关联提供了有趣的研究视角。