The effect of environmental temperature on reptilian peripheral blood B cell functions

• Published in: Hormones and behavior 2017-02, Vol.88, p.87-94
• Main Authors: Palackdharry, Sarah, Sadd, Ben M., Vogel, Laura A., Bowden, Rachel M.
• Format: Article
• Language: English
• Subjects: Animals; B cell; B-Lymphocytes - physiology; Environment; Immune function; Immune System - physiology; Phagocytosis; Phagocytosis - immunology; Red-eared slider turtle; Temperature; Turtles - immunology
• ISSN: 0018-506X; 1095-6867
• DOI: 10.1016/j.yhbeh.2016.10.008

Recent studies have identified phagocytic B cells in a variety of species, yet little is understood about their function and how it is influenced by natural environmental variation, such as temperature. Phagocytic B-cells are present in red-eared slider turtles, Trachemys scripta, and the wide range of temperatures experienced by these ectotherms may have an effect on immunity, including B cell antibody secretion and phagocytosis. We examined the impact of environmental temperature on B cell function in vitro using phagocytic and ELISpot assays conducted at biologically relevant temperatures. We found a significant effect of temperature on antibody secretion, with maximal antibody secretion occurring at intermediate temperatures (estimated maximum of 28.8°C). There was no effect of temperature on phagocytosis. We also noted a difference in the efficiency of phagocytosis in this assay between B cells and non-B cells. Interestingly, in our in vitro assay, phagocytic B cells engulfed more foreign fluorescent beads per cell than phagocytes lacking surface immunoglobulin. This work sheds light on our understanding of phagocytic B cells and the importance of environmental temperature on the behavior of reptilian immune cells, which may have relevance for organismal fitness. •Ectotherm physiology can be sensitive to changes in temperature.•We examined temperature and B cell immune function in red-eared sliders.•Temperature affected B cell antibody secretion but not phagocytic ability.•Phagocytosis by B cells was greater than by professional phagocytes in our assay.•Behavioral thermal modifications may allow ectotherms to fine-tune their immunity.