Intestinal B cells in the red-eared slider turtle, Trachemys scripta: Anatomical distribution and implications for...

Area of Science:

• Immunology
• Herpetology
• Microbiology

Background:

• Reptile species face significant disease threats, impacting global populations.
• Aquatic reptiles inhabit pathogen-rich environments, but their immune systems remain poorly understood.
• Mammalian gut immunity relies on mucosal B cells and antibodies, but reptile equivalents are unknown.

Purpose of the Study:

• To investigate the presence and distribution of B cells in the intestinal tissues of red-eared slider turtles (Trachemys scripta).
• To determine if these B cell structures are inducible in response to microbial exposure.

Main Methods:

• Whole-mount immunochemistry using an antibody against turtle antibody light chains to detect B cells.
• Analysis of intestinal tissues from hatchling turtles, comparing proximal and distal sections.
• Introduction of Salmonella species via oral gavage to assess immune response.

Main Results:

• Widely distributed B cell aggregates, resembling mammalian isolated lymphoid follicles (ILFs), were identified in the small intestine.
• These ILF-like structures were more frequent in distal intestinal sections.
• Salmonella exposure significantly increased the number of these B cell aggregates.

Conclusions:

• This study provides the first evidence of B cell-containing ILF-like structures in reptiles.
• These findings offer novel insights into the gut immunity of nonmammalian vertebrates.
• Understanding reptile gut immunity is crucial for addressing ecological interactions with pathogens and conservation efforts.