Immune Deficiency Affects Juvenile Social Behavior in Mice and Is Altered by Splenocyte Transfer
K. M. Quinnies1, K. H. Cox1,2 and E. Rissman3, (1)Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, (2)Reproductive Endocrine Unit, Massachusetts General Hospital, Boston, MA, (3)University of Virginia School of Medicine, Charlottsville, VA
Background: Severe Combined Immunodeficiency (SCID) mice are frequently used for immunological research, however, little behavioral work has been conducted using these mice. Although SCIDs grow and develop normally, adults display impaired learning in comparison to wild type C57BL/6 mice, which can be rescued with splenocyte transfer, and more specifically T cell replacement. It has been hypothesized that immune deficiency is linked to autism spectrum disorders.
Objectives: To test whether juvenile social behaviors are altered in mice with severe immune deficiency and determine whether an injection of healthy splenocytes modifies behavioral differences.
Methods: Male SCID and wild-type (WT) C57BL/6J mice were tested for social and anxiety behaviors between postnatal days 21 and 27 (after weaning but before puberty onset) in an elevated plus maze, social preference task, and social recognition task. A second group of mice received splenocyte transfers from an age matched C57BL/6J mouse, and behavior was evaluated in these groups as well.
Results: Young SCID mice spent more time investigating a novel mouse than did C57BL/6J juveniles, displayed impaired responses to unfamiliar mice in the social recognition task and were more anxious than controls in the elevated plus maze.
A second set of SCID mice received saline or donor splenocytes on post-natal day 7. When tested in the same tasks, splenocyte transfer changed behavior in the social recognition task, and the social preference task. In the social recognition task, behavior was rescued to that of a C57BL/6J mouse with an intraperitoneal injection of healthy splenocytes on P7. Following the injection SCID mice that received splenocytes had a reduced preference in the social novelty task compared to C57BL/6J mice and SCID mice that did not receive splenocytes.
Conclusions: These data reveal that the immune system is important for juvenile social behavior related to autism spectrum disorders and that splenocyte transfer can mitigate some of these social deficits.