Environmental regulation of T-cell function in mice: Group housing of males affects accessory cell function

Abstract

The number of mice housed in a cage was found to exert a major impact on immune function in male mice. Lymph node cells from hen lysozyme (HEL)-primed C57BL/6 male mice, housed in groups of 6/cage or individually, were tested for T-cell proliferative response. Group-housed males showed markedly lower responses than age-matched females. However, in males housed singly for 4-15 weeks, responses were considerably higher, approaching those of female controls. To examine the cellular site of action of the housing effect, the efficiency of splenic antigen-presenting cells (APC) was examined. APC from grouped males were considerably less efficient than APC from females, whereas males housed singly; had increased APC function, reaching female levels. Our results demonstrate that environmental manipulation can profoundly modulate cellular immunity, and provide a first mechanistic indication that APC function is a major target for this modulation.