Quantitative differences in interleukin-2 and interleukin-4 production by antigen-stimulated splenocytes from individually- and group-housed mice.

The effects of differential housing on T-helper (TH) cell activation were investigated. BALB/c and C57Bl/6 male mice housed 1 or 4 per cage were administered three i.p. injections of keyhole limpet hemocyanin (KLH) over several weeks. Effects of differential housing on in vitro antigen-specific interleukin (IL)-2 (a TH1 cell derived cytokine) and IL-4 (a TH2 cell derived cytokine) production were observed. BALB/c mice housed alone produced significantly more IL-4 than BALB/c mice housed in groups. C57Bl/6 mice housed alone produced significantly more IL-2 than C57Bl/6 mice housed in groups. Differential housing did not influence either IL-2 production among BALB/c mice or IL-4 production among C57Bl/6 mice. These data demonstrate that environmental conditions can influence cytokine production by both TH-1 dominant (C57Bl/6) and TH-2 dominant (BALB/c) mice.