Bone marrow cell-dependency of delayed-type hypersensitivity response in mice infected with mouse hepatitis virus

The mechanisms underlying delayed-type hypersensitivity (DTH) response in mouse hepatitis virus (MHV) infection was studied using high responder B10.D2 and low responder DBA/2 mice. Bone-marrow chimeras expressed the DTH responses at the same degree as the donors. The involvement of suppressor cells in low DTH response in DBA/2 mice seems unlikely since transfer of DBA/2 spleen cells to B10.D2 mice did not suppress the response. Transfer of B10.D2 spleen cells to DBA/2 mice caused no changes in DTH response of the recipients. MHV-infected mice, which were irradiated with 500 rad of gamma-ray and then given B10.D2 bone-marrow cells 8 days p.i., showed higher DTH responses than those given DBA/2 bone-marrow cells. These results suggest that the difference in DTH responsiveness to MHV between the two mouse strains is dependent on the activity of bone-marrow cells.