Effect of concurrent graft-versus-host reaction on tissue distribution and infectious titer of murine cytomegalovirus.

Infection with cytomegalovirus is a major concern following bone marrow transplantation. Previously, we have described a model whereby infection by MCMV concurrent with the injection of parental strain lymphoid cells into F1 recipient mice results in a severe graft-versus-host reaction (GvHR) when the donor and host differ at the class I MHC locus (i.e., class I MHC disparate GvHR). The present studies were performed to determine whether one consequence of this severe GvHR is the alteration of the tissue distribution and/or levels of infectious virus as compared to mice not undergoing GvHR. Using PCR to detect MCMV DNA, it was observed that the tissue distribution of virus 3 days after injection was identical in recipients of virus alone and of GvHR plus virus inocula. At two weeks post injection, virus was recovered from the salivary gland and pancreas in both groups. In contrast to recipients of MCMV alone, lung tissue from GvHR plus virus mice also contained viral DNA. Notably, these results were corroborated by the plaque assay. Moreover, salivary gland and pancreas from recipients of GvHR plus virus were found to contain higher titers of infectious virus. In total, the data demonstrate that, with the notable exception of the lung, the distribution of virus was not changed in the animals despite the presence of a concurrent severe GvHR. However, viral replication in infected tissues appeared less restricted in these recipients.