MCMV Infection Lowers the Threshold for the Development of Clinical GvHD After Allogeneic Bone Marrow Transplantation

The study investigated the impact of MCMV infection on the development of graft-versus-host disease (GvHD) following allogeneic bone marrow transplantation using a mouse model. It was found that MCMV infection led to generalized immune activation, increasing the number of donor-derived allo-reactive T cells and GvHD activity. Mice receiving untreated donor splenocytes developed GvHD characterized by weight loss and higher mortality, while those receiving Amotosalen-treated splenocytes showed more gradual T-cell expansion and sustained lymphoid reconstitution. The study concluded that CMV infection caused extensive expansion of allo-reactive T cells in GvHD+ mice, damaging the spleen and thymus microenvironment. Effective prophylaxis and treatment of GvHD in clinical transplantation would likely require improved management of CMV infection.