Donor Fibroblast Chimerism in Animal Model of Ocular Chronic Graft versus Host Disease

Abstract

Purpose: : Immune response and excessive fibrosis are prominent features of chronic graft-versus-host disease (GVHD) following allogeneic hematopoietic stem cell transplantation (HSCT). We investigated whether the fibroblasts increased at the site of pathogenic fibrosis originated from transplanted donor cells in animal model of chronic GVHD.

Methods: : Lacrimal gland and conjunctival specimens were obtained from Balb/c female recipient mice with chronic GVHD mediated fibrosis. The male-specific sequences detected by fluorescein in situ hybridization (FISH) and HSP47 immunostaining were used as markers for the donor fibroblasts in 5 female recipient mice that had received a transplant from male B10.D2 mice and male Balb/c mice as control. Primary fibroblast cultures were generated from 3 lacrimal gland and conjunctival specimens from GVHD mice and controls and examined for mismatched genetic markers between recipients and donors. Fibrotic areas were analyzed using tissue section by mallory staining both at 3 weeks and 8 weeks after HSCT in allogeneic HSCT compared with syngeneic HSCT.

Results: : Fibrotic areas were gradually increasing after HSCT in allogenic HSCT compared to controls. In lacrimal gland and conjuctival specimens obtained from 5 female Balb/c mice that received a sex-mismatched transplant, HSP47+ fibroblasts that accumulated in the fibrotic lesion were donor-derived, as determined by FISH for the Y-chromosome. Primary lacrimal gland and conjunctival fibroblast showed the presence of donor-origin of the fibroblasts by detecting the Y-chromosome sequence.

Conclusions: : These findings together indicate the chimeric status of accumulated HSP47+ fibroblasts in ocular chronic GVHD mice. Fibroblasts originated from circulating donor-derived precursors may participate in the excessive fibrosis in animal model of ocular chronic GVHD. These findings in animal model of chronic GVHD are useful for analyzing some aspects of pathology on human ocular chronic GVHD.

Keywords: lacrimal gland • cell-cell communication • cornea: tears/tear film/dry eye