title: Subclinical GvHD in non-irradiated F1 hybrids: severe lymphoid-tissue GvHD causing prolonged immune dysfunction.
abstract: GvHD is an important complication of allogeneic hematopoietic SCT. Parent-in-F1 models are frequently used to study GvHD immunobiology; the characteristics of parent-in-F1 GvHD vary between strain combinations and induction protocols. Here, we observed that a high-dose challenge of non-irradiated B6DBA2F1 and B6SJLF1 recipients with C57BL/6 splenocytes left the majority of recipients clinically healthy, while inducing progressive high-grade donor T-cell chimerism. We investigated this previously undescribed pattern of parent-in-F1 T-cell alloreactivity and studied the effect of serial parental splenocyte infusions on epithelial and lymphohematopoietic tissues. The majority of recipients of 4 weekly splenocyte infusions showed long-term survival with gradual establishment of high-grade donor chimerism and without any signs of epithelial-tissue GvHD. A minority of recipients showed BM failure type of GvHD and, respectively, graft rejection. Moreover, long-term F1 chimeras showed protracted pancytopenia, and in peripheral lymphoid tissues severe lymphopenia and near-complete eradication of APCs and dysfunction in antigen-presenting capacity in remaining APC. Hematopoiesis and lymphoid tissue composition recovered only after multilineage donor chimerism had established. In conclusion, we report on a novel type of parent-in-F1 hybrid GvHD, where a cumulative high dose of C57BL/6 parental splenocytes in non-irradiated F1 mice induces subclinical but severe hematolymphoid-tissue GvHD, causing prolonged immuno-incompetence.
authors.affiliation: Laboratory of Experimental Transplantation, University of Leuven, Leuven, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Sprangers
authors.forename: B
authors.initials: B
authors.lastname: Van Wijmeersch
authors.forename: A
authors.initials: A
authors.lastname: Luyckx
authors.forename: X
authors.initials: X
authors.lastname: Sagaert
authors.forename: B
authors.initials: B
authors.lastname: Verbinnen
authors.forename: O
authors.initials: O
authors.lastname: Rutgeerts
authors.forename: C
authors.initials: C
authors.lastname: Lenaerts
authors.forename: T
authors.initials: T
authors.lastname: Tousseyn
authors.forename: B
authors.initials: B
authors.lastname: Dubois
authors.forename: M
authors.initials: M
authors.lastname: Waer
authors.forename: A D
authors.initials: AD
authors.lastname: Billiau
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000473:pathology; D017690:Cell Transplantation / Q000009:adverse effects*; D002678:Chimera; D006084:Graft Rejection; D006086:Graft vs Host Disease / Q000276:immunology*; D007107:Immune System / Q000473:pathology; D008221:Lymphoid Tissue / Q000276:immunology / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology*