Immunophenotyping fish-to-mouse islet xenograft rejection: a time course study.
Tilapia islets, Brockmann bodies (BBs), transplanted under the kidney capsule (KC) of diabetic nude mice provide long-term normoglycemia, but, when transplanted into euthymic mice, reject in about one week.


OBJECTIVE
The present study characterizes the cellular infiltrates at several time points during the xenograft rejection process.


METHODS
Tilapia BBs were harvested, fragmented, cultured overnight, and then transplanted under the KC of streptozotocin-diabetic Balb/c mice. Glucose levels were measured daily until the mice were killed at 1 (n = 2), 2 (n = 2), 3 (n = 3), and 5 days (n = 3) post transplantation and at the time of BB graft rejection (n = 6). Serial frozen sections of graft-bearing kidneys were stained for murine macrophages (MOMA-2, F4/80, M170), CD4+ (L3T4) T-cells (YTS 191.1), and CD8+ (Ly-2) T-cells (YTS 169.4) by indirect immunoperoxidase; the presence of granulocytes and plasma cells was assessed with H&E stained sections.


RESULTS
At 1 day, the grafts have undergone some central necrosis with macrophage infiltration. By 2 days, these changes are very well-developed and granulocytes, almost exclusively eosinophils, begin to surround the graft. At 3 days, rare CD4+ and CD8+ T-cells are seen at the graft kidney interface. Macrophages massively infiltrate the necrotic foci and pepper the graft. At 5 days and at rejection, macrophages and eosinophils predominated in the center of rejecting grafts while CD8+ T-cells and CD4+ T-cells were present at the periphery. Plasma cells were rare.


CONCLUSIONS
We conclude that cell-mediated processes and eosinophils play roles in the rejection of cellular xenografts across this very wide phylogenetic barrier.
Wright
J R
JR
Department of Pathology, Izaak Walton Killam-Grace Health Centre, Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada. jwright@iwkgrace.ns.ca
Kearns
H
H
Yang
H
H
Fraser
R B
RB
Colp
P
P
Rowden
G
G
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000601:surgery*; D006084:Graft Rejection / Q000276:immunology* / Q000473:pathology; D016130:Immunophenotyping; D007515:Islets of Langerhans / Q000166:cytology; D016381:Islets of Langerhans Transplantation / Q000276:immunology* / Q000473:pathology / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology; D017210:Tilapia; D013997:Time Factors; D014183:Transplantation, Heterologous / Q000276:immunology* / Q000473:pathology / Q000502:physiology
D001786:Blood Glucose