Graft versus Host Disease in the Bone Marrow, Liver and Thymus Humanized Mouse Model

Matthew B Greenblatt,Antonios O Aliprantis,Kelly Tsang,Andrew M Tager,Vladimir Vbranac,Trevor Tivey,Cheryl A Stoddart

doi:10.1371/journal.pone.0044664

Abstract

Mice bearing a “humanized” immune system are valuable tools to experimentally manipulate human cells in vivo and facilitate disease models not normally possible in laboratory animals. Here we describe a form of GVHD that develops in NOD/SCID mice reconstituted with human fetal bone marrow, liver and thymus (NS BLT mice). The skin, lungs, gastrointestinal tract and parotid glands are affected with progressive inflammation and sclerosis. Although all mice showed involvement of at least one organ site, the incidence of overt clinical disease was approximately 35% by 22 weeks after reconstitution. The use of hosts lacking the IL2 common gamma chain (NOD/SCID/γc−/−) delayed the onset of disease, but ultimately did not affect incidence. Genetic analysis revealed that particular donor HLA class I alleles influenced the risk for the development of GVHD. At a cellular level, GVHD is associated with the infiltration of human CD4+ T cells into the skin and a shift towards Th1 cytokine production. GVHD also induced a mixed M1/M2 polarization phenotype in a dermal murine CD11b+, MHC class II+ macrophage population. The presence of xenogenic GVHD in BLT mice both presents a major obstacle in the use of humanized mice and an opportunity to conduct preclinical studies on GVHD in a humanized model.

Highlights

Humanized mice have proven to be a valuable model that enables both the study of human-specific diseases such as HIV and the experimental manipulation of human cells in vivo [1,2,3]
graft versus host disease (GVHD) in NOD SCID (NS) and NOD SCID cc2/2 (NSG) BLT mice developed via a stereotypic order of events (Figure 1)
Skin involvement is characterized by a lymphocytic infiltrate of the epidermis, hair follicle, and dermal/subcutaneous junction with corresponding dropout of hair follicles, loss of subcutenaous fat, epidermal hyperplasia and hyalinization of dermal collagen, features similar to those observed in human GVHD or scleroderma (Figure 1C, Information S1)

Summary

Introduction

Humanized mice have proven to be a valuable model that enables both the study of human-specific diseases such as HIV and the experimental manipulation of human cells in vivo [1,2,3]. The nonobese diabetic/severe combined immunodeficiency (NOD/SCID, hereafter NS) model, whereby immunodeficient NS or NOD Rag22/2 mouse hosts are reconstituted with human CD34+ cells, has been widely used and informative [2] Advances on this model include the use of NOD/SCID/cc2/2 (hereafter, NSG) hosts where deficiency for the IL2 receptor gamma chain promotes improved engraftment [1,4,5]. As the technology of humanized mice as a platform to study T and B cells advances and donor cellular function improves, these advances will be met with commensurate increases in the incidence of GVHD. The occurrence of GVHD simultaneously presents an opportunity for the experimental study of GVHD and similar fibrotic autoimmune disorders, such as slceroderma, in a humanized system

Methods

Results

Conclusion