Induction of Graft-versus-host Disease and <em>In Vivo</em> T Cell Monitoring Using an MHC-matched Murine Model

Abstract

Graft-versus-host disease (GVHD) is the limiting barrier to the broad use of bone marrow transplant as a curative therapy for a variety of hematological deficiencies. GVHD is caused by mature alloreactive T cells present in the bone marrow graft that are infused into the recipient and cause damage to host organs. However, in mice, T cells must be added to the bone marrow inoculum to cause GVHD. Although extensive work has been done to characterize T cell responses post transplant, bioluminescent imaging technology is a non-invasive method to monitor T cell trafficking patterns in vivo.Following lethal irradiation, recipient mice are transplanted with bone marrow cells and splenocytes from donor mice. T cell subsets from L2G85.B6 (transgenic mice that constitutively express luciferase) are included in the transplant. By only transplanting certain T cell subsets, one is able to track specific T cell subsets in vivo, and based on their location, develop hypotheses regarding the role of specific T cell subsets in promoting GVHD at various time points. At predetermined intervals post transplant, recipient mice are imaged using a Xenogen IVIS CCD camera. Light intensity can be quantified using Living Image software to generate a pseudo-color image based on photon intensity (red = high intensity, violet = low intensity).Between 4-7 days post transplant, recipient mice begin to show clinical signs of GVHD. Cooke et al.1 developed a scoring system to quantitate disease progression based on the recipient mice fur texture, skin integrity, activity, weight loss, and posture. Mice are scored daily, and euthanized when they become moribund. Recipient mice generally become moribund 20-30 days post transplant.Murine models are valuable tools for studying the immunology of GVHD. Selectively transplanting particular T cell subsets allows for careful identification of the roles each subset plays. Non-invasively tracking T cell responses in vivo adds another layer of value to murine GVHD models.

Spatio-Temporal Bone Remodeling after Hematopoietic Stem Cell Transplantation

“…The clinical aGVHD score was assessed by the summation of individual score numbers of five clinical parameters (weight loss, posture, activity, fur texture and skin integrity) according to the established Cooke grading system [ 45 , 46 ]. Each clinical parameter was rated on a scale of 0–2 and mice were sacrificed when their total score exceeded 6, or if one parameter reached a score of 2.…”

Multipotentialmesenchymal Stromal Cells (MMSC) Ameliorate Graft versus Host Disease (GVHD) in a Mouse Model, But Major Suppression of GVHD Permits Leukemic Relapse

“…In vitro, MMSC suppress lymphocyte proliferation [35] and produce immunomodulatory factors [59]. In vivo, MMSC are immunomodulatory and alter immune cell populations [60] [61]. These immune cell populations play significant roles in engraftment and GVHD [62] including in xenogeneic GVHD [63].…”