Use of molecular modeling and site-directed mutagenesis to define the structural basis for the immune response to carbohydrate xenoantigens.

Background: Natural antibodies directed at carbohydrates reject porcine xenografts. They are initially expressed in germline configuration and are encoded by a small number of structurally-related germline progenitors. The transplantation of genetically-modified pig organs prevents hyperacute rejection, but delayed graft rejection still occurs, partly due to humoral responses.

Transforming growth factor-beta/interleukin-2-induced regulatory CD4+ T cells prolong cardiac allograft survival in rats.

Background: Treatment of naive CD4+ T cells in vitro with transforming growth factor-beta (TGF-beta) or TGF-beta/interleukin-2 (IL-2), combined with stimulation in a mixed lymphoid culture (MLC), has been shown to generate CD4+ CD25+ regulatory T cells. However, little is known about the effect of these regulatory T cells on cardiac allograft survival in vivo.

Methods: CD4+ CD25+ T cells were generated from Lewis (LEW) rat spleen through a primary MLC with TGF-beta (10 ng/ml) or TGF-beta/IL-2 (10 U/ml).

Identification, functional analysis and expression in a heterotopic heart transplant model of CXCL9 in the rat.

CXCR3 chemokines are of particular interest because of their potential involvement in a variety of inflammatory diseases, including the rejection of organ transplants. Although the rat is one of the most appropriate animals for using to study transplantation biology, the structural and functional characteristics of CXCL9 [monokine induced by interferon-gamma (Mig)] in this experimental model have not been described. Therefore, we recently conducted a series of experiments to identify and characterize the rat CXCL9 gene.