Development of a major histocompatibility complex class II conditional knockout mouse to study cell-specific and time-dependent adaptive immune responses in peripheral nerves

Abstract

AbstractIntroductionMajor histocompatibility complex (MHC) class II professional antigen presenting cell-naïve CD4+ T cell interactions via the T-cell receptor complex are necessary for adaptive immunity. MHC class II upregulation in multiple cell types occurs in human autoimmune polyneuropathy patient biopsies, necessitating studies to ascertain cellular signaling pathways required for tissue-specific autoimmunity.MethodsCryopreserved Guillain-Barré syndrome (GBS) patient sural nerve biopsies and sciatic nerves from the severe murine experimental autoimmune neuritis (sm-EAN) GBS model were studied. Cultured conditional ready MHC Class II antigen A-alpha chain (H2-Aa) embryonic stem cells were used to generate H2-Aaflox/+C57BL/6 mice. Mice were backcrossed and intercrossed to the SJL background to generate H2-Aaflox/floxSJL mice, bred with hemizygous Tamoxifen-inducible von Willebrand factor Cre recombinase (vWF-iCre/+) SJL mice to generate H2-Aaflox/flox; vWF-iCre/+ to study microvascular endothelial cell adaptive immune responses. Sm-EAN was induced in adult female SJL Tamoxifen-treated H2-Aaflox/flox; vWF-iCre/+ mice and H2-Aaflox/flox; +/+ littermate controls. Neurobehavioral, electrophysiological and histopathological assessments were performed at predefined time points.ResultsEndoneurial endothelial cell MHC class II expression was observed in normal and inflamed human and mouse peripheral nerves. Adult female Tamoxifen-treated H2-Aaflox/flox; vWF-iCre/+ did not develop sm-EAN despite extensive MHC class II expression in lymphoid and non-lymphoid tissues.DiscussionA conditional MHC class II knockout mouse to study cell- and time-dependent adaptive immune responsesin vivois developed. Initial studies show microvascular endothelial cell MHC class II expression is necessary for peripheral nerve specific autoimmunity, as advocated by humanin vitroadaptive immunity andex vivotransplant rejection studies.