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Residual expression of functional MHC class II molecules in twin brothers with MHC class II deficiency is cell type specific
Author(s) -
Wolf Hermann M.,
Thon Vojtech,
Gulle Heinz,
Lechleitner Sonja,
Eibl Martha M.,
Petzelbauer Peter
Publication year - 2001
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1046/j.1365-2141.2001.03105.x
Subject(s) - mhc class ii , immunology , major histocompatibility complex , cd1 , biology , mhc class i , antigen presenting cell , monocyte , cytotoxic t cell , human leukocyte antigen , immune system , dendritic cell , mhc restriction , t cell , antigen , in vitro , genetics
We examined major histocompatibility complex (MHC) class II expression in B cells, peripheral blood monocytes, activated T cells, epidermal Langerhans cells, monocyte‐derived dendritic cells, dermal microvascular endothelial cells (DMEC) and fibroblasts of twin brothers with MHC class II deficiency. Although residual human leucocyte antigen (HLA)‐DR expression was found on a subpopulation of epidermal Langerhans cells and a subset of peripheral blood monocyte‐derived dendritic cells, the patients' B cells, monocytes and activated T cells were HLA‐DR negative. After treatment with interferon‐γ (IFN‐γ), the patients' DMEC expressed HLA‐DR but not ‐DP and ‐DQ at the protein and mRNA level, whereas IFN‐γ failed to induce HLA‐DR expression on dermal fibroblasts. The patients' monocyte‐derived dendritic cells were capable of processing and presenting tetanus toxoid to autologous T cells, and patient‐derived DMEC induced the proliferation of allogeneic CD4 + T cells in an MHC class II‐restricted fashion, indicating that the observed residual MHC class II surface expression was functional. The findings reported show that the defect encountered in these patients is not necessarily expressed to the same extent in different cell lineages, which is relevant for the understanding of the patients' phenotype and also illustrates that only small amounts of MHC class II are needed to mount a functional cellular immune response in vivo .