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R Pacasova

Publications and source records attributed to R Pacasova.

4 recordsLinked to original sources
PubMed1999

Cutting edge: requirement of class I signal sequence-derived peptides for HLA-E recognition by a mouse cytotoxic T cell clone.

The human nonclassical MHC class I molecule HLA-E has recently been shown to act as a major ligand for NK cell inhibitory receptors. Using HLA-E-expressing transgenic mice, we produced a cytotoxic T cell clone that specifically recognizes the HLA-E molecule. We report here that this T cell clone lyses HLA-E-transfected RMA-S target cells sensitized with synthetic class I signal sequence nonamers. Moreover, this T cell clone lyses human EBV-infected B lymphocytes, PHA blasts, and PBL, formally demonstrating the surface expression of HLA-E/class I signal-derived peptide complex on human cells. Furthermore, these data show that HLA-E complexed with class I signal sequence-derived peptides is not only a ligand for NK cell inhibitory receptors, but can also trigger cytotoxic T cells (CTL).

Animals↗
PubMed1999

Cell-surface expression and alloantigenic function of a human nonclassical class I molecule (HLA-E) in transgenic mice.

We have introduced the gene (E*01033) encoding the heavy chain of the human nonclassical MHC class I Ag, HLA-E, into the mouse genome. Two founder mice carry a 21-kb fragment, the others bear an 8-kb fragment. Each of the founder mice was mated to mice of an already established C57BL/10 transgenic line expressing human beta2-microglobulin (beta2m). Cell surface HLA-E was detected on lymph node cells by flow cytometry only in the presence of endogenous human beta2m. However, HLA-E-reactive mouse CTL (H-2-unrestricted) lysed efficiently the target cells originating from HLA-E transgenic mice without human beta2m, showing that the HLA-E protein can be transported to the cell surface in the absence of human beta2m, presumably by association with murine beta2m. Rejection of skin grafts from HLA-E transgenic mice demonstrates that HLA-E behaves as a transplantation Ag in mice. HLA-E transgenic spleen cells are effective in stimulating an allogeneic CTL response in normal and human classical class I (HLA-B27) transgenic mice. Furthermore, results from split-well analysis indicate that the majority of the primary in vivo-induced CTL recognizes HLA-E as an intact molecule (H-2-unrestricted recognition) and not as an HLA-E-derived peptide presented by a mouse MHC molecule, although a small fraction (ranging from 4 to 21%) of the primary in vivo-induced CTL is able to recognize HLA-E in an H-2-restricted manner. Based on these observations, we conclude that HLA-E exhibits alloantigenic properties that are indistinguishable from classical HLA class I molecules when expressed in transgenic mice.

Animals↗
PubMed1999

Cell surface detection of HLA-E gene products with a specific monoclonal antibody.

An HLA-E-specific monoclonal antibody (mAb) was obtained by immunization of human beta2-microglobulin transgenic mice (M-TGM) with spleen cells from double transgenic mice expressing HLA-E molecules (EM-TGM). This mAb, designated V16, specifically recognizes in flow cytometry analysis the HLA-E expressing mouse cells, whereas it does not bind to mouse cells expressing various HLA class I molecules (HLA-A2, -A3, -A11, -A26, A29, -B7, -B27, -Cw3, -Cw7, and HLA-G). V16 mAb binds efficiently to human EBV-infected B lymphocytes, PHA blasts and PBL, thus establishing the surface expression of HLA-E in vivo on these cells.

Animals↗