FcεRI-mediated antigen endocytosis turns interferon-γ-treated mouse mast cells from inefficient into potent antigen-presenting cells

Previous studies in our laboratory have shown that bone-marrow-derived mast cells (BMMC) could present immunogenic peptides, from soluble antigens endocytosed through fluid phase, only if they were subjected to a 48-hr treatment with interleukin-4 (IL-4) and granulocyte–macrophage colony-stimulating factor (GM-CSF). In contrast to GM-CSF, interferon-γ (IFN-γ) which highly upregulates major histocompatibility complex (MHC) class II expression, completely inhibits the generation of immunogenic peptides. We have used this model to study the role of FcεRI-mediated antigen internalization in the regulation of the antigen-presenting function of IFN-γ-treated mast cells. Here, we report that FcεRI can reverse the IFN-γ-treated mast cells from inefficient to highly efficient antigen-presenting cells. Inhibition of the antigen presenting capacity by piceatannol, a protein tyrosine kinase (PTK) syk inhibitor, indicates that this is an active process resulting from immunoglobulin E (IgE)–antigen–FcεRI engagement which involves tyrosines found in the immunoreceptor tyrosine-based activation motif (ITAM) embedded in the cytoplasmic tail of the FcεRI β and γ chains. Antigen-presenting function was also shown to require the activation of phosphatidyl inositol 3 (PI3) kinase, downstream of PTK syk phosphorylation, since this activity was completely blocked by wortmannin, a PI3 kinase inhibitor. These data suggest that signalling generated by FcεRI provides mast cells with IgE-mediated enhanced antigen presentation to T cells and emphasize a so far unknown immunoregulatory mast-cell function that might take place in inflammatory sites

Global transformations of the state, governance and teachers’ labour: Putting Bernstein’s conceptual grammar to work

This paper presents and engages with Basil Bernstein’s rich conceptual grammar in order to generate a sociological account of the outcomes for teachers’ work, identity and social class, of strategic shifts in governance to the global scale. Our aim is to develop a two-way conversation between Bernstein’s conceptual grammar and how best to theorise the nature of the social regulation of teachers as a result of the dominance of the Organisation for Economic Cooperation and Development (OECD) in setting the rules for pedagogic governance of teachers through its Teaching and Learning International Survey (TALIS). We show that important functions for symbolic agents have been relocated to the economic arena away from the state, as well as being rescaled to sit within the governing ambit of the OECD. We also reflect on the prominence of constructivism in TALIS as a preferred pedagogy and the eschewing of disciplinary knowledge as the basis of expertise. We ask what this new market identity means for teacher knowledge, consciousness, identity, the division of labour, and the social base. </jats:p