Showing papers on "Antigen processing published in 1972"
TL;DR: The positive immunogenic role of macrophages is related to their capacity to remove extracellular antigen, which might be capable of interacting with and eliminating isolated T or B lymphocytes and retain antigen in lymphoid tissues and promote its necessary meeting with both T and B cells.
Abstract: Publisher Summary This chapter focuses on the role of the macrophage in removing antigen from extracellular fluids, degrading the larger part of this antigen while presenting a small part of it in persisting immunogenic form. This handling of antigen is done without contributing to the specificity of the immune response, which is determined by the antigenreactive T and B lymphocytes. During the process of uptake of antigen, macrophages appear to retain a few molecules of antigen, undegraded or with few chemical changes. Macrophage-associated antigen becomes an effective immunogenic stimulus mainly in conditions that require two types of lymphocytes to meet with antigen molecules. These lymphocytes are specifically antigen-committed and few in number. The positive immunogenic role of macrophages is related to their capacity to (1) remove extracellular antigen, which might be capable of interacting with and eliminating isolated T or B lymphocytes and (2) retain antigen in lymphoid tissues and promote its necessary meeting with both T and B cells.
574 citations
TL;DR: The data suggest that sufficient crosslinking of receptors by the antigen to cause their aggregation triggers the cell to differentiate and to increase its density of antigen receptors, in the presence of antigen concentrations favoring high zone tolerance.
Abstract: The rate of antigen binding by mouse lymphoid cells has been investigated with polymerized flagellin of Salmonella adelaide that had been biosynthetically labeled with tritium. Autoradiographs of lymphnode cells incubated with the tritiated antigen at 37° showed aggregation of antigen receptors to one cell pole. This was followed 4-5 hr later by the appearance of antigen receptors on the cell surface, at a density severalfold higher than at the time of first contact with the antigen. Antigen-binding cells exposed in vitro to antigen concentrations known to cause high zone tolerance induction failed to form polar antigen caps once they had entered the phase of increased receptor formation. The data suggest that sufficient crosslinking of receptors by the antigen to cause their aggregation triggers the cell to differentiate and to increase its density of antigen receptors. In the presence of antigen concentrations favoring high zone tolerance, receptors may become interlinked to such an extent that they are prevented from aggregation. Such a “frozen” state of the antigen recognition system would render the cell unresponsive to antigenic stimuli.
67 citations
Journal Article•
TL;DR: The results are interpreted as suggesting that competition occurs at the level of the antigen `processing' or `localizing' step in the immune response.
Abstract: Antigenic competition between two haptenic determinants was studied. It was shown that antigenic competition was greater if a 1- or 2-week interval is imposed between injection of the two antigens. Preimmunization with one antigen or with the carrier protein to which one hapten is coupled will decrease the effect of antigenic competition on the antibody response to that antigen or hapten and bring about a greater degree of depression of the antibody response to the second haptenic determinant. Finally, antigenic competition does not occur if the two antigens are injected so as to drain into different groups of regional lymph nodes. This is true even if a 3- or 7-day time interval is imposed between injection of the two antigens.
The results are interpreted as suggesting that competition occurs at the level of the antigen `processing' or `localizing' step in the immune response.
16 citations
3 citations