antigens

When an infective organism invades the tissues, a precise series of events are set up to limit spread of the foreigner and ultimately to destroy it. First a macrophage will encounter the intruder. It engulfs it and then ‘displays’ its characteristic proteins on the surface of the cell as a kind of “flag” or gotcha trophy. We call this chemical flag the antigen, since it generates the rest of the reaction. By means of chemical language (a sort of local hormone called a lymphokine), the macrophage attracts nearby T-helper lymphocytes. They ‘read’ the antigenic matter and go off to program B-cells to produce antibodies to this pattern. The antibody is our own, the good guys’ response, to lock onto antigen carriers and cripple them.

When an infective organism invades the tissues, a precise series of events are set up to limit spread of the foreigner and ultimately to destroy it. First a macrophage will encounter the intruder. It engulfs it and then ‘displays’ its characteristic proteins on the surface of the cell as a kind of “flag” or gotcha trophy. We call this chemical flag the antigen, since it generates the rest of the reaction. By means of chemical language (a sort of local hormone called a lymphokine), the macrophage attracts nearby T-helper lymphocytes. They ‘read’ the antigenic matter and go off to program B-cells to produce antibodies to this pattern. The antibody is our own, the good guys’ response, to lock onto antigen carriers and cripple them.