We introduce a new model for the dynamics of centroblasts and centrocytes in a germinal
center. The model reduces the germinal center reaction to the elements considered as
essential and embeds proliferation of centroblasts, point mutations of the corresponding
antibody types represented in a shape space, differentiation to centrocytes, selection with
respect to initial antigens, differentiation of positively selected centrocytes to plasma or
memory cells and recycling of centrocytes to centroblasts. We use exclusively parameters …