Mechanism of follicular antigen trapping. Migration of antigen-antibody complexes from marginal zone towards follicle centres.

In spleens of normal mice transport of immune complexes takes place from the marginal zone towards the follicle centres. Some hours after an injection with paratyphoid vaccine the marginal zone in the spleen of mice shows a significant lack of lymphoid cells. In such mice trapping of immune complexes in lymphoid follicles is severely inhibited or delayed. These results strongly support the idea that lymphoid cells carry immune complexes from the marginal zone towards follicle centres. A strong follicle centre reaction induced with paratyphoid vaccine did not remove previously trapped immune complexes, confirming that once trapped, immune complexes are well fixed in follicle centres.