Border of a marginal zone in spleen (rat)

Stain: Immunoelectron microscopy (gold labeling of heparan sulfate in Lowicryl embedding, using the single chain antibody HS4C3). The zone of red pulp immediately surrounding a lymphatic nodule is called the marginal zone (perilymphoid zone) and is composed of a scaffold of basal lamina material where a dendritic cell cytoplasm (antigen-presenting cell, APC) (1) and its cell projections are protruding into a capillary with thin lining cells (2) belonging to the system of anastomosing vascular channels at the border between the white and red pulp. (3) erythrocyte. Arrows indicate parts of sectioned scaffold consisting of thin basal lamina material where electron-dense particles of heparan sulfate molecules are localized (only visible by enlargement of this image). The glycosaminoglycan heparan sulfate is generally integrated in these scaffolds of basal laminae and is secreted by the lining cells.