Reticular connective tissue Reticular connective tissue Reticular connective tissue is a type of connective tissue with a network of reticular fibers, made of type III collagen ("reticulum" = net or network). Reticular fibers are not unique to reticular connective tissue, but only in this type are they dominant. Reticular fibers are synthesized by special fibroblasts called reticular cells. The fibers are thin branching structures. Reticular connective tissue is found around the kidney, the spleen, and lymph nodes, Peyer's patches as well as in bone marrow. The fibers form a soft skeleton (stroma) to support the lymphoid organs (lymph node stromal cells, red bone
Follicular dendritic cells Noncognate B cells play a significant role as an antigen transporter to FDCs. They capture immune complexes in CR1/2-dependent way either directly from the blood or from macrophages, and putate to the lymphoid tissue, where they upload FDCs with opsonized antigen. FDCs, in turn, attract B cells with chemoattractant CXCL13. B cells lacking CXCR5, the receptor for CXCL13, still enter the white pulp, but are mislocalized and disorganized. To generate follicular structures, FDCs need to be stimulated by lymphotoxin (LT), a mediator produced by B cells. The stimulation of CXCR5 on B cells upregulates LT production, which leads to FDCs