Cluster Of Differentiation 320 (CD320)

Transcobalamin II (TCN2), a plasma protein secreted by endothelial cells, binds the cobalamin absorbed in the distal ileum and carries 10 to 30% of total circulating cobalamin. CD320 encodes a transcobalamin receptor that binds TCN2-cobalamin at the plasma membrane and internalizes the complex by endocytosis .Functional analysis by Li et al. (2000) indicated that expression of 8D6 enhanced B-cell proliferation and immunoglobulin secretion. Treatment of the FDC cell line and a lymphoma cell line coculture with anti-8D6 resulted in at least partial inhibition of lymphoma growth. Li et al. (2000) proposed that antagonists of the 8D6 signaling pathway may counter the growth of follicular lymphomas or other tumors that metastasize to lymphoid follicles.