Characterization of soluble folate receptors (folate binding proteins) in humans. Biological roles and clinical potentials in infection and malignancy.

Jan Holm, Steen Ingemann Hansen

Biochimica et biophysica acta. Proteins and proteomics 2020 Oct

filter terms:

This review surveys soluble Folate Receptors (FOLRs) in humans. FOLR1 and FOLR2 are equipped with cellular glycosylphosphatidylinositol (GPI) anchors. FOLR1 is secreted from epithelia with or without a micelle-encapsulated GPI-anchor into milk and other body fluids/secretions, e.g. semen where its interaction with spermatozoa indicates a role in male fertility. FOLR1 and FOLR2 serve as serum biomarkers of various diseases. FOLR3 possesses no GPI-anchor and originates from secretory granules of neutrophil granulocytes; its concentration in serum correlates to the FOLR3 content in leukocytes and rises with increased leukocyte counts (infection, malignancy and pregnancy). FOLR3 exerts anti-microbial and anti-tumor effects by depriving bacteria and tumor cells of natural folates. Megalin receptors mediate reabsorption of ultrafiltered folate-bound FOLR into cells of proximal kidney tubules and of folate-bound FOLR uptake in growing embryos. Megalin receptors overexpressed in malignant tumors could be suitable therapeutic targets for folate-conjugated cytotoxic agents utilizing soluble FOLRs as vectors. Copyright © 2020 Elsevier B.V. All rights reserved.

Citation

Jan Holm, Steen Ingemann Hansen. Characterization of soluble folate receptors (folate binding proteins) in humans. Biological roles and clinical potentials in infection and malignancy. Biochimica et biophysica acta. Proteins and proteomics. 2020 Oct;1868(10):140466