Anti-Human CD71 [Clone OKT-9] – Purified in vivo GOLD™ Functional Grade

Human acute lymphocytic leukemia cells

This monoclonal antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4 with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of antibodies, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.

Liquid

Functional grade preclinical antibodies are manufactured in an animal free facility using only in vitro protein free cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.

Functional grade preclinical antibodies may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.

Research Use Only

2 – 8° C Wet Ice

OKT-9 activity is directed against human CD71, the T cell transferrin receptor. OKT- 9 reacts with approximately 10% of normal human thymocytes, specifically immature thymic lymphocytes and their corresponding leukemias.

CD71 is a transferrin receptor that mediates cellular proliferation by promoting iron uptake^1,2. Iron uptake occurs when diferric transferrin binds to CD71 at the cell surface, the transferrin-iron complex is internalized by endocytic vesicles, and the diferric iron is released into the cytoplasm^1,3,4. CD71 is highly expressed on malignant cells, as iron uptake is necessary for aberrant cell proliferation⁵. Additionally, CD71 is involved in the pathogenesis of clade B New World mammarenaviruses (NWM), which cause the South American hemorrhagic fevers⁶. NWM viruses share a binding site on the apical domain of CD71, and blockade of this site is a research target for producing a broadly neutralizing immunotherapy.

OKT-9 was generated by immunizing CAF₁ mice with human T cell leukemia cells (acute lymphoblastic leukemia, T-ALL cells) from donor patients^7,8. Hybridomas were produced by fusing the resulting splenocytes with P3X63Ag8U1 myeloma cells and screening by indirect immunofluorescence. OKT-9 reactivity was shown to correlate with proliferation status in both normal and malignant cell populations⁸.

OKT-9 has been found to target the same apical domain of CD71 as NWM viruses and can sterically block cellular entry of clade B NWM viral particles by blocking the GP1-CD71 interaction⁶. This in turn reduces cellular infection and presents an opportunity for the development of an immunotherapeutic agent capable of broad viral neutralization.

CD71 is expressed on the surface of proliferating cells, reticulocytes, erythroid precursors, cerebral capillaries, blood brain barrier endothelia, neurons of all cortical layers and in the brain stem, Schwann cells, and some macrophages.

Receptor: CD71 / Ligand: Transferrin

1 Aisen P. Int J Biochem Cell Biol. 36(11):2137-2143. 2004.
2 Lawrence CM, Ray S, Babyonyshev M, et. al. Science. 286(5440):779-782. 1999.
3 Dautry-Varsat A, Ciechanover A, Lodish HF. Proc Natl Acad Sci U S A. 80(8):2258-2262.1983.
4 Marsee DK, Pinkus GS, Yu H. Am J Clin Pathol. 134(3):429-435. 2010.
5 Candelaria PV, Leoh LS, Penichet ML, et al. Front Immunol. 12:607692. 2021
6 Ferrero S, Flores MD, Short C, et al. J Virol. 95(17):e0186820. 2021.
7 https://patents.google.com/patent/US4364934A/en
8 Sutherland R, Delia D, Schneider C, et al. Proc Natl Acad Sci U S A. 78(7):4515-4519. 1981.
9 Reinherz EL, Kung PC, Goldstein G, et al. Proc Natl Acad Sci U S A. 77(3):1588-1592. 1980.
10 Panaccio M, Zalcberg JR, Thompson CH, et al. Immunol Cell Biol. 65 (Pt 6):461-472. 1987.
11 Fuchs H, Orberger G, Tauber R, et al. J Immunol Methods. 188(2):197-208. 1995.