Anti-RSV F protein (Palivizumab) – Fc Muted™

Human RSV strain A2

This biosimilar 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

Recombinant biosimilar 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 (RUO). Non-Therapeutic.

2-8°C Wet Ice

Palivizumab binds to an epitope present in Site II, on the linear region of the F₁ subunit, of both the prefusion and postfusion forms of RSV F protein.

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection and hospitalization in infants¹. RSV F protein is a type I integral membrane protein essential for viral membrane fusion that is highly conserved among isolates of RSV A and B subgroups². F protein has been investigated as a target for neutralizing antibodies, small molecular antiviral drug development, as a vaccine antigen, and as an antibody target for passive prophylaxis.

F protein is synthesized as an inactive, palmitoylated precursor (F₀) and is decorated with N-linked glycans². Three F₀ monomers form a trimer and become activated by a furin-like host protease as they pass through the Golgi. The protease cleaves twice, generating three polypeptides: F₂ and F₁, which are covalently linked, and pep27, an intervening peptide that dissociates after cleavage. When functional F protein trimer in the virion membrane is triggered, it undergoes a major conformational change from a prefusion to a postfusion form.

Palivizumab is a humanized monoclonal antibody developed for the prevention of serious RSV in high risk infants³ and is the first monoclonal antibody introduced into clinical practice for the prevention of an infectious disease⁴. Palivizumab was generated by immunizing BALB/c mouse with human RSV strain A2 and fusing the lymphocytes with murine myeloma cell line NS0 to produce a hybridoma^{4, 5}. The murine monoclonal antibody Mab 1129 was then humanized by grafting the antigen binding site to gene segments coding for an intact human IgG1 molecule. The resulting antibody sequence is 95% human, with a small number of murine residues retained to ensure the structural integrity of the binding site. Palivizumab effectively neutralizes over 500 clinical isolates of RSV subtypes A and B³. Its binding epitope is present in both prefusion and postfusion forms of RSV F⁶ and binding to the postfusion F ectodomain has been experimentally confirmed^{7, 8}.

F protein is found in RSV virion membranes in either an inactive prefusion conformation or an active postfusion conformation.

site A of the RSV-F glycoprotein

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6. Espeseth AS, Cejas PJ, Citron MP, et al. NPJ Vaccines. 5(1):16. 2020.
7. Swanson KA, Settembre EC, Shaw CA, et al. Proc Natl Acad Sci U S A. 108(23):9619-9624.
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8. McLellan JS, Yang Y, Graham BS, et al. J Virol. 85(15):7788-7796. 2011.
9. Johnson S, Griego SD, Pfarr DS, et al. J Infect Dis. 180: 35–40. 1999
10. The IMpact-RSV Study Group. Pediatrics. 102(3 Pt 1):531-537. 1998.
11. Subramanian KN, Weisman LE, Rhodes T, et al. Pediatr Infect Dis J.;17(2):110-115. 1998.
12. Feltes TF, Cabalka AK, Meissner HC, et al. J Pediatr. 143(4):532-540. 2003.
13. Steff AM, Monroe J, Friedrich K, et al. Nat Commun. 8(1):1085. 2017.