Anti-Human CD4 (Ibalizumab) – Fc Muted™ - 500 µg

Recombinant Antibodies>Biosimilar Recombinant Antibodies|Primary Monoclonal Antibodies

2 - 8°C Wet Ice

CD4 is a cell surface glycoprotein essential for both T cell activation and human immunodeficiency virus type-1 (HIV-1) infection 1, 2. CD4 consists of an extracellular segment composed of four tandem immunoglobulin-like domains (D1 to D4), a single transmembrane span, and a short C-terminal cytoplasmic tail 1. HIV-1 entry into host CD4 cells is a complex process that occurs through the interaction of HIV-1 glycoprotein 120 (gp120) with extracellular CD4 D1 3, 4. When gp120 binds to CD4, a conformational shift occurs that allows co-receptors to bind to the gp120/receptor complex, leading to viral fusion and entry. Ibalizumab is the first CD4-directed post-attachment HIV-1 entry inhibitor and prevents entry of a broad spectrum of HIV-1 isolates 1, 5, 6, 7, 8. Ibalizumab selectively binds to an epitope on CD4 D2 (residues 121-124 and 127-134 9 and especially L96, P121, P122, and Q163 1, 7) as well as residues E77 and S79 on D1 at the interface between D1 and D2 4, 7. Ibalizumab primarily contacts the BC-loop in D2 at the D1-D2 junction on the opposite side to the gp120 and major histocompatibility complex II (MHC-II) binding sites 2. Ibalizumab does not inhibit HIV-1 gp120 binding to D1, but instead induces conformational changes that via steric hindrance block gp120 and HIV co-receptors from interacting, thereby preventing viral fusion and entry 3, 4, 7, 10, 11. Additionally, because the cellular epitope is distant from the D1 MHC-II binding site 4, MHC-II mediated immunosuppression is prevented 3. Furthermore, as a humanized IgG4 antibody, ibalizumab displays low affinity for C1q and FcɣRI receptors of natural killer cells and consequently has low cellular cytotoxic dependent activity and no Fc-mediated CD4+ T cell depletion 3. Ibalizumab was derived from mu5A8 by grafting the mouse complementary-determining region onto a human IgG4 construct 1, 3, 12. The chemical name is immunoglobulin G4, anti-(human CD4 (antigen)) (human-mouse monoclonal 5A8 γ4-chain), disulphide with human-mouse monoclonal 5A8 κ-chain, dimer 5.

≥ 5.0 mg/ml

CD4 is primarily found on T lymphocytes.