Anti-CD4 [3F11], Camelid VHH, His-tagged,

Absolute Antibody

Anti-CD4 [3F11], Camelid VHH, His-tagged,

9

This antibody is specific for human CD4

The binding of the original version of this antibody (VHH) to CD4 was characterized in an ELISA. In a FACS binding assay, this antibody exhibited an EC50 of 0.7 nM, 1.0 nM, and 0.76 nM for MOLM-13, THP-1, and T cells, respectively, and in an HIV-1 neutralization it exhibited an IC50 of 29.3 nM for PMBCs + NL4.3. This antibody was used to construct two bi-specific nanobodies with clone 281F12 (Ab04369 Anti-CXCR4), one where it was in the 1st position and one where it was in the 2nd position. Alone, it bound CXCR4+/CD4+ MOLM-13 cells with a binding EC50 of 0.6 nM and CXCR4+/CD4low Jurkat E6-1 cells with a binding EC50 of 61 nM. Its bi-specific constructs bound the CXCR4+/CD4+ MOLM-13 and CXCR4+/CD4low Jurkat E6-1 cells with a binding EC50 of 1.1 and 11 nM when it was in the 2nd position and 0.7 and 1.1 nM when it was in the 1st position. Furthermore, its bi-specific constructs exhibited a chemotaxis IC50 of 0.59 and 110 nM on CXCR4+/CD4+ MOLM-13 and CXCR4+/CD4low Jurkat E6-1 cells when it was in the 2nd position, and 1.29 and 460 nM when it was in the 1st position. This nanobody was effective at blocking CXCR4-tropic HIV1 strain NL4.3 and the CCR5-tropic BaL, and its bi-specific construction was extremely potent in inhibiting HIV-1 X4 virus replication, especially when evaluated in PHA-stimulated PBMCs. This antibody was also used to construct bi-specific nanobodies with Ab04390 and Ab04391 (anti-IL23R [150D02] and [150H07]) and Ab04392 and Ab04393 (Anti-IL12RB1 [148C09] and [148F09]). In these bi-specific constructions, it served as an anchor (US20220242958).

Flow Cytometry, ELISA, Neutralisation/Blocking

Research Use Only

Monoclonal

3F11

CD4

CD4 molecule

CD4 antigen (p55); CD4 receptor; CD4mut; IMD79; OKT4D; T-cell surface antigen T4/Leu-3; T-cell surface glycoprotein CD4

Camel

T-cell surface glycoprotein CD4

Human

-20°C,2°C to 8°C

12352203