Anti-Human CD18 (ITGB2) (Clone IB4) – Purified in vivo GOLD^TM Functional Grade

Human peripheral blood lymphocytes

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 in vitro 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

IF Microscopy,
FA

IB4 activity is directed against human CD18 and can also stain rabbit bone marrow leukocytes.

Integrins are a large family of α/β heterodimeric transmembrane molecules that mediate adhesion, migration, cell survival, and cell differentiation¹. The leukocytic cell-adhesion molecule (Leu-CAM) family has three members, LFA-1 (CD18/CD11a), CR3 (CD18/CD11b), and p150,95 (CD18/CD11c), all of which share the β chain CD18².

Murine (m) 1B4 was humanized (h) by the CDR-grafting method to create an anti-CD18 antibody with similar avidity, specificity, and efficacy as the murine antibody³. In rhesus monkeys, h1B4 is less immunogenic than m1B4 and elicits only anti-idiotypic antibodies. Additionally, h1B4 and m1B4 exhibit equivalent staining specificity and intensity in rabbit bone marrow leukocytes.

For humanization, human V_H and V_L FR were chosen based on high identity with their corresponding m1B4 FR³. Once grafted with the m1B4 CDR, the human V_H and V_L FR were expressed as fusion proteins with the IgG4 and Cκ human constant regions, respectively.

The h1B4 monoclonal antibody has been used in multiple studies of adhesion in different model systems^{4, 5, 6} and to measure the expression of CD18 in B-ALL cell lines⁷.

Depending on its heterodimeric configuration, CD18 is expressed in leukocytes, monocytes, macrophages, some lymphocytes, polymorphonuclear lymphocytes (PMNs), natural killer cells, neutrophils, granulocytes, certain lymphocytic tumor cell lines, macrophage foam cells, activated platelets, and splenic red pulp macrophages.

Receptor

1. Luo BH, Carman CV, Springer TA. Annu Rev Immunol. 25:619-647. 2007.
2. Sanchez-Madrid F, Nagy JA, Robbins E, et al. J Exp Med. 158(6):1785-1803. 1983.
3. Singer II, Kawka DW, DeMartino JA, et al. J Immunol. 150(7):2844-2857. 1993.
4. Hanlon WA, Stolk J, Davies P, et al. J Leukoc Biol. 50(1):43-48. 1991.
5. Seth R, Salcedo R, Patarroyo M, et al. FEBS Lett. 282(1):193-196. 1991.
6. McDonald RJ, St George JA, Pan LC, et al. Inflammation. 17(2):145-151. 1993.
7. Velázquez-Avila M, Balandrán JC, Ramírez-Ramírez D, et al. Leukemia. 33(6):1337-1348. 2019.