The G-25.2 monoclonal antibody specifically recognizes CD11a which is also known as Leukocyte function-associated molecule 1 alpha chain (LFA-1A or LFA-1α). CD11a is a ~180 kDa type I transmembrane glycoprotein that is encoded by ITGAL (Integrin subunit alpha L) that belongs to integrin α-chain family. CD11a is a leucocyte adhesion receptor that noncovalently complexes with CD18 to form the LFA-1 heterodimer (CD11a/CD18) which binds to intercellular adhesion molecules (ICAMs) expressed on target tissues including ICAM-1 (CD54), ICAM-2 (CD102), ICAM-3 (CD50), ICAM-4, or ICAM-5. The CD11a antigen is expressed on virtually all normal peripheral blood leucocytes. It is essential for many immune responses that require cell-to-cell contact, such as lymphocyte adhesion, natural killer (NK) and T-lymphocyte cytolysis, and T lymphocyte proliferation. Activation of lymphocytes through the T-cell antigen receptor (TCR) upregulates LFA-1 function, converting the antigen to a high-avidity state. Expression of LFA-1 on monocytes is upregulated by γ-interferon (IFN-γ). While normal cells possess both the α and β LFA-1 chains, cells of subjects with some leukemias, lymphomas, or leucocyte adhesion deficiency (LAD) may lack the entire LFA-1 molecule or the α or β chain. The absence of LFA-1 on tumor cells may provide a mechanism for their escape from immune surveillance.
The antibody was conjugated to BD Horizon Red 718, which has been developed exclusively for BD Biosciences as a better alternative to Alexa Fluor® 700. BD Horizon Red 718 can be excited by the red laser (628 – 640 nm) and, with an Em Max around 718 nm, it can be detected using a 730/45 nm filter. Due to similar excitation and emission properties, we do not recommend using R718 in combination with APC-R700 or Alexa Fluor® 700.