The H-2K[b]:Ig fusion protein consists of three extracellular major histocompatibility complex (MHC) class I H-2Kb domains that are fused to the VH regions of mouse IgG1. In order for the MHC class I to be functional, i.e., capable of binding peptides, β2 Microglobulin (β2M) must be present. For this reason, BD™ DimerX consists of recombinant H-2K[b]:Ig fusion protein, supplemented with recombinant β2M. Recombinant MHC molecules, like the BD DimerX fusion protein, are useful for studying T-cell function by immunofluorescent staining and flow cytometric analysis of antigen-specific T cells. The MHC gene locus encodes a group of highly polymorphic, cell-surface proteins that play a broad role in the immune response to protein antigens. MHC molecules function by binding and presenting small antigenic protein fragments to antigen-specific receptors expressed by T cells (TCR). Human (human leukocyte antigen/HLA) and mouse (histocompatibility 2/H-2) MHC molecules are structurally and functionally related proteins that comprise two major classes. Class I MHC molecules consist of two separate polypeptide chains. The class I α chain is an MHC encoded, transmembrane polypeptide containing three extracellular domains: α1, α2, and α3. The second chain consists of a non-MHC encoded polypeptide called β2M. Since β2M does not contain a transmembrane domain, it associates with the α chain through noncovalent interaction. Functionally, class I MHC molecules can bind peptides derived from intracellular antigens (e.g., viral and some bacterial antigens) that are specifically recognized by CD8+ T cells. Class II MHC molecules consist of two different transmembrane proteins that can bind peptide fragments derived from extracellular proteins (e.g., bacteria and fungi) and are specifically recognized by CD4+ T cells. TCR recognize both processed peptides bound to MHC, as well as regions of the MHC molecule itself. CD4 and CD8 accessory molecules strengthen formation of the TCR-MHC complex through their interaction with nonpolymorphic regions of the MHC molecule.

克隆 DimerX/H-2Kb (RUO)

0.2 mg/ml

Flow cytometry (Routinely Tested)

Kb/IgG1

Aqueous buffered solution containing ≤0.09% sodium azide.

Development References(4) 1. Cai Z, Brunmark AB, Luxembourg AT, et al. Probing the activation requirements for naive CD8+ T cells with Drosophila cell transfectants as antigen presenting cells. Immunol Rev. 1998; 165:249-265. (Biology). 2. Cai Z, Kishimoto H, Brunmark A, Jackson MR, Peterson PA, Sprent J. Requirements for peptide-induced T cell receptor downregulation on naive CD8+ T cells. J Exp Med. 1997; 185(4):641-651. (Biology). 3. Dal Porto J, Johansen TE, Catipovic B, et al. A soluble divalent class I major histocompatibility complex molecule inhibits alloreactive T cells at nanomolar concentrations. Proc Natl Acad Sci U S A. 1993; 90(14):6671-6675. (Biology). 4. Schneck JP, Slansky JE, O'Herrin SM, Greten TF . Monitoring antigen-specific T cells using MHC-Ig dimers. In: Coligan J, Kruisbeek D, Margulies EM, Shevach EM, Strober W, ed. Current Protocols in Immunology. New York: John Wiley & Sons, Inc; 2000:17.2.1-17.2.17.