Detection of CD28H/IGPR‑1 in HEK293 Human Cell Line Transfected with Human CD28L/IGPR-1 and eGFP by Flow Cytometry. HEK293 human embryonic kidney cell line transfected with either (A) human CD28H/IGPR-1 or (B) irrelevant transfectants and eGFP was stained with Mouse Anti-Human CD28H/IGPR‑1 Monoclonal Antibody (Catalog # MAB8316) followed by Allophycocyanin-conjugated Anti-Mouse IgG Secondary Antibody (Catalog # F0101B). Quadrant markers were set based on control antibody staining (Catalog # MAB004). View our protocol for Staining Membrane-associated Proteins.
CD28H/IGPR‑1 in Human Thymus. CD28H/IGPR‑1 was detected in immersion fixed paraffin-embedded sections of human thymus using Mouse Anti-Human CD28H/IGPR‑1 Monoclonal Antibody (Catalog # MAB8316) at 5 µg/mL for 1 hour at room temperature followed by incubation with the Anti-Mouse IgG VisUCyte™ HRP Polymer Antibody (Catalog # VC001). Tissue was stained using DAB (brown) and counterstained with hematoxylin (blue). Specific staining was localized to cell surfaces. View our protocol for IHC Staining with VisUCyte HRP Polymer Detection Reagents.
Preparation and Storage
Reconstitute at 0.5 mg/mL in sterile PBS.
The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. *Small pack size (SP) is shipped with polar packs. Upon receipt, store it immediately at -20 to -70 °C
Stability & Storage
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
12 months from date of receipt, -20 to -70 °C as supplied.
1 month, 2 to 8 °C under sterile conditions after reconstitution.
6 months, -20 to -70 °C under sterile conditions after reconstitution.
CD28 homolog (CD28H), also called TMIG2 and IGPR-1, is a 55 kDa glycosylated transmembrane protein that shares approximately 10% amino acid (aa) sequence identity with CD28, CTLA-4, ICOS, and PD-1. CD28H is composed of a single extracellular immunoglobulin variable-like domain (IgV) (aa 23-109), a transmembrane domain (aa 151-171), and a long cytoplasmic domain (aa172-282). CD28H is constitutively expressed on naive T and NK cells. Similar to the interaction of B7 with CD28, the interaction of CD28H with B7-H7 activates the Akt-dependent signaling cascade and promotes the proliferation and activation of newly generated peripheral effector and memory T cells (1, 2). CD28H is additionally expressed in the skin and epithelium lining the lung, airway, mammary gland, and gastrointestinal tract (3). It regulates cellular morphology, focal adhesion contact formation, and cell migration (3, 4). CD28H also participates in angiogenesis in vitro (3). CD28H interacts with multiple cytoskeletal proteins including Actin, Paxillin, SPIN90, CACNB2, and BPAG1. Interactions between the cytoplasmic proline-rich domain of CD28H and SPIN90 modulate the activity of CD28H in both angiogenesis and cell adhesion (3, 5).
Zhu, Y. et al. (2013) Nat. Commun. 4:2043.
Parry, R.V. et al. (2003) J.Immunol. 171:166.
Rahimi, N. et al. (2012) Mol. Biol. Cell. 23:1646.
Huang, C. et al. (2003) Nature 424:219.
Kaneko, T. et al. (2008) Front. Biosci. 13:4938.
Transmembrane And Immunoglobulin Domain Containing 2