Human CD28 is an important costimulatory molecule found on all CD4+ T cells and on about half of the CD8+ T cells. T cell activities attributed to CD28 include prevention of anergy, induction of cytokine gene transcription, stabilization of cytokine mRNA and activation of CD8+ cytotoxic T lymphocytes. the ligands for CD28 identified as CD80(B7-1) and CD86(B7-2), are immunglobulin superfamily monomeric transmembrane glycoproteins of 60 kd and 80 kd respectively. Anti-CD28 antibodies have been shown to have a strong adjuvant effect when conjugated to an immunogen (4). Monovalency of the CD28 receptor for its natural ligands is essential to provide costimulation without inducing responses in the absense of TCR engagement (7).
Isotype: Murine IgG1kappa
Immunogen: Recombinant Human CD28 and HPB-MLT human tumor cells
Specificity: Antibody ANC28.1 recognizes CD28 expressed on T cells and also on BHK cells transfected with human CD28. This antibody has been characterized as a superagonist (5)
Functional Application: ANC28.1 stimulates expression of IL-2 from CD28+ cells. Divalent ANC28.1 can induce Antigen Independent T cell proliferation (5). the F(ab’)2 form of this antibody is fully mitogenic (8). In combination with anti-CD81 mAb, it can prime naive T cells to acquire effector function independently (6) or in combination(9) with TCR ligation. This antibody recognizes an epitope resistant to fixation with 2% buffered formaldehyde. This clone is not suitable for Western Blot.
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4) J. Carlring, et al, (2003) Eur J Immunol 33: 135-142.
5) Waibler1 Z., B. Schraven, et al, (2008) PLoS ONE 3(3): e1708
6) A Serra, A Wack, et al.(2008) J Immunol 181:174-185.
7) K M Dennehy, T Hunig, et al, (2006) J Immunol 176: 5725-5729.
8) Singh M, Lewis DE, et al. (2008) 38(6): 1522-32. PMID: 18446791.
9) N Frankish, B McHale, H Sheridan (Jan 2018) J Pharm Pharmacol 70(1): 101-110. https://doi.org/10.1111/jphp.12846 PMID: 29057517