Anti-Rat CD28 (Clone JJ319) – Biotin

Rat CD28 transfected A20/J cells

This Biotinylated antibody is formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.4, 1% BSA and 0.09% sodium azide as a preservative.

Liquid

This biotinylated antibody is stable when stored at 2-8°C. Do not freeze.

Research Use Only

2 – 8° C Wet Ice

JJ319 activity is directed against rat CD28.

CD28 is a 44 kD glycoprotein and member of the Ig superfamily that produces co-stimulatory signals necessary for T cell activation and survival as part of the B7-1/B7-2–CD28/CTLA-4 pathway¹. The two B7 family proteins, B7-1 (CD80) and B7-2 (CD86), have dual specificity for the stimulatory receptor CD28 and the inhibitory receptor CTLA-4 (CD152). When B7-1 and B7-2 interact with CD28, an important co-stimulatory signal, transmitted via CD28, synergizes with the TCR signal to regulate the threshold for T cell activation and promote T cell survival, clonal expansion, and differentiation. CD28 also promotes interleukin-2 (IL-2) production. In contrast, when B7-1 and B7-2 engage with CTLA-4, a negative signal inhibits TCR- and CD28- mediated signaling as well as IL-2 synthesis, and the T-cell response is terminated.

JJ319 was generated by immunizing a BALB/c mouse with rat CD28-transfected A20/J cells (A28-4-1). Spleen cells were subsequently fused with the X63-Ag 8.653 cell line and B-cell hybridomas were produced. Hybridomas were screened against rat T cells and CD28 transfected vs untransfected L929 cells. JJ319 effectively co-stimulates T cell proliferation and IL-2 secretion by resting rat T cells in the presence of TCR engagement^2,3. JJ319 has been used in the study of allograft tolerance^4,5,6 and experimental autoimmune neuritis⁷.

CD28 is constitutively expressed on the surface of T cells. CD28 is also expressed on a subset of rat natural killer cells.

CD80 (B7-1), CD86 (B7-2), PIK3R1, PRKCQ

1. Sharpe AH, Freeman GJ. Nat Rev Immunol. 2(2):116-26. 2002.
2. Tacke M, Clark GJ, Dallman MJ, et al. J Immunol. 154(10):5121-5127. 1995.
3. Tacke M, Hanke G, Hanke T, et al. Eur J Immunol. 27(1):239-247. 1997.
4. Dengler TJ, Szabo G, Sido B, et al. Transplantation. 67(3):392-398. 1999.
5. Laskowski IA, Pratschke J, Wilhelm MJ, et al. J Am Soc Nephrol. 13(2):519-527. 2002.
6. Urakami H, Ostanin DV, Hünig T, et al. Transplant Proc. 38(10):3244-3246. 2006.
7. Schmidt J, Elflein K, Stienekemeier M, et al. J Neuroimmunol. 140(1-2):143-152. 2003.
8. Haspot F, Villemain F, Laflamme G, et al. Blood. 99(6):2228-2234. 2002.
9. Thiel MA, Steiger JU, O'Connell PJ, et al. Clin Exp Ophthalmol. 33(2):176-180. 2005.
10. Rodríguez-Palmero M, Franch A, Castell M, et al. J Rheumatol. 33(1):110-118. 2006.