Anti-Rat CD28 (Clone JJ319) – Purified in vivo PLATINUM™ Functional Grade

Rat CD28 transfected A20/J cells

This monoclonal antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4 with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of antibodies, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.

Liquid

Functional grade preclinical antibodies are manufactured in an animal free facility using in vitro cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.

To protect mouse colonies from infection by pathogens and to assure that experimental preclinical data is not affected by such pathogens, all of Leinco’s Purified Functional PLATINUM^TM antibodies are tested and guaranteed to be negative for all pathogens in the IDEXX IMPACT I Mouse Profile.

Functional grade preclinical antibodies may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.

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.