Mouse Anti-COL2A1 Recombinant Antibody (clone ACC4) (CAT#: PABZ-088)

Figure 1 ACC mAb antibody specifi city in vitro and in vivo.

(a) ACC mAb specifi city in ELISA. Several arginine-containing peptides and their citrulline analogues have been tested to characterize the citrulline specifi city of our generated antibodies. Some of the epitopes were accessible in the triple helical form of the citrulline-containing C1ᴵᴵᴵ epitope (THPCII-Cit) for some of the antibodies (ACC1 – 3 and ACC5; A and B). Nevertheless, this epitope seems not to be accessible for ACC4. Some of the antibodies cross react to selected citrullinated peptides even with a noncollageneous backbone. ACC2, ACC3, and ACC5 bind not only to CII but also to the citrullinated derivative of fi brinogen (C and D). Furthermore, ACC4 and ACC5 bind stronger to the citrullinated form of cyclic fi laggrin (cyc-Cit) than to its arginine-containing form (cyc-Arg; E and F). Enzymatic deimination of CII with PAD4 generates neoepitopes, which are recognized by ACC2 – 4 (G – I). C1ᴵᴵᴵ peptides containing an additional biotinylated lysine have been synthesized, which in turn bind to NeutrAvidin-precoated ELISA plates (J – M). This setup allows free accessibility of the different antibodies specifi c for the citrulline-modifi ed immunodominant CII epitopes. All of the assays were done in duplicate. (b) Staining of arthritic joints. Citrulline-specifi c antibodies bind to arthritic cartilage. Joint sections (10 mm) from arthritic BALB/c (A, C, and D), naive (BALB/c × B10.Q) F1 (B), or BALB/c (E) mice are shown. Results shown are representative histological pictures of arthritic ( n = 4) and control ( n = 3) mice used in the staining of joints with anticitrulline antibodies. Arthritis was induced in 4 – 6- mo-old naive male BALB/c mice ( n = 36) by injecting 9 mg of an arthritogenic anti-CII mAb cocktail containing antibodies M2139 (binding to the J1 epitope) and CIIC1 (binding to the C1 I epitope). The arthritis induction experiment was performed four times independently with 100% incidence and a mean maximum arthritis score of 32.9 ± 3. The four mice that were used for histology had arthritis scores of 59, 60, 47, and 50. Paw samples were taken on day 11 after antibody transfer (5 d after LPS injection). Sections were treated with no antibodies (A), ACC1 (B), or ACC4 (C – E) mAbs. Magnification, × 10.

Uysal, H., Bockermann, R., Nandakumar, K. S., Sehnert, B., Bajtner, E., Engström, Å., ... & Holmdahl, R. (2009). Structure and pathogenicity of antibodies specific for citrullinated collagen type II in experimental arthritis. Journal of Experimental Medicine, 206(2), 449-462.

Figure 2 Enforced sialylation reduces the arthritogenic activity of ACPAs.

(a) An experimental scheme for enforced sialylation. (b) LC-ESI-MS analysis of ACC4 and M2139 was performed to detect desialylated glycoforms (G0F, G1F and G2F) and sialylated glycoforms (G1FS1, G2FS1 and G2FS2) of IgG Fc glycans. To normalize the variability, summation of peak areas of all complex type N-glycans were deliberately set at 100%. (c) Antigen-binding ability of Sia (+) and control ACC4/M2139 was compared by ELISA. (d) An experimental scheme for CAIA. (e) Frequency (upper panel) and score (lower panel) of arthritis is plotted. Data for arthritis scores are shown as mean±s.d. (n=13 for ACC4/M2139 and n=10 for ACC4/M2139 Sia (+)). The data are representative of two independent experiments. (f) Histological analysis of joint inflammation at day 14 post-LPS injection. Paraffin sections of the limb were stained by HE (upper panel) and Safranin O/Fast green for cartilage (red) staining (lower panel). Scale bar, 60 μm.

Ohmi, Y., Ise, W., Harazono, A., Takakura, D., Fukuyama, H., Baba, Y., ... & Ji, S. (2016). Sialylation converts arthritogenic IgG into inhibitors of collagen-induced arthritis. Nature communications, 7, 11205.