Role of Fc in Antibody-Mediated Protection from Ricin Toxin

Toxins

Seth. H. Pincus¹  Anushka Das¹  Kejing Song¹  Grace A. Maresh¹  Miriam Corti¹ 

[1] Children’s Hospital New Orleans, New Orleans, LA 70118, USA; E-Mails:

关键词: ricin;    monoclonal antibody;    polyclonal antiserum;    Fc region;    Fc receptor;    Fab;    neutralization;    in vivo protection;   

DOI  :  10.3390/toxins6051512

来源: mdpi

【 摘 要 】

We have studied the role of the antibody (Ab) Fc region in mediating protection from ricin toxicity. We compared the in vitro and in vivo effects of intact Ig and of Fab fragments derived from two different neutralizing Ab preparations, one monoclonal, the other polyclonal. Consistent results were obtained from each, showing little difference between Ig and Fab in terms of antigen binding and in vitro neutralization, but with relatively large differences in protection of animals. We also studied whether importing Ab into the cell by Fc receptors enhanced the intracellular neutralization of ricin toxin. We found that the imported Ab was found in the ER and Golgi, a compartment traversed by ricin, as it traffics through the cell, but intracellular Ab did not contribute to the neutralization of ricin. These results indicate that the Fc region of antibody is important for in vivo protection, although the mechanism of enhanced protection by intact Ig does not appear to operate at the single cell level. When using xenogeneic antibodies, the diminished immunogenicity of Fab/F(ab’)₂ preparations should be balanced against possible loss of protective efficacy.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.