Journal of Clinical and Cellular Immunology
Open Access
ISSN: 2155-9899
+44 1223 790975
ISSN: 2155-9899
+44 1223 790975
Sidra Islam and Moin Uddin
Aligarh Muslim University, India
Posters & Accepted Abstracts: J Clin Cell Immunol
Immunoglobulin G (IgG) is the most abundant immunoglobulin of the total immunoglobulin pool in the serum and has been found susceptible to damage by reactive oxygen species (ROS). This study aims at exploring the alterations in the structural characteristics using various biophysical and biochemical methods. Modified IgG showed hyperchromicity in UVvis spectroscopy, quenching in tyrosine fluorescence and cross linking in SDS PAGE. Changes in secondary structure were evident by Far UV-CD and FTIR. The modified IgG showed enhanced hydrophobicity, increase in carbonyl and reduction in the sulfydryl content. DLS studies point towards increase in the hydrodynamic radii, while DSC analysis showed enhanced thermodynamic stability of the modified IgG. Hydroxyl radical induced aggregation was confirmed by enhanced ThT specific fluorescence intensity and a red shift in the Congo red specific fluorescence intensity in the modified IgG and by the transmission electron microscopy. The immunogenic potential of native and OHâ�?¢ treated IgG was probed in experimental animal. The modified IgG was highly immunogenic inducing high titer antibodies. Furthermore, antibodies against native and OHâ�?¢ modified IgG in RA patients were detected by direct binding and inhibition ELISA. The data showed preferential binding of RA autoantibodies to hydroxylated IgG in comparison to the native counterpart. Thus it can be concluded that structural changes generated neoepitopes on IgG causing enhanced antibody production. Also, OHâ�?¢ modified IgG can serve as a novel antigen with a possible role in etiopathogenesis of RA.
Email: sidraa.islam11@gmail.com