Detection of anti-PL-12 autoantibodies by ELISA using a recombinant antigen; study of the immunoreactive region

Abstract

SUMMARYAutoantibodies to aminoacyl-tRNA synthetases are highly associated with myositis and detection is important in clinical diagnosis; however, current methods of screening limit its clinical utility. In the present study, alanyl-tRNA synthetase (PL-12) recombinant protein was obtained by immunological screening of a HeLa expression library and used in an ELISA with 22 anti-PL-12 sera, 200 autoimmune sera negative for PL-12 and 100 healthy individual sera. Sensitivity of the method was 95% (21/22) and specificity 100%. Mapping of the immunoreactive region was carried out using three anti-PL-12 sera and different recombinant protein-derived peptides. Results show that the same conformational epitope located within amino acids 730-951 of the PL-12 antigen outside the catalytic region was recognized by the three anti-PL-12 sera tested. We conclude that ELISA using recombinant protein is an effective and useful method for routine screening for anti-PL-12 autoantibodies.

Association of anti-SARS-COV-2 vaccine with increased incidence of myositis-related anti-RNA-synthetases auto-antibodies

“…On the other hand, in 2021 there was an increase in anti-PL-7 and anti-PL-12 autoantibodies, suggesting that SARS-CoV-2 vaccination might induce a strong reactions between Spike 1 proteins and a variety of tissue antigens in genetically predisposed individuals. It has been postulated that the presence of IIM antibodies in sera from patients suffering from myositis reflects a previous specific viral infection, based on previously reported interaction between some synthetases and the RNA of certain picornaviruses [ 18 , 19 ]. A study in dermatomyositis patients identified three T cell receptor epitopes specific to SARS-CoV-2 suggesting a potential for the virus to contribute to myositis development [ 20 ].…”