Detection of recombinant antigen 38 and epitope antigen 38 antibody as humoral immune response of tuberculosis as a new marker of tuberculous meningitis

Antigen 38 (PstS-1), is a lipoprotein secreted by M. tb and capable of enhancing B and T cell responses with high specificity. Previous study of recombinantantigen 38 (RecAg38) from Mycobacterium tuberculosis local strain showed high homology of M.tb. Epitope is playinga significant role in the diagnosis of TB and TB meningitis. Previous study, antigen 38 could be detected in liquor cerebrospinal (LCS) tuberculosis meningitis in children. The purpose of this study was to prove recombinant antigen 38 and epitope antigen 38 can induce IgG and IgM antibodies. RecAg38 was overexpressed in E. coli BL21-(DE-3) strains. The purity of antigen was verified using SDS-PAGE and Western Blot. Using bioinformatic two dominant epitope antigen 38 was identified: QGTIKTWDDPQIAALNPGVNLP and Both antigen 38 and two dominant epitopes were used to immunize mice. As many as 12 male mice were divided into two groups. Group 1 received 50ug/0,3ml Antigen 38 intra peritoneal, whereas group 2 received 50ug/0,3 ml epitope. Booster at week 2,3, and 4. Detection of antibodies was conducted using ELISA assay. The results showed that Ag38 rec as well as epitopes of Ag38 rec could induce the synthesis of antibody IgG and IgM. the highest OD (Optical Density) value of IgG and IgM antibodies was 3,508 and 1,368 upon induction with Ag38 protein. Groups with an antibody concentration of 1/1000 and an antigen concentration of 10ug/mL. The highest OD IgM antibodies it was 1,368 in the peptide epitope dominant group 2 with an antibody concentration of 1/5000 and an antigen concentration of 10ug/mL. The conclusion is that recombinant protein and epitope antigen 38 has capacity to induce IgG antibodies, IgM in in vivo a hence potential to be used as a marker tuberculosis diagnosis test and candidate a biomarker for the diagnosis of TB meningitis.