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Identification of immunodominant antigens of Chlamydia trachomatis using proteome microarraysD. Molina, S. Pal, M. Kayala, A. Teng, P. Kim, P. Kim, P. Baldi, P. Felgner, X. Liang, L. de la Mazapresentation by: Julian Lopez and Jessica CisnerosExperimental Approach: Using C. trachomatismice, mimic a human infection closest than other animal forms. Chlamydia was grown in tissue with 5% fetal bovine serum and 1ug/ml of cycloheximide. Purified elementary bodies (EB) and reticulate bodies (RB) were acquired and exposed to an UV transilluminator box at 302nm wavelength . Genes were randomly selected and a few known proteins were included. Protein Microarray chips were prepared so that the number of antibodies would be easier to be determinedThere were groups of 18-20 8-week old mice (3 different strains), serum from these mice was collected and used as a negative control. Later, different routes for immunization innoculation was done: intranasal, intravaginal. For a specific group of mice (BALB/C), UV-inactivated EB and RB were administered subcutaneous and intramuscuclar three times at two week intervals. The microarray chips were probed with pre and post immunization sera. Intensitites of antibodies were scanned using QuantArray software. Microarrays were quantified and signal intensities were corrected. Statistical Analysis was used to analyze data, t-test, p values were adjusted and the data was retransformed into barplot graphs.
Main Findings: • Novel antigens were detected that can be tested for ability to induce immune response. • UV treated antibodies produced an immune response and created only two antibodies in comparison to the live immunization. • In this report, it was the first time that humoral immune responses to specific C. trachomatis had been reported, this suggest that it may be possble to create a vaccine regardless of immunogenetic background. Relative quantities of IgG2a and IgG1 antibodies from C3H/HeN mice and IgG2c and IgG1 from C57BL/6 mice immunized with live C. trachomatisMoPn. Sera from female C3H/HeN mice inoculated by the (A) i.n. and (B) i.vag. routes. (C) Samples from male C3H/HeN mice immunized i.n. Sera from female C57BL/6 mice inoculated by the (D) i.n. and (E) i.vag. routes.
Critiques: In the study, the quantitatively value of the antibody response was not able to be compared, because the variation could be due to the different levels of protein expression. The total number of mice used was not mentioned and the data can be inaccurate is more in one group was used than the other. Overall the paper was good because they addressed all the limitations of the experiment. Ie. Experiment based expression systems where proteins that recognize post-translational modification will not be identified such as phosphorylation, glycosylation or lipidation Discussion