Screening of Serum Biomarkers for Distinguishing between Latent and Active Tuberculosis Using Proteome Microarray

Objective To identify potential serum biomarkers for distinguishing between latent tuberculosis infection（LTBI） and active tuberculosis（TB）. Methods A proteome microarray containing 4,262 antigens was used for screening serum biomarkers of 40 serum samples from patients with LTBI and active TB at the systems level. The interaction network and functional classification of differentially expressed antigens were analyzed using STRING 10.0 and the TB database, respectively. Enzyme-linked immunosorbent assays（ELISA） were used to validate candidate antigens further using 279 samples. The diagnostic performances of candidate antigens were evaluated by receiver operating characteristic curve（ROC） analysis. Both antigen combination and logistic regression analysis were used to improve diagnostic ability. Results Microarray results showed that levels of 152 Mycobacterium tuberculosis（Mtb）-antigenspecific IgG were significantly higher in active TB patients than in LTBI patients（P 〈 0.05）, and these differentially expressed antigens showed stronger associations with each other and were involved in various biological processes. Eleven candidate antigens were further validated using ELISA and showed consistent results in microarray analysis. ROC analysis showed that antigens Rv2031 c, Rv1408, and Rv2421 c had higher areas under the curve（AUCs） of 0.8520, 0.8152, and 0.7970, respectively. In addition, both antigen combination and logistic regression analysis improved the diagnostic ability. Conclusion Several antigens have the potential to serve as serum biomarkers for discrimination between LTBI and active TB.

Autoantigen Microarray for High-throughput Autoantibody Profiling in Systemic Lupus Erythematosus

Systemic lupus erythematosus （SLE） is a complex autoimmune disease characterized by the production of autoantibodies to a broad range of self-antigens. Profiling the autoantibody repertoire using array-based technology has emerged as a powerful tool for the identification of biomarkers in SLE and other autoimmune diseases. Proteomic microarray has the capacity to hold large number of self-antigens on a solid surface and serve as a high-throughput screening method for the determination of autoantibody specificities. The autoantigen arrays carrying a wide variety of self-antigens, such as cell nuclear components （nucleic acids and associated proteins）, cytoplas- mic proteins, phospholipid proteins, cell matrix proteins, mucosal/secreted proteins, glomeruli, and other tissue-specific proteins, have been used for screening of autoantibody specificities associated with different manifestations of SLE. Arrays containing synthetic peptides and molecular modified proteins are also being utilized for identification of autoantibodies targeting to special antigenic epi- topes. Different isotypes of autoantibodies, including IgG, IgM, IgA, and IgE, as well as other Ig subtypes, can be detected simultaneously with multi-color labeled secondary antibodies. Serum and plasma are the most common biologic materials for autoantibody detection, but other body fluids such as cerebrospinal fluid, synovial fluid, and saliva can also be a source of autoantibody detection.

Integrated transcriptomic and proteomic study on the different molecular mechanisms of PC12 cell growth on chitosan and collagen/chitosan films

The purpose of this article is to integrate the transcriptomic analysis and the proteomic profiles and to reveal and compare the different molecular mechanisms of PC12 cell growth on the surface of chitosan films and collagen/chitosan films.First,the chitosan films and the collagen/chitosan films were prepared.Subsequently,the cell viability assay was performed;the cell viability of the PC12 cells cultured on the collagen/chitosan films for 24 h was significantly higher than that on the chitosan films.Then,with cDNA microarray,the numbers of differentially expressed genes of PC12 cells on the surface of chitosan and collagen/chitosan films were 13349 and 5165,respectively.Next,the biological pathway analysis indicated that the differentially expressed genes were involved in 40 pathways directly related to cell adhesion and growth.The integrated transcriptomic and our previous proteomic analysis revealed that three biological pathways-extracellular matrix-receptor interaction,focal adhesion and regulation of actin cytoskeleton-were regulated in the processes of protein adsorption,cell adhesion and growth.The adsorbed proteins on the material surfaces further influenced the expression of important downstream genes by regulating the expression of related receptor genes in these three pathways.In comparison,chitosan films had a strong inhibitory effect on PC12 cell adhesion and growth,resulting in the significantly lower cell viability on its surface;on the contrary,collagen/chitosan films were more conducive to promoting PC12 cell adhesion and growth,resulting in higher cell viability.