‘Multi-Epitope-Targeted’ Immune-Specific Therapy for a Multiple Sclerosis-Like Disease via Engineered Multi-Epitope Protein Is Superior to Peptides

Antigen-induced peripheral tolerance is potentially one of the most efficient and specific therapeutic approaches for autoimmune diseases. Although highly effective in animal models, antigen-based strategies have not yet been translated into practicable human therapy, and several clinical trials using a single antigen or peptidic-epitope in multiple sclerosis (MS) yielded disappointing results. In these clinical trials, however, the apparent complexity and dynamics of the pathogenic autoimmunity associated with MS, which result from the multiplicity of potential target antigens and “epitope spread”, have not been sufficiently considered. Thus, targeting pathogenic T-cells reactive against a single antigen/epitope is unlikely to be sufficient; to be effective, immunospecific therapy to MS should logically neutralize concomitantly T-cells reactive against as many major target antigens/epitopes as possible. We investigated such “multi-epitope-targeting” approach in murine experimental autoimmune encephalomyelitis (EAE) associated with a single (“classical”) or multiple (“complex”) anti-myelin autoreactivities, using cocktail of different encephalitogenic peptides vis-a-vis artificial multi-epitope-protein (designated Y-MSPc) encompassing rationally selected MS-relevant epitopes of five major myelin antigens, as “multi-epitope-targeting” agents. Y-MSPc was superior to peptide(s) in concomitantly downregulating pathogenic T-cells reactive against multiple myelin antigens/epitopes, via inducing more effective, longer lasting peripheral regulatory mechanisms (cytokine shift, anergy, and Foxp3+ CTLA4+ regulatory T-cells). Y-MSPc was also consistently more effective than the disease-inducing single peptide or peptide cocktail, not only in suppressing the development of “classical” or “complex EAE” or ameliorating ongoing disease, but most importantly, in reversing chronic EAE. Overall, our data emphasize that a “multi-epitope-targeting” strategy is required for effective immune-specific therapy of organ-specific autoimmune diseases associated with complex and dynamic pathogenic autoimmunity, such as MS; our data further demonstrate that the “multi-epitope-targeting” approach to therapy is optimized through specifically designed multi-epitope-proteins, rather than myelin peptide cocktails, as “multi-epitope-targeting” agents. Such artificial multi-epitope proteins can be tailored to other organ-specific autoimmune diseases

Mean platelet volume as an inflammation marker in active pulmonary tuberculosis

Background: The mean platelet volume (MPV) reflects the size of platelets. It has been shown to be inversely correlated with level of the inflammation in some chronic inflammatory diseases. This prospective study aims to show the usability of MPV as an inflammation marker in patients with active pulmonary tuberculosis (PTB) by comparison with healthy controls. In addition, its relationships with other inflammatory markers such as C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) as well as with the radiological extent of disease were examined. Methods: This study included 82 patients with active PTB and 95 healthy subjects (control group). Whole blood counts, CRP level, and ESR were compared between the two groups. In the PTB group, the relationships between the radiological extent of disease and the MPV and other inflammation markers were investigated. Results: The MPV was 7.74 ± 1.33/µL in the PTB group and 8.20 ± 1.13/µL in the control group (p = 0.005). The blood platelet count, CRP level, and ESR were significantly higher in the active PTB group than in the control group (p < 0.0001). In the PTB group, CRP levels (r = 0.26, p = 0.003) and ESR (r = 0.39, p = 0.003), but not MPV (p = 0.80), were significantly correlated with the radiologic extent of the disease. Conclusions: The MPV was lower in patients with PTB than in healthy controls, however, the difference was limited. The MPV does not reflect the severity of the disease. The use of MPV as an inflammation marker and a negative acute-phase reactant in PTB does not seem to be reliable

Completion of Proteomic Data Sets by Kd Measurement Using Cell-Free Synthesis of Site-Specifically Labeled Proteins

The characterization of phosphotyrosine mediated protein-protein interactions is vital for the interpretation of downstream pathways of transmembrane signaling processes. Currently however, there is a gap between the initial identification and characterization of cellular binding events by proteomic methods and the in vitro generation of quantitative binding information in the form of equilibrium rate constants (Kd values). In this work we present a systematic, accelerated and simplified approach to fill this gap: using cell-free protein synthesis with site-specific labeling for pull-down and microscale thermophoresis (MST) we were able to validate interactions and to establish a binding hierarchy based on Kd values as a completion of existing proteomic data sets. As a model system we analyzed SH2-mediated interactions of the human T-cell phosphoprotein ADAP. Putative SH2 domain-containing binding partners were synthesized from a cDNA library using Expression-PCR with site-specific biotinylation in order to analyze their interaction with fluorescently labeled and in vitro phosphorylated ADAP by pull-down. On the basis of the pull-down results, selected SH2’s were subjected to MST to determine Kd values. In particular, we could identify an unexpectedly strong binding of ADAP to the previously found binding partner Rasa1 of about 100 nM, while no evidence of interaction was found for the also predicted SH2D1A. Moreover, Kd values between ADAP and its known binding partners SLP-76 and Fyn were determined. Next to expanding data on ADAP suggesting promising candidates for further analysis in vivo, this work marks the first Kd values for phosphotyrosine/SH2 interactions on a phosphoprotein level