Vaccine-like and Prophylactic Treatments of EAE with Novel IDomain Antigen Conjugates (IDAC): Targeting Multiple Antigenic Peptides to APC

The objective of this work is to utilize novel I-domain antigenic-peptide conjugates (IDAC) for targeting antigenic peptides to antigen-presenting cells (APC) to simulate tolerance in experimental autoimmune encephalomyelitis (EAE). IDAC-1 and IDAC-3 molecules are conjugates between the I-domain protein and PLP-Cys and Ac-PLP-Cys-NH2 peptides, respectively, tethered to N-terminus and Lys residues on the I-domain. The hypothesis is that the I-domain protein binds to ICAM-1 and PLP peptide binds to MHC-II on the surface of APC; this binding event inhibits the formation of the immunological synapse at the APC-T-cell interface to alter T-cell differentiation from inflammatory to regulatory phenotypes. Conjugation of peptides to the I-domain did not change the secondary structure of IDAC molecules as determined by circular dichroism spectroscopy. The efficacies of IDAC-1 and -3 were evaluated in EAE mice by administering i.v or s.c. injections of IDAC in a prophylactic or a vaccine-like dosing schedule. IDAC-3 was better than IDAC-1 in suppressing and delaying the onset of EAE when delivered in prophylactic and vaccine-like manners. IDAC-3 also suppressed subsequent relapse of the disease. The production of IL-17 was lowered in the IDAC-33 treated mice compared to those treated with PBS. In contrast, the production of IL-10 was increased, suggesting that there is a shift from inflammatory to regulatory T-cell populations in IDAC-33treated mice. In conclusion, the Idomain can effectively deliver antigenic peptides in a vaccine-like or prophylactic manner for inducing immunotolerance in the EAE mouse model

A Peptide from the Beta-strand Region of CD2 Protein that Inhibits Cell Adhesion and Suppresses Arthritis in a Mouse Model

This is the peer reviewed version of the following article: Satyanarayanajois, S. D., Büyüktimkin, B., Gokhale, A., Ronald, S., Siahaan, T. J. and Latendresse, J. R. (2010), A Peptide from the Beta-strand Region of CD2 Protein that Inhibits Cell Adhesion and Suppresses Arthritis in a Mouse Model. Chemical Biology & Drug Design, 76: 234–244. doi:10.1111/j.1747-0285.2010.01001.x, which has been published in final form at http://doi.org/10.1111/j.1747-0285.2010.01001.x. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Cell adhesion molecules play a central role at every step of the immune response. The function of leukocytes can be regulated by modulating adhesion interactions between cell adhesion molecules to develop therapeutic agents against autoimmune diseases. Among the different cell adhesion molecules that participate in the immunological response, CD2 and its ligand CD58 (LFA-3) are two of the best-characterized adhesion molecules mediating the immune response. To modulate the cell adhesion interaction, peptides were designed from the discontinuous epitopes of the β-strand region of CD2 protein. The two strands were linked by a peptide bond. β-Strands in the peptides were nucleated by inserting a β-sheet-inducing Pro-Gly sequence with key amino acid sequences from CD2 protein that binds to CD58. Using a fluorescence assay, peptides that exhibited potential inhibitory activity in cell adhesion were evaluated for their ability to bind to CD58 protein. A model for peptide binding to CD58 protein was proposed based on docking studies. Administration of one of the peptides, P3 in collagen-induced arthritis (CIA) in the mouse model, indicated that peptide P3 was able to suppress rheumatoid arthritis in mice

I-Domain-Antigen Conjugate (IDAC) for Delivering Antigenic Peptides to APC: Synthesis, Characterization, and in vivo EAE Suppression

The objectives of this work are to characterize the identity of I-domain-antigen conjugate (IDAC) and to evaluate the in vivo efficacy of IDAC in suppressing experimental autoimmune encephalomyelitis (EAE) in mouse model. The hypothesis is that the I-domain delivers PLP139-151 peptides to antigen-presenting cells (APC) and alters the immune system by simultaneously binding to ICAM-1 and MHC-II, blocking immunological synapse formation. IDAC was synthesized by derivatizing the lysine residues with maleimide groups followed by conjugation with PLP-Cys-OH peptide. Conjugation with PLP peptide does not alter the secondary structure of the protein as determined by CD. IDAC suppresses the progression of EAE while I-domain and GMB-I-domain could only delay the onset of EAE. As a positive control, Ac-PLP-BPI-NH2-2 can effectively suppress the progress of EAE. The number of conjugation sites and the sites of conjugations in IDAC were determined using tryptic digest followed by LC-MS analysis. In conclusion, conjugation of I-domain with an antigenic peptide (PLP) resulted in an active molecule to suppress EAE in vivo

Vaccine-like Controlled-Release Delivery of an Immunomodulating Peptide to Treat Experimental Autoimmune Encephalomyelitis

The objective of this work is to use colloidal gel from alginate-chitosan-PLGA complex to deliver Ac-PLP-BPI-NH2-2 peptide in a controlled-release manner as a vaccine-like therapeutic to suppress experimental autoimmune encephalomyelitis (EAE) in the mouse model. Oppositely charged PLGA nanoparticles were prepared by a solvent diffusion method. The carboxyl group of the alginate and the amine group of the chitosan coated the nanoparticles with negative and positive charges, respectively. The peptide (Ac-PLP-BPI-NH2-2), designed to bind to MHC-II and ICAM-1 simultaneously, was formulated into the colloidal gel by physical mixture. Vaccine-like administration of the peptide-loaded colloidal gel (Ac-PLP-BPI-NH2-2-NP) was achieved by subcutaneous (s.c.) injection to EAE mice. Disease severity was measured using clinical scoring and percent change in body weight. Cytokine production was determined using the splenocytes from Ac-PLP-BPI-NH2-2-NP-treated mice and compared to that of controls. Ac-PLP-BPI-NH2-2-NP suppressed and delayed the onset of EAE as well as Ac-PLP-BPI-NH2-2 when delivered in a vaccine-like manner. IL-6 and IL-17 levels were significantly lower in the Ac-PLP-BPI-NH2-2-NP-treated mice compared to the mice group treated with blank colloidal gel, suggesting that the mechanism of suppression of EAE is due to a shift in the immune response away from Th17 production. The results of this study suggest that a one-time s.c. administration of Ac-PLP-BPI-NH2-2 formulated in a colloidal gel can produce long-term suppression of EAE by reducing Th17 proliferation