Modulation of Recombinant Antigenic Constructs Containing Multi-Epitopes towards Effective Reduction of Atherosclerotic Lesion in B6;129S-Ldlr(tm1Her)Apob(tm2Sgy)/J Mice

Atherosclerosis is increasingly recognized as a complex chronic inflammatory disease. Many more studies have extended vaccination against atherosclerosis by using epitopes from self-antigens or beyond and demonstrated that vaccination with antigens or derivatives could reduce the extent of the lesions in atherosclerosis-prone mice. Our previous study has demonstrated that construct AHHC [ApoB100(688-707) + hHSP60(303-312) + hHSP60(153-163) + Cpn derived peptide (C)] significantly reduced atherosclerotic lesion. The aim of this study was to investigate whether AHHC can be modulated towards increased lesion reduction in mice by creating two other derivatives with a sequential epitope-substitution named RHHC in which A was replaced by an “R” (C5aR(1-31)) and RPHC with a further “H” (hHSP60(303-312)) conversion into “P” (protease-activated receptor-1(42-55)) in mice. Antigenic epitopes were incorporated into a dendroaspin scaffold. Immunization of B6;129S-Ldlr(tm1Her)Apob(tm2Sgy)/J mice with three constructs elicited production of high levels of antibodies against each epitope (apart from hHSP60(153-163) and P which induced a low antibody response). Histological analyses demonstrated that the mice immunized with either RPHC or RHHC showed significant reductions in the size of atherosclerostic lesions compared to those with AHHC (69.5±1.1% versus 55.7±3.4%, P<0.01 or 65.6±1.3% versus 55.7±3.4%, P<0.01). Reduction of plaque size in the aortic sinus and descending aorta correlated with alterations in cellular immune responses when compared with controls. We conclude that a recombinant construct RPHC may provide new antigenic and structural features which are favorable for significant reduction in atherosclerotic lesion formation. This approach offers a novel strategy for developing anti-atherosclerotic agents.