Daniel Engelbertsen1, Sara Rattik2, Anki Knutsson2, Harry Björkbacka2, Eva Bengtsson2, Jan Nilsson2. 1. Department of Clinical Sciences, Lund University, Malmö University Hospital, CRC 60:13, Jan Waldenströms gata 35, 20502 Malmö, Sweden daniel.engelbertsen@med.lu.se. 2. Department of Clinical Sciences, Lund University, Malmö University Hospital, CRC 60:13, Jan Waldenströms gata 35, 20502 Malmö, Sweden.
Abstract
AIMS: Immune responses against LDL antigens have been found to play an important modulatory role in atherosclerosis. Immunization with homologous oxidized LDL, as well as human apolipoprotein B100 (ApoB)-derived peptides, inhibits atherosclerosis in hypercholesterolaemic animal models of atherosclerosis. However, the role of antigen-specific T helper 2 (Th2) responses in atherosclerosis remains to be fully clarified. METHODS AND RESULTS: ApoE(-/-) mice on high-fat diet were immunized with human ApoB using Alum as an adjuvant at 12, 14, and 16 weeks of age. Alum-injected and non-treated mice were used as controls. At 17 weeks of age, a matrigel plug containing ApoB was placed subcutaneously and T-cell infiltration into the plug as well as the development of aortic root atherosclerotic lesions were analysed after an additional 7 days. Immunization with ApoB resulted in four-fold increased accumulation of effector T cells in ApoB-containing matrigel when compared with control groups. The levels of the Th2 cytokines IL-4, IL-5, and IL-10 were also increased in ApoB-containing matrigel plugs. Moreover, the levels of Th2-associated IgG1 against human and also mouse LDL were increased in the plasma of ApoB-immunized mice. In spite of the induction of a Th2 response partially reacting also with the endogenous LDL, there was no difference in atherosclerosis when compared with the Alum group. CONCLUSIONS: This study describes a novel model to study antigen-specific T-cell responses in vivo in mouse models of atherosclerosis. The results suggest that activation of Th2 immunity does not mediate the protective effect of immunization with LDL antigens described previously. Published on behalf of the European Society of Cardiology. All rights reserved.
AIMS: Immune responses against LDL antigens have been found to play an important modulatory role in atherosclerosis. Immunization with homologous oxidized LDL, as well as humanapolipoprotein B100 (ApoB)-derived peptides, inhibits atherosclerosis in hypercholesterolaemic animal models of atherosclerosis. However, the role of antigen-specific T helper 2 (Th2) responses in atherosclerosis remains to be fully clarified. METHODS AND RESULTS:ApoE(-/-) mice on high-fat diet were immunized with humanApoB using Alum as an adjuvant at 12, 14, and 16 weeks of age. Alum-injected and non-treated mice were used as controls. At 17 weeks of age, a matrigel plug containing ApoB was placed subcutaneously and T-cell infiltration into the plug as well as the development of aortic root atherosclerotic lesions were analysed after an additional 7 days. Immunization with ApoB resulted in four-fold increased accumulation of effector T cells in ApoB-containing matrigel when compared with control groups. The levels of the Th2 cytokines IL-4, IL-5, and IL-10 were also increased in ApoB-containing matrigel plugs. Moreover, the levels of Th2-associated IgG1 against human and also mouse LDL were increased in the plasma of ApoB-immunized mice. In spite of the induction of a Th2 response partially reacting also with the endogenous LDL, there was no difference in atherosclerosis when compared with the Alum group. CONCLUSIONS: This study describes a novel model to study antigen-specific T-cell responses in vivo in mouse models of atherosclerosis. The results suggest that activation of Th2 immunity does not mediate the protective effect of immunization with LDL antigens described previously. Published on behalf of the European Society of Cardiology. All rights reserved.
Authors: Peter M Mihailovic; Wai Man Lio; Juliana Yano; Jianchang Zhou; Xiaoning Zhao; Kuang-Yuh Chyu; Prediman K Shah; Bojan Cercek; Paul C Dimayuga Journal: Biochem Biophys Rep Date: 2019-05-13