Malondialdehyde Conjugated With Albumin Induces Pro-Inflammatory Activation of T Cells Isolated From Human Atherosclerotic Plaques Both Directly and Via Dendritic Cell–Mediated Mechanism

Visual Abstract
Highlights • MDA conjugated with HSA activates T cells from human atherosclerotic plaques through a direct mechanism. • MDA-HSA also induces maturation and activation of human dendritic cells, which in turn promote activation of autologous T cells from the same donor's plaques, although this effect appears somewhat weaker than the direct activation. • M1 polarization of macrophages, potentially an atherogenic effect, were also induced by MDA-HSA. • Heat shock protein 60 was induced in T cells by MDA-HSA, is atherogenic, and could promote dendritic cell/T cell activation. • Two peptide modifications of serum albumin in atherosclerotic patients’ HSA were similar to those generated by treatment of HSA with MDA in vitro.
Summary Human dendritic cells were differentiated from blood monocytes and treated with malondialdehyde (MDA) conjugated with human serum albumin (HSA). Autologous T cells from human plaques or blood were co-cultured with the pre-treated dendritic cells or treated directly. MDA modifications were studied by mass spectrometry. MDA-HSA induced a pro-inflammatory DC-mediated T-cell activation and also a strong direct effect on T cells, inhibited by an inhibitor of oxidative stress and antibodies against MDA. Atherogenic heat shock protein-60 was strongly induced in T cells activated by MDA-HSA. Two peptide modifications in atherosclerotic patients' HSA were similar to those present in in vitro MDA-modified HSA.