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Evidence for superantigen involvement in cardiovascular injury due to Kawasaki syndrome
D Y Leung1, R C Giorno, L V Kazemi
1Division of Allergy-Immunology, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206, USA.
Insights
Kawasaki syndrome (KS) involves T cell expansion in the heart, suggesting these cells contribute to cardiovascular damage in children. This finding offers new insights into the etiology of this childhood vasculitis.
Area of Science:
- Immunology
- Pediatric Cardiology
- Vascular Biology
Background:
- Kawasaki syndrome (KS) is a leading cause of acquired heart disease in children, characterized by systemic vasculitis.
- The exact cause of KS remains unknown, though infectious triggers are suspected.
- Previous research indicated selective expansion of V beta 2+ T cells in acute KS patients' peripheral blood.
Observation:
- This study investigated T cell populations in the heart tissue of a child who died from acute KS.
- V beta 2+ T cells were found to be selectively expanded in the myocardium and coronary arteries.
- Analysis revealed diverse TCR beta-chain gene sequences in myocardial V beta 2+ T cells, present in both CD4+ and CD8+ subsets.
Findings:
- The presence of expanded V beta 2+ T cells within the cardiovascular tissues of a fatal KS case.
- Evidence of T cell receptor diversity suggests an antigen-driven response.
- V beta 2+ T cell activation in the myocardium and coronary arteries was observed.
Implications:
- These findings support the hypothesis that bacterial superantigens may trigger KS by activating V beta 2+ T cells.
- The infiltration and activation of these T cells are implicated in the cardiovascular damage seen in KS.
- This research provides a potential mechanism linking T cell responses to the development of heart disease in Kawasaki syndrome.
Abstract:
Kawasaki syndrome (KS), the major cause of acquired heart disease in children, is an acute multisystem vasculitis frequently associated with the development of myocarditis and coronary artery abnormalities. Despite the widely held belief that KS is an infectious disease, its etiology has remained elusive. Recently, we and others have reported the selective expansion of V beta 2+ T cells in the peripheral blood of most patients in the acute, but not in the convalescent, phase of KS. These data were consistent with the concept that this illness is triggered by a bacterial superantigen. We report here that a patient who died of acute KS had selective expansion of V beta 2+ T cells in her myocardium and coronary artery. Sequence analysis of TCR beta-chain genes of V beta 2+ T cells from the myocardium showed extensive junctional region diversity. These observations, along with the demonstration of V beta 2 expansion in both the CD4+ and CD8+ T cell subsets, support the concept that the activation of infiltrating V beta 2+ T cells are involved in the cardiovascular damage associated with KS.