Quantitative analysis of myocardial inflammation by flow cytometry in murine autoimmune myocarditis: correlation with cardiac function.
Inflammation has been increasingly recognized as an important pathological component of heart failure. Existing methods of assessing myocardial infiltrate are labor-intensive and provide data that are difficult to quantify and not representative of the whole heart. As a result, little effort has been made to systematically assess the components of myocardial inflammation. We established an alternative method of quantitative assessment of myocardial inflammation by flow cytometry after enzymatic digestion of hearts to characterize the infiltrate and study the association between inflammation and cardiac function in murine experimental autoimmune myocarditis. The severity of acute myocarditis uniquely correlated with the proportion of neutrophils, but not T cells, B cells, or macrophages. Both acute and chronic phases were characterized by the presence of CD44high (activated) T cells in the heart, whereas T cells trafficking through normal hearts exhibited CD44low phenotype. During the chronic phase, the proportion of CD4+ T cells was associated with increased left-ventricular volumes and deterioration of systolic function, the hallmarks of dilated cardiomyopathy. We conclude that flow cytometry on uniformly digested mouse hearts provides sensitive and reproducible assessment of myocardial infiltrate and can be used to dissect out the specific role of individual immune components from the overall inflammatory response in the heart.
Department of Pathology, the Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
Marina
M
Afanasyeva
Dimitrios
D
Georgakopoulos
Diego F
DF
Belardi
Amrish C
AC
Ramsundar
Jobert G
JG
Barin
David A
DA
Kass
Noel R
NR
Rose
D000818:Animals; D001327:Autoimmune Diseases / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D001402:B-Lymphocytes / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D018960:Hyaluronan Receptors / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D008297:Male; D051379:Mice; D009205:Myocarditis / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D009504:Neutrophils / Q000276:immunology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013601:T-Lymphocytes / Q000276:immunology
D018960:Hyaluronan Receptors