A QUALITATIVE AND QUANTITATIVE METHOD FOR INSITU CHARACTERIZATION OF THE INFLAMMATORY RESPONSE IN EXPERIMENTAL MYOCARDITIS

Coxsackie virus B3 causes myocarditis in Balb/c inbred mice. In this model mortality is about 60% on day 7 and 95% on day 12 after inoculation. Significant inflammatory infiltrates appear on day 7. Recent research has focused on the immune response to explain the ensuing tissue damage. Thus we were interested in mapping cellular interaction and time course to understand the development of a possible autoimmune attack. By a newly developed immunohistochemical staining technique single lymphocytes could be visualized and different lymphocyte subpopulations enumerated. Stained cells were easily detectable and readily distinguishable from non-stained cells. Before day 7 T(h) cells could only occasionally be seen. The number of pan T lymphocytes increased almost 10-fold from day 7 to 12. The T helper/T killer ratio did not change significantly but indicated a predominant increase in T(k)-cells. The B cell population also increased, roughly about ten times. The number of class II positive cells was constant. No expression of Il-2 receptor was found. In preliminary studies, exercise and methylprednisolone treatment tended to influence the expression of class II antigens. Cyclophosphamide and cyclosporine A reduced the number of inflammatory cells more than 10-fold. No clear concurrent reduction in mortality was observed.