Detection of cardiac myosin-specific CD4 T cells by using MHC II / IAk tetramers in A/J mice (93.12)

Abstract

Abstract Myocarditis is one of the predominant causes of heart failure in young adolescents, and Coxsackievirus B strains (CVB1-6) are common suspects. CVB3 isolates from humans induce myocarditis in A/J mice, but the infectious virus cannot be isolated 18-21 days postinoculation. However viral nucleic acids showing deletions in the 5’ non-translated regions persist. The extent to which continuing low level replication of CVB causes inflammation is not known and an autoimmune response is suspected in late disease progression, and cardiac myosin heavy chain-alpha (MYHC-α) has been identified as a dominant autoantigen. To delineate the contribution of autoimmune response to postinfectious myocarditis, it is critical to demonstrate the generation of pathogenic autoreactive T cells as they expand to a significant proportion to cause disease. To this end, we have created major histocompatibility complex class II / IAk tetramers for MYHC-α, 334-352. By using IAk / RNase 43-56 tetramers as controls, we have optimized the conditions to detect MYHC-α 334-352-specific CD4 T cells in lymph node cell cultures derived from A/J mice immunized with MYHC-α 334-352. Preliminary studies suggest that the reagents can also be used to enumerate the frequency of myosin-specific T cells ex vivo in immunized mice. These reagents will now permit us to determine the generation and functions of myosin-reactive T cells as an indicator of autoimmune response to cardiac myosin in mice infected with CVB3.