The goals of this proposal are to identify mechanisms by which a small nonenveloped RNA genome virus induces severe focal inflammation in heart tissues of mice, as a model of human disease myocarditis. Most human patients with chronic myocarditis produce autoantibodies to antigens on cardiac tissue. In a murine model of coxsackievirus B3 (CVB3)-induced chronic myocarditis, autoantibodies are also produced against cardiac cell antigens. Administration of murine sera containing CVB3-neutralizing antibodies into CVB3-inoculated mice at 3 days post-inoculation exacerbates myocarditis, suggesting the presence of pathologic antibodies. Preliminary studies of neutralizing monoclonal antibodies (mAbs) against CVB3 demonstrate shared epitopes between CVB3 particles and cultured murine cardiac fibroblasts, as assessed by antibody binding studies, complement- mediated lysis of fibroblasts and stimulation of synthesis of a macrophage chemoattractant by fibroblasts. One mAb induces myocarditis in normal mice. Mechanisms by which eight mAbs could contribute to pathogenesis of myocarditis in mice will be identified. Induction of myocarditis by mAB will be confirmed. The capacity of mAbs for participating in complement- or killer cell-mediated lysis of murine cardiac fibroblasts will be quantitatively assessed. mAb-enhanced production of soluble factors from cardiac fibroblasts will be quantified. The viral polypeptide(s) to which the eight mAbs bind will be identified. Several laboratories have shown that enteroviral genomes are present in heart tissues of 15-25% of patients with myocarditis when infectious virus cannot be detected. CVB3 murine models of chronic myocarditis will be used to determine whether viral genomes persist in heart tissues, using in situ transcription and polymerase chain reaction. To understand the molecular basis of CVB3- induced myocarditis, the genomes of highly myocarditic (CVB3m) and amyocarditic (CVB3o) variants will be cloned. Reciprocal recombinant viruses will be generated by construction of hybrid genomes from infectious cDNA molecules of each genome and assessed for myocarditis-inducing ability in adolescent mice. Infectious hybrid cDNA molecules will be constructed with progressively smaller nucleotide regions associated with myocarditis to generate recombinant viruses. The nucleotide regions associated with myocarditis will be sequenced. CVB3 infection of some murine strains induces T cells which lyse uninfected target cells. Experiments will determine whether T lymphocytes from CVB3m-inoculated mice with chronic myocarditis will proliferate in vitro in response to soluble antigens extracted from normal murine hearts/cultured cardiac fibroblasts and whether extent of proliferation is predictive of severity of myocarditis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL045979-02
Application #
3365094
Study Section
Experimental Virology Study Section (EVR)
Project Start
1991-01-01
Project End
1995-12-31
Budget Start
1992-01-01
Budget End
1992-12-31
Support Year
2
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Texas Health Science Center San Antonio
Department
Type
Schools of Dentistry
DUNS #
800772162
City
San Antonio
State
TX
Country
United States
Zip Code
78229
Lee, C; Maull, E; Chapman, N et al. (1997) Generation of an infectious cDNA of a highly cardiovirulent coxsackievirus B3(CVB3m) and comparison to other infectious CVB3 cDNAs. Virus Res 50:225-35
Lee, C; Maull, E; Chapman, N et al. (1997) Genomic regions of coxsackievirus B3 associated with cardiovirulence. J Med Virol 52:341-7
Gauntt, C J; Pallansch, M A (1996) Coxsackievirus B3 clinical isolates and murine myocarditis. Virus Res 41:89-99
Gauntt, C J; Tracy, S M; Chapman, N et al. (1995) Coxsackievirus-induced chronic myocarditis in murine models. Eur Heart J 16 Suppl O:56-8
Gauntt, C J; Arizpe, H M; Higdon, A L et al. (1995) Molecular mimicry, anti-coxsackievirus B3 neutralizing monoclonal antibodies, and myocarditis. J Immunol 154:2983-95
Chapman, N M; Tu, Z; Tracy, S et al. (1994) An infectious cDNA copy of the genome of a non-cardiovirulent coxsackievirus B3 strain: its complete sequence analysis and comparison to the genomes of cardiovirulent coxsackieviruses. Arch Virol 135:115-30
Gauntt, C; Higdon, A; Bowers, D et al. (1993) What lessons can be learned from animal model studies in viral heart disease? Scand J Infect Dis Suppl 88:49-65
Gauntt, C J; Higdon, A L; Arizpe, H M et al. (1993) Epitopes shared between coxsackievirus B3 (CVB3) and normal heart tissue contribute to CVB3-induced murine myocarditis. Clin Immunol Immunopathol 68:129-34
Cunningham, M W; Antone, S M; Gulizia, J M et al. (1992) Cytotoxic and viral neutralizing antibodies crossreact with streptococcal M protein, enteroviruses, and human cardiac myosin. Proc Natl Acad Sci U S A 89:1320-4