Mapping of Molecular determinants of pathogenicity of coxsackievirus B1

QUINTANA, SILVINA; ROMANOWSKI, VICTOR; GÓMEZ , RICARDO M.

Iguazú, Misiones, Argentina

Congreso; XL Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología molecular; 2004

Sociedad Argentina de Investigación en Bioquímica y Biología molecular

Coxsakievirus B (CVB) is an etiological agent of myocarditis, which precedes dilated cardiomyopathy. Our aim was to characterize the molecular determinants of the pathogenicity of CVB1 (CVB serotype 1). To this end, we intraperitoneally inoculated viruses derived from infectious cDNA clones into several inbred strains of weanling mice. We first studied the effect of clone CVB1o (provided by Dr. Nomoto; University of Tokyo) which showed no signs of pathology. By inoculation of SCID mice with CVB1o a variant (CVB1m) was obtained that induced a severe pancreatitis and myocarditis in weanling C3H/HeJ mice. The genome of this variant was amplified by RT-PCR in three partially overlapping segments comprising nts 1-3448, 1571-5135 and 4916- polyA (the CVB1 genome contains ~7400 nts plus a ~100 nt long polyA tail). These cDNA fragments were cloned into pGEM-T vector and used to construct chimeras. A chimera including the 5? UTR of CVB1m and has a phenotype similar to that of CVB1o. In contrast, a chimera including the first 4300 nts of CVB1m exhibited a behavior similar to that of CVB1m. These results indicate that determinants of pancreatitis and myocarditis are located between nts 800 to 4300. We are generating additional chimeras that will allow us to narrow down the genomic sequences associated with pathogenicity, as well as to verify if cardiotropism and pancreatropism determinants correspond to the same region.