Receptor for the group B coxsackieviruses and adenoviruses: CAR

Fatty acid modification of the coxsackievirus and adenovirus receptor

Membrane-proximal cysteines 259 and 260 in the cytoplasmic tail of the coxsackievirus and adenovirus receptor (CAR) are known to be essential for the tumor suppression activity of CAR. We demonstrate that these residues provide an S-acylation motif for modification of CAR with the fatty acid palmitate. Substitution of alanine for cysteines 259 and 260 results in the additional localization of CAR in perinuclear compartments with no effect on the efficiency of adenovirus infection. The results indicate that palmitylation is important for stable plasma membrane expression and biological activity of CAR but is not critical for adenovirus receptor performance.

The group B coxsackieviruses and myocarditis

The six serotypes of the group B coxsackieviruses (CVB) are common human enteroviruses linked etiologically to inflammatory cardiomyopathies. This has been demonstrated by molecular detection of enteroviral RNA in human heart tissue, serologic associations with disease, and virus isolation from cases of fulminant myocarditis. The murine model of CVB-associated myocarditis has demonstrated that CVB can be attenuated through mutations at different genomic sites. Human CVB3 isolates demonstrate varying degrees of cardiovirulence in the murine model; one site of virulence determination has been mapped to domain II of the 5' non-translated region. The interplay of CVB replication and the immune response to that replication in the heart is a complex interaction determining the extent to which the virus replication is limited and the degree to which a pathogenic inflammation of cardiac muscle occurs. Studies of CVB3-induced myocarditis in murine strains lacking subsets of the immune system or genes regulating the immune response have demonstrated a pivotal role of the T cell response to the generation of myocarditis. While CVB are associated with 20-25% of cases of myocarditis or cardiomyopathy, the severity of the disease and the existence of attenuated strains shown to generate protective immunity in animal models indicates that vaccination against the CVBs would be valuable.