Vitamin B12 and hepatitis C: molecular biology and human pathology.
Lott WB; Takyar SS; Tuppen J; Crawford DH; Harrison M; Sloots TP; Gowans
Proc Natl Acad Sci U S A 2001 Apr 24;98(9):4916-21
are stored in high concentrations in the human liver and thus are available
to participate in the regulation of hepatotropic virus functions. We
show that cyanocobalamin (vitamin B12) inhibited the HCV internal ribosome
entry site (IRES)-dependent translation of a reporter gene in vitro in
a dose-dependent manner without significantly affecting the cap-dependent
mechanism. Vitamin B12 failed to inhibit translation by IRES
elements from encephalomyocarditis virus (EMCV) or classical swine fever
virus (CSFV). We also demonstrate a relationship between the total cobalamin
concentration in human sera and HCV viral load (a measure of viral replication
in the host). The mean viral load was two orders of magnitude greater
when the serum cobalamin concentration was above 200 pM (P < 0.003),
suggesting that the total cobalamin concentration in an HCV-infected liver
is biologically significant in HCV replication.