Unlike the MBLs, which block HIV only through binding to the glycosylated envelope proteins (gp120 and gp41) of the virus, SBL inhibited HIV at multiple steps of the virus infection/replication cycle.
It was shown that the N-glycan environment around well-defined disulphide bridges of gp120 is highly critical to allow efficient viral infection and transmission.
The finding that HIV-1 itself (possibly through its gp120) can induce a potent antiviral factor (IFN-beta) in macrophages underlines the complex physiological function of these cells in maintaining normal homeostasis in vivo in response to virus infection.
Finally, we demonstrate that the inhibition of virus infection and virus-mediated cell fusion by soluble CD4 proteins depends on their association with gp120 at this binding site.