NCIt definition : A guanine ribonucleotide derivative with immunostimulatory and immunomodulatory activity.
Loxoribine undergoes facilitated transport across the plasma membrane into the cytoplasmic
compartment of the cell and acts intracellularly, bypassing the biochemical steps
involved in the membrane signal transduction pathway used by Ag or anti-IgM Abs to
activate B cells. This agent activates the Toll-like receptor 7 (TLR7), a member of
the TLR family of pathogen-associated molecular pattern recognition receptors thereby
activating the innate immune system. This activation requires endosomal maturation
and recognition is restricted to TLR7. As a result, loxoribine induces cycling B cells
to proliferate and differentiate non-specifically and recruit antigen-reactive B cells
to undergo differentiation to antibody production, markedly amplifying the underlying
response in the process.;