NCIt definition : A recombinant form of CD4 antigen with anti-HIV application. Recombinant soluble T4
antigen (rsT4) is derived from cell surface antigen CD4 lacking its transmembrane
and cytoplasmic domains, thereby the agent is mobile within tissues. rsT4 binds to
the envelope glycoprotein gp110 of HIV and prevents the binding of virus to CD4 positive
lymphocytes, resulting in an inhibition of virus infectivity.;