Myelopeptide-5 abolishes virus-induced immunosuppression by restoring T cell functions.

Myelopeptide-5 (MP-5; synthetic analog of endogenous low-molecular-weight peptide Val-Val-Tyr-Pro-Asp) neutralized the immunosuppressive effects of antiviral vaccines (influenza, measles, and measles/parotitis) and stimulated their immunogenicity by restoring functional activity of T cells, suppressed by the viruses. Specific binding of MP-5 to CD4(+) lymphocyte (its target cell) was studied using [(3)H]MP-5 (dissociation constant 2.03 x 10(-7) M).