The immunomodulatory activity of the plant proteins Momordica charantia inhibitor and pokeweed antiviral protein.
The immunological activity of Momordica Charantia inhibitor (MCI) and of Pokeweed antiviral protein (PAP-S), 30,000 daltons plant proteins possessing close similarity to Ricin A chain as inhibitor of protein synthesis, was investigated in mice. In vivo, single nontoxic injections of microgram amount of these substances delayed H2-incompatible skin allograft rejection, splenocyte responsiveness to ConA and PHA, but not to LPS, and abrogated the PFC response to a T-dependent (SRBC) antigen while totally sparing that to a T-independent (S III) stimulus. Injection of these substances could also reduce NK cell activity while increasing macrophage-mediated spontaneous cytotoxicity. In vitro, MCI and PAP-S at non-cytotoxic concentrations inhibited lymphoid cell responsiveness to PHA and ConA, but not to LPS, and markedly enhanced macrophage-dependent cytotoxicity.
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D006084:Graft Rejection / Q000187:drug effects; D007113:Immunity, Innate / Q000187:drug effects; D007694:Killer Cells, Natural / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D009699:N-Glycosyl Hydrolases; D010940:Plant Proteins / Q000276:immunology*; D014176:Protein Biosynthesis / Q000187:drug effects; D054789:Ribosome Inactivating Proteins, Type 1; D054790:Ribosome Inactivating Proteins, Type 2; D013154:Spleen / Q000276:immunology
D010940:Plant Proteins; D054789:Ribosome Inactivating Proteins, Type 1; D054790:Ribosome Inactivating Proteins, Type 2; D009699:N-Glycosyl Hydrolases; C024275:pokeweed antiviral protein