title: Immunomodulatory properties of certain amino acids influence the immunostimulating properties of specific peptides.
abstract: Using the previously obtained data that amino acids could influence the thymus-dependent immune response, the significance of amino acids in the immunostimulating activity of peptides has been studied. The effect of seven synthetic fragments of murine Thy-1 antigen, non-sulfated cholecystokinin (CCK-8), the two tetrapeptides at the N- and C-terminal fragments of CCK-8, as well as neurotensin (NT) have been investigated. It has been found that both NT and those Thy-1 fragments which consisted of immunologically inert amino acids, did not influence the immune response in mice. CCK-8, its C-terminal fragment and those Thy-1-antigen peptides which contained immunoactive amino acids at C- or N-terminus or both, stimulated IgM-plaque forming cells (PFC) in animals. The N-terminal CCK-8 tetrapeptide showed negligible activity. The possibility of the existence of two independent immunoregulatory systems--one amino acids based and the other dependent upon a sequence of amino acids in the peptide is being discussed.
authors.affiliation: Immunology Department, Academy of Medical Sciences, Leningrad, U.S.S.R.
authors.forename: G A
authors.initials: GA
authors.lastname: Belokrylov
authors.forename: I V
authors.initials: IV
authors.lastname: Molchanova
authors.forename: E I
authors.initials: EI
authors.lastname: Sorochinskaya
mesh_terms: D000276:Adjuvants, Immunologic; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D000921:Antibody-Producing Cells / Q000187:drug effects / Q000276:immunology; D000954:Antigens, Surface / Q000737:chemistry / Q000494:pharmacology; D002766:Cholecystokinin / Q000737:chemistry / Q000494:pharmacology; D007075:Immunoglobulin M / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D009496:Neurotensin / Q000737:chemistry / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D018800:Thy-1 Antigens
chemical_list: D000276:Adjuvants, Immunologic; D000596:Amino Acids; D000954:Antigens, Surface; D007075:Immunoglobulin M; D010446:Peptide Fragments; D010455:Peptides; D018800:Thy-1 Antigens; D009496:Neurotensin; D002766:Cholecystokinin