Abstract: Immunoregulatory 2,5-diketopiperazine compounds of formula: ##STR1## wherein m is 1 or 2 and n is 3 or 4 possess the ability to regulate the immune system of humans and animals. Administration of the compounds will return to a normal state an immune system in need of regulation.

Abstract: Immunoregulatory 2,5-diketopiperazine compounds of formula: ##STR1## wherein m is 1 or 2 and n is 3 or 4 possess the ability to regulate the immune system of humans and animals. Administration of the compounds will return to a normal state an immune system in need of regulation.

Abstract: There are disclosed peptides having the following formula:12 A-X-Z-Y-Bwherein A is ##STR1## X is a suitable neutral, aliphatic or aromatic amino acid residue; e.g., one selected from the group consisting of ALA, 2-Me-ALA, GLY, LEU, ILE, LYS, THR, SER, PHE, MET, D-ALA, D-LEU, D-ILE, D-LYS, D-THR, allo-THR, D-SER, D-PHE, D-MET, and SAR; Z is ##STR2## Y is GLY, SER, THR, LEU, ILE, VAl, or SAR; B is TYR-R', D-TYR-R', decarboxy-TYR, or ##STR3## m is 3 or 4; n is 1, 2, or 3; R''' is hydrogen, C.sub.1 -C.sub.7 alkyl, C.sub.6 -C.sub.12 aryl, or C.sub.1 -C.sub.7 alkanoyl; and R and R' are substituents which do not substantially affect the biological activity of the peptides, provided that R-ARG-LYS-ASP-VAL-TYR-R' is excluded. These peptides have the capability of inducing the differentiation of T-lymphocytes but not of complement receptor (CR.sup.+) B-lymphocytes and thus are useful in a number of therapeutic areas.

Abstract: There are disclosed polypeptide compositions having the following amino acid sequence as the active site:ARG-LYS-ASP-VAL-TYRThese polypeptides have the capability of inducing the differentiation of T-lymphocytes but not of complement receptor (CR.sup.+) B-lymphocytes and thus are useful in a number of therapeutic areas. Also provided are derivatives of the pentapeptide, novel intermediate polypeptides, methods of manufacture of the peptides, therapeutic compositions, and methods for use of the compositions.

Abstract: There are disclosed new polypeptide compositions having the following amino acid sequence as the active site:TYR-ASN-ILE-GLN-LYSThis polypeptide has the capability of inducing the differentiation of both T-precursor cells as measured by the acquisition of the thymic differentiation antigens TL and THY-1 (.theta.), as well as B-precursor cells as measured by the acquisition of receptors for complement, a distinctive marker of B cells. The peptide is thus useful in thymic function and immunity areas such as in treatment for a congenital absence of thymus. The peptide is active in very low concentrations. Also provided are derivatives of the pentapeptide, novel intermediate polypeptides, methods of manufacture of the peptides, therapeutic compositions, and methods for use of the compositions.

Abstract: There are disclosed new biologically active polypeptides containing the following polypeptide segment:--ALA--LYS--SER--GLN--Biological activity is generally retained upon substitution of a natural or non-natural amino acid residue for either or both of L-alanyl in the first position and L-seryl in the third position.These polypeptides have the capability of inducing the differentiation of T-lymphocytes as measured by the acquisition of the thymic differentiation antigen Th-1, as well as B-lymphocytes as measured by the acquisition of the differentiation antigen Bu-1. The polypeptides are thus useful in thymic function and immunity areas such as in treatment for congenital absence of thymus. Also provided are substituted polypeptides, methods of manufacture of the polypeptides, therapeutic compositions, and methods for use of the polypeptides.

Abstract: There are disclosed new biological active polypeptides:A--X--Bwherein A is deamino-LYS or LYS; X is a suitable neutral aliphatic amino acid residue; e.g., one selected from the group consisting of SER, ALA, 2-Me-ALA, GLY, LEU, THR, D-SER, D-ALA, D-THR, allo-THR, D-LEU, and SAR; B is GLN-R', decarboxy-GLN, or ##STR1## and R' is a substituent which does not substantially affect the biological activity of the tripeptide.These polypeptides have the capability of inducing the differentiation of T-lymphocytes as measured by the acquisition of the thymic differentiation antigen Th-1, as well as B-lymphocytes as measured by the acquisition of the differentiation antigen Bu-1. The polypeptides are thus useful in thymic function and immunity areas such as in treatment for congenital absence of thymus. Also provided are therapeutic compositions and methods for use of the polypeptides.

Abstract: Peptides of the following formula:A-Bwherein A is a member selected from the group consisting of deamino-GLN, GLN, and (SAR).sub.n -GLN; n is an integer from 1 to 4; and B is a member selected from the group consisting of LYS-OH, LYS-NH.sub.2, decarboxy-LYS, ##STR1## LYS-SAR-OH and LYS-SAR-NH.sub.2, have significantly increased ubiquitin-like activity. Also provided are therapeutic compositions and methods for use thereof.

Abstract: There are disclosed polypeptide compositions having the following amino acid sequence as the active site:ARG-LYS-ASP-VAL-TYRThese polypeptides have the capability of inducing the differentiation of T-lymphocytes but not of complement receptor (CR.sup.+) B-lymphocytes and thus are useful in a number of therapeutic areas. Also provided are derivatives of the pentapeptide, novel intermediate polypeptides, methods of manufacture of the peptides, therapeutic compositions, and methods for use of the compositions.

Abstract: There are disclosed new polypeptide compositions having the following amino acid sequence as the active site:TYR-ASN-ILE-GLN-LYSThis polypeptide has the capability of inducing the differentiation of both T-precursor cells as measured by the acquisition of the thymic differentiation antigens TL and THY-1 (.theta.), as well as B-precursor cells as measured by the acquisition of receptors for complement, a distinctive marker of B cells. The peptide is thus useful in thymic function and immunity areas such as in treatment for a congenital absence of thymus. The peptide is active in very low concentrations. Also provided are derivatives of the pentapeptide, novel intermediate polypeptides, methods of manufacture of the peptides, therapeutic compositions, and methods for use of the compositions.

Abstract: There is disclosed a new Ubiquitous Immunopoietic Polypeptide (UBIP) which has been isolated in fluffy white powder form from bovine thymus but which has been found to be present in living cellular tissue of all animals and plants tested including various guinea pig tissues, cells in tissue cultures and tissues from birds, fish, squid, plants, fungi and bacteria, the polypeptide being characterized by its ability to induce in vitro, in nanogram concentrations, the differentiation of both T cell and B cell immunocytes from precursors present in bone marrow or spleen and thus the polypeptide is useful in therapeutic areas involving thymic or immunity deficiencies and the like. The polypeptide also exhibits hypotensive properties. The polypeptide is isolated from living source materials by a combination of sizing techniques and ion-exchange chromatography and may be described by the following amino acid structural sequence:H.sub.

Abstract: An immunoassay for the polypeptide thymic hormone thymopoietin is described. Determination of thymopoietin levels in biological fluids provides a useful diagnostic test for myasthenia gravis (elevated levels), immune deficiency diseases (reduced levels), (immunologically mediated diseases such as rheumatoid arthritis, systemic lupus erythematosus and allergy (reduced levels), cancer (reduced levels), malnutrition (reduced levels) and infections (reduced levels). The present assay is also useful as a monitor of the effectiveness of therapy in each of the aforementioned types of disease states.

Abstract: There are disclosed closely related new polypeptides isolated from bovine thymus, which are distinct polypeptides denoted as Thymin I and Thymin II or Thymopoietin I and Thymopoietin II, respectively. Thymin I may be characterized as having a relative mobility (Rf) on 7% polyacrylamide gel disc electrophoresis of 0.63 with respect to methyl green at a pH of 4.3, and having the following structural sequence:H.sub.2 n--gly--gln--phe--leu--glu--asp--pro--ser--val--leu--thr--lys--glu--lys--l eu--lys--ser--glu--leu--val--ala--asn--asn--val--thr--leu--pro--ala--gly--g lu--gln--arg--lys--asp--val--tyr--val--gln--leu--tyr--leu--gln--his--leu--t hr--ala--val--lys--arg--coohThymin II may be characterized as having a relative mobility (Rf) on 7% polyacrylamide gel disc electrophoresis of 0.57 with respect to methyl green at a pH of 4.3, and having the following structural sequence:H.sub.

Abstract: There are disclosed closely related new polypeptides isolated from bovine thymus, which are distinct polypeptides denoted as Thymin I and Thymin II or Thymopoietin I and Thymopoietin II, respectively. Thymin I may be characterized as having a relative mobility (Rf) on 7% polyacrylamide gel disc electrophoresis of 0.63 with respect to methyl green at a pH of 4.3, and having the following structural sequence:H.sub.2 n-gly-gln-phe-leu-glu-asp-pro-ser-val-leu-thr-lys-glu-lys-leu-lys-ser-glu- leu-val-ala-asn-asn-val-thr-leu-pro-ala-gly-glu-gln-arg-lys-asp-val-tyr-val -gln-leu-tyr-leu-gln-his-leu-thr-ala-val-lys-arg-cooh.Thymin II may be characterized as having a relative mobility (Rf) on 7% polyacrylamide gel disc electrophoresis of 0.57 with respect to methyl green at a pH of 4.3, and having the following structural sequence:H.sub.

Abstract: An immunoassay for the polypeptidic thymic hormone thymopoietin (thymin) is described. Determination of thymopoietin levels in biological fluids provides a useful diagnostic test for myasthenia gravis (elevated levels), immune deficiency diseases (reduced levels), immunologically mediated diseases such as rheumatoid arthritis, systemic lupus erythematosus and allergy (reduced levels) cancer (reduced levels), malnutrition (reduced levels) and infections (reduced levels). The present assay is also useful as a monitor of the effectiveness of therapy in each of the aforementioned types of disease states.

Abstract: There is disclosed a new Ubiquitous Immunopoietic Polypeptide (UBIP) which has been isolated in fluffy white powder form from bovine thymus but which has been found to be present in living cellular tissue of all animals and plants tested including various guinea pig tissues, cells in tissue cultures and tissues from birds, fish, squid, plants, fungi and bacteria, the polypeptide being characterized by its ability to induce in vitro, in nanogram concentrations, the differentiation of both T cell and B cell immunocytes from precursors present in bone marrow or spleen and thus the polypeptide is useful in therapeutic areas involving thymic or immunity deficiencies and the like. The polypeptide also exhibits hypotensive properties. The polypeptide is isolated from living source materials by a combination of sizing techniques and ion-exchange chromatography and may be described by the following amino acid structural sequence:H.sub.

Abstract: There is disclosed a tridecapeptide of the following sequence:H.sub.2 N--Gly--Glu--Gln--Arg--Lys--Asp--Val--Tyr--Val--Gln--Leu--Tyr--Leu--COOHthis tridecapeptide has the capability of including the differentiation of T lymphocytes but not of complement receptor (CR.sup.+) B lymphocytes and thus is useful in a number of therapeutic areas. Also provided are novel intermediate polypeptides and methods of manufacture of the peptides.