Abstract: DNA molecules that code for IL-1 antagonists with improved biological activity arc described. DNA molecules coding for improved IL-1 antagonists inserted into expression vectors and host cells transformed with the said vectors containing the DNA coding for improved IL-1 antagonists and a method for the production of improved IL-1 antagonists in essentially pure form are also described. Preparations that can be injected or can be administered by some other route, consisting of a pharmaceutical preparation of the said mutants, are particularly useful as drugs in the field of therapy.

Abstract: The specification relates to a synthetic peptide converted into a salt comprising one or more amine groups and capable of potentiating in vivo the primary and secondary antibody response to thymo-dependent and thymo-independent antigens having low immunogenicity.Injectable preparations comprising a solution of the peptide in a pharmacologically acceptable solvent are particularly useful as adjuvants in therapy.

Abstract: New partially retro-inverted tuftsin analogues of general formula I ##STR1## wherein R represents the side-chain of the amino acids threonine, methionine or leucineR.sup.1 represents the side-chain of the amino acids lysine or arginineR.sup.2 is hydrogen or a metabolically labile acyl group,all the asymmetric carbon atoms are either of the S- or R-configuration, or, alternatively, the first, third, and fourth asymmetric carbons, starting from the N-terminal residue, are of the S-configuration while the second one is of the R- or (R,S)-configuration, and the corresponding pharmacologically acceptable salts, esters and amides. The new compounds which share the same pharmacological properties of tuftsin, are much more stable toward the enzymatic degradation than the parent molecule.

Abstract: Synthetic peptide with human interleukin 1 activity, which peptide can be used as a stimulant of the immune functions and can be defined by the general formula:Val-Gln-Gly-Glu-Glu-Ser-Asn-Asp-Lys-X (I)where: Val=L-valine; Gln=L-glutamine; Gly=glycine; Glu=L-glutamic acid; Ser=L-serine; Asn=L-asparagine; Asp=L-aspartic acid; Lys=L-lysine; X=cysteine (Cys), OH, NH.sub.2, a benzyl ester or an alkyl ester group having a number of carbon atoms from 1 to 7.