Abstract: The invention relates to a biologically-active peptide fragment of the Nef protein of human immunodeficiency virus, to pharmaceutical compositions comprising these peptides or biologically-active analogues thereof, to antagonists of the peptides and to pharmaceutical compositions comprising these antagonists, and to therapeutic and screening methods utilizing compounds and compositions of the invention.

Abstract: This invention relates to the cloning and characterization of the infectious bursal disease virus (IBDV) genome, to the identification of cloned genes for host-protective antigens of IBDV, to the expression of cDNA inserts encoding the whole or part of host-protective antigens of IBDV in E.coli or other host cells, and to the use of the expressed antigens in the production of virus neutralizing antibodies in chickens. The invention also relates to the production of an effective sub-unit vaccine against IBDV utilizing the expressed antigens, as well as to the use of the expressed antigens in diagnostic tests, assays and the like.

Abstract: A biologically-active peptide fragment of the Nef protein of human immunodeficiency virus is provided, pharmaceutical compositions comprising the peptide, analogs or derivatives of the peptide and therepeutic and screening methods which utilize the peptide and compositions which comprise them. The invention is particularly useful in the suppression of the immnune respons or in the suppression of symptoms of autoimmune disease.

Abstract: A recombinant DNA molecule comprising a nucleotide sequence substantially corresponding to all or a portion of IBDV RNA, particularly the IBDV RNA segment of approximately 3400 b.p. In particular, a DNA molecule coding for all or a part of at least one structural protein of IBDV, for example, the 32 Kd and/or the 41/37 Kd structural proteins. Synthetic peptides or polypeptides, and fused polypeptides, prepared by expression of host cells containing these DNA molecules are also disclosed.