Abstract: Plasmid vectors are provided that carry cDNA clones coding for polypeptides exhibiting B-cell, T-cell and mast cell stimulatory activities, all of which are enhanced in the presence of other immune-reactive agents. The polypeptides also augment the activity of various CSF's, such as G-CSF and G/M-CSF, and depress proliferation of macrophages in the presence of M-CSF. The cDNA is derived from mRNA isolated from a mammalian cell source, such as T-cells typically after activation with a mitogen. The plasmid vector also contains DNA segments from the SV40 virus, permitting expression of the cDNA after transfection into a mammalian host cell, such as COS cells. Two expressed polypeptides of the present invention from different mammals are about 140 and 150 amino acids in length, including potential leader sequences. An E. coli culture containing a plasmid (pcD-2A-E3) carrying a mouse cDNA insert of the present invention was deposited with the American Type Culture Collection (A.T.C.C.) on Nov.

Abstract: The invention provides in vivo methods and compositions for using IL-10 to treat inflammatory bowel disease in a mammal. The method comprises administering to the mammal an effective amount of IL-10, preferably intravascularly, alone or in combination with other therapeutic reagents.

Abstract: Mammalian proteins and muteins thereof, designated interleukin-4s (IL-4s), are provided which exhibit both B cell growth factor activity and T cell growth factor activity. Compounds of the invention include native human and murine IL-4s, muteins thereof, and nucleic acids which are effectively homologous to disclosed cDNAs, and/or which are capable of coding for mammalian IL-4s and their muteins.

Abstract: Plasmid vectors are provided that carry complementary DNA (cDNA) clones coding for polypeptides exhibiting mammalian multi-lineage growth cell activity. One of these polypeptides is 166 amino acids in length, including a potential leader sequence of about 19 amino acids. The cDNA is derived from messenger RNA isolated from a mouse T-cell line after activation with concanavalin A. The cDNA was cloned by incorporation into a plasmid vector, which was then transformed into E. coli. The plasmid vector also contains DNA segments from the SV40 virus, permitting expression of the cDNA after transfection into a mammalian host cell, such as monkey COS-7 cells.