The expression and biologic effects of ovine interleukin-4 on T and B cell proliferation.
Using the reverse-transcriptase polymerase chain reaction (RT-PCR), cDNA encoding ovine (Ov) interleukin-4 (OvIL-4) was generated from mitogen-stimulated peripheral blood mononuclear cells (PBMC). Two identical clones generated from separate RT-PCR reactions differed from a published OvIL-4 sequence, although they had a high degree of identity with the bovine and human homologs. We show by sequence analysis that the OvIL-4 cDNA retained the four alpha-helix structure and disulfide bonds identified in human IL-4 (HuIL-4). Moreover, the cDNA encoding OvIL-4 was expressed in insect cells using the baculovirus Autographa californica nuclear polyhedrosis virus (AcMNPV) as a vector. Supernatants from insect cells infected with the recombinant virus secreted an additional protein with a relative molecular mass of 17,000. This protein was recognized by an anticervine IL-4 monoclonal antibody (mAb) in a Western blot and did not react with any proteins in supernatants from uninfected insect cells or cells infected with the wild-type AcMNPV. Supernatants from insect cells infected with the recombinant virus induced the proliferation of activated B cells in a dose-dependent manner and typically demonstrated 5 x 105 dilution U/ml of activity. However, OvIL-4 had no effect on the proliferation of resting T cells isolated from efferent lymph and actually inhibited the ability of a mitogen to stimulate these resting lymphocytes. In contrast, OvIL-4 induced the proliferation of mitogen-activated lymphoblast, demonstrating the complex role(s) OvIL-4 plays in the regulation of B and T cells.
Chaplin
P J
PJ
Cooperative Research Centre for Vaccine Technology, CSIRO Animal Health, Parkville, Victoria, Australia. chaplin@bavarian-nordic.de
Casey
G
G
De Rose
R
R
Buchan
G
G
Wood
P R
PR
Scheerlinck
J P
JP
D000276:Adjuvants, Immunologic / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002417:Cattle; D002455:Cell Division / Q000276:immunology; D003001:Cloning, Molecular; D005260:Female; D006801:Humans; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008969:Molecular Sequence Data; D012756:Sheep; D013601:T-Lymphocytes / Q000276:immunology*
D000276:Adjuvants, Immunologic; D015847:Interleukin-4