Invertebrate cytokines: tunicate cell proliferation stimulated by an interleukin 1-like molecule.
Tunicate pharyngeal cells include lymphocyte-like cells and granular amoebocytes. They are involved in the specific allogeneic and phagocytic reactions of tunicates. Little is known about their regulation or control. A tunicate interleukin 1 (IL-1)-like fraction is shown to stimulate the proliferation of these cells in vitro. This fraction, designated tunicate IL-1 beta, was isolated from tunicate hemolymph by gel filtration and chromatofocusing chromatography. Mitogenic responses to tunicate IL-1 beta were dose dependent and could be eliminated rapidly by removing tunicate IL-1 beta from culture medium. A second tunicate hemolymph fraction had no effect on tunicate cell proliferation even though it exhibited IL-1-like activity in a mouse thymocyte proliferation assay. Phytohemagglutin did not act synergistically with either fraction. These data are discussed in terms of the function and evolution of IL-1-like molecules in invertebrates.
Raftos
D A
DA
Department of Anatomy and Cell Biology, University of California, Los Angeles 90024.
Cooper
E L
EL
Habicht
G S
GS
Beck
G
G
D000818:Animals; D001681:Biological Assay; D002455:Cell Division; D002478:Cells, Cultured; D016207:Cytokines / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*; D006458:Hemolymph / Q000502:physiology; D066298:In Vitro Techniques; D007962:Leukocytes / Q000502:physiology; D010614:Pharynx / Q000502:physiology; D014561:Urochordata / Q000502:physiology*
D016207:Cytokines