title: Phylogeny of lymphocyte heterogeneity: the cellular requirements for in vitro antibody responses of channel catfish leukocytes.
abstract: Three functionally distinct leukocyte subpopulations were isolated from the peripheral blood of channel catfish. Surface immunoglobulin-positive (sIg+) and sIg- lymphocytes were isolated by an indirect "planning" procedure employing monoclonal antibodies specific for channel catfish Ig. A third population composed of macrophages was isolated by adherence to baby hamster kidney cell microexudate-coated surfaces. Functional features of these three cell types were established by assessing their role(s) in primary in vitro anti-hapten PFC responses to known murine thymus-dependent (TD) and thymus-independent (TI) antigens. The results indicated that anti-hapten PFC responses to a TI antigen required the presence of sIg+ lymphocytes and macrophages. In contrast, all three cell types were required for responses to TD antigens. Furthermore, the results of studies involving the depletion of antigen-reactive lymphocytes demonstrated that both hapten-specific sIg+ cells and carrier-specific sIg- cells were required for anti-hapten responses to TD antigens. These studies provide direct evidence that catfish have separable B cells (sIg+ lymphocytes), T helper cells (sIg- lymphocytes), and accessory cells (macrophages) quite similar to those seen in higher animals.
authors.forename: N W
authors.initials: NW
authors.lastname: Miller
authors.forename: R C
authors.initials: RC
authors.lastname: Sizemore
authors.forename: L W
authors.initials: LW
authors.lastname: Clem
mesh_terms: D000818:Animals; D000917:Antibody Formation; D002352:Carrier Proteins / Q000276:immunology; D002469:Cell Separation; D000939:Epitopes; D005399:Fishes / Q000276:immunology*; D006241:Haptens / Q000276:immunology; D006462:Hemolytic Plaque Technique; D007111:Immunity, Cellular; D008214:Lymphocytes / Q000145:classification* / Q000276:immunology / Q000502:physiology; D010802:Phylogeny; D011947:Receptors, Antigen, B-Cell
chemical_list: D002352:Carrier Proteins; D000939:Epitopes; D006241:Haptens; D011947:Receptors, Antigen, B-Cell