A subpopulation of allospecific cytotoxic T-cell precursors with phenotypic characteristics of natural killer cells.
We have proposed that natural killer (NK) cells are germ-line V-gene encoded prothymocytes specific for either self or non-self histocompatibility antigens. This hypothesis predicts that at least some precursors of allospecific cytotoxic T cells (allo-CTL) are NK cells. To test this we examined the effect of depleting NK cells and/or T cells (by complement lysis with anti-asialo GM1 and/or anti-Thy 1) on the development of allo-CTL induced during mixed lymphocyte culture (MLC). Removal of Thy 1+ cells from MLC responder populations prevented development of allo-CTL. This was partially reversed by addition of concanavalin A-conditioned medium (Con A-CM) to the MLC at day 0. Removal of asialo GM1+ cells eliminated NK activity measured at day 0, but failed to prevent development of allo-CTL of otherwise intact responder cells. However, removal of asialo GM1+ cells did prevent the Con A-CM dependent development of allo-CTL by responder cells depleted of Thy 1+ cells. These findings indicate that a subpopulation of allo-CTL precursors has the phenotypic characteristics of NK cells: absence or low density of Thy 1, and susceptibility to complement lysis by anti-asialo GM1.
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J
Kaplan
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K
Wasserman
D000818:Animals; D002478:Cells, Cultured; D003165:Complement System Proteins / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D000939:Epitopes; D005677:G(M1) Ganglioside; D006028:Glycosphingolipids / Q000276:immunology; D007518:Isoantibodies / Q000276:immunology; D007519:Isoantigens / Q000276:immunology*; D007694:Killer Cells, Natural / Q000145:classification* / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects*; D008212:Lymphocyte Depletion; D051379:Mice; D008808:Mice, Inbred CBA; D010641:Phenotype; D013154:Spleen / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification* / Q000276:immunology
D000939:Epitopes; D006028:Glycosphingolipids; D007518:Isoantibodies; D007519:Isoantigens; C035678:anti-Thy antibody; D005677:G(M1) Ganglioside; C018835:asialo GM1 ganglioside; D003165:Complement System Proteins