Serological identification of thymocyte differentiation antigens.
We have examined subfractions of human thymocytes for the expression of novel differentiation antigens. Non-HLA alloantisera procured from multiparous women served as antibody probes. Thymocytes from five individuals were sequentially separated by discontinuous Percoll density gradient centrifugation and a peanut agglutinin (PNA) panning technique. Subfractions were selected and examined for their relative intensity of HLA class I and CD1 antigens as determined by cytofluorometric analysis. Two subfractions were characterized as follows: an immature population (Fr6 PNA-) expressed a high level of CD1 (OKT6 binding) antigen and a low level of class I HLA antigen; and a more mature fraction (Fr3 PNA-) expressed minimal amounts of CD1 antigen and relatively high levels of HLA class I molecules. Fr6 PNA+ and Fr3 PNA- thymocytes were tested for their reactivity with a panel of non-HLA alloantibodies as determined by cytofluorometric analysis. We observed that three alloantibodies demonstrated strong fluorescence staining with Fr6 PNA+ thymocytes only, whereas three other alloantibodies reacted with both the Fr6 PNA+ and the Fr3 PNA- subfractions. All six alloantibodies failed to react with peripheral T cells. However, the six antibodies did react with a panel of cultured T lymphoblastoid leukemic cells and fresh leukemic T cells. Blocking studies demonstrated that these alloantibodies do not bind beta 2-microglobulin-associated determinants. These results suggest that the alloantibodies detect thymocyte differentiation antigens (TDA) that are shared by or are cross-reactive with antigens expressed on certain leukemia T cells. The non-beta 2m-associated TDA antigens are not expressed on normal resting T cells.
Park
S
S
Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115.
Mahoney
R J
RJ
Given
S R
SR
Fajardo
M A
MA
Dubey
D P
DP
Yunis
E J
EJ
D018949:Antigens, CD1; D000943:Antigens, Differentiation / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology / Q000302:isolation & purification*; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007518:Isoantibodies / Q000276:immunology; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014407:Tumor Cells, Cultured / Q000276:immunology; D001613:beta 2-Microglobulin / Q000276:immunology
D018949:Antigens, CD1; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D006680:HLA Antigens; D007518:Isoantibodies; D001613:beta 2-Microglobulin