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THE IMMUNOGLOBULIN‐LIKE T‐CELL RECEPTOR: II. CODISTRIBUTION OF Fab DETERMINANTS AND ANTIGEN ON THE SURFACE OF ANTIGEN‐BINDING LYMPHOCYTES OF MOUSE THYMUS *
Author(s) -
DeLuca D.,
Warr G. W.,
Marchalonis J. J.
Publication year - 1979
Publication title -
international journal of immunogenetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.41
H-Index - 47
eISSN - 1744-313X
pISSN - 1744-3121
DOI - 10.1111/j.1744-313x.1979.tb00691.x
Subject(s) - antigen , microbiology and biotechnology , antibody , biology , antiserum , immunology
Summary Chicken antibodies showing rigorous specificity for mouse immunoglobulins (Ig) allow the direct visualization of an Ig‐like surface component on thymusderived lymphocytes (T‐cells). These antibodies, therefore, provide a direct means of testing the hypothesis that the Ig‐like molecules function in antigen recognition on these cells. In an attempt to determine if avian antisera to mouse Fab determinants recognize antigen‐binding receptors, the surface distribution of three large fluorescent (red) protein antigens, keyhole limpet haemocyanin (KLH), horse spleen ferritin (HSF), and whale skeletal myoglobin (MYO) on BALB/c thymus antigen‐binding lymphocytes (ABL), was compared with that of fluorescent (green) labelled chicken antibodies to mouse Fab fragments [CAM(Fab') 2 ]. The distribution of antigen and antisera against the Thy‐1 antigen and H‐2 d determinants was also compared. The frequency of ABL ranged from 0.2 to 1% and binding to these cells could be inhibited by the appropriate unlabelled antigen and CAM(Fab') 2 . Thymus ABL were 100% positive for Thy‐1 antigen when doubly stained using fluorescent rabbit anti‐mouse immunoglobulin (RAM Ig) in an indirect fluorescence assay, but only 0‐10% of ABL were positive for binding of RAM Ig alone, indicating that nearly all ABL are T‐cells. Coincidence studies of patches of antigen and the various ligands were carried out by comparing coded fluorescence photomicrographs of randomly selected thymus ABL. Of thirty‐six ABL stained with anti‐thy‐1 antiserum, all but four cells had at least one patch of antigen which was not shared with antiserum. Of thirty‐six ABL stained with anti‐H‐2 d serum, none had completely shared patches of antigen and antiserum. Of the forty ABL stained with CAM(Fab') 2 , every cell had every patch of antigen also patched with the anti‐Ig reagent. We intepret our results to indicate that the primary receptor for antigen on antigen‐binding T‐cells is either the Ig‐like molecule on the T‐cell surface or exists in close proximity to this molecule.