An attempt to assess the overall diversity of murine T cells using two‐dimensional gel electrophoresis

The technique of two‐dimensional gel electrophoresis has been applied to study the changes in protein patterns occurring in murine T lymphocytes after activation by a T cell mitogen. The protein maps of individual T cell clones obtained by limiting dilution were also compared. Whole cell lysates from [³⁵S]methionine‐labeled cell clones or cell populations were analyzed and radiofluorographs of gels compared. We found that, during the events of differentiation and clonal proliferation, a T cell population undergoes dramatic changes resulting in pronounced changes in the protein pattern. In a typical gel with about 1000 detectable spots, there were about 50 changes from one day to the next. Certain regions of gels were compared using highly exposed films; in these, a much higher proportion of spots was found to vary (47/255 spots). Furthermore, we found that T cell clones obtained by limiting dilution yield a protein pattern that contains both “stable” and “diverse” regions. In the molecular weight region from about 35000–43000, there are 0 to 5 differences when one clone is compared with another. Due to a relatively small number of clones analyzed [16], it is probable that the revealed changes are only a fraction of the diversity which remains to be uncovered.