IGA-SPECIFIC HELPER ACTIVITY OF T-ALPHA-CELLS IN HUMAN PERIPHERAL-BLOOD

  • 1 January 1981
    • journal article
    • research article
    • Vol. 127  (6) , 2612-2613
Abstract
A subpopulation of human T lymphocytes that express IgA receptors (T.alpha. cells) was separated by a FACS (fluorescence-activated cell sorter) using fluorescein isothiocyanate-conjugated human IgA myeloma protein to determine whether they have helper activity for in vitro Ig synthesis in comparison with a T.alpha. cell population separated by rosette formation using picrylsulfonic acid trinitrobenzene sulfonic acid-ox erythrocytes conjugated with MOPC-315 mouse IgA myeloma protein. FACS-separated T.alpha. cells have IgA specific helper activity and rosette-separated T.alpha. cells have polyclonal helper activity for in vitro Ig synthesis in pokeweed mitogen-stimulated B cells. The polyclonal helper activity observed in rosette-separated T.alpha. cells might be due to contamination of non-T.alpha. cells in the T.alpha. cell fraction. Purified T.alpha. cells in normal human peripheral blood show IgA-specific helper activity in vitro.