THE INTERACTION OF IgE WITH RAT BASOPHILIC LEUKEMIA CELLS

Abstract

It has been previously shown that alloantisera prepared by reciprocal immunization of strain 2 and strain 13 guinea pigs specifically block the activation of T lymphocytes from immune guinea pigs by antigens, the response to which is controlled by Ir genes. In this report we have examined the effect of absorption of the 13 anti-2 serum with different populations of lymphoid cells. It is unlikely that the inhibitory activity of the anti-2 serum on the proliferation of (2 x 13)F₁ lymphocytes to a DNP derivative of a copolymer of L-glutamic and L-lysine (DNP-GL) is due to the presence of antibodies specific for the unique antigenic determinants (idiotypes) of clonally distributed T-lymphocyte receptors. Thus, cells obtained from a normal animal and a DNP-GL immune animal were equivalent in their absorptive capacity. Populations of T lymphocytes were ineffective in absorbing either the cytotoxic or inhibitory activity of the anti-2 serum, while L₂C leukemia cells, a malignant B-cell population, were most efficient in absorbing both activities. Thus, the antigen(s) against which the cytotoxic and inhibitory activities are directed are present to a greater extent on B lymphocytes than on T lymphocytes. However, these results do not allow us to definitively determine whether the inhibitory activity of the alloantisera is due to antibodies specific for Ir gene products or antibodies specific for linked antigens in the MHC.