Ovalbumin-specific induction of IL2 responsiveness in lymphocytes from patients with hen egg allergy and its regulation by the culture supernatant of normal lymphocytes.

Interleukin 2 (IL2) responsiveness of ovalbumin (OVA)-stimulated lymphocytes from patients with hen-egg allergy was studied. The number of viable cells of 5-day cultured lymphocytes stimulated with OVA was increased by an additional three days incubation with recombinant IL2. This phenomenon was not observed when the lymphocytes of patients allergic to OVA but not to Dermatophagoides farinae extract antigen (Df) were stimulated with Df. Normal lymphocytes stimulated with OVA expressed Tac antigen (low affinity IL2 receptor) but, in contrast to those from the allergic patients, did not absorb nor respond to IL2. The induction of OVA-specific IL2 responsiveness in patient lymphocytes was markedly suppressed on the addition of culture supernatant from OVA-stimulated normal T cells, but Df-specific IL2 responsiveness of the lymphocytes from Df-sensitized patients with bronchial asthma was not suppressed by the same supernatant. The supernatant of lymphocytes from allergic patients did not show such suppressive effect. The patient lymphocytes whose IL2 responsiveness was suppressed with the supernatant from normal lymphocytes still expressed Tac antigen. These observations suggest that the culture supernatant of normal T lymphocytes stimulated with OVA contained an antigen-specific factor suppressing the induction of IL2 responsiveness of OVA-stimulated patient lymphocytes. The production of such a suppressive factor was impaired in the patient, and further, the factor may have inhibited the triggering signal of IL2 receptors having absorbed IL2. The existence of some allogeneic barrier between the factor(s) and patient lymphocytes was suggested, since the supernatant from OVA-stimulated normal T cells did not necessarily suppress the response of all patients tested.