Specific induction of IL2-responsiveness by
ovalbumin-stimulated lymphocytes was studied in patients with hen
egg allergy. Fluorescence-activated cell sorter analysis of the cells showed that the IL2-absorbing and IL2-responding cells mainly consisted of CD3+2+4+8-45RA+ cells that may act as helper cells for
IgE production and/or as effector cells for delayed type
hypersensitivity. beta-Chains (P75) of
IL2 receptors were involved in
ovalbumin-induced
IL2 responsiveness of the patients' lymphocytes, whereas the alpha-chains (p55) were expressed on normal lymphocytes stimulated with
ovalbumin as well. Adhering mononuclear cells from patients allergic to
ovalbumin but not to Dermatophagoides farinae (Df) were pulsed with
ovalbumin antigen then added to a T cell-rich population. After five days of culture, we evaluated cell growth for
IL-2 sensitivity during an additional 3-day culture in the presence of
IL-2. Responder cells from the patients, which were cocultured with
ovalbumin-pulsed autologous adhering cells, acquired
IL2 responsiveness; whereas, those cultured with Df-pulsed adhering cells did not. This reaction was specific for
antigen. The
monoclonal antibody to
HLA-DQ (Leu 10) and
HLA-DP (
HLA-DP) frameworks, but not the one to the
HLA-DR framework (OKIa1), blocked the antigen presenting cells ability to induce responses. T Cell-rich responder cells depleted of CD4+ cells did not acquire IL2-responsiveness, whereas the depletion of CD8+ cells had no effect. As a whole, the results indicate that DQ-bearing and/or DP-bearing adhering cells have a key function in presenting
ovalbumin-
antigen to
allergen-specific responder T cells that very likely belong to CD4+ subsets.