T cells from atopic individuals produce IgE-inducing activity incompletely blocked by anti-interleukin-4 antibody.
We investigated peripheral blood B and T lymphocyte functions in atopic individuals. B cells were co-cultured with mutant EL4 thymoma cells in the presence of a standard T cell supernatant (T-SN) with or without exogenous interleukin (IL)-4. IgE secretion in this assay was found to be IL-4 dependent, but not significantly different for atopic patients (n = 25) vs. normal controls (n = 25). Phytohemagglutinin plus phorbol 12-myristate 13-acetate (PHA+PMA)- induced T-SN from patients or controls was tested on normal B cells in the same assay system (in the absence of exogenous IL-4). Compared to the controls, the IgE-inducing activity was significantly increased for patients with asthma or allergic rhinitis (n = 12; p less than 0.005) but not for patients with atopic dermatitis (n = 13). The difference between the asthma or allergic rhinitis vs. the atopic dermatitis groups was significant (p greater than 0.05). Since the assay was not inhibited by interferon (IFN)-gamma, this difference can not be attributed to IFN-gamma concentrations. Other T cell activities may be different between the patient groups or atopic T cells from the respiratory mucosa may recirculate more than those from the skin. In any case, the T cells rather than the B cells were found to be abnormal in atopic individuals. If atopic T cells were stimulated with PHA+PMA not as immediately but after a resting period of 48 h in culture medium alone, the IgE-inducing activity, but not the total Ig-inducing activity or the IL-2 secretion, disappeared. In addition, a mean of 37% of the IgE-inducing activity (range of 13% to 79% for five very active T-SN) was not inhibited by an anti-IL-4 antibody which neutralized exogenous IL-4, indicating a participation of factors capable of bypassing the requirement for IL-4 for the IgE response.
Zhang
X
X
Department of Medicine, Hôpital Cantonal Universitaire, Genève, Switzerland.
Polla
B
B
Hauser
C
C
Zubler
R H
RH
D000911:Antibodies, Monoclonal / Q000276:immunology*; D001249:Asthma / Q000276:immunology; D001402:B-Lymphocytes / Q000502:physiology; D002478:Cells, Cultured; D003876:Dermatitis, Atopic / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000502:physiology*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology; D013601:T-Lymphocytes / Q000502:physiology*
D000911:Antibodies, Monoclonal; D015847:Interleukin-4; D007073:Immunoglobulin E