INDUCIBLE INTERLEUKIN-4-SECRETING CELLS PROVOKED IN MICE DURING CHEMICAL SENSITIZATION

It has been demonstrated previously that chemical contact and respirat ory allergens differ with respect to the quality of immune responses t hey will provoke in mice. Trimellitic anhydride (TMA), a human respira tory allergen, induces in mice responses consistent with the preferent ial activation of Th2-type cells, resulting in the production ofIgE an ti-hapten antibody and an increase in the serum concentration of IgE. In contrast, oxazolone (OX), a potent contact allergen considered not to cause respiratory hypersensitivity, induces instead Th1-type respon ses in mice characterized by vigorous Igc2a antibody production and a failure to elicit IgE. In the present study we have extended these inv estigations and have examined the capacity of these chemicals to stimu late inducible interleukin-4 (IL-4) production by draining lymph node cells (LNC). IL-4 was measured in the supernatants of draining LNC cul tured for various periods in the presence or absence of concanavalin A (Con A). Following primary topical exposure to the chemical allergens , Con A-stimulated LNC from OX-treated mice secreted significantly mor e IL-4 than did LNC from mice exposed to trimellitic anhydride (TMA). A different pattern of IL-4 secretion was observed following culture w ith Con A of LNC prepared from lymph nodes draining the sites of secon dary exposure to these chemicals. In this case significantly higher co ncentrations of IL-4 were produced by TMA-treated mice. Detectable lev els of IL-4 (> 300 pg/ml) were not found following culture of draining LNC from sensitized mice in the absence of Con A or following culture of LNC from naive mice with or without Con A. These data demonstrate that chemical allergens of different types stimulate discrete and chan ging patterns of inducible IL-4 synthesis consistent with the selectiv e activation of Th-cell subpopulations.