Human T cell responses to recombinant mite antigens of Dermatophagoides farinae

We studied T cell responses to four glutathione S transferase (GST)‐fused mite antigens prepared in our laboratory using peripheral blood lymphocytes from mite‐sensitive patients with bronchial asthma. Of the four recombinant antigens, purified GST‐Mag3 had the strongest ability to cause patients' lymphocytes to proliferate, and its potency was almost comparable to that of crude mite bodies (Dfb) and faeces (Dff) antigens and a purified major antigen, Der f 2. The responder lymphocytes were mainly T cells, because the proliferative response was depleted by the treatment of lymphocytes with anti‐CD3 antibody and complement, but not with anti‐CD20 antibody and complement. The responsiveness of lymphocytes to GST‐Mag3 correlated with that to Der f 2, but GST‐Mag3 displayed slightly higher activity to stimulate lymphocytes than Der f 2. Simultaneously, the levels of Dff‐ and GST‐Mag3‐specific IgE antibodies correlated with the responsiveness of lymphocytes to GST‐Mag3. These results suggest that Mag3 is a new valuable antigen for the response of T cell proliferation in mite‐sensitive patients.