The proportion ofP25TCRTh1 cells producing IFN-γ was highest (∼10%) on day 14(Figure 3A and 3C).These results indicate that during the acute stage of infection, adoptivelytransferred P25TCRTh1 cells are stimulated in the lungs at a frequencycomparable to that of TCR transgenic CD4+ effector cells at thesite of injection of a protein antigen and adjuvant [35]. The gene discussed is CD4; the disease is infection.