{'fraction_non_alphanumeric': 0.036249014972419225, 'fraction_numerical': 0.01260835303388495, 'mean_word_length': 5.287128712871287, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Priming of Cytotoxic T‐Cell Precursors is Strictly Helper T Cell‐Dependent

Allogeneic chimaeras that utilize C. B. 17 SCID mice (H‐2d) as recipients of MHC mismatched bone marrow from C57B1/6(H‐2nd) or SJL/J (H‐2d) mice have been used to provide experimental evidence demonstrating the necessity for a direct interaction between an effector T helper and the cytotoxic T‐cell precursor in order to generate cytotoxic effector T cells specific for the minor histocompatibility (H) antigens of DBA/2 (H) mice. No effect of helpers specific for antigen processed or not‐presented on antigen‐presenting cells could be observed. Allo‐chimaeras that contain T cells hearing H‐2d, and which are restricted to H‐2d, make a cytotoxic T‐cell response to minor H antigens which is H‐2d restricted if, and only cloned anti‐H‐2d effector T helpers are present during the vivo printing step. Cloned anti‐H‐2d effector helpers, which are without effect in the allo‐chimaeras, do provide a strong helper activity when tested in normal H‐2d mice. These findings cannot reconciled with a strict single recognitive model of restrictive antigen recognition, but they are consistent with a dual recognitive model, which incorporates many of the features of the single recognitive model.