{'fraction_non_alphanumeric': 0.030100334448160536, 'fraction_numerical': 0.0, 'mean_word_length': 5.527272727272727, '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}}
Injury-induced allograft rejection: A rendezvous with evolution.

Modern immunology, in many ways, is based on three major paradigms: the clonal selection theory, the pattern recognition theory, and the danger/injury theory. The last theory holds that any cell stress and tissue injury, including allograft injury, via induction of damage-associated molecular patterns, induces immunity, including alloimmunity, leading to allograft rejection. On the other hand, the concept precludes that non-self per se induces immunity as proposed by the two former theories. Recently, the danger/injury model has gained considerable acceptance by immunologists, in particular as promoted by new insights into the function of the mammalian gut microbiota, representing a huge assemblage of non-self. Harboring microbiota by hosts is characterized by the fact that harmless noninjurious commensal microbes are protected by innate immunity-based tolerance, whereas intestinal injury-causing pathogenic microbes are immunologically attacked. Plausibility and validity of the danger/injury concept is stringently supported by observations of similar phenomena across the tree of life: the ability of the immune system to discriminate between harmful life-threatening non-self to induce immunity and harmless beneficial non-self to induce tolerance has apparently emerged during evolution. Immune defense responses to injuring/injured non-self (e.g., as reflected by plant resistance to biotic and abiotic stresses on one hand, and allograft rejection on the other hand) as well as immunity-controlled protection of beneficial non-self (e.g., as reflected by microbiota and the fetus of placental mammals) are processes in the interest of evolution and, thus, evolved under pressure across the phylogenetic tree.