Pathogen-associated molecular patterns decisively influence antiviral immune responses, whereas the contribution of endogenous signals of tissue damage, also known as damage-associated molecular patterns or alarmins, remains ill defined. We show that interleukin-33 (IL-33), an alarmin released from necrotic cells, is necessary for potent CD8(+) T cell (CTL) responses to replicating, prototypic RNA and DNA viruses in mice. IL-33 signaled through its receptor on activated CTLs, enhanced clonal expansion in a CTL-intrinsic fashion, determined plurifunctional effector cell differentiation, and was necessary for virus control. Moreover, recombinant IL-33 augmented vaccine-induced CTL responses. Radio-resistant cells of the splenic T cell zone produced IL-33, and efficient CTL responses required IL-33 from radio-resistant cells but not from hematopoietic cells. Thus, alarmin release by radio-resistant cells orchestrates protective antiviral CTL responses.

4 studies investigated the broad claim that preschoolers understand biological inheritance. In Study 1, 4-7-year-old children were told a story in which a boy was born to one man and adopted by another. The biological father was described as having one set of features (e.g., green eyes) and the adoptive father as having another (e.g., brown eyes). Subjects were asked which man the boy would resemble when he grew up. Preschoolers showed little understanding that selective chains of processes mediate resemblance to parents. It was not until age 7 that children substantially associated the boy with his biological father on physical features and his adoptive father on beliefs. That is, it was not until age 7 that children demonstrated that they understood birth as part of a process selectively mediating the acquisition of physical traits and learning or nurturance as mediating the acquisition of beliefs. In Study 2, subjects were asked whether, as a boy grew up, various of his features could change. Children generally shared our adult intuitions, indicating that their failure in Study 1 was not due to their having a different sense of what features can change. Studies 3 and 4 replicated Study 1, with stories involving mothers instead of fathers and with lessened task demands. Taken together, the results of the 4 studies refute the claim that preschoolers understand biological inheritance. The findings are discussed in terms of whether children understand biology as an autonomous cognitive domain.

Eighty-three 12-month-old infants faced a noisy, active, object for one minute, after which the object turned 45 degrees to the left or the right. Five conditions explored what object features elicited gaze-following behavior in the infants. In one condition, the object was an adult stranger. The other four conditions used a soft, brown, dog-sized, amorphouslyshaped, asymmetrical novel object that varied along two dimensions theorized as central to the identification of intentional beings: facial features and contingently interactive behavior. Infants shifted their own attentional direction to match the orientation of the actor or object in every condition except the one in which the object lacked both a face and contingently interactive behavior. Infants' 'gaze'-following behavior in general, therefore, appears to have been driven selectively by a particular configuration of behavioral and morphological characteristics, specifically those theorized as underlying attributions of intentionality rather than attributions of person per se.

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