The in Vitro Immune-Modulating Properties of a Sweat Gland-Derived Antimicrobial Peptide Dermcidin.

The epidermal barriers of the skin serve as the first layer of defense by limiting the access of many pathogens to the blood circulation. In addition, human skin also contains sweat glands that can secrete a wide array of antimicrobial peptides to restrain the growth of various microbes. In the case of microbial infection, macrophages and monocytes constitute the first line of defense by producing a wide array of proinflammatory cytokines and chemokines. This process is triggered either by pathogen-associated molecular pattern molecules (such as bacterial endotoxin) or damage-associated molecular pattern molecules (such as HMGB1). In light of our findings that a sweat gland-derived antimicrobial peptide, dermcidin, affected both pathogen-associated molecular pattern and damage-associated molecular pattern-induced cytokines/chemokines by macrophages/monocytes, we propose that dermcidin may play an important role in the regulation of the innate immune responses to infection and injury. Future investigations are warranted to further test this understudied hypothesis in both preclinical and clinical settings.

Ethnic identity salience improves recognition memory in Tibetan students via priming.

OBJECTIVES: Social identity salience affects group-reference effect in memory. However, limited studies have examined the influence of ethnic identity salience on group-reference effect among minority group people in conditions where the minority group dominates. In the present research, we aim to investigate, in a Tibetan-dominant context, whether the salience of ethnic identity among Tibetan students could display an influence on their group-reference effect via priming method. METHOD: We recruited 50 Tibetan and 62 Han Chinese students from Tibetan University in Lhasa, the capital of Tibet Autonomous Region, where Tibetans were the majority. A month before the experiment, we tested the baseline of ethnic identity salience of both Tibetan and Han Chinese students using the Twenty Statements Test. In the formal experiment, we assessed the effectiveness of priming method first and then conducted a recognition memory test 2 week later via priming approach. RESULTS: The results showed that the ethnic identity both of Tibetan and Han Chinese participants was not salient in the baseline assessment. However, it was successfully induced via priming among Tibetan students. Tibetan students showed a significant group-reference effect in recognition memory task when their ethnic identity was induced via priming. On the contrary, Han Chinese students did not show increased ethnic awareness and superiority of ethnic in-group reference memory after being primed. CONCLUSIONS: Current research provides new evidence for the influence of salience of ethnic identity on group-reference effect, contributing to the application and extension of social identity theory among minority group people.