Looi, C. Y. | bioRxiv Science

bioRxiv2018

Interleukin-17A Secreted from the Lung-infiltrating T Helper 17 Cells Renders Protective Immunity to Pulmonary Cryptococcus neoformans Infection

IL-17A has emerged as a key player in the pathologies of inflammation, autoimmune disease, and immunity to microbes since its discovery two decades ago. In this study, we aim to elucidate the activity of IL-17A in the protection against Cryptococcus neoformans, an opportunistic fungus that causes fatal meningoencephalitis among AIDS patients. For this purpose, we examined if C. neoformans infection triggers IL-17A secretion in the in vitro setting using RAW264.7 murine macrophage cells, and in vivo using wildtype C57BL/6 mice. In addition, an enhanced green fluorescence protein (eGFP) reporter and a knockout (KO) mouse models were used to track the source of IL-17A secretion and explore the protective function of IL-17A, respectively. Our findings showed that both in vivo and in vitro models of C. neoformans infection demonstrated induction of abundant IL-17A secretion. By examining the lung bronchoalveolar lavage fluid (BALF), mediastinal lymph node (mLN) and spleen of the IL-17A- EGFP reporter mice, we showed that intranasal inoculation with C. neoformans promoted leukocytes lung infiltration. A large proportion (~50%) of the infiltrated CD4+ helper T cell population secreted EGFP, indicating vigorous TH17 activity in the C. neoformans-infected lung. The infection study in IL-17A-KO mice, on the other hand, revealed that absence of IL-17A marginally boosted fungal burden in the lung and accelerated the mouse death. Therefore, our data suggest that IL-17A, released predominantly from TH17 cells in vivo, is essential in providing a protective immunity against C. neoformans infection.

immunology↗

bioRxiv2017

The Neurocognitive Architecture of Individual Differences in Math Anxiety in Typical Children

Math Anxiety (MA) is characterized by a negative emotional response when facing math-related situations. MA is distinct from general anxiety and can emerge during primary education. Prior studies typically comprise adults and comparisons between high-versus low-MA, where neuroimaging work has focused on differences in network activation between groups when completing numerical tasks. The present study used voxel-based morphometry to identify the structural brain correlates of MA in a sample of 79 healthy children aged 7-12 years. Given that MA is thought to develop in later primary education, the study focused on the level of MA, rather than categorically defining it as present or absent. Using a battery of cognitive- and numerical-function tasks, this study identified that increased MA was associated with reduced attention, working memory and math achievement. Increased MA was associated with reduced grey matter in the left anterior intraparietal sulcus. This region was also associated with attention, suggesting that baseline differences in morphology may underpin attentional differences. Future studies should clarify whether poorer attentional capacity due to reduced grey matter density results in the later emergence of MA. Further, our data highlight the role of working memory in propagating reduced math achievement in children with higher MA.

neuroscience↗