Do residents with a 20-min neighbourhood walk more? Findings from ProjectPLAN

Background: The 20-min neighbourhood (20 MN) concept aims to provide people the ability to meet their daily needs within a 20-min non-motorised trip from home. Evidence as to whether the 20 MN encourages more walking for transport or recreation is currently absent. Methods: This cross-sectional study used self-reported data from the Places and Locations for Activity and Nutrition study (ProjectPLAN) targeting adults (n = 843) residing in Melbourne or Adelaide, Australia. Multiple services and amenities were used to represent access to five service domains (healthy food, community resources, recreational resources, public open space, public transport). Address points meeting the access criteria for each of the five domains were defined as having a 20 MN. Non-20 MNs were defined as having five or fewer individual services and amenities. This study examined if those residing in a 20 MN compared with a non-20MN undertook more walking for transport or for recreation. The analysis considered separately each of the cities to support the estimation of effects specific to each local context. Results: Respondents residing in a 20 MN relative to a non-20MN had higher odds of walking for transport in Melbourne (OR = 4.24, 95% CI = 2.38, 7.56), whilst in Adelaide there was no evidence of a difference (OR = 1.31, 95% CI = 0.80, 2.13). In Melbourne, the mean time spent walking for transport was greater for 20 MNs (82.5 min/week, 95% CI = 65.3, 99.7) compared to non-20MNs (41.2 min/week, 95% CI = 32.7, 49.7). Whilst minutes spent walking for recreation was higher than minutes spent walking for transport, no differences were found between neighbourhood types and walking for recreation in either city. Conclusion: 20 MNs appeared to promote walking for transport in the higher density setting of Melbourne, but no association was observed in the lower density city of Adelaide. Further investigation is required to determine other factors beyond service provision that can promote walking for transport in Adelaide (e.g. pedestrian safety). Recreational walking did not differ across neighbourhood types highlighting that service provision and thus the 20 MN is not related to walking for exercise/recreation purposes.Ana M. Contardo Ayala, Karen E. Lamb, Venurs Loh, Mark Daniel, Neil T. Coffee, Laura H. Oostenbach, Lukar E. Thornto

Characterization of human Mucosal-associated Invariant T (MAIT) cells

Mucosal-associated invariant T (MAIT) cells are a subset of unconventional T cells restricted by the major histocompatibility complex (MHC) class I–like molecule MHC-related protein 1 (MR1). MAIT cells are found throughout the body, especially in human blood and liver. Unlike conventional T cells, which are stimulated by peptide antigens presented by MHC molecules, MAIT cells recognize metabolite antigens derived from an intermediate in the microbial biosynthesis of riboflavin. MAIT cells mediate protective immunity to infections by riboflavin-producing microbes via the production of cytokines and cytotoxicity. The discovery of stimulating MAIT cell antigens allowed for the development of an analytical tool, the MR1 tetramer, that binds specifically to the MAIT T cell receptor (TCR) and is becoming the gold standard for identification of MAIT cells by flow cytometry. This article describes protocols to characterize the phenotype of human MAIT cells in blood and tissues by flow cytometry using fluorescently labeled human MR1 tetramers alongside antibodies specific for MAIT cell markers