Publications

Protective immunoglobulin A (IgA) responses to oral antigens are usually orchestrated by gut dendritic cells (DCs). Here, we show that lung CD103(+) and CD24(+)CD11b(+) DCs induced IgA class-switch recombination (CSR) by activating B cells through T cell-dependent or -independent pathways. Compared with lung DCs (LDC), lung CD64(+) macrophages had decreased expression of B cell activation genes and induced significantly less IgA production. Microbial stimuli, acting through Toll-like receptors, induced transforming growth factor-β (TGF-β) production by LDCs and exerted a profound influence on LDC-mediated IgA CSR. After intranasal immunization with inactive cholera toxin (CT), LDCs stimulated retinoic acid-dependent up-regulation of α4β7 and CCR9 gut-homing receptors on local IgA-expressing B cells. Migration of these B cells to the gut resulted in IgA-mediated protection against an oral challenge with active CT. However, in germ-free mice, the levels of LDC-induced, CT-specific IgA in the gut are significantly reduced. Herein, we demonstrate an unexpected role of the microbiota in modulating the protective efficacy of intranasal vaccination through their effect on the IgA class-switching function of LDCs.

Social benefits likely play a role in young adult tobacco use. The Social Prioritization Index (SPI) was developed to measure the degree to which young adults place a great importance on their social lives. We examined the usefulness of this measure as a potential predictor of tobacco use controlling for demographics and tobacco-related attitudes. Young adults completed cross-sectional surveys between 2012 and 2014 in bars in seven U.S. cities (N = 5,503). The SPI is a 13-item scale that includes personality items and information on how frequently participants attend bars and how late they stay out. Three step-by-step multinomial regression models were run using the SPI as a predictor of smoking status (nondaily and daily smoking vs. nonsmoking): (1) SPI as the sole predictor, (2) SPI and demographics, and (3) SPI, demographics, and tobacco-related attitude variables. Next, we conducted an exploratory factor analysis to examine if the number of items in SPI could be reduced and retain its strong relationship with smoking. Higher scores on the SPI were related to an increased probability of being a Nondaily Smoker (odds ratio = 1.09, 95% confidence interval [1.04, 1.14], p < .001) or Daily Smoker (odds ratio = 1.14, 95% confidence interval [1.07, 1.22], p < .0001) compared to a Nonsmoker, controlling for demographics and other tobacco-related attitudes. The SPI and reduced SPI were independently related to young adult tobacco use. The measure's brevity, ease of use, and strong association with tobacco use may make it useful to tobacco and other prevention researchers.