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Bcl6 is required for CD4 T cell differentiation into T follicular helper cells (Tfh). In this study, we examined the role of IL-6 in early processes of in vivo Tfh differentiation, because the timing and mechanism of action of IL-6 in Tfh differentiation have been controversial in vivo. We found that early Bcl6(+)CXCR5(+) Tfh differentiation was severely impaired in the absence of IL-6; however, STAT3 deficiency failed to recapitulate that defect. IL-6R signaling activates the transcription fact

B-1 cells are known to contribute most of the "natural antibodies" that are secreted in the steady state, antibodies which are crucial for protection against many pathogens including influenza virus. Whether the CD5(+) B-1a subset plays a role during an active immune response is incompletely understood. In contrast to recent data suggesting a passive role for B-1a cells, data provided here show strong highly localized activation of B-1 cells in the draining lymph nodes of the respiratory tract a

Follicular helper CD4 T (Tfh) cells are a distinct type of differentiated CD4 T cells uniquely specialized for B cell help. In this study, we examined Tfh cell fate commitment, including distinguishing features of Tfh versus Th1 proliferation and survival. Using cell transfer approaches at early time points after an acute viral infection, we demonstrate that early Tfh cells and Th1 cells are already strongly cell fate committed by day 3. Nevertheless, Tfh cell proliferation was tightly regulated

Natural IgM antibodies secreted in the absence of antigenic challenge are important contributors to antimicrobial immunity and tissue homeostasis. Early studies identified BM and, to a lesser extent the spleen, as main tissue sources of this spontaneously secreted IgM. However, the responsible B-cell subset has never been identified. Using multicolor flow cytometry, cell sorting and chimeric mice in which B-1 and B-2 cells and their secreted antibodies are distinguished by their Ig-allotype, we

Column observations of NO 2 by GOME and CO by MOPITT over North America and surrounding oceans for April 2000 are analyzed using a regional chemical transport model. Transient enhancements in these measurements due to lightning NO x production or convective transport are examined. Evidence is found for lightning enhancements of NO 2 over the continent and western North Atlantic and for convective transport enhancements of CO over the ocean. The two independent satellite measurements show consist

Abstract. To show how remote-sensing products can be used to classify the entire CONUS domain into "geographical regions" and "chemical regimes", we analyzed the results of simulation from the Community Multiscale Air Quality (CMAQ) model version 4.7.1 over the Conterminous United States (CONUS) for August 2009. In addition, we observe how these classifications capture the weekly cycles of ground-level nitrogen oxide (NOx) and ozone (O3) at US EPA Air Quality System (AQS) sites. We use the Advan

Abstract Recent regulatory policies in East Asia reduce ozone precursors, but these changes are spatially and temporally nonuniform. This study investigates variations in the long‐term trends of tropospheric NO 2 , HCHO, and HCHO/NO 2 ratios to diagnose ozone sensitivity to changes in NO x and volatile organic compound using the Ozone Monitoring Instrument (OMI). Using an adaptive‐degree polynomial filter, we identify extremums of time series of NO 2 to determine when and how NO 2 change. Due to

To quantify the impact of the direct aerosol effect accurately, this study incorporated the Geostationary Ocean Color Imager (GOCI) aerosol optical depth (AOD) into a coupled meteorology-chemistry model. We designed three model simulations to observe the impact of AOD assimilation and aerosol feedback during the KORUS-AQ campaign (May - June 2016). By assimilating the GOCI AOD with high temporal and spatial resolutions, we improve the statistics from the comparison AOD and AERONET data (RMSE: 0.