Hyaluronan Receptor LYVE-1-Expressing Macrophages Maintain Arterial Tone through Hyaluronan-Mediated Regulation of Smooth Muscle Cell Collagen.

The maintenance of appropriate arterial tone is critically important for normal physiological arterial function. However, the cellular and molecular mechanisms remain poorly defined. Here, we have shown that in the mouse aorta, resident macrophages prevented arterial stiffness and collagen deposition in the steady state.

CD41 is a reliable identification and activation marker for murine basophils in the steady state and during helminth and malarial infections.

Basophils, a rare leukocyte population in peripheral circulation, are conventionally identified as CD45(int) CD49b(+) FcεRI(+) cells. Here, we show that basophils from blood and several organs of naïve wild-type mice express CD41, the α subunit of α(IIb)β₃ integrin. CD41 expression on basophils is upregulated after in vivo IL-3 treatment and during infection with Nippostrongylus brasiliensis (Nb).

Neutrophil mobilization via plerixafor-mediated CXCR4 inhibition arises from lung demargination and blockade of neutrophil homing to the bone marrow.

Blood neutrophil homeostasis is essential for successful host defense against invading pathogens. Circulating neutrophil counts are positively regulated by CXCR2 signaling and negatively regulated by the CXCR4-CXCL12 axis. In particular, G-CSF, a known CXCR2 signaler, and plerixafor, a CXCR4 antagonist, have both been shown to correct neutropenia in human patients.

IRF4 transcription factor-dependent CD11b+ dendritic cells in human and mouse control mucosal IL-17 cytokine responses.

Mouse and human dendritic cells (DCs) are composed of functionally specialized subsets, but precise interspecies correlation is currently incomplete. Here, we showed that murine lung and gut lamina propria CD11b+ DC populations were comprised of two subsets: FLT3- and IRF4-dependent CD24(+)CD64(-) DCs and contaminating CSF-1R-dependent CD24(-)CD64(+) macrophages. Functionally, loss of CD24(+)CD11b(+) DCs abrogated CD4+ T cell-mediated interleukin-17 (IL-17) production in steady state and after Aspergillus fumigatus challenge.