Wiskott-Aldrich syndrome protein deficiency in innate immune cells leads to mucosal immune dysregulation and colitis in mice

BACKGROUND & AIMS: Immunodeficiency and autoimmune sequelae, including colitis, develop in patients and mice deficient in Wiskott-Aldrich Syndrome protein (WASP), a hematopoietic-specific intracellular signaling molecule that regulates the actin cytoskeleton. Development of colitis in WASP-deficient mice requires lymphocytes; transfer of T cells is sufficient to induce colitis in immunodeficient mice. We investigated the interactions between innate and adaptive immune cells in mucosal regulation during development of T-cell-mediated colitis in mice with WASP-deficient cells of the innate immune system. METHODS: Naïve and/or regulatory CD4(+) T cells were transferred from 129 SvEv mice into RAG-2 deficient (RAG-2 KO) mice or mice lacking WASP and RAG-2 (WRDKO). Animals were observed for the development of colitis; effector and regulatory functions of innate immune and T cells were analyzed with in vivo and in vitro assays. RESULTS: Transfer of unfractionated CD4(+) T cells induced severe colitis in WRDKO, but not RAG-2 KO, mice. Naïve wild-type T cells had higher levels of effector activity and regulatory T cells had reduced suppressive function when transferred into WRDKO mice compared to RAG-2 KO mice. Regulatory T-cell proliferation, generation, and maintenance of FoxP3 expression were reduced in WRDKO recipients, and associated with reduced numbers of CD103(+) tolerogenic dendritic cells and levels of interleukin (IL)-10. Administration of IL-10 prevented induction of colitis following transfer of T cells into WRDKO mice. CONCLUSIONS: Defective interactions between WASP-deficient innate immune cells and normal T cells disrupt mucosal regulation, potentially by altering the functions of tolerogenic dendritic cells, production of IL-10, and homeostasis of regulatory T cells

DOCK8 deficiency impairs CD8 T cell survival and function in humans and mice

As shown by analysis of mice and humans bearing DOCK8-inactivating mutations, DOCK8 plays a cell-autonomous role in survival of naive CD8 T cells, LFA-1 polarization toward the immune synapse, and CD8 T cell memory and recall responses following viral infection

Efectos de la adición de probiótico Saccharomyces cerevisiae sobre histomorfología intestinal en pollos de engorde

This work describes the effects of the probiotic Saccharomyces cerevisiae on the area, number of Lieberkühn crypts in the duodenum and jejunum, and mucus production in both intestinal sections. Tissues from a total of 27 individuals were used, classified in control group - GC (n = 12) and group supplemented with probiotics - GP (n = 15). The results revealed that the group supplemented with S. cerevisiae presented a greater area of the crypts in the duodenum (p = 0.0119) and jejunum (p = 0.0355), less number of crypts per millimeter in the duodenum (p = 0.0420) and higher mucus production in the duodenum compared to the control group (p = 0.0185), while in the jejunum no significant differences were observed. It was concluded that the use of Saccharomyces cerevisiae increased the size of the crypt area in both intestinal sections and increased mucus production in the duodenum; which by increasing the intestinal absorption surface could surely result in improvements in the productive parameters.Este trabajo describe los efectos del probiótico Saccharomyces cerevisiae sobre el área, número de criptas de Lieberkühn en duodeno y yeyuno, y producción de moco en ambas secciones intestinales de pollos de engorde. Fueron empleados los tejidos de un total de 27 individuos clasificados en un grupo control GC (n=12) y un grupo suplementado con probióticos GP (n=15). Los resultados revelaron que los grupos suplementados con el S. cerevisiae presentaron una mayor amplitud del área de las criptas en duodeno (p= 0,0119) y yeyuno (p= 0,0355), menor número de criptas por milímetro en duodeno (p= 0,0420) y mayor producción de moco en duodeno respecto al grupo control (p= 0,0185), mientras que en yeyuno no se observaron diferencias significativas. Se conclu-yó que el uso de Saccharomyces cerevisiae aumentó el tamaño del área de las criptas en ambas secciones intestinales y aumentó la producción de moco en duodeno; lo cual, al aumentar la superficie de absorción intestinal, seguramente podría resultar en mejoras de los parámetros productivos

Symmetry breaking of magnetic vortices before annihilation

Magnetic vortices in nanoscopic ferromagnetic elements can be treated as solitons that exhibit static and dynamic stability even above room temperature, making them promising for technological applications. Although their properties at low energy configurations have been well studied, the properties of solitons undergoing structural breakdown are poorly understood. Here, we destabilize the soliton through Zeeman and demagnetization interactions and investigate the symmetry breaking of the magnetic vortex state. Using high-resolution Lorentz imaging and numerical simulations, we observe phase transitions of the core from the characteristic point-like structure into distinct extended asymmetric states differentiated by the polarity. The deformations start at intermediate displacements and are traced until the point of annihilation at the disc\u27s edge. We discuss the use of these asymmetric states as a method to determine the core polarity for in-plane magnetic imaging techniques

Coherence and modality of driven interlayer-coupled magnetic vortices

The high-frequency dynamics of mode-coupled magnetic vortices have generated great interest for spintronic technologies, such as spin-torque nano-oscillators. While the spectroscopic characteristics of vortex oscillators have been reported, direct imaging of driven coupled magnetic quasi-particles is essential to the fundamental understanding of the dynamics involved. Here, we present the first direct imaging study of driven interlayer coaxial vortices in the dipolar- and indirect exchange-coupled regimes. Employing in situ high-frequency excitation with Lorentz microscopy, we directly observe the steady-state orbital amplitudes in real space with sub-5nm spatial resolution. We discuss the unique frequency response of dipolar- and exchange-coupled vortex motion, wherein mode splitting and locking demonstrates large variations in coherent motion, as well as detail the resultant orbital amplitudes. This provides critical insights of the fundamental features of collective vortex-based microwave generators, such as their steady-state amplitudes, tunability and mode-coupled motion. © 2014 Macmillan Publishers Limited