Lack of PPARγ in myeloid cells confers resistance to Listeria monocytogenes infection.

The peroxisomal proliferator-activated receptor γ (PPARγ) is a nuclear receptor that controls inflammation and immunity. Innate immune defense against bacterial infection appears to be compromised by PPARγ. The relevance of PPARγ in myeloid cells, that organize anti-bacterial immunity, for the outcome of immune responses against intracellular bacteria such as Listeria monocytogenes in vivo is unknown.

Licensing of myeloid cells promotes central nervous system autoimmunity and is controlled by peroxisome proliferator-activated receptor γ.

During central nervous system autoimmunity, interactions between infiltrating immune cells and brain-resident cells are critical for disease progression and ultimately organ damage. Here, we demonstrate that local cross-talk between invading autoreactive T cells and auto-antigen-presenting myeloid cells within the central nervous system results in myeloid cell activation, which is crucial for disease progression during experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis. This T cell-mediated licensing of central nervous system myeloid cells triggered astrocytic CCL2-release and promoted recruitment of inflammatory CCR2(+)-monocytes, which are the main effectors of disease progression.

Nanoparticles induce changes of the electrical activity of neuronal networks on microelectrode array neurochips.

Background: Nanomaterials are extensively used in industry and daily life, but little is known about possible health effects. An intensified research regarding toxicity of nanomaterials is urgently needed. Several studies have demonstrated that nanoparticles (NPs; diameter < 100 nm) can be transported to the central nervous system; however, interference of NPs with the electrical activity of neurons has not yet been shown.

The nuclear receptor PPAR gamma selectively inhibits Th17 differentiation in a T cell-intrinsic fashion and suppresses CNS autoimmunity.

T helper cells secreting interleukin (IL)-17 (Th17 cells) play a crucial role in autoimmune diseases like multiple sclerosis (MS). Th17 differentiation, which is induced by a combination of transforming growth factor (TGF)-beta/IL-6 or IL-21, requires expression of the transcription factor retinoic acid receptor-related orphan receptor gamma t (ROR gamma t). We identify the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR gamma) as a key negative regulator of human and mouse Th17 differentiation.

Mycoplasma crocodyli sp. nov., a new species from crocodiles.

Organisms with the typical characteristics of mycoplasmas were isolated from joints and lungs of crocodiles. The results of growth inhibition tests and immunobinding assays showed that the 24 mycoplasma strains isolated were identical and distinct from previously described Mycoplasma, Entomoplasma, Mesoplasma, and Acholeplasma species. These organisms represent a new species, for which the name Mycoplasma crocodyli is proposed.