Immunotherapy with MVA-BN®-HER2 induces HER-2-specific Th1 immunity and alters the intratumoral balance of effector and regulatory T cells

MVA-BN®-HER2 is a new candidate immunotherapy designed for the treatment of HER-2-positive breast cancer. Here, we demonstrate that a single treatment with MVA-BN®-HER2 exerts potent anti-tumor efficacy in a murine model of experimental pulmonary metastasis. This anti-tumor efficacy occurred despite a strong tumor-mediated immunosuppressive environment characterized by a high frequency of regulatory T cells (Treg) in the lungs of tumor-bearing mice. Immunogenicity studies showed that treatment with MVA-BN®-HER2 induced strongly Th1-dominated HER-2-specific antibody and T-cell responses. MVA-BN®-HER2-induced anti-tumor activity was characterized by an increased infiltration of lungs with highly activated, HER-2-specific, CD8+CD11c+ T cells accompanied by a decrease in the frequency of Treg cells in the lung, resulting in a significantly increased ratio of effector T cells to Treg cells. In contrast, administration of HER2 protein formulated in Complete Freund’s Adjuvant (CFA) induced a strongly Th2-biased immune response to HER-2. However, this did not lead to significant infiltration of the tumor-bearing lungs by CD8+ T cells or the decrease in the frequency of Treg cells nor did it result in anti-tumor efficacy. In vivo depletion of CD8+ cells confirmed that CD8 T cells were required for the anti-tumor activity of MVA-BN®-HER2. Furthermore, depletion of CD4+ or CD25+ cells demonstrated that tumor-induced Treg cells promoted tumor growth and that CD4 effector cells also contribute to MVA-BN®-HER2-mediated anti-tumor efficacy. Taken together, our data demonstrate that treatment with MVA-BN®-HER2 controls tumor growth through mechanisms including the induction of Th1-biased HER-2-specific immune responses and the control of tumor-mediated immunosuppression

Diversity of Staphylococcus aureus Isolates in European Wildlife

Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle- associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock- associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Poxvirus-Based Active Immunotherapy with PD-1 and LAG-3 Dual Immune Checkpoint Inhibition Overcomes Compensatory Immune Regulation, Yielding Complete Tumor Regression in Mice.

Poxvirus-based active immunotherapies mediate anti-tumor efficacy by triggering broad and durable Th1 dominated T cell responses against the tumor. While monotherapy significantly delays tumor growth, it often does not lead to complete tumor regression. It was hypothesized that the induced robust infiltration of IFNγ-producing T cells into the tumor could provoke an adaptive immune evasive response by the tumor through the upregulation of PD-L1 expression. In therapeutic CT26-HER-2 tumor models, MVA-BN-HER2 poxvirus immunotherapy resulted in significant tumor growth delay accompanied by a robust, tumor-infiltrating T cell response that was characterized by low to mid-levels of PD-1 expression on T cells. As hypothesized, this response was countered by significantly increased PD-L1 expression on the tumor and, unexpectedly, also on infiltrating T cells. Synergistic benefit of anti-tumor therapy was observed when MVA-BN-HER2 immunotherapy was combined with PD-1 immune checkpoint blockade. Interestingly, PD-1 blockade stimulated a second immune checkpoint molecule, LAG-3, to be expressed on T cells. Combining MVA-BN-HER2 immunotherapy with dual PD-1 plus LAG-3 blockade resulted in comprehensive tumor regression in all mice treated with the triple combination therapy. Subsequent rejection of tumors lacking the HER-2 antigen by treatment-responsive mice without further therapy six months after the original challenge demonstrated long lasting memory and suggested that effective T cell immunity to novel, non-targeted tumor antigens (antigen spread) had occurred. These data support the clinical investigation of this triple therapy regimen, especially in cancer patients harboring PD-L1neg/low tumors unlikely to benefit from immune checkpoint blockade alone

A Genetic System to Drive Gene Recombination in Developing Joints

<div><p>(A) A 140-kb BAC from the <i>Gdf5</i> locus was modified by inserting <i>Cre</i>-IRES-<i>hPLAP</i> into the translation start site of <i>Gdf5</i> and used to make transgenic mice. Not to scale. See <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020355#s4" target="_blank">Materials and Methods</a> for details.</p> <p>(B–E) Visualization of <i>Gdf5-Cre</i> driven recombination patterns based on activation of <i>lacZ</i> expression from the <i>R26R</i> Cre reporter allele. (B) LACZ activity is visible as blue staining in the ear (ea) and the joints of the shoulder (s), elbow (eb), wrist (w), knee (k), ankle (a), vertebra (vj), and phalanges (black arrowheads) of an E14.5 mouse embryo. (C) E14.5 hindlimb double-stained to show both HPLAP expression from the transgene (grey/purple staining) and LACZ expression from the rearranged <i>R26R</i> allele (blue staining). Note that both markers are visible in the oldest, proximal interphalangeal joint (black arrowhead), only HPLAP activity is visible in the more recently formed medial interphalangeal joint (black arrow), and neither HPLAP nor LACZ expression is visible in the youngest, most distal joint of the digit (white arrowhead). (D) Newborn (P0) forelimb with skin partially removed showing LACZ activity expressed in all phalangeal joints (red Salmon gal staining, black arrowheads) and regions of some tendons (asterisk). (E) Section through the most distal phalangeal joint of a P0 hindlimb stained with Alcian blue to mark cartilage showing LACZ expression (stained red) in all tissues of developing joints: articular cartilage (black arrowhead), precursors of ligaments and synovial membranes (black arrow), and cells where cavitation is occurring (asterisk).</p></div

Synovial Membrane Expansion, Articular Surface Erosion, and Accelerated Maturation of Underlying Cartilage in Ankles of <i>Bmpr1a</i> Mutant Mice

<p>Near adjacent sections from the tarsal 2-metatarsal II joint of 7-d-old mice. (A and B) LACZ staining (blue) shows Cre-mediated recombination is largely restricted to articular (arrowheads) and synovial cells (asterisks) in both controls and mutants. (C and D) In situ hybridization shows <i>Col10</i> expression expands in mutants toward regions of synovial membrane expansion and articular surface erosion (brackets and arrows). This may be a cell nonautonomous effect of joint damage, since the LACZ expressing cells at the articular surface do not show upregulation of <i>Col10</i> (arrowheads) and the region of expanded <i>Col10</i> expression is largely made up of cells that have not undergone Cre-mediated recombination. Note the formation of a cartilaginous bridge along the joint capsule of the mutant where joint formation is disrupted at earlier stages (B, white arrowhead, and <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020355#pbio-0020355-g003" target="_blank">Figure 3</a>, white arrowheads). (A) Scale bar = 75 μm.</p