Immunotherapeutic strategies are increasingly important in neuro-oncology, and the elucidation of escape mechanisms that lead to treatment resistance is crucial. We investigated the impact of immune pressure on the clonal dynamics and immune escape signature by comparing glioma growth in immunocompetent versus immunodeficient mice. Glioma-bearing WT and Pd-1–/– mice survived significantly longer than immunodeficient Pfp–/– Rag2–/– mice. While tumors in Pfp–/– Rag2–/– mice were highly polyclonal, immunoedited tumors in WT and Pd-1–/– mice displayed reduced clonality with emergence of immune escape clones. Tumor cells in WT mice were distinguished by an IFN-γ–mediated response signature with upregulation of genes involved in immunosuppression. Tumor-infiltrating stromal cells, which include macrophages/microglia, contributed even more strongly to the immunosuppressive signature than the actual tumor cells. The identified murine immune escape signature was reflected in human patients and correlated with poor survival. In conclusion, immune pressure profoundly shapes the clonal composition and gene regulation in malignant gliomas.
The chemokine CXCL12 plays a fundamental role in cardiovascular development, cell trafficking, and myocardial repair. Human genome-wide association studies even have identified novel loci downstream of the CXCL12 gene locus associated with coronary artery disease and myocardial infarction. Nevertheless, cell and tissue specific effects of CXCL12 are barely understood. Since we detected high expression of CXCL12 in smooth muscle (SM) cells, we generated a SM22-alpha-Cre driven mouse model to ablate CXCL12 (SM-CXCL12−/−). SM-CXCL12−/− mice revealed high embryonic lethality (50%) with developmental defects, including aberrant topology of coronary arteries. Postnatally, SM-CXCL12−/− mice developed severe cardiac hypertrophy associated with fibrosis, apoptotic cell death, impaired heart function, and severe coronary vascular defects characterized by thinned and dilated arteries. Transcriptome analyses showed specific upregulation of pathways associated with hypertrophic cardiomyopathy, collagen protein network, heart-related proteoglycans, and downregulation of the M2 macrophage modulators. CXCL12 mutants showed endothelial downregulation of the CXCL12 co-receptor CXCR7. Treatment of SM-CXCL12−/− mice with the CXCR7 agonist TC14012 attenuated cardiac hypertrophy associated with increased pERK signaling. Our data suggest a critical role of smooth muscle-specific CXCL12 in arterial development, vessel maturation, and cardiac hypertrophy. Pharmacological stimulation of CXCR7 might be a promising target to attenuate adverse hypertrophic remodeling.
Background: Severe infections that culminate in sepsis are associated with high morbidity and mortality. Despite continuous efforts in basis science and clinical research, evidence based-therapy is mostly limited to basic causal and supportive measures. Adjuvant therapies often remain without clear evidence. The objective of this study was to evaluate the septic volvulus ischemia-reperfusion model in comparison to two already established models and the role of neutrophil extacellular traps (NETs) in this model. Methods: The technique of the murine model of midgut volvulus was optimized and was compared to two established models of murine sepsis, namely cecal ligation and puncture (CLP) and intra-peritoneal (i.p.) injection of lipopolysaccharide (LPS). Results: Midgut volvulus for 15 min caused a comparable mortality (38%) as CLP (55%) and peritoneal LPS injection (25%) at 48 h. While oxidative stress was comparable, levels of circulating free DNA (cfDNA), and splenic/hepatic and pulmonary translocation of bacteria were decreased and increased, respectively at 48 h. DNases were increased compared to the established models. Proteomic analysis revealed an upregulation of systemic Epo, IL-1b, Prdx5, Parp1, Ccl2 and IL-6 at 48 h in comparison to the healthy controls. Discussion and Conclusion: Midgut volvulus is a stable and physiological model for sepsis. Depending on the duration and subsequent tissue damage, it represents a combination of ischemia-reperfusion injury and hyperinflammation.
Resettlers are a large migrant group of more than 2 million people in Germany who migrated mainly from the former Soviet Union to Germany after 1989. We sought to compare the distribution of the major risk factors for cardiovascular disease (CVD) and to investigate the overall genetic differences in a study population which consisted of resettlers and native (autochthone) Germans. This was a joint analysis of two cohort studies which were performed in the region of Augsburg, Bavaria, Germany, with 3363 native Germans and 363 resettlers. Data from questionnaires and physical examinations were used to compare the risk factors for cardiovascular diseases between the resettlers and native Germans. A population-based genome-wide association analysis was performed in order to identify the genetic differences between the two groups. The distribution of the major risk factors for CVD differed between the two groups. The resettlers lead a less active lifestyle. While female resettlers smoked less than their German counterparts, the men showed similar smoking behavior. SNPs from three genes (BTNL2, DGKB, TGFBR3) indicated a difference in the two populations. In other studies, these genes have been shown to be associated with CVD, rheumatoid arthritis and osteoporosis, respectively.