Type I IFN induces protein ISGylation to enhance cytokine expression and augments colonic inflammation

Type I IFNs have broad activity in tissue inflammation and malignant progression that depends on the expression of IFN-stimulated genes (ISGs). ISG15, one such ISG, can form covalent conjugates to many cellular proteins, a process termed "protein ISGylation." Although type I IFNs are involved in multiple inflammatory disorders, the role of protein ISGylation during inflammation has not been evaluated. Here we report that protein ISGylation exacerbates intestinal inflammation and colitis-associated colon cancer in mice. Mechanistically, we demonstrate that protein ISGylation negatively regulates the ubiquitin-proteasome system, leading to increased production of IFN-induced reactive oxygen species (ROS). The increased cellular ROS then enhances LPS-induced activation of p38 MAP kinase and the expression of inflammation-related cytokines in macrophages. Thus our studies reveal a regulatory role for protein ISGylation in colonic inflammation and its related malignant progression, indicating that targeting ubiquitin-activating enzyme E1 homolog has therapeutic potential in treating inflammatory diseases

Interações entre bactérias diazotróficas e fungo micorrízico em genótipos de milho

Some diazotrophic bacteria can fix nitrogen biologically in gramineous host plants. Generally, gramineous plants are also associated with mycorrhizal fungi, that can improve mainly plant P uptake. Among the factors affecting plant-microbe interactions, the plant genotype plays an important role. This study evaluates the effect of diazotrophic bacteria and an arbuscular mycorrhizal fungus (AMF), on five genotypes of maize (Zea mays L.), in relation to plant biomass, shoot N and P concentrations, and fine root morphological traits. The experimental design was entirely randomized in a factorial 5 × 4 × 2 arrangement, i.e., five maize genotypes (hybrids C333B, AS3466, and PREMIUM, and the inbreed lines lg40897-1 and lg40505-1), three diazotrophic bacteria (Azospirillum lipoferum, A. amazonense, and Burkholderia sp.) in addition to a control without bacterial inoculation, co-inoculated or not with the AMF Glomus clarum. The non-mycorrhizal plants inoculated with Azospirillum exhibited the highest N concentrations. The lines lg40897-1 and lg40505-1 showed higher P concentrations as compared to the hybrids, mainly when colonized by AMF. The higher levels of mycorrhizal colonization (90%) occurred in the C333B and lg40897-1 genotypes, which also exhibited a greater root diameter. Mycorrhiza increased shoot and root biomass, besides root traits as total length, specific length, total surface, and incidence of root hairs in all genotypes. In addition, mycorrhiza also stimulated the root colonization by diazotrophic bacteria. The bacteria did not affect root morphological traits and mycorrhizal colonization.Algumas bactérias diazotróficas podem fixar N biologicamente em gramíneas, as quais se associam a fungos micorrízicos, o que pode levar a um aumento principalmente da absorção de P. Dentre os fatores que afetam as interações planta-microrganismos, o genótipo da planta tem importante papel. Esse trabalho avalia o efeito de bactérias diazotróficas e de um fungo micorrízico arbuscular (FMA) em cinco genótipos de milho (Zea mays L.), em relação à biomassa das plantas, teores de N e P na parte aérea e parâmetros relacionados à morfologia das raízes finas. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 5 × 4 × 2, sendo cinco genótipos de milho (híbridos C333B, AS3466, PREMIUM e as linhagens lg40897-1 e lg40505-1), três bactérias diazotróficas (Azospirillum lipoferum, A. amazonense e Burkholderia sp.), mais um controle sem bactéria, co-inoculadas ou não com o FMA Glomus clarum. As plantas sem FMA e inoculadas com Azospirillum apresentaram os maiores teores de N. As linhagens lg40897-1 e lg40505-1 apresentaram maior concentração de P em relação aos híbridos, principalmente quando micorrizadas. Os maiores níveis de colonização micorrízica (90%) ocorreram nos genótipos C333B e lg40897-1 que, por sua vez, apresentaram maior diâmetro de raízes. O FMA aumentou a biomassa da parte aérea e das raízes, comprimento total e específico, superfície total e incidência de pêlos nas raízes em todos os genótipos. O fungo micorrízico também estimulou a colonização das raízes pelas bactérias diazotróficas. Já as bactérias não alteraram as características morfológicas das raízes e nem a colonização micorrízica

Radiation Therapy Combined With Checkpoint Blockade Immunotherapy for Metastatic Undifferentiated Pleomorphic Sarcoma of the Maxillary Sinus With a Complete Response

Background: Undifferentiated pleomorphic sarcoma (UPS) of the maxillary sinus is an extremely rare malignancy of the head and neck. Surgery is the mainstay of treatment for UPS; however, proximity to vital structures makes it challenging to achieve negative surgical margins. Adjuvant therapy including radiation therapy with or without chemotherapy is generally indicated. Despite advances in multimodality treatment, objective response rates to available therapies and prognosis of metastatic UPS remain dismal. Immunotherapy has become a fourth cornerstone of cancer therapy and checkpoint blockade immunotherapy is a standard of care for recurrent or metastatic cisplatin-refractory head and neck squamous cell carcinoma. Checkpoint blockade immunotherapy is being studied in metastatic sarcoma, including UPS, and while initial results are promising, objective response rates remain below 20%. However, adding radiation therapy to checkpoint blockade immunotherapy has been shown, in both preclinical and retrospective clinical studies, to have combinatorial effects on both local and metastatic disease. Thus, further investigation into the effects of radiation therapy combined with immunotherapy in head and neck sarcomas is warranted.Case Presentation: We present a case of metastatic, chemotherapy-refractory, UPS of the maxillary sinus in a 55-year-old male treated with checkpoint blockade immunotherapy combined with radiation, which resulted in a complete response.Conclusions: This is the first report to our knowledge of metastatic UPS treated with a combination of radiation and dual agent checkpoint blockade immunotherapy. Further investigation is warranted to study the effects of this combination in patients with metastatic UPS that fail to respond to currently available therapies

Chronic Oral Infection with Porphyromonas gingivalis Accelerates Atheroma Formation by Shifting the Lipid Profile

BACKGROUND: Recent studies have suggested that periodontal disease increases the risk of atherothrombotic disease. Atherosclerosis has been characterized as a chronic inflammatory response to cholesterol deposition in the arteries. Although several studies have suggested that certain periodontopathic bacteria accelerate atherogenesis in apolipoprotein E-deficient mice, the mechanistic link between cholesterol accumulation and periodontal infection-induced inflammation is largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We orally infected C57BL/6 and C57BL/6.KOR-Apoe(shl) (B6.Apoeshl) mice with Porphyromonas gingivalis, which is a representative periodontopathic bacterium, and evaluated atherogenesis, gene expression in the aorta and liver and systemic inflammatory and lipid profiles in the blood. Furthermore, the effect of lipopolysaccharide (LPS) from P. gingivalis on cholesterol transport and the related gene expression was examined in peritoneal macrophages. Alveolar bone resorption and elevation of systemic inflammatory responses were induced in both strains. Despite early changes in the expression of key genes involved in cholesterol turnover, such as liver X receptor and ATP-binding cassette A1, serum lipid profiles did not change with short-term infection. Long-term infection was associated with a reduction in serum high-density lipoprotein (HDL) cholesterol but not with the development of atherosclerotic lesions in wild-type mice. In B6.Apoeshl mice, long-term infection resulted in the elevation of very low-density lipoprotein (VLDL), LDL and total cholesterols in addition to the reduction of HDL cholesterol. This shift in the lipid profile was concomitant with a significant increase in atherosclerotic lesions. Stimulation with P. gingivalis LPS induced the change of cholesterol transport via targeting the expression of LDL receptor-related genes and resulted in the disturbance of regulatory mechanisms of the cholesterol level in macrophages. CONCLUSIONS/SIGNIFICANCE: Periodontal infection itself does not cause atherosclerosis, but it accelerates it by inducing systemic inflammation and deteriorating lipid metabolism, particularly when underlying hyperlidemia or susceptibility to hyperlipidemia exists, and it may contribute to the development of coronary heart disease

Effect of <it>Porphyromonas gingivalis</it> infection on post-transcriptional regulation of the low-density lipoprotein receptor in mice

<p>Abstract</p> <p>Background</p> <p>Periodontal disease is suggested to increase the risk of atherothrombotic disease by inducing dyslipidemia. Recently, we demonstrated that proprotein convertase subtilisin/kexin type 9 (PCSK9), which is known to play a critical role in the regulation of circulating low-density lipoprotein (LDL) cholesterol levels, is elevated in periodontitis patients. However, the underlying mechanisms of elevation of PCSK9 in periodontitis patients are largely unknown. Here, we explored whether <it>Porphyromonas gingivalis,</it> a representative periodontopathic bacterium, -induced inflammatory response regulates serum PCSK9 and cholesterol levels using animal models.</p> <p>Methods</p> <p>We infected C57BL/6 mice intraperitoneally with <it>Porphyromonas gingivalis</it>, a representative strain of periodontopathic bacteria, and evaluated serum PCSK9 levels and the serum lipid profile. PCSK9 and LDL receptor (LDLR) gene and protein expression, as well as liver X receptors (<it>Lxrs</it>), inducible degrader of the LDLR (<it>Idol</it>), and sterol regulatory element binding transcription factor (<it>Srebf</it>)<it>2</it> gene expression, were examined in the liver.</p> <p>Results</p> <p><it>P. gingivalis</it> infection induced a significant elevation of serum PCSK9 levels and a concomitant elevation of total and LDL cholesterol compared with sham-infected mice. The LDL cholesterol levels were significantly correlated with PCSK9 levels. Expression of the <it>Pcsk9</it>, <it>Ldlr</it>, and <it>Srebf2</it> genes was upregulated in the livers of the <it>P. gingivalis</it>-infected mice compared with the sham-infected mice. Although <it>Pcsk9</it> gene expression is known to be positively regulated by sterol regulatory element binding protein (SREBP)2 (human homologue of Srebf2), whereas <it>Srebf2</it> is negatively regulated by cholesterol, the elevated expression of <it>Srebf2</it> found in the infected mice is thought to be mediated by <it>P. gingivalis</it> infection.</p> <p>Conclusions</p> <p><it>P. gingivalis</it> infection upregulates PCSK9 production via upregulation of <it>Srebf2</it>, independent of cholesterol levels. Further studies are required to elucidate how infection regulates <it>Srebf2</it> expression and subsequently influences lipid metabolism.</p

Role of B Cells in Responses to Checkpoint Blockade Immunotherapy and Overall Survival of Cancer Patients

The role of B cells in the tumor microenvironment and B-cell-mediated antitumor immune responses remains relatively understudied. Recent seminal studies have discovered that B cells and associated tertiary lymphoid structures correlate with responses to checkpoint blockade immunotherapy and are prognostic for overall survival of cancer patients. B-cell subsets have remarkable functional diversity and include professional antigen-presenting cells, regulatory cells, memory populations, and antibody-producing plasma cells. Importantly, secreted antibodies can independently activate innate immune responses and induce the cancer immunity cycle. Thus, B cells and B-cell-mediated antibody responses comprise the largely underappreciated second arm of the adaptive immune system and certainly deserve further attention in the field of oncology. Here, we review the known functions of B cells in the tumor microenvironment, the contribution of B cells to the antitumor activity of immunotherapies, and the role of B cells in the overall survival of cancer patients

Human papillomavirus E5 suppresses immunity via inhibition of the immunoproteasome and STING pathway.

The role that human papillomavirus (HPV) oncogenes play in suppressing responses to immunotherapy in cancer deserves further investigation. In particular, the effects of HPV E5 remain poorly understood relative to E6 and E7. Here, we demonstrate that HPV E5 is a negative regulator of anti-viral interferon (IFN) response pathways, antigen processing, and antigen presentation. Using head and neck cancer as a model, we identify that E5 decreases expression and function of the immunoproteasome and that the immunoproteasome, but not the constitutive proteasome, is associated with improved overall survival in patients. Moreover, immunopeptidome analysis reveals that HPV E5 restricts the repertoire of antigens presented on the cell surface, likely contributing to immune escape. Mechanistically, we discover a direct interaction between E5 and stimulator of interferon genes (STING), which suppresses downstream IFN signaling. Taken together, these findings identify a powerful molecular mechanism by which HPV E5 limits immune detection and mediates resistance to immunotherapy

Type I IFN induces protein ISGylation to enhance cytokine expression and augments colonic inflammation.

Type I IFNs have broad activity in tissue inflammation and malignant progression that depends on the expression of IFN-stimulated genes (ISGs). ISG15, one such ISG, can form covalent conjugates to many cellular proteins, a process termed "protein ISGylation." Although type I IFNs are involved in multiple inflammatory disorders, the role of protein ISGylation during inflammation has not been evaluated. Here we report that protein ISGylation exacerbates intestinal inflammation and colitis-associated colon cancer in mice. Mechanistically, we demonstrate that protein ISGylation negatively regulates the ubiquitin-proteasome system, leading to increased production of IFN-induced reactive oxygen species (ROS). The increased cellular ROS then enhances LPS-induced activation of p38 MAP kinase and the expression of inflammation-related cytokines in macrophages. Thus our studies reveal a regulatory role for protein ISGylation in colonic inflammation and its related malignant progression, indicating that targeting ubiquitin-activating enzyme E1 homolog has therapeutic potential in treating inflammatory diseases