Stimulator of interferon genes is required for Toll-Like Receptor-8 induced interferon response.

The innate immune system is equipped with multiple receptors to detect microbial nucleic acids and induce type I interferon (IFN) to restrict viral replication. When dysregulated these receptor pathways induce inflammation in response to host nucleic acids and promote development and persistence of autoimmune diseases like Systemic Lupus Erythematosus (SLE). IFN production is regulated by the Interferon Regulatory Factor (IRF) transcription factor family of proteins that function downstream of several innate immune receptors such as Toll-like receptors (TLRs) and Stimulator of Interferon Genes (STING). Although both TLRs and STING activate the same downstream molecules, the pathway by which TLRs and STING activate IFN response are thought to be independent. Here we show that STING plays a previously undescribed role in human TLR8 signaling. Stimulation with the TLR8 ligands induced IFN secretion in primary human monocytes, and inhibition of STING reduced IFN secretion from primary monocytes from 8 healthy donors. We demonstrate that TLR8-induced IRF activity was reduced by STING inhibitors. Moreover, TLR8-induced IRF activity was blocked by inhibition or loss of IKKε, but not TBK1. Bulk RNA transcriptomic analysis supported a model where TLR8 induces transcriptional responses associated with SLE that can be downregulated by inhibition of STING. These data demonstrate that STING is required for full TLR8-to-IRF signaling and provide evidence for a new framework of crosstalk between cytosolic and endosomal innate immune receptors, which could be leveraged to treat IFN driven autoimmune diseases. Background: High levels of type I interferon (IFN) is characteristic of multiple autoimmune diseases, and while TLR8 is associated with autoimmune disease and IFN production, the mechanisms of TLR8-induced IFN production are not fully understood. Results: STING is phosphorylated following TLR8 signaling, which is selectively required for the IRF arm of TLR8 signaling and for TLR8-induced IFN production in primary human monocytes. Conclusion: STING plays a previously unappreciated role in TLR8-induced IFN production. Significance: Nucleic acid-sensing TLRs contribute to development and progression of autoimmune disease including interferonopathies, and we show a novel role for STING in TLR-induced IFN production that could be a therapeutic target.

The decidua of preeclamptic-like BPH/5 mice exhibits an exaggerated inflammatory response during early pregnancy.

Preeclampsia is a devastating complication of pregnancy characterized by late-gestation hypertension and proteinuria. Because the only definitive treatment is delivery of the fetus and placenta, preeclampsia contributes to increased morbidity and mortality of both mother and fetus. The BPH/5 mouse model, which spontaneously develops a syndrome strikingly similar to preeclampsia, displays excessive inflammation and suppression of inflammation improves pregnancy outcomes. During early pregnancy, decidual macrophages play an important role in promoting maternal tolerance to fetal antigens and regulating tissue remodeling, two functions that are critical for normal placental development. BPH/5 pregnancies are characterized by abnormal placentation; therefore, we hypothesized that macrophage localization and/or function is altered during early pregnancy at the site of placental formation (the decidua) compared to C57BL/6 controls. At early gestation time points, before the onset of maternal hypertension or proteinuria, there was a reduction in the number of macrophages in BPH/5 decidua and a concomitant increase in activated T cells compared with C57BL/6. BPH/5 decidua also exhibited decreased expression of the immunosuppressive cytokine, IL-10, and increased expression of pro-inflammatory, inducible nitric oxide synthase. Together, these data suggest that a reduction in decidual macrophages during pregnancy is associated with immune activation in BPH/5 mice, inadequate placental development and may contribute to adverse pregnancy outcomes in this model.

Genetic diversity of Toxoplasma gondii isolates from chickens from Brazil.

Until recently, Toxoplasma gondii was considered clonal with very little genetic variability. Recent studies indicate that T. gondii isolates from Brazil are genetically and biologically different from T. gondii isolates from USA and Europe. In the present study, we retyped 151 free range chicken isolates from Brazil including 117 newly isolated samples from 11 geographically areas (Alagoas, Bahia, Ceará, Maranhão, Paraná, Pernambuco, Rio de Janeiro, Rio Grande do Norte, São Paulo, Sergipe, and Rondonia) and 34 previously reported isolates from the very north (Pará) and the very south (Rio Grande do Sul). Ten PCR-RFLP markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico were used to genotype all isolates. Overall analysis of 151 T. gondii isolates revealed 58 genotypes. Half (29/58) of these genotypes had single isolate and the other half of the genotypes were characterized with two or more isolates. Only 1 of 151 isolates was clonal Type I strain and 5 were clonal Type III strains. Two isolates had mixed infections. Clonal Type II strain was absent. One strain was Type II at all loci, except BTUB. The results confirm high genetic diversity of T. gondii isolates from Brazil.

Cutting edge: Role of Toll-like receptor 9 in CpG DNA-induced activation of human cells.

Unmethylated CpG motifs present in bacterial DNA stimulate a rapid and robust innate immune response. Human cell lines and PBMC that recognize CpG DNA express membrane-bound human Toll-like receptor 9 (hTLR9). Cells that are not responsive to CpG DNA become responsive when transfected with hTLR9. Expression of hTLR9 dramatically increases uptake of CpG (but not control) DNA into endocytic vesicles. Upon cell stimulation, hTLR9 and CpG DNA are found in the same endocytic vesicles. Cells expressing hTLR9 are stimulated by CpG motifs that are active in primates but not rodents, suggesting that evolutionary divergence between TLR9 molecules underlies species-specific differences in the recognition of bacterial DNA. These findings indicate that hTLR9 plays a critical role in the CpG DNA-mediated activation of human cells.

The role of MyD88 and TLR4 in the LPS-mimetic activity of Taxol.

Taxol can mimic bacterial lipopolysaccharide (LPS) by activating mouse macrophages in a cell cycle-independent, LPS antagonist-inhibitable manner. Macrophages from C3H/HeJ mice, which have a spontaneous mutation in Toll-like receptor 4 (TLR4), are hyporesponsive to both LPS and Taxol, suggesting that LPS and Taxol may share a signaling pathway involving TLR4. To determine whether TLR4 and its interacting adaptor molecule MyD88 are necessary for Taxol's LPS mimetic actions, we examined Taxol responses of primary macrophages from genetically defective mice lacking either TLR4 (C57BL/10ScNCr) or MyD88 (MyD88 knockout). When stimulated with Taxol, macrophages from wild-type mice responded robustly by secreting both TNF and NO, while macrophages from either TLR4-deficient C57BL/10ScNCr mice or MyD88 knockout mice produced only minimal amounts of TNF and NO. Taxol-induced NF-kappa B-driven luciferase activity was reduced after transfection of RAW 264.7 macrophages with a dominant negative version of mouse MyD88. Taxol-induced microtubule-associated protein kinase (MAPK) activation and NF-kappa B nuclear translocation were absent from TLR4-null macrophages, but were preserved in MyD88 knockout macrophages with a slight delay in kinetics. Neither Taxol-induced NF-kappa B activation, nor I kappa B degradation was affected by the presence of phosphatidylinositol 3-kinase inhibitors. These results suggest that Taxol and LPS not only share a TLR4/MyD88-dependent pathway in generating inflammatory mediators, but also share a TLR4-dependent/MyD88-independent pathway leading to activation of MAPK and NF-kappa B.

Homeless lesbians: psychology of the hidden, the disenfranchised, and the forgotten.

1. Lesbians in general, and homeless lesbians in particular, are neglected and ignored not only in our culture but in the nursing profession as well. 2. Nurses who work with homeless women must be aware of and sensitive to lesbian issues when interacting with any clients. 3. The problems of individual lesbians cna be as diverse as they are for any client.

Ultrastructural study of the histogenesis of salivary gland mucoepidermoid carcinoma.

This electronmicroscope study of the histogenesis of mucoepidermoid carcinoma is based on 15 cases from the major and minor salivary glands. Six major cell types were identified: undifferentiated (cuboid) stem cells, intermediate (columnar) cells, serous/mucoid secretory cells, mucus-producing goblet cells, squamous/epidermoid cells and myoepithelium. It is proposed that undifferentiated stem cells serve as pluripotential reserves which give rise to the various cell types seen in mucoepidermoid carcinoma. Reserve cells in the acinar-intercalated duct components of the salivary glands appeared to give rise to the serous/mucoid and myoepithelial cell populations of mucoepidermoid carcinoma. Reserve cells in the proximal ducts system (intra/extralobular striated ducts and excretory ducts) differentiated into myoepithelium, intermediate (columnar) cells, squamous/epidermoid and mucus-producing goblet cell lines. It is proposed that neoplastic reserve cells give rise to different tumor types in the salivary glands. These types result from varying admixtures and arrangements of tumor cells at different stages of their structural and functional cytodifferentiation from reserve cells. It is further proposed that neoplastic reserve cells differentiate along similar cell lines as the embryonic "stem cells" in the development of normal salivary glands.

Chemotherapy versus chemotherapy plus radiotherapy in the treatment of tonsillar squamous cell carcinoma in the dog.

The effect of adjuvant chemotherapy and combined chemotherapy and radiotherapy in 22 dogs with advanced canine tonsillar carcinoma (World Health Organization [WHO], T2-3 primary tumor with infiltration into surrounding tissues) was evaluated. There were four treatment groups of at least five dogs each. Combinations of chemotherapeutic drugs reported to have activity against squamous cell carcinoma in humans and dogs (doxorubicin, cisplatin, vinblastine, and cyclophosphamide) were administered after tonsillectomy. Radiation therapy (orthovoltage type, external beam) was combined with chemotherapy in one treatment group. The dogs that had combination radiation therapy and chemotherapy had higher response rates and significantly longer survival times. However, most dogs died of progression of disease.

Use of splenectomy in the management of lymphoma in dogs: 16 cases (1976-1985).

Sixteen dogs with lymphoma underwent splenectomy to relieve signs of massive splenomegaly including splenic rupture. The most common preoperative hematologic abnormalities, anemia and thrombocytopenia, were reversed in all dogs surviving the initial postoperative period. Within 6 weeks after surgery, 5 dogs died because of disseminated intravascular coagulation and sepsis. The remaining 11 dogs underwent chemotherapy. These 11 dogs had a complete response rate of 66% at one month after surgery; the mean and median survival times were 9.3 and 5 months, respectively. In 7 dogs evaluated until death, the mean and median survival times were 13.4 months and 14 months, respectively.

Use of plasmapheresis and chemotherapy for treatment of monoclonal gammopathy associated with Ehrlichia canis infection in a dog.

Monoclonal gammopathy associated with Ehrlichia canis infection was diagnosed in a German Shepherd Dog. The dog was treated by use of chemotherapy and tetracycline and by plasmapheresis. The dog tolerated plasmapheresis and long-term drug therapy well, and clinical signs resolved over a 90-day period. The monoclonal gammopathy resolved after treatment, but specific antibody to E canis indicated suppression followed by a rebound to the initial high titer.

Histogenesis of adenoid cystic carcinoma of the salivary glands. Light and electronmicroscopic study.

This ultrastructural study, based on 12 cases of adenoid cystic carcinoma of the major and minor salivary glands, was conducted to determine the role and extent of participation of myoepithelial cells in their histogenesis. The tumors were composed of four major cell types; intercalated duct, myoepithelial, secretory, and pluripotential reserve/stem cells. The cellular composition of adenoid cystic carcinoma is similar to that in the "terminal tubule" complex stage of a developing salivary gland except that in the tumor the pluripotential reserve/stem cells differentiate predominantly along the intercalated duct cell line rather than secretory cells as in the acinic cell carcinoma. Furthermore, adenoid cystic carcinoma appears to contain a far greater number of myoepithelial cells than acinic cell carcinomas.

Chronic lymphocytic leukemia in the dog: 22 cases (1974-1984).

Chronic lymphocytic leukemia was diagnosed in 22 dogs. Diagnosis was based primarily on detection of lymphocytosis and bone marrow infiltration with small lymphocytes similar to those seen in the blood. More than 50% of the dogs had monoclonal gammopathy, and, of these, 40% had monoclonal light-chain (Bence Jones) proteinuria. Hyperviscosity syndrome was observed occasionally. Most dogs were treated with chemotherapy. For the 17 dogs treated greater than or equal to 30 days, the survival times ranged from 30 to 1,000 days.

Prognostic factors for multiple myeloma in the dog.

Multiple myeloma was diagnosed in 60 dogs. Diagnosis was confirmed in each case by observation of greater than 5% plasma cells on examination of a bone marrow aspirate and detection of monoclonal gammopathy of immunoglobulin (Ig) A or IgG. Treatment with melphalan, cyclophosphamide, and prednisone was associated with long-term survival (median, 540 days). Response to therapy was significantly related to prognosis (P less than 0.01), whereas hypercalcemia and Ig light chain proteinuria (Bence Jones) were associated with shorter median survival times.

Histogenesis of acinic cell carcinoma of the major and minor salivary glands. An ultrastructural study.

This study describes the light microscopic, histochemical and electron-microscopic findings of 10 acinic cell carcinomas from the major and minor salivary glands. Ultrastructurally, four cell types were identified: secretory acinar cells, intercalated duct-like cells, pluripotential reserve/stem cells and myoepithelial cells. This cellular composition suggests that the tumours are derived from neoplastic proliferation, cytodifferentiation and functional maturation of pluripotential reserve/stem cells which normally reside at the acinar-intercalated duct junctions and/or in the intercalated ducts proper of adult salivary glands. This study further supports the concept that different salivary gland tumours recapitulate various developmental stages in the normal embryogenesis of the salivary glands.

Uric acid and phosphorus excretion in dogs with lymphosarcoma.

Serum uric acid and phosphorus concentrations were determined for 27 dogs with multicentric lymphosarcoma before and after chemotherapy. Mean serum uric acid values in dogs before treatment were significantly higher (P less than 0.05) than those of a control group of healthy dogs. Serum uric acid values did not change after treatment. Of the 27 dogs, 13 had 24-hour urine collections to determine endogenous creatinine clearance and quantitation of uric acid and phosphorus excretion before and after treatment for lymphosarcoma. Mean values for 24-hour creatinine clearance before and after treatment were statistically similar in dogs with lymphosarcoma, although the values were lower than those in a normal range. Total urinary phosphorus excretions were increased significantly (P less than 0.01) after treatment without change in fractional excretion. Chemotherapeutic agents used accounted for the significant (P less than 0.05) increase in urine volume after treatment and may have affected the excretion of uric acid and phosphorus. Seemingly, dogs with uncomplicated lymphosarcoma rarely have renal dysfunction or clinically important alterations in uric acid or phosphorus excretion secondary to rapid tumor lysis. However, preexisting renal disease or systemic complications, such as hypercalcemia, may be associated with increased risk of further renal impairment during treatment.

Insulin-secreting tumor: diagnosis and medical and surgical management in 55 dogs.

Insulin-secreting tumor of the pancreas was diagnosed in 55 dogs. Diagnosis was based mainly on the increase of serum insulin concentrations in the presence of hypoglycemia. The use of the amended insulin/glucose ratio to diagnose the tumor, although providing less false-negative results than did increased serum insulin concentrations alone, appeared less specific and gave false-positive results in dogs without insulin-secreting tumors. Management of the disease included surgical intervention alone (26 dogs), surgery plus medical management with diazoxide (14 dogs), and medical management with diazoxide alone (4 dogs). Eleven dogs were euthanatized at the time of diagnosis. Diazoxide therapy controlled hypoglycemia in about 70% of the dogs.

Plasmapheresis in five dogs with systemic immune-mediated disease.

Five dogs with signs referable to systemic immune-mediated disease, four with systemic lupus erythematosus, and one with probable lupus myopathy were treated with plasmapheresis in combination with low-dose immunosuppressive drug therapy. Previous treatment with conventional dosages of prednisone was not satisfactory and was associated with adverse side effects. Two dogs had short-term responses to combined therapy, and 3 dogs had sustained responses. Clinical remission was associated with normalization of serum complement levels and decreases in antinuclear antibody titers. Toxicosis potentially related to plasma component depletion was observed in 2 dogs. Acute clinical illness and disease states refractory to conventional immunosuppressive therapy should be considered indications for plasmapheresis.

Lymphoid leukemia in the dog. Acute lymphoblastic leukemia and chronic lymphocytic leukemia.

True lymphoid leukemia of bone-marrow origin may present as two distinct clinical forms in the dog. Acute lymphoblastic leukemia is a rapidly progressive disease associated with proliferation of malignant, undifferentiated lymphoblasts. Chronic lymphocytic leukemia is a more insidious form of malignancy associated with abnormal proliferation of small lymphocytes. Recognition of these clinically distinct forms of leukemia and their differentiation from lymphosarcoma are important in considering prognosis and approach to therapy.