IL28B Alleles Exert an Additive Dose Effect When Applied to HCV-HIV Coinfected Persons Undergoing Peginterferon and Ribavirin Therapy

BACKGROUND: Genetic studies have demonstrated a strong association between single nucleotide polymorphisms (SNPs) at IL28B and response to treatment with peginterferon (PEG) and ribavirin (RBV) in HCV monoinfected persons. We sought to test these associations in a prospective PEG / weight based ribavirin (WBR) treatment trial (ACTG A5178) (National Institution of Health registration number NCT00078403) in persons with HCV-HIV coinfection, and to develop a prediction score. METHODS: We selected subjects enrolled in A5178 who completed at least the first 12 weeks of the trial and had DNA available, and genotyped three SNPs at IL28B (rs12979860, rs12980275, rs8099917). We used multivariate logistic regression analysis to evaluate the association between IL28B SNPs and HCV treatment outcomes and to develop the prediction score. RESULTS: 231 HCV/HIV coinfected subjects were included. We observed a strong association between IL28B genotype and response to therapy among those with genotypes 1 or 4 (odds ratio for complete early virologic responses (cEVR) and sustained virologic response (SVR) was 2.98 [1.7-5.3] and 3.4 [1.7-6.9], respectively, for each additional copy of the C allele of rs12979860). Differences in frequency of the responder allele explained some of the discrepancy in HCV treatment outcomes between blacks and whites. A simple pretreatment prediction score that incorporates the IL28B genotype and baseline HCV viral load has a 93% negative predictive value (NPV) for SVR. CONCLUSIONS: IL28B SNPs have an additive allele dose effect in predicting HCV treatment outcomes in HCV/HIV coinfected persons and can be incorporated into a simple pretreatment prediction score that could minimize the risk of exposure to PEG/RBV therapy for persons with unfavorable scores

Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNF and IFN

In cutaneous leishmaniasis, Leishmania amazonensis activates macrophage double-stranded, RNA-activated protein kinase R (PKR) to promote parasite growth. In our study, Leishmania major grew normally in RAW cells, RAW-expressing dominant-negative PKR (PKR-DN) cells, and macrophages of PKR-knockout mice, revealing that PKR is dispensable for L. major growth in macrophages. PKR activation in infected macrophages with poly I:C resulted in parasite death. Fifty percent of L. major-knockout lines for the ecotin-like serine peptidase inhibitor (ISP2; Δisp2/isp3), an inhibitor of neutrophil elastase (NE), died in RAW cells or macrophages from 129Sv mice, as a result of PKR activation. Inhibition of PKR or NE or neutralization of Toll-like receptor 4 or 2(TLR4 or TLR2) prevented the death of Δisp2/isp3. Δisp2/isp3 grew normally in RAW-PKR-DN cells or macrophages from 129Sv pkr−/−, tlr2−/−, trif−/−, and myd88−/− mice, associating NE activity, PKR, and TLR responses with parasite death. Δisp2/isp3 increased the expression of mRNA for TNF-α by 2-fold and of interferon β (IFNβ) in a PKR-dependent manner. Antibodies to TNF-α reversed the 95% killing by Δisp2/isp3, whereas they grew normally in macrophages from IFN receptor–knockout mice. We propose that ISP2 prevents the activation of PKR via an NE-TLR4-TLR2 axis to control innate responses that contribute to the killing of L. major.—Faria, M. S., Calegari-Silva, T. C., de Carvalho Vivarini, A., Mottram, J. C., Lopes, U. G., Lima, A. P. C. A. Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNFα and IFNβ

Curative Effect of 18β-Glycyrrhetinic Acid in Experimental Visceral Leishmaniasis Depends on Phosphatase-Dependent Modulation of Cellular MAP Kinases

We earlier showed that 18β-glycyrrhetinic acid (GRA), a pentacyclic triterpenoid from licorice root, could completely cure visceral leishmaniasis in BALB/c mouse model. This was associated with induction of nitric oxide and proinflammatory cytokine production through the up regulation of NF-κB. In the present study we tried to decipher the underlying cellular mechanisms of the curative effect of GRA. Analysis of MAP kinase pathways revealed that GRA caused strong activation of p38 and to a lesser extent, ERK in bone marrow-derived macrophages (BMDM). Almost complete abrogation of GRA-induced cytokine production in presence of specific inhibitors of p38 and ERK1/2 confirmed the involvement of these MAP kinases in GRA-mediated responses. GRA induced mitogen- and stress-activated protein kinase (MSK1) activity in a time-dependent manner suggested that GRA-mediated NF-κB transactivation is mediated by p38, ERK and MSK1 pathway. As kinase/phosphatase balance plays an important role in modulating infection, the effect of GRA on MAPK directed phosphatases (MKP) was studied. GRA markedly reduced the expression and activities of three phosphatases, MKP1, MKP3 and protein phosphatase 2A (PP2A) along with a substantial reduction of p38 and ERK dephosphorylation in infected BMDM. Similarly in the in vivo situation, GRA treatment of L. donovani-infected BALB/c mice caused marked reduction of spleen parasite burden associated with concomitant decrease of individual phosphatase levels. However, activation of kinases also played an important role as the protective effect of GRA was significantly abrogated by pharmacological inhibition of p38 and ERK pathway. Curative effect of GRA may, therefore, be associated with restoration of proper cellular kinase/phosphatase balance, rather than modulation of either kinases or phosphatases

Immunization against Leishmania major Infection Using LACK- and IL-12-Expressing Lactococcus lactis Induces Delay in Footpad Swelling

BACKGROUND: Leishmania is a mammalian parasite affecting over 12 million individuals worldwide. Current treatments are expensive, cause severe side effects, and emerging drug resistance has been reported. Vaccination is the most cost-effective means to control infectious disease but currently there is no vaccine available against Leishmaniasis. Lactococcus lactis is a non-pathogenic, non-colonizing Gram-positive lactic acid bacterium commonly used in the dairy industry. Recently, L. lactis was used to express biologically active molecules including vaccine antigens and cytokines. METHODOLOGY/PRINCIPAL FINDINGS: We report the generation of L. lactis strains expressing the protective Leishmania antigen, LACK, in the cytoplasm, secreted or anchored to the bacterial cell wall. L. lactis was also engineered to secrete biologically active single chain mouse IL-12. Subcutaneous immunization with live L. lactis expressing LACK anchored to the cell wall and L. lactis secreting IL-12 significantly delayed footpad swelling in Leishmania major infected BALB/c mice. The delay in footpad swelling correlated with a significant reduction of parasite burden in immunized animals compared to control groups. Immunization with these two L. lactis strains induced antigen-specific multifunctional T(H)1 CD4(+) and CD8(+) T cells and a systemic LACK-specific T(H)1 immune response. Further, protection in immunized animals correlated with a Leishmania-specific T(H)1 immune response post-challenge. L. lactis secreting mouse IL-12 was essential for directing immune responses to LACK towards a protective T(H)1 response. CONCLUSIONS/SIGNIFICANCE: This report demonstrates the use of L. lactis as a live vaccine against L. major infection in BALB/c mice. The strains generated in this study provide the basis for the development of an inexpensive and safe vaccine against the human parasite Leishmania

Leishmania-Induced Inactivation of the Macrophage Transcription Factor AP-1 Is Mediated by the Parasite Metalloprotease GP63

Leishmania parasites have evolved sophisticated mechanisms to subvert macrophage immune responses by altering the host cell signal transduction machinery, including inhibition of JAK/STAT signalling and other transcription factors such as AP-1, CREB and NF-κB. AP-1 regulates pro-inflammatory cytokines, chemokines and nitric oxide production. Herein we show that upon Leishmania infection, AP-1 activity within host cells is abolished and correlates with lower expression of 5 of the 7 AP-1 subunits. Of interest, c-Jun, the central component of AP-1, is cleaved by Leishmania. Furthermore, the cleavage of c-Jun is dependent on the expression and activity of the major Leishmania surface protease GP63. Immunoprecipitation of c-Jun from nuclear extracts showed that GP63 interacts, and cleaves c-Jun at the perinuclear area shortly after infection. Phagocytosis inhibition by cytochalasin D did not block c-Jun down-regulation, suggesting that internalization of the parasite might not be necessary to deliver GP63 molecules inside the host cell. This observation was corroborated by the maintenance of c-Jun cleavage upon incubation with L. mexicana culture supernatant, suggesting that secreted, soluble GP63 could use a phagocytosis-independent mechanism to enter the host cell. In support of this, disruption of macrophage lipid raft microdomains by Methyl β-Cyclodextrin (MβCD) partially inhibits the degradation of full length c-Jun. Together our results indicate a novel role of the surface protease GP63 in the Leishmania-mediated subversion of host AP-1 activity

Esophageal and Gastric Malignancies After Bariatric Surgery: a Retrospective Global Study

Background: Bariatric surgery can influence the presentation, diagnosis, and management of gastrointestinal cancers. Esophagogastric (EG) malignancies in patients who have had a prior bariatric procedure have not been fully characterized. Objective: To characterize EG malignancies after bariatric procedures. Setting: University Hospital, United Kingdom. Methods: We performed a retrospective, multicenter observational study of patients with EG malignancies after bariatric surgery to characterize this condition. Results: This study includes 170 patients from 75 centers in 25 countries who underwent bariatric procedures between 1985 and 2020. At the time of the bariatric procedure, the mean age was 50.2 ± 10 years, and the mean weight 128.8 ± 28.9 kg. Women composed 57.3% (n = 98) of the population. Most (n = 64) patients underwent a Roux-en-Y gastric bypass (RYGB) followed by adjustable gastric band (AGB; n = 46) and sleeve gastrectomy (SG; n = 43). Time to cancer diagnosis after bariatric surgery was 9.5 ± 7.4 years, and mean weight at diagnosis was 87.4 ± 21.9 kg. The time lag was 5.9 ± 4.1 years after SG compared to 9.4 ± 7.1 years after RYGB and 10.5 ± 5.7 years after AGB. One third of patients presented with metastatic disease. The majority of tumors were adenocarcinoma (82.9%). Approximately 1 in 5 patients underwent palliative treatment from the outset. Time from diagnosis to mortality was under 1 year for most patients who died over the intervening period. Conclusion: The Oesophago-Gastric Malignancies After Obesity/Bariatric Surgery study presents the largest series to date of patients developing EG malignancies after bariatric surgery and attempts to characterize this condition.info:eu-repo/semantics/publishedVersio

Acute myeloid leukemia creates an arginase-dependent immunosuppressive microenvironment.

Acute myeloid leukemia (AML) is the most common acute leukemia in adults and the second most common frequent leukemia of childhood. Patients may present with lymphopenia or pancytopenia at diagnosis. We investigated the mechanisms by which AML causes pancytopenia and suppresses patients' immune response. This study identified for the first time that AML blasts alter the immune microenvironment through enhanced arginine metabolism. Arginase II is expressed and released from AML blasts and is present at high concentrations in the plasma of patients with AML, resulting in suppression of T-cell proliferation. We extended these results by demonstrating an arginase-dependent ability of AML blasts to polarize surrounding monocytes into a suppressive M2-like phenotype in vitro and in engrafted nonobese diabetic-severe combined immunodeficiency mice. In addition, AML blasts can suppress the proliferation and differentiation of murine granulocyte-monocyte progenitors and human CD34(+) progenitors. Finally, the study showed that the immunosuppressive activity of AML blasts can be modulated through small-molecule inhibitors of arginase and inducible nitric oxide synthase, suggesting a novel therapeutic target in AML. The results strongly support the hypothesis that AML creates an immunosuppressive microenvironment that contributes to the pancytopenia observed at diagnosis

A proposed HCV pretreatment decision tree utilizing our prediction score and its application to the HCV/HIV coinfected cohort.

<p>A proposed HCV pretreatment decision tree utilizing our prediction score and its application to the HCV/HIV coinfected cohort.</p

Area under ROC for predicting SVR from a model including <i>IL28B</i> genotype (rs12979860) and baseline HCV viral load.

<p>Area under ROC for predicting SVR from a model including <i>IL28B</i> genotype (rs12979860) and baseline HCV viral load.</p