Overexpression of MicroRNAs from the miR-17-92 Paralog Clusters in AIDS-Related Non-Hodgkin's Lymphomas

Individuals infected by HIV are at an increased risk for developing non-Hodgkin's lymphomas (AIDS-NHL). In the highly active antiretroviral therapy (HAART) era, there has been a significant decline in the incidence of AIDS-associated primary central nervous system lymphoma (PCNSL). However, only a modest decrease in incidence has been reported for other AIDS-NHL subtypes. Thus, AIDS-NHLs remain a significant cause of morbidity and mortality in HIV infected individuals. Recently, much attention has been directed toward the role of miRNAs in cancer, including NHL. Several miRNAs, including those encoded by the miR-17-92 polycistron, have been shown to play significant roles in B cell tumorigenesis. However, the role of miRNAs in NHL in the setting of HIV infection has not been defined.We used quantitative realtime PCR to assess the expression of miRNAs from three different paralog clusters, miR-17-92, miR-106a-363, and miR-106b-25 in 24 cases of AIDS-NHLs representing four tumor types, Burkitt's lymphoma (BL, n = 6), diffuse large B-cell lymphoma (DLBCL, n = 8), primary central nervous system lymphoma (PCNSL, n = 5), and primary effusion lymphoma (PEL, n = 5). We also used microarray analysis to identify a differentiation specific miRNA signature of naïve, germinal center, and memory B cell subsets from tonsils (n = 4). miRNAs from the miR-17-92 paralog clusters were upregulated by B cells, specifically during the GC differentiation stage. We also found overexpression of these miRNA clusters in all four AIDS-NHL subtypes. Finally, we also show that select miRNAs from these clusters (miR-17, miR-106a, and miR-106b) inhibited p21 in AIDS-BL and DLBCL cases, thus providing a mechanistic role for these miRNAs in AIDS-NHL pathogenesis.Dysregulation of miR-17-92 paralog clusters is a common feature of AIDS-associated NHLs

Community mobilisation and health management committee strengthening to increase birth attendance by trained health workers in rural Makwanpur, Nepal: study protocol for a cluster randomised controlled trial

Background: Birth attendance by trained health workers is low in rural Nepal. Local participation in improving health services and increased interaction between health systems and communities may stimulate demand for health services. Significant increases in birth attendance by trained health workers may be affected through community mobilisation by local women's groups and health management committee strengthening. We will test the effect of community mobilisation through women's groups, and health management committee strengthening, on institutional deliveries and home deliveries attended by trained health workers in Makwanpur District. Design: Cluster randomised controlled trial involving 43 village development committee clusters. 21 clusters will receive the intervention and 22 clusters will serve as control areas. In intervention areas, Female Community Health Volunteers are supported in convening monthly women's groups. The groups work through an action research cycle in which they consider barriers to institutional delivery, plan and implement strategies to address these barriers with their communities, and evaluate their progress. Health management committees participate in three-day workshops that use appreciative inquiry methods to explore and plan ways to improve maternal and newborn health services. Follow-up meetings are conducted every three months to review progress. Primary outcomes are institutional deliveries and home deliveries conducted by trained health workers. Secondary outcome measures include uptake of antenatal and postnatal care, neonatal mortality and stillbirth rates, and maternal morbidity

Decreased Clearance Of Pseudomonas Aeruginosa From Airways Of Mice Deficient In Lysozyme M

Lysozyme is a ubiquitous and abundant, cationic, antimicrobial polypeptide of leukocytes and epithelia, but its biological function in host defense is largely unexplored. To ascertain the role of lysozyme during bacterial infection of murine airways, we exposed the airways of lysozyme M-deficient (lys M -/-) mice to the pulmonary pathogen Pseudomonas aeruginosa and examined the host\u27s response to infection. Despite partial compensation as a result of the appearance of lysozyme P in the infected airways of lys M -/- mice, these lys M-/- mice showed decreased clearance of P. aeruginosa compared with their lys M+/- or lys M+/+ littermates. Lysozyme contributes to optimal clearance of P. aeruginosa from the murine airways. © Society for Leukocyte Biology

CD40 ligand (CD154) incorporated into HIV virions induces activation-induced cytidine deaminase (AID) expression in human B lymphocytes.

Most AIDS-associated non-Hodgkin's lymphoma (AIDS-NHL) arises from errors in immunoglobulin heavy-chain gene (IgH) class switch recombination (CSR) or somatic hypermutation (SHM), events that occur in germinal center (GC) B cells and require the activity of activation induced cytidine deaminase (AID). Several oncogenic viruses (EBV, HCV, HPV) can induce AID gene (AID) expression, and elevated AID expression is seen in circulating lymphocytes prior to AIDS-NHL diagnosis. Here, we report that HIV produced in peripheral blood mononuclear cells (PBMC) induced AID expression in normal human B cells. Since HIV produced in PBMC contains host cell CD40 ligand (CD40L) incorporated into the viral membrane, and CD40L is known to induce AID expression in human B cells, the role of virion-associated CD40L in HIV-induced AID expression was examined. Only viruses expressing functional CD40L were seen to induce AID expression; CD40L-negative HIV did not induce AID expression. The induction of AID expression by CD40L+ HIV was abrogated by addition of blocking anti-CD40L antibody. AID protein was detected in B cells exposed to CD40L+ HIV using intracellular multicolor flow cytometry, with most AID producing B cells expressing the CD71 activation marker on their surface. Therefore, HIV virions that express CD40L induce AID expression in B cells, and this induction appears to be due to a direct interaction between CD40L on these viruses and CD40 on B cells. These findings are consistent with a role for HIV in the direct stimulation of B cells, potentially leading to the accumulation of molecular lesions that have the potential to contribute to the development of NHL

Injury-induced innate immune response in human skin mediated by transactivation of the epidermal growth factor receptor

We found that sterile wounding of human skin induced epidermal expression of the antimicrobial (poly)peptides human β-defensin–3, neutrophil gelatinase–associated lipocalin, and secretory leukocyte protease inhibitor through activation of the epidermal growth factor receptor. After skin wounding, the receptor was activated by heparin-binding epidermal growth factor that was released by a metalloprotease-dependent mechanism. Activation of the epidermal growth factor receptor generated antimicrobial concentrations of human β-defensin–3 and increased the activity of organotypic epidermal cultures against Staphylococcus aureus. These data demonstrate that sterile wounding initiates an innate immune response that increases resistance to overt infection and microbial colonization

Serum microRNAs in HIV-infected individuals as pre-diagnosis biomarkers for AIDS-NHL.

ObjectiveTo determine if changes in levels of serum microRNAs (miRNAs) were seen preceding the diagnosis of AIDS-related non-Hodgkin lymphoma (AIDS-NHL).DesignSerum miRNA levels were compared in 3 subject groups from the Multicenter AIDS Cohort Study: HIV-negative men (n = 43), HIV-positive men who did not develop NHL (n = 45), and HIV-positive men before AIDS-NHL diagnosis (n = 62, median time before diagnosis, 8.8 months).MethodsA total of 175 serum-enriched miRNAs were initially screened to identify differentially expressed miRNAs among these groups and the results validated by quantitative polymerase chain reaction. Receiver-operating characteristic analysis was then performed to assess biomarker utility.ResultsHigher levels of miR-21 and miR-122, and a lower level of miR-223, were able to discriminate HIV-infected from the HIV-uninfected groups, suggesting that these miRNAs are biomarkers for HIV infection but are not AIDS-NHL specific. Among the HIV-infected groups, a higher level of miR-222 was able to discriminate diffuse large B-cell lymphoma (DLBCL) and primary central nervous system lymphoma (PCNSL) subjects from HIV-infected subjects who did not develop NHL, with area under the receiver-operating characteristic curve of 0.777 and 0.792, respectively. At miR-222 cutoff values of 0.105 for DLBCL and 0.109 for PCNSL, the sensitivity and specificity were 75% and 77%, and 80% and 82%, respectively.ConclusionsAltered serum levels of miR-21, miR-122, and miR-223 are seen in HIV-infected individuals. Higher serum level of miR-222 has clear potential as a serum biomarker for earlier detection of DLBCL and PCNSL among HIV-infected individuals