Dengue fever and dengue haemorrhagic fever are important arthropod-borne viral diseases. Each year, there are ∼50 million dengue infections and ∼500,000 individuals are hospitalized with dengue haemorrhagic fever, mainly in Southeast Asia, the Pacific and the Americas. Illness is produced by any of the four dengue virus serotypes. A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently under development could also make an important contribution to dengue control in the future.

Dengue: a continuing global threat

From the Oxford University Clinical Research Unit and Wellcome Trust Major Overseas Programme (C.P.S., J.J.F., B.W.), Hospital for Tropical Diseases (N.V.C.), Ho Chi Minh City, Vietnam; and the Centre for Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, United Kingdom (C.P.S., J.J.F., B.W.). Address reprint requests to Dr. Farrar at the Hospital for Tropical Diseases, Oxford University Clinical Research Unit, 190 Ben Ham Tu, Quan 5, Ho Chi Minh City, Vietnam, or at jfarrar@oucru.org.

/pdf/current-concepts-dengue-6c6i5h8gym.pdf

Current concepts: Dengue

Summary: Much remains to be learned about the pathogenesis of the different manifestations of dengue virus (DENV) infections in humans. They may range from subclinical infection to dengue fever, dengue hemorrhagic fever (DHF), and eventually dengue shock syndrome (DSS). As both cell tropism and tissue tropism of DENV are considered major determinants in the pathogenesis of dengue, there is a critical need for adequate tropism assays, animal models, and human autopsy data. More than 50 years of research on dengue has resulted in a host of literature, which strongly suggests that the pathogenesis of DHF and DSS involves viral virulence factors and detrimental host responses, collectively resulting in abnormal hemostasis and increased vascular permeability. Differential targeting of specific vascular beds is likely to trigger the localized vascular hyperpermeability underlying DSS. A personalized approach to the study of pathogenesis will elucidate the basis of individual risk for development of DHF and DSS as well as identify the genetic and environmental bases for differences in risk for development of severe disease.

Dengue Virus Pathogenesis: an Integrated View

Dengue is a mosquito-borne viral disease of expanding geographical range and incidence. The existence of four viral serotypes and the association of prior dengue virus infection with an increased risk for more severe disease have presented significant obstacles to vaccine development. An increased understanding of the adaptive immune response to natural dengue virus infection and candidate dengue vaccines has helped to define the specific antibody and T cell responses that are associated with either protective or pathological immunity during dengue infection. Further characterization of immunological correlates of disease outcome and the validation of these findings in vaccine trials will be invaluable for developing effective dengue vaccines.

/pdf/immunity-to-dengue-virus-a-tale-of-original-antigenic-sin-44rwsw383h.pdf

Immunity to dengue virus: a tale of original antigenic sin and tropical cytokine storms

The number of cases of severe dengue disease continues to grow in endemic areas of southeast Asia, Central and South America, and other subtropical regions. Children bear the greatest burden of disease, and the development of an effective vaccine remains a global public health priority. A tetravalent vaccine is urgently needed and must be effective against all four dengue virus serotypes, be cost-effective and provide long-term protection. In this Review we discuss the unique immunological concerns in dengue virus vaccine development and the current prospects for the development of an acceptable vaccine, a goal that is likely to be reached in the near future.

/pdf/prospects-for-a-dengue-virus-vaccine-54zhcfxely.pdf

Prospects for a dengue virus vaccine.

Dengue viral antigens have been demonstrated in several types of naturally infected human tissues, but little is known of whether these same tissues have detectable viral RNA. We studied tissue specimens from patients with serologically or virologically confirmed dengue infections by immunohistochemistry (IHC) and in situ hybridization (ISH), to localize viral antigen and RNA, respectively. IHC was performed on specimens obtained from 5 autopsies and 24 biopsies and on 20 blood-clot samples. For ISH, antisense riboprobes to the dengue E gene were applied to tissue specimens in which IHC was positive. Viral antigens were demonstrated in Kupffer and sinusoidal endothelial cells of the liver; macrophages, multinucleated cells, and reactive lymphoid cells in the spleen; macrophages and vascular endothelium in the lung; kidney tubules; and monocytes and lymphocytes in blood-clot samples. Positive-strand viral RNA was detected in the same IHC-positive cells found in the spleen and blood-clot samples. The strong, positive ISH signal in these cells indicated a high copy number of viral RNA, suggesting replication.

Localization of Dengue Virus in Naturally Infected Human Tissues, by Immunohistochemistry and In Situ Hybridization

Confirmation of oral squamous cell cancer (OSCC) currently relies on histological analysis, which does not provide clear indication of cancer development from precancerous lesions. In the present study, whole saliva proteins of patients with OSCC (n = 12) and healthy subjects (n = 12) were separated by 2DE to identify potential candidate biomarkers that are much needed to improve detection of the cancer. The OSCC patients' 2DE saliva protein profiles appeared unique and different from those obtained from the healthy subjects. The patients' saliva α1-antitrypsin (AAT) and haptoglobin (HAP) β chains were resolved into polypeptide spots with increased microheterogeneity, although these were not apparent in their sera. Their 2DE protein profiles also showed presence of hemopexin and α-1B glycoprotein, which were not detected in the profiles of the control saliva. When subjected to densitometry analysis, significant altered levels of AAT, complement C3, transferrin, transthyretin, and β chains of fibrinogen and HAP were detected. The increased levels of saliva AAT, HAP, complement C3, hemopexin, and transthyretin in the OSCC patients were validated by ELISA. The strong association of AAT and HAP with OSCC was further supported by immunohistochemical staining of cancer tissues. The differently expressed saliva proteins may be useful complementary biomarkers for the early detection and/or monitoring of OSCC, although this requires validation in clinically representative populations.

Aberrant proteins in the saliva of patients with oral squamous cell carcinoma.

A gel-based proteomics approach was used to screen for proteins of differential abundance between the saliva of smokers and those who had never smoked. Subjecting precipitated proteins from whole human saliva of healthy non-smokers to two-dimensional electrophoresis (2-DE) generated typical profiles comprising more than 50 proteins. While 35 of the proteins were previously established by other researchers, an additional 22 proteins were detected in the 2-DE saliva protein profiles generated in the present study. When the 2-DE profiles were compared to those obtained from subjects considered to be heavy cigarette smokers, three saliva proteins, including interleukin-1 receptor antagonist, thioredoxin and lipocalin-1, showed significant enhanced expression. The distribution patterns of lipocalin-1 isoforms were also different between cigarette smokers and non-smokers. The three saliva proteins have good potential to be used as biomarkers for the adverse effects of smoking and the risk for inflammatory and chronic diseases that are associated with it.

https://www.mdpi.com/1422-0067/11/11/4488/pdf

Proteomic analysis of whole human saliva detects enhanced expression of interleukin-1 receptor antagonist, thioredoxin and lipocalin-1 in cigarette smokers compared to non-smokers.

The objective of this study was to investigate the salivary proteins that are associated with periodontitis in patients with Type 2 diabetes mellitus (T2DM). Volunteers for the study were patients from the Diabetic Unit, University of Malaya Medical Centre, whose periodontal status was determined. The diabetic volunteers were divided into two groups, i.e., patients with periodontitis and those who were periodontally healthy. Saliva samples were collected and treated with 10% TCA/acetone/20 mM DTT to precipitate the proteins, which were then separated using two-dimensional polyacrylamide gel electrophoresis. Gel images were scanned using the GS-800TM Calibrated Densitometer. The protein spots were analyzed and expressed in percentage volumes. The percentage volume of each protein spot was subjected to Mann-Whitney statistical analysis using SPSS software and false discovery rate correction. When the expression of the salivary proteins was compared between the T2DM patients with periodontitis with those who were periodontally healthy, seven proteins, including polymeric immunoglobulin receptor, plastin-2, actin related protein 3, leukocyte elastase inhibitor, carbonic anhydrases 6, immunoglobulin J and interleukin-1 receptor antagonist, were found to be differentially expressed (p < 0.01304). This implies that the proteins may have the potential to be used as biomarkers for the prediction of T2DM patients who may be prone to periodontitis.

https://www.mdpi.com/1422-0067/13/4/4642/pdf

Salivary Proteins Associated with Periodontitis in Patients with Type 2 Diabetes Mellitus

Precipitants for salivary proteins and rehydration buffers for two-dimensional electrophoresis (2-DE) analysis were, respectively compared and evaluated. Five different protein precipitants: TCA, TCA-acetone-DTT, TCA-acetone-mercaptoethanol, acetone and alcohol were used to precipitate proteins of the saliva samples. The efficiency of the precipitants was evaluated from protein content of the precipitate reflecting protein recovery. The precipitate with the highest protein content was subsequently solubilized using different rehydration buffers (RB1, RB2, RB3 and RB4) before being subjected to the 2-DE. The efficiency of the different rehydration buffers was compared with respect to the resolution and focusing time taken to attain the maximum voltage. Each of the saliva samples was subjected to the above experiments, carried out in triplicates. The precipitant containing TCA-acetone-DTT exhibited the highest protein recovery (82.2) demonstrating significant difference when compared with the other precipitants (p<0.05). The RB4 containing DTT (reducing agent) and 0.5 IPG buffer 3-10 non-linear (carrier ampholyte) exhibited more protein spots indicating better separation resolution. The results obtained suggested that protein recovery depends on the precipitant used in the precipitation and resolution of proteins separation is influenced by the reducing agent and the ampholyte used in the rehydration buffer

/pdf/protein-precipitation-method-for-salivary-proteins-and-4q4n2m3zs3.pdf

Kala Jessie

Papers

Localization of Dengue Virus in Naturally Infected Human Tissues, by Immunohistochemistry and In Situ Hybridization

Aberrant proteins in the saliva of patients with oral squamous cell carcinoma.

Proteomic analysis of whole human saliva detects enhanced expression of interleukin-1 receptor antagonist, thioredoxin and lipocalin-1 in cigarette smokers compared to non-smokers.

Salivary Proteins Associated with Periodontitis in Patients with Type 2 Diabetes Mellitus

Protein precipitation method for salivary proteins and rehydration buffer for two-dimensional electrophoresis