Advaita Ganguly

Overview of Plant-Derived Vaccine Antigens: Dengue Virus

This review highlights the advantages and current status of plant-derived vaccine development with special reference to the dengue virus. There are numerous problems involved in dengue vaccine development, and there is no vaccine against all four dengue serotypes. Dengue vaccine development using traditional approaches has not been satisfactory in terms of inducing neutralizing antibodies. Recently, these issues were addressed by showing a very good response to inducing neutralizing antibodies by plant-derived dengue vaccine antigens. This indicates the feasibility of using plant-derived vaccine antigens as a low-cost method to combat dengue and other infectious diseases. The application of new methods and strategies such as dendritic cell targeting in cancer therapy, severe acute respiratory syndrome, tuberculosis, human immune deficiency virus, and malaria might play an important role. These new methods are more efficient than traditional protocols. It is expected that in the near future, plant-derived vaccine antigens or antibodies will play an important role in the control of human infectious diseases.

Chondroitin sulphate extracted from antler cartilage using high hydrostatic pressure and enzymatic hydrolysis

Chondroitin sulphate (CS), a major glycosaminoglycan, is an essential component of the extracellular matrix in cartilaginous tissues. Wapiti velvet antlers are a rich source of these molecules. The purpose of the present study was to develop an effective isolation procedure of CS from fresh velvet antlers using a combination of high hydrostatic pressure (100 MPa) and enzymatic hydrolysis (papain). High CS extractability (95.1 ± 2.5%) of total uronic acid was obtained following incubation (4 h at 50 °C) with papain at pH 6.0 in 100 MPa compared to low extractability (19 ± 1.1%) in ambient pressure (0.1 MPa). Antler CS fractions were isolated by Sephacryl S-300 chromatography and identified by western blot using an anti-CS monoclonal antibody. The antler CS fraction did not aggregate with hyaluronic acid in CL-2B chromatography and possessed DPPH radical scavenging activity at 78.3 ± 1.5%. The results indicated that high hydrostatic pressure and enzymatic hydrolysis procedure may be a useful tool for the isolation of CS from antler cartilaginous tissues.

Quantitative and sensitive detection of the SARS-CoV spike protein using bispecific monoclonal antibody-based enzyme-linked immunoassay

Abstract The severe acute respiratory syndrome coronavirus (SARS-CoV) spike protein is known to mediate receptor interaction and immune recognition and thus it is considered as a major target for vaccine design. The spike protein plays an important role in virus entry, virus receptor interactions, and virus tropism. Sensitive diagnosis of SARS is essential for the control of the disease in humans. Recombinant SARS-CoV S1 antigen was produced and purified for the development of monoclonal and bi-specific monoclonal antibodies. The hybridomas secreting anti-S1 antibodies, F26G18 and P136.8D12, were fused respectively with the YP4 hybridoma to generate quadromas. The sandwich ELISA was formed by using F26G18 as a coating antibody and biotinylated F26G18 as a detection antibody with a detection limit of 0.037μg/ml (p <0.02). The same detection limit was found with P136.8D12 as a coating antibody and biotinylated F26G18 as a detection antibody. The sensitivity was improved (detection limit of 0.019μg/ml), however, when using bi-specific monoclonal antibody (F157) as the detection antibody. In conclusion, the method described in this study allows sensitive detection of a recombinant SARS spike protein by sandwich ELISA with bi-specific monoclonal antibody and could be used for the diagnosis of patients suspected with SARS.

Bispecific Antibodies for Diagnostic Applications

Bispecific monoclonal antibodies (BsMAb) are unique engineered macromolecules that have two different pre-determined binding specificities. Their ability to simultaneously bind to a specific antigen and a given detection moiety enables them to function as excellent bifunctional immunoprobes in diagnostic assays. BsMAb are being exploited for the development of simple, rapid, and highly sensitive immunoassays for diagnosis of bacterial and viral infectious diseases. This chapter describes the use of BsMAb for the detection of Mycobacterium tuberculosis, Escherichia coli O157:H7, Bordetella pertussis, Severe Acute Respiratory Syndrome coronavirus, and Dengue virus. Further, BsMAb have been utilized for diagnosis of various types of cancers. The use of BsMAb in detection of prostate cancer and in cancer diagnostic imaging is also discussed.

Gene Delivery System: A Developing Arena of Study for the New Era of Medicine

Gene therapy concept has been being overcome massive challenges from 1972 in ethical, socio-economical and developmental issues. In this review, we have attempted to go through almost all the arenas and described in a methodical way that reflects not only the initial ethical and scientific thoughts but also adorned a solid depiction of gene therapy related physico-chemical barriers, approaches and strategies till to date.

Current and Future Diagnostic Tests for Ebola Virus Disease

Ebola virus disease (EVD) is a major public health concern with a high mortality rate in infected individuals. Outbreaks of Ebola have been widespread-there is no rapid, sensitive, specific, and affordable diagnostic test for the virus, nor there is any treatment for the disease. Overlapping symptoms of other endemic diseases, such as malaria and cholera, make it difficult to diagnose EVD. For clinical management, outbreak investigation, and proper surveillance, EVD requires a detection system, which should be fast, sensitive, specific, efficient, affordable, and user-friendly with in-country staff. In this review, we discuss the current diagnostics available for Ebola screening, along with the limitations and key improvements necessary for a more robust system to facilitate efficient management in case of another major outbreak.

Production and characterization of monospecific and bispecific antibodies against dengue virus NS1 protein.

Dengue is a mosquito borne infection, which in recent years has become a major international public health concern. Annually, 100 million dengue virus infections are reported worldwide. The nonstructural protein 1 (NS1) of dengue virus is a useful target for diagnostics of dengue infection since the protein is abundantly circulating in the blood during acute phase of the disease, in both primary and secondary infections. This research paper highlights the development of a panel of Mab and bsMab for dengue NS1 detection. The P148 series of Mabs showed high specificity for recombinant dengue NS1 antigen. These antibodies showed no cross reactivity with recombinant dengue envelope protein and other viral proteins. The hybrid-hybridoma approach to generate the P156.1 and P156.2 bsMabs from the P148 monoclonal antibody method was used during this study. Furthermore, the affinity purification provided good yields of quadromas associated with HRPO in two steps. Direct detection method involved coating of plates with different concentrations of recombinant antigen and detecting with bsMab. Sensitive sandwich assay with Mabs and bsMabs was also done. Detection of nonstructural dengue antigens may be of benefit for early and rapid diagnosis of dengue infection due to their long half-life in the blood.

Heterosandwich immunoswab assay for dengue virus Ns1 antigen detection.

Dengue and the more severe dengue hemorrhagic fever have been a very critical public health problem globally. Millions of people especially in the tropical areas get infected with dengue. An efficient diagnostic is very important for early screening of dengue infection. In dengue-infected patients, the nonstructural protein NS1 is present on the surface of infected cells and secreted in plasma. The NS1 antigen is an important target for developing a quick diagnostic largely due to its long presence in the blood. We have developed a simple-to-use immunoswab-based diagnostic procedure employing monoclonal antibodies and the second-generation quadromas. The detection limit for NS1 has been established to be in the subnanogram range. The assay is very sensitive, has a visual end point, and also being extremely inexpensive. With this assay, screening time for a dengue-infected person would be very rapid.