RESEARCH

EARLY DETECTION (ZIKA, DENGUE, CARDIAC TROPONIN I)

Zika–MMB Assay

Research topic 3 Zika virus (ZIbut can also be spread through sexual transmission. Zika infection in pregnant women is a major conceKV) is a member of the flavivirus in the Flaviviridae family. ZIKV is most commonly transmitted by mosquitos, rn, as it is linked to catastrophic fetal abnormalities. Therefore, the ability to accurately diagnose ZIKV, is important for both spouses and especially in pregnant women. ZIKV usually disappears from the blood a few days after the onset of symptoms, for this reason indirect serologic tests were developed, such as an enzyme-linked immunosorbent assay (ELISA) and plaque-reduction neutralization test that detects virus-specific neutralization antibodies. These methods are not limited to the period in which the virus is still in the blood stream, and they constitute the bulk of the workload of many virology laboratories. Current ZIKV serological diagnosis is designed to detect IgM and IgG antibodies for either envelope or NS1 proteins. The envelope-based ELISA tests are sensitive, but lack specificity and have high cross-reactivity. NS1 protein-based ELISA is more specific. However, low levels of IgG/IgM antibodies against the NS1 protein are produced, which can result in a higher rate of false negative results. In our lab we evaluate novel Zika virus serological assays, utilizing the highly-specific NS1 antigen and a novel and highly sensitive detection technology—named Magnetic Modulation Biosensing (MMB)—that significantly improves clinical performance. MMB utilizes magnetic beads that are conjugated to NS1 protein, which specifically captures the Zika IgM/IgG antibodies. A second, fluorescently-labeled antibody is then added to form a “sandwich” assay with the analyte and the capture protein. The MMB ZIKV assays provide high sensitivity and specificity, and low cross-reactivity compare to ELISA-ZIKA assays.

Our paper on zika was publishe at the Journal of Infectious Diseases. The paper, entitled: "Highly Sensitive and Specific Zika Virus Serological Assays Using a Magnetic Modulation Biosensing System" can be found in the Publications section, and at can be found in the Publications section, and at DOI:10.1093/infdis/jiy606.

Dengue–MMB Assay

Dengue virus (DENV) is a member of the flavivirus in the Flaviviridae family. There are 4 serotypes of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4). Dengue fever is transmitted to humans through the bites of infective female Aedes mosquitoes. The symptoms of first infection are clinically characterised by high fever, severe headache, pain behind the eyes, muscle and joint pain, nausea, vomiting, swollen lymph nodes and rash. After recovery, lifelong immunity to that serotype of dengue virus will develop. However, cross-immunity to the other three serotypes after recovery is only partial and temporary. Hence, infections with other serotypes of dengue virus are more likely to result in severe dengue. Severe dengue is a potentially deadly complication due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding, or organ impairment.
Current DENV serological diagnosis is designed to detect IgM and IgG antibodies for either envelope or NS1 proteins. The envelope-based ELISA tests are sensitive, but lack specificity and have high cross-reactivity. NS1 protein-based ELISA is more specific. However, low levels of IgG/IgM antibodies against the NS1 protein are produced, which can result in a higher rate of false negative results.
In our lab we develop novel Dengue virus serological assays, utilizing the highly-specific to all 4 serotypes of NS1 antigen and a novel and highly sensitive detection technology—named Magnetic Modulation Biosensing (MMB)—that significantly improves clinical performance. MMB utilizes magnetic beads that are conjugated to NS1 protein (DEN-1, DEN-2, DEN-3 and DEN-4), which specifically captures the Dengue IgM/IgG antibodies. A second, fluorescently-labeled antibody is then added to form a “sandwich” assay with the analyte and the capture protein. The MMB DENV assays are compared to ELISA-DENV assays.

West Nile–MMB Assay

West Nile virus (WNV) is a member of the flavivirus genus in the Flaviviridae family, and it is capable of causing severe neurological disease and even death. The virus is transferred to humans and animals through bites of over 150 species of mosquitoes. Humans can also be infected by blood transfusion or organ transplantation. Symptoms for West Nile fever (WNF) may include fever, headache, weakness, joint and muscle pain, conjunctivitis, rash, nausea, and diarrhea. Approximately 80% of infections are asymptomatic and 20% will show mild infection symptoms. Less than 1% will develop a fatal neurological disease, namely West Nile Neuroinvasive Disease (WNND), such as meningitis, encephalitis, or acute flaccid paralysis
Current WNV diagnostic assays do not possess the necessary combination of high clinical sensitivity and specificity, minimal cross-reactivity, and rapid detection capabilities. Here, using our unique Magnetic Modulation Biosensing (MMB) platform and a thorough analysis of large libraries of antibodies and patients’ clinical samples, we propose to develop a quantitative WNV diagnostic assays that overcome the limitations and challenges of current diagnostics methods.

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