Though with millions of cured cases, COVID-19, a complex and highly variable syndrome, is still spreading globally and continues to cause infection and deaths worldwide. Researchers believe that methods that can evaluate the antigen-specific T-cell immunity in patients, survivors, and vaccinees can effectively help understand the immune persistence, prognosis assessment, and vaccine development for COVID-19. And evaluation of virus-specific immune function from both humoral and cellular immunity is equally important, in which techniques based on humoral immunity, such as virus-specific antibody neutralization tests using serum, have already been widely investigated. On the contrary, cellular immunity detecting methods, due to complex operations and specialized facilities, have not been standardized.
The enzyme-linked immunospot (ELISpot) assay, as one of the most sensitive cellular immunoassays that can detect the functional cytokine producing T-cells even at the single-cell level, has been adjusted by researchers to measure the cytokines released by T-cells in responses to SARS-CoV-2-specific immune responses.
ELISpot is a method based on ELISA used for the detection of secreted proteins of cells, such as cytokines and growth factors. ELISpot usually uses a PVDF or nitrocellulose (NC) membrane 96-well plate that is pre-coated with an antibody specific to the secreted protein. Then, the cells required to be evaluated are added to the plate and attached to the coated membrane. After being stimulated, cells would secret proteins that can bind to the antibody, and a detection antibody is added finally. An antibody complex would form in this process and it can be detected either through enzymatic action to produce a colored substrate or with fluorescent tags. The membrane can be analyzed by manually counting the spots or with an automated reader designed for this purpose. Each secreting cell appears as a spot of color or fluorescence, thus this is a quantitative method for evaluating protein secretion.
Compared to ELISA assays that determine the total concentration of secreted signaling proteins leveraging the antibody/antigen binding principle, ELISpot is also an enzyme-linked immunosorbent assay but it detects individual cytokine-secreting cells. Another difference between ELISA and ELISpot assays is that the antigen should be firstly immobilized onto the microlitre wells for ELISA tests while ELISpot tests required firstly immobilizing the antibody onto the microlitre wells.
Adjusted ELISpot-based Immunoassay for SARS-CoV-2-specific T-cell Responses
However, researchers shortly notice the main limitation of ELISpot technology that ELISpot lacks the ability to detect cytokines released by T-cells in responses to specific immune responses once T-cells simultaneously produce multiple cytokines. The human interferon-γ (IFN-γ) enzyme-linked immunospot (ELISpot) assay is commonly used with the stimulation of pathogen-specific peptides, such as mycobacterium tuberculosis. Therefore, researchers in a recently published study evaluated an empirically adjusted human interferon-γ (IFN-γ) enzyme-linked immunospot assay for detecting SARS-CoV-2-specific T-cell immunity in 175 peripheral blood samples from COVID-19 convalescents and healthy individuals who were neither infected with SARS-CoV-2 nor vaccinated against COVID-19.
Researchers can quantify the SARS-CoV-2-specific T-cell responses by subtracting the number of spots counted by the ELISpot Reader system in the negative control from the corresponding experimental well. The results showed that this adjusted T-cell immunity detection assay based on ELISpot can effectively evaluate SARS-CoV-2-specific responses with high sensitivity and specificity. Though with some deficiencies like the insufficient number of blood samples and healthy controls as well as the lack of repeated measurements after ELISpot troubleshooting, this study is still significantly important to promote the standardized assessment of immune responses to SARS-CoV-2 variants, vaccines, and diagnostics.
The COVID-19 pandemic has caused more than 600,000 deaths in the United States since the start of 2020 and more than 4 million globally.
RNA is a type of genetic code that can be translated into proteins that allow the virus to replicate.
During its RNA duplication, the virus would typically have a distinct chemical genetic signature -; a string of molecules, or bases, that appends to one end of SARS-CoV-2's RNA backbone.This chemical signature would normally be recognizable by the body and produce an immune response, but the virus has a special way of hiding the extra molecules and sneaking into the body undetected.
The research team used the resources of the Advanced Photon Source (APS), a DOE Office of Science User Facility at Argonne, to test a new treatment option that may foil this mechanism.The research was led by Andrzej Joachimiak of Argonne and the University of Chicago, with Argonne protein crystallographer Youngchang Kim and University of Chicago structural biologist Natalia Maltseva and their colleagues.
Joachimiak is the director of the Structural Biology Center (SBC) at the APS, and the research team used the high-powered X-ray beams generated there to study one of the virus's proteins, called Nsp15.This protein acts like a molecular scissors, cutting regions of the virus that are involved in its ability to make copies of itself.
As more and more of those strings of molecules -; made up of uridine, one of the main components of nucleic acid -; are produced, the Nsp15 molecule removes them, essentially giving the virus the haircut it needs to pass undetected undercover.
Severe Acute Respiratory Syndrome-Related Coronavirus 2(SARS-CoV2) or the COVID-19 virus has led to a global pandemic causing havoc all across.
At Medical PPE Resource, we care about the health of our community.
This test helps to find the IgG antibody to SARS-CoV-2.
The IgG antibody test is intended for the qualitative detection of IgG-class antibodies against COVID-19.
A positive IgG result indicates the previous infection with COVID-19.
A negative test result ensures that the antibodies to the virus that causes COVID-19 were not found in your sample.
This test is designed to detect antibodies up against the virus that causes COVID-19.
Fighting with Coronavirus is becoming tough for the country and hence, the Government of India has decided to take some extra steps that can forward it to all.
Early in the month of April, the health department of India withdrew its plans to promote Coronavirus Tests through antibody test method, and now it has moved back to RT-PCR i.e.
the known “gold standard” for Covid-19 diagnosis.
ICMR has approved more than 200 labs that include the public and private labs for SARS CoV 2 Test.
This testing can be done through RT-PCR machines that can genetically detect the pathogen.
From very start Metropolis India is conducting COVID 19 Test by RT-PCR Method in India.
The introduction of automation eliminates human labor form process associated with mining.
The report reveals about ongoing trends, market size, growth opportunities, and competitive landscape.
MRFR study on the global mining automation market states that the market can expand at 8.6% CAGR.
The penetration of automation solutions in mining processes can cause escalation in the valuation of the mining automation market.
Control systems, robots, computers, programmable controllers, and technology sets are utilized by automation solutions that increase efficacy and productivity of operations.
Intensive mining activities, such as loading, drilling, transporting, and hauling among others are automated using automation control devices, such as programmable logic controllers (PLCs), software, PCs, and distributed control systems (DCS).
