Covid-19 is extremely hazardous.
Although most
countries took measures to control its spread, some regions of the world are still facing the threat of
the virus. Also, it is unknown whether Covid-19 will mutate in the future, so there are still potential
threats that may be caused by the virus
(N. Zhu et al., 2020)
. Currently, vaccination is the most
effective way
to control the virus, so RecoImmuno would like to create a recombinant protein vaccine against Covid-19
in the hope of solving the problem of virus transmission in this way.
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Significance:
So far, despite the availability of many
different
types of COVID-19 vaccines, many problems remain, including but not limited to:
1. The duration of vaccine effectiveness
is unclear,
long-term follow-up studies are needed to determine the duration of immune protection after
vaccination.
2. The mutant strains of the virus are
constantly
emerging, and the immune protection ability of the existing vaccines against the mutant strains needs to
be further studied.
3. Some people may experience immune
reactions after
vaccination, and a better understanding of the causes and duration of these reactions is needed in order
to provide better vaccination services to the population in the future.
4. The suitability of vaccines for
different groups
of people varies, especially special groups such as the elderly, children, and pregnant
women.
As a result:
From a variety of perspectives, the
development of
different kinds of vaccines, learning from each other's strengths, and complementary advantages can be
regarded as a strategy to improve the effectiveness of virus prevention and control, and the recombinant
protein vaccine development that RecoImmuno wants to carry out can undoubtedly contribute to virus
prevention and control.
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Inspiration:
The Covid-19 recombinant protein vaccine
is one of
the important directions of the current Covid-19 vaccine research, and there are a lot of studies
worldwide. RecoImmuno was influenced by this trend and decided to conduct research on recombinant
protein vaccines.
Experimental principle:
Spike protein is the key protein for Covid-19 to infect the
human body.
It mediates the entry of the virus into host cells by binding to the ACE2 receptor on the surface of
host cells.
(R. Lu et al, 2020)
Therefore, spike protein is the preferred choice for
designing
recombinant protein vaccine against Covid-19. The spike protein is divided into two
sub-units
(P. Zhou et al., 2020)
, S1 and S2, in which the S1 sub-unit contains a receptor
binding
domain (RBD), which is the key structure for the virus to enter the host cell.
(A. C. Walls et al., 2020)
Therefore, it is appropriate to select RBD as the
target antigen
for designing recombinant protein vaccines.
Experiment goal:
This experiment
was
plan
ned
to evaluate the ability of spike proteins to act as
antigens by
constructing them with different RBDS.
Experiment procedures:
This experiment is mainly divided into three
stages-
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Stage 1 - construction of recombinant plasmid
The corresponding target gene
s were ordered from the company
and were attached to the pET-28a vector plasmid by
enzyme-binding
technology.
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Stage 2 - protein expression and purification
The recombinant plasmid was transferred into Escherichia
coli DH5α for
expanded cultivation, then transformed into Escherichia coli BL21, and then expressed RBD under
different IPTG concentrations induction conditions. After the above experiments, the optimal protein
expression conditions were determined by SDS-PAGE, and then the RBD was purified by nickel
column.
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Stage 3 - Functional verification
ELISA was used to detect the binding ability of SARS-CoV-2
RBD to
ACE2.
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Problems we tend to solve:
To evaluate the ability of four reconstituted spike proteins (Wuhan,
Delta, BQ1.1, XBB1.5) to bind to ACE2 as antigens
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Products we want to develop:
A recombinant protein vaccine against Covid-19 virus