SARS-CoV-2: New insights into antibody response against viral variants


Date:
January 25, 2022
Source:
DZNE - German Center for Neurodegenerative Diseases
Summary:
Researchers present new findings on the immune response against
the coronavirus SARS-CoV-2. Their study is based on investigations
of antibodies elicited by infection with the Beta variant of the
virus. The researchers conclude that the Beta variant can confer
broad immunity to multiple viral strains, which could be beneficial
for protection against the currently prevalent Delta and Omicron
variants, as well as against future viral variants.



FULL STORY ==========================================================================
In the journal Science, researchers from Deutsches Zentrum fu"r Neurodegenerative Erkrankungen (DZNE) and Charite' -- Universita"tsmedizin Berlin present new findings on the immune response against the coronavirus SARS-CoV-2. Their study is based on investigations of antibodies elicited
by infection with the Beta variant of the virus. The researchers conclude
that the Beta variant can confer broad immunity to multiple viral strains, which could be beneficial for protection against the currently prevalent
Delta and Omicron variants, as well as against future viral variants. In
their view, this aspect should be taken into account in the development
of vaccination strategies.


==========================================================================
"The Beta variant of the coronavirus shows marked differences from the
wild type, the original strain of the virus. Until the emergence of the
now dominating Omicron variant, it was the viral form that had evolved
furthest from the wild type, against which the existing vaccines have
been developed," says Dr. Momsen Reincke, a researcher at DZNE and the Department of Neurology with Experimental Neurology on Campus Charite'
Mitte as well as one of the first authors of the current publication in Science. "We were interested in learning more about the exact antibody
response to this variant -- to see what conclusions can be drawn from
this about the immune response to other variants.

Since the coronavirus is likely to continue mutating, we were interested
in whether the antibodies we found acted only against the Beta variant
or had broader potential." Antibody Diversity Antibodies are proteins
that the body uses to defend itself against pathogens.

The human immune system can produce an almost inexhaustible variety of
them by making use of various mechanisms: in particular, by repeatedly recombining the blueprints for the components of an antibody that are
stored in the genome.

"The immune response to coronavirus also produces a spectrum of antibodies
that bind to different areas of the pathogen," Reincke says. From an
immune defense perspective, binding to the so-called spike protein is particularly effective.

"In a nutshell, this is the hook that the virus uses to attach itself
to body cells so that it can then slip in. Some antibodies bind to this
protein and thereby render the hook useless. These are the neutralizing antibodies. In our study, these were exactly the antibodies we looked at." Replication in the Laboratory The findings of the Berlin scientists
are based on an analysis of antibodies that they isolated from the
blood of 40 individuals. All patients had been infected with the Beta
variant of SARS-CoV-2. Of the approximately 300 antibodies initially
surveyed, 81 bound particularly strongly to the spike protein of the coronavirus. Reincke and his colleagues unraveled the genetic blueprints
of the antibodies. This enabled them to understand which genes play a
role in the assembly of these antibodies and to artificially produce
these immune proteins for further studies. In doing so, they benefited
from a project funded by the Helmholtz Association: the "BaoBab Innovation Lab." Within the framework of BaoBab, they develop and refine technologies
for the characterization and production of antibodies.



========================================================================== Effective against Delta and Omicron "We tested if antibodies against the
Beta variant are also effective against other virus variants. This is
called cross-reactivity. Our analyses show that some of these antibodies
do little against the wild type. Others, however, are very effective
against the original virus strain and also against some of the Variants of Concern. Some of the antibodies against Beta are even effective against
the currently circulating variants Delta and Omicron," says Dr. Jakob
Kreye, last author of the study and a scientist at DZNE and Charite''s Department of Pediatric Neurology as well as the Department of Neurology
with Experimental Neurology.

It Depends on the Binding Site The key to cross-reactivity is the site
of the spike protein a particular antibody binds to and whether this
site has changed between viral variants.

"The antibodies with broad efficacy target areas of the spike protein
that have remained largely the same in the previous viral variants," Kreye says. However, there are exceptions to this in the case of Omicron. "Yet
we have found antibodies that work well against both Beta and Omicron and
only weakly against other variants. These particular antibodies bind to
sites of the spike protein that are quite similar in Beta and Omicron but
not in other variants." Protection Against New Variants Cross-reactivity
could prove to be an important aspect of future vaccinations: "Individual antibodies against the wild type also have broad efficacy. This has
been described in the literature and is also shown by studies in our laboratory. Taking together these data and our current findings, we
conclude that antibodies generated against different viral variants
can complement each other and thus jointly improve the potency of the
immune response against emerging variants. Largest possible diversity
in the antibody response seems to make sense," says Prof. Dr. Harald
Pru"ss, research group leader at DZNE and senior physician at the
Department of Neurology with Experimental Neurology on Campus Charite'
Mitte. "Simultaneous or even sequential vaccination against different
variants would likely provide enhanced protection against potential
further forms of the coronavirus," Kreye adds. "This approach could
be relevant for the further development of vaccination strategies,
because the pathogen can be expected to keep changing in the future."
Partners in Research For the current studies, the DZNE research group lead
by Prof. Harald Pru"ss collaborated closely with the team of Dr. Victor
Corman at Charite''s Institute of Virology. Scripps Research in the US
was also significantly involved.

========================================================================== Story Source: Materials provided by DZNE_-_German_Center_for_Neurodegenerative_Diseases.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. S. Momsen Reincke, Meng Yuan, Hans-Christian Kornau, Victor
M. Corman et
al. SARS-CoV-2 Beta variant infection elicits potent
lineage-specific and cross-reactive antibodies. Science, Jan. 25,
2022; DOI: 10.1126/ science.abm5835 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220125112516.htm

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