SCIENCE science.org 14 JANUARY 2022 • VOL 375 ISSUE 6577 157-C
RESEARCHgravitational interaction with a
large mass (see the Perspective
by Roura). The authors state
that the observed phase shift is
consistent with a gravitational
Aharonov-Bohm effect. —ISO
Science, abl7152, this issue p. 226;
see also abm6854, p. 142
CORONAVIRUS
Immune imprinting
For severe acute respiratory
syndrome coronavirus 2 (SARS-
CoV-2), immune responses
to heterologous variants are
influenced by a person’s infec-
tion history. Healthcare workers
(HCWs) may be exposed to
several doses and types of anti-
gens, either by natural infection
or by vaccination. Reynolds et
al. studied a cohort of UK HCWs
followed since March 2020. The
immunological profiles of these
people depended on how often
the subject had encountered
antigen and which variant was
involved. Vaccine responses
after infection were found to
be less effective if the infection
involved heterologous spike from
a variant virus. Unfortunately,
the N501Y spike mutation,
found in many variants, seems
to induce the regulatory T cell
transcription factor FOXP3,
indicating that the virus could
subvert effective T cell function.
Changes to antibody binding
between variants also means
that serology data using the
Wuhan Hu-1 S1 receptor-binding
domain sequence may not be a
reliable measure of protection.
—CA
Science, abm0811, this issue p. 183
ECOLOGY
Seed dispersal in decline
Most plant species depend
on animals to disperse their
seeds, but this vital function is
threatened by the declines in
animal populations, limiting the
potential for plants to adapt to
climate change by shifting their
ranges. Using data from more
than 400 networks of seed
dispersal interactions, Fricke
et al. quantified the changes in
seed disposal function brought
about globally by defaunation.
Their analyses indicate that
past defaunation has severely
reduced long-distance seed dis-
persal, cutting by more than half
the number of seeds dispersed
far enough keep up with range
shifts caused by climate change.
In addition, their approach
enables the prediction of seed
dispersal interactions using spe-
cies traits and an estimation of
how these interactions translate
into ecosystem functioning, thus
informing ecological forecasting
and the consequences of animal
declines. —AMS
Science, abk3510, this issue p. 210ATHEROSCLEROSIS
Sniffing out
atherosclerosis
Olfactory receptors are best
known for their presence in the
nose and their role in detect-
ing smell s, but they are also
present in other tissues and
perform additional biological
functions. For example, vascular
macrophages involved in the
pathogenesis of atherosclerosis
express multiple subtypes of
olfactory receptors. Orecchioni
et al. focused on olfactory
receptor 2, a receptor for
the compound octanal, and
identified its contribution to ath-
erosclerosis pathogenesis and
the formation of atherosclerotic
plaques (see the Perspective
by Rayner and Rasheed). The
authors show that most of the
octanal was not directly derived
from the diet, but rather was
generated as a by-product of
lipid peroxidation, suggesting a
potential pathway for interven-
tion. —YN
Science, abg3067, this issue p. 214;
see also abn4708, p. 145REGENERATIVE MEDICINE
Exciting scaffolds
regenerate cartilage
Osteoarthritis is a common
condition, but curative therapies
are limited. Liu et al. developed
a biodegradable scaffold using
poly(L-lactic acid) (PLLA)
nanofibers that, when placed
under applied force, generated
a piezoelectric charge, leading
to improved chondrogenesis in
vitro. Rabbits with osteochondral
defects in the medial femoral
condyle that were treated with
the PLLA scaffold demonstrated
improved cartilage regeneration
and subchondral bone regen-
eration after 1 or 2 months of
exercise to generate piezo-
electric charge from the joint
loads. Although further work is
needed to optimize the scaffold
microstructure and components,
this study provides evidence
that biodegradable piezoelectric
scaffolds can use joint-loading
exercise to treat osteoarthritis.
—MN
Sci. Transl. Med. 13 , eabi7282 (2022).CELL BIOLOGY
Redox control of GPCR
desensitization
Activated G protein–coupled
receptors (GPCRs) undergo
internalization and desensitiza-
tion. Nishiyama et al. identified
a mechanism through which
electrophilic compounds
modified the purinergic receptor
P2Y 6 R, leading to ubiquitylation,
receptor internalization, and
proteasomal degradation. Mice
expressing a form of P2Y 6 R that
could not be electrophilically
modified were more susceptible
to experimentally induced colitis.
The positions of these cysteine
and lysine residues were con-
served in several other GPCRs,
suggesting that this mechanism
of desensitization may be shared
by other GPCRs. —AMV
Sci. Signal. 15 , eabj0644 (2022).