Science - USA (2021-12-10)

for miniaturized and minimally
invasive 3D endoscopic imaging
applications. —ISO
Science, abl3771, this issue p. 1395

CANCER

Chimeric costimulation
Improving chimeric antigen
receptor (CAR) T cell therapy is
essential for avoiding relapses
in patients with hematological
cancers. To address common
mediators of relapse, Katsarou
et al. developed chimeric
costimulatory receptors,
which bind to a second tumor-
associated antigen and provide
intracellular signaling to sup-
port CAR T cell activation. The
authors observed increased
tumor cell killing in vitro and in
vivo, even against tumor cells
with very low antigen density,
and this was associated with
improved CAR T cell persis-
tence. —CSM
Sci. Transl. Med. 13 , eabh1962 (2021).

FOREST ECOLOGY

Resilient secondary

tropical forests?

Although deforestation is
rampant across the tropics,
forest has a strong capacity to
regrow on abandoned lands.
These “secondary” forests may
increasingly play important
roles in biodiversity conserva-
tion, climate change mitigation,
and landscape restoration.
Poorter et al. analyzed the

CELL BIOLOGY

Taking a sip

from the lumen

The gut continuously samples its

contents for potentially harmful

substances. Intestinal goblet

cells help to maintain the gut

epithelium by secreting mucus.

These cells also help to moni-

tor the gut lumen by forming

so-called goblet cell–associ-

ated antigen passages. In mice,

Gustafsson et al. used high-res-

olution imaging approaches to

show that gut luminal contents

were transcytosed across goblet

cells. Endocytosed material was

also delivered in a more con-

ventional fashion to endosomes

and lysosomes. Acetylcholine

triggered both endocytosis and

goblet cell mucus secretion;

however, both processes could

be independently modulated to

balance the needs of intesti-

nal barrier maintenance and

immune sampling of the gut

contents. —SMH

eLife 10 , e67292 (2021).

FOREST ECOLOGY

Drying reduces tropical

tree growth

Long-term climate changes

and climate extremes can

reduce tree growth and limit

potential carbon sequestration

by forests. Bauman et al. used

demographic data from 23 sites

over 49 years to disentangle the

effects of mean and anoma-

lous climate conditions on tree

growth in Australia’s tropical

forests. They found that trees

in warmer (low-elevation) sites

patterns of recovery in forest

attributes (related to soil, plant

functioning, structure, and

diversity) in 77 secondary forest

sites in the Americas and West

Africa. They found that different

attributes recovered at different

rates, with soil recovering in

less than a decade and species

diversity and biomass recover-

ing in little more than a century.

The authors discuss how these

findings can be applied in

efforts to promote forest resto-

ration. —AMS

Science, abh3629, this issue p. 1370

NEUROSCIENCE

Insight into brain repair

One approach to enhancing

cellular regeneration in the

brain is to exploit the molecular

mechanisms used by the juve-

nile brain when regeneration

potential is high. Bayin et al.

found that irradiation injury in

the neonatal cerebellum causes

a progenitor cell that usually

makes glial cells to instead

switch its potential and make

neurons. Single-cell sequenc-

ing implicated the transcription

factor Ascl1 as the factor that

controls this switch in potential,

and the switch did not occur in

the absence of Ascl1. This study

provides new insight into the

plasticity potential of the juve-

nile brain and potential targets

to enhance regeneration after

injury. — NJA

S c i. Ad v. 10.1126/

sciadv.abj1598 (2021).

PHOTOS: (LEFT TO RIGHT AMAZONIMAGES/ALAMY STOCK PHOTO; IMAGEBROKER/ALAMY STOCK PHOTO

1336 10 DECEMBER 2021 • VOL 374 ISSUE 6573

Forests such as this secondary tropical forest along the Amazon River near Iquitos,
Peru, can recover some, but not all, old-growth attributes quickly.

IN OTHER JOURNALS

Edited by Caroline Ash

and Jesse Smith

RESEARCH | IN SCIENCE JOURNALS

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