RESEARCH | IN OTHER JOURNALS
sciencemag.org SCIENCEIMMUNOLOGY
Lymph node
mass transport
Cytokines are transported around
the body via a network of lymph
ducts and lymph nodes. Conduits
within lymph nodes convey cyto-
kines from the subcapsular sinus
(SCS) into the deep parenchyma.
From there, they discharge into
high endothelial venules. In the
SCS, sinus-lining cells prevent
molecules greater than 70 kilo-
daltons from entering conduits.
Nevertheless, Thierry et al. found
that the massive 970-kilodalton
pentamers of immunoglobulin M
antibodies can cross into con-
duits. Transport is mediated by
transient, activated, antigen-spe-
cific B cells, thus enabling rapid
mobilization of the first wave of
antibodies produced during an
acute infection. —STS
J. Exp. Med. 215 , 2972 (2018).
VIROLOGY
Revelation in the
gut virome
Some of the trillions of bacteria
in the human gut are beginning
to disclose their secrets. By
contrast, we know little about
the viruses other than that there
are even more of them and most
parasitize bacteria and other
microbiota. Guerin et al. system-
atically investigated fecal DNA
bacteriophages called crAss-
phages, which appear to infect
Bacteroidetes. These phages are
found in about half of individuals,
constitute 90% of fecal DNA,
and show differences in health
and disease (for example, in
malnourished infants). crAss-
phage genes tend not to match
known sequences, but, through
the use of a variety of methods
on almost 100 complete circular
genomes extracted from more
than 700 human gut microbiota,
four crAssphage subfamilies
were found, each composed of
10 genera and with short-tailed
icosahedral podovirus structures.
—CA
Cell Host Microbe 24 , 653 (2018).BIOORGANIC CHEMISTRY
Electrochemically
clicking on tyrosine
Proteins are readily modified
at lysine or cysteine residues,
but for the other amino acids,
general methods still need to
be developed. For example, for
electron-rich tyrosine, click
methods have been developed
based on cyclic diazodicarboxy-
amide anchors, but activation
with chemical oxidants can also
modify lysine residues or createproducts with limited aque-
ous stability. Alvarez-Dorta et
al. show that tyrosine residues
on proteins, including insulin
and bovine serum albumin, can
be targeted by electrochemi-
cally oxidizing phenyl urazoles
without affecting amine or thiol
groups of other amino acids. A
reactive N=N species gener-
ated in the five-membered ring
reacts with the C–H bonds
adjacent to the tyrosine OH
group. —PDS
J. Am. Chem. Soc. 140 , 17120 (2018).MATERIALS SCIENCE
Connecting the dots
Much of the power of chemistry
comes from the wide range of
methods that can be used to
connect atoms and molecules
selectively at desired posi-
tions. Colloidal nanoparticles
offer their own range of tunable
properties that can be enhanced
by connecting them together
into superstructures through
the bonding of their oligomeric
surface ligands. Chen et al.
developed a method using a
block copolymer and solvent
to selectively cover part of the
nanoparticles, creating a mask for
subsequent attachment of DNA.
The coverage of the particles can
be tuned by adjusting the ratio of
hydrophilic to hydrophobic ligand,because this changes the way the
ligands pack on the surface of the
nanoparticles. —MSL
Nat. Mater. 10.1038/
s41563-018-0231-1 (2018).DIVERSITY IN STEM
With role models come
persistence
Role model programs centered
on women and underrepresented
groups have been successful
for early career scientists, but
are they successful for under-
graduate students? Hernandez
et al. describe PROGRESS, a role
modeling and mentoring program
aimed at supporting undergradu-
ate women in the geosciences,
a historically male-dominated
field. PROGRESS participants
reported higher rates of per-
sistence in geoscience-related
majors, which was related to the
number of female STEM career
role models that they were able
to identify; participants’ odds of
persisting in geoscience approxi-
mately doubled for each role
model identified. The preliminary
evidence suggests that present-
ing undergraduate students with
successful female role models
can encourage undergraduates
to believe that they, too, can be
successful scientists. —MMc
Geosphere 14 , 2585 (2018).1374 21 DECEMBER 2018 • VOL 362 ISSUE 6421
Heat production by brown fat cells (shown)
might reduce appetite.IMAGE: STEVE GSCHMEISSNER/SCIENCE SOURCEPHYSIOLOGYTargeting brown fat to
make less fat
B
rown fat can release energy from
food as heat instead of storing it and
could thus help in battling obesity. Li
et al. found that after a meal, brown
fat in mice was stimulated to increase
thermogenesis by direct action of the gut
hormone secretin. The heat produced may be
detected by the brain and thus induce a sense
of satiety. This signaling relay may increase
energy expenditure and decrease appetite,
making it a potential target for therapies that
attempt to control obesity. —LBR
Cell 175 , 1561 (2018).Published by AAAS