Sasirekha Ramani, PhD
Assistant Professor of Molecular Virology and Microbiology,
Baylor College of Medicine, Houston, Texas, USA
Despite the introduction of vaccines,
rotavirus remains a leading cause of severe,
dehydrating gastroenteritis in children under
the age of five. Recent work from our
laboratory and others have demonstrated
that genetically regulated differences in
histo-blood group antigen (HBGA) glycan
expression affect susceptibility to infection
with different human rotavirus strains, including
vaccine viruses. Since structural analogs to
cell surface glycans are present in breast milk,
we asked: How do HMOs in breast milk affect
rotavirus infectivity, particularly in neonates?
Using a multidisciplinary translational science
approach involving virologists, structural
biologists, glycobiologists, physicians,
and epidemiologists, we are testing the
hypothesis that complex interactions between
intestinal glycan expression during neonatal
development and both the breast milk
microbiome and HMOs affect susceptibility
to neonatal rotavirus infections. Our studies
are primarily carried out with a bovine-human
reassortant rotavirus strain G10P[11] that almost
exclusively infects neonates in India.
Recently, we have begun utilizing a new
model of the human gastrointestinal epithelium
to answer fundamental questions on how
bioactive components in breast milk affect
rotavirus infectivity. Advances in the field
of stem cell biology have facilitated the
development of non-transformed, human
intestinal epithelial cultures called HIEs
that recapitulate many biological and
physiological properties of the human small
intestine. We are currently using HIEs to
understand the molecular basis of rotavirus-
HMO interactions. Our present studies serve as
a foundation for future work on understanding
the effect of breast milk components on
clinically relevant rotavirus strains and
vaccines, as well as other enteric pathogens
for which glycans are critical for infection.