Research Profile - College of Medicine and Health Science - United ...

Department of Medical Microbiology & Immunology
effective in inhibiting the growth of malignant
melanoma. They have also shown that this form
of immunotherapy is active when given orally,
which is of significant benefit as it decreases
the toxicity often associated with systemic
cytokine therapies. The exact mechanism(s) by
which recombinant Salmonella strains inhibit
tumor growth are not yet fully known. However,
evidence to date indicates that the process is
independent of T lymphocytes but is dependent
on Toll-like receptors (TLRs), implying a critical
role for the innate immune response in the antitumor
effect. A report describing the
experimental model system and findings was
published recently in Clinical Immunology
130:89-97, 2009 (Figure 1).
Professor Senarath Dissanayake - Dr.
Dissanayake’s research interests are in parasite
glycan immunobiology and tuberculosis.
Current emphasis in glycan immunobiology is
on molecular characterization of parasite
glycans with respect to upregulation of the
transcription factor NF-kB and signaling effects
and mechanisms leading to IFN-g and IL-6
expression (Figure 2). With respect to IFN-Á,
one specific area of research is negative
regulation of TLR signaling. Long-term objective
is development of synthetic immunoadjuvants
with defined Th-1 and Th-2 immunomodulatory
properties. Based on the previous finding that
terminal ‚-(1-4) galactose residues on GlcNAc
backbones is an epitope regulating IFN-Á (a Th-
1 cytokine), a panel of synthetic glycans is being
investigated for further development as
adjuvants. In tuberculosis research,
epidemiological studies are being carried out to
determine the source(s) of infection, patterns of
transmission and the possible causes of likely reactivation
in long-term residents of UAE.
Figure 1: Treatment of B16 melanoma-bearing mice with
multiple low doses of IL2-expressing Salmonella
typhimurium (strain GIDIL2) prolongs host survival and
inhibits tumor growth. Tumor-bearing mice were given three
i.p. injections at the indicated days (arrows) of either saline
or low doses (103-104 per mouse) of the GIDIL2 strain. Tumor
volume (A) and animal survival (B) were then followed over
the next 60 day s. Each data point represents the mean ±
SEM of 8–10 mice per group. Asterisks denote statistically
significant differences from saline control group (***, p <
0.001; **, p