REPU MAGAZINE N 3
2015 REPU Research Projects
2017
Brenda D’Acunha - Vanderbilt University
Marnett Laboratory, USA
Fever, pain and inflammation are immune responses that are induced by
a series of cell-specific prostaglandins that come from prostaglandin H2
(PGH2) as part of the oxygenation process of arachidonate, catalyzed by
the cyclooxygenase (COX) enzymes. There are two COX isoforms:
COX-1 and COX-2, being the last one only induced at sites of tissue
damage and infection and able to generate prostaglandins that mediate
these processes. Because of its biological roles, its inhibition is the main
objective of many pharmaceutical industries, especially for the treatment
of chronic diseases like cancer, arthritis and Crohn's disease. A properly
designed drug should be specific (block only COX-2 and not COX-1) and
also potent. In order to achieve this, there is a need to study the structure
of the COX-2 enzyme and its interactions with different substrates to
completely understand the mechanism of action and to learn which are
the desirable chemical characteristics in the drugs in order to block this
enzyme. As part of these efforts, Brenda investigated the substrate selective activation and inhibition of
endocannabinoid oxygenation by COX-2. She worked, specifically, with two enzymes that had mutations at
the interphase between the two subunits (COX-2 is a heterodimer).
*Update: Brenda is currently a PhD student at University of British Columbia
Daisy Unsihuay - University of Navarra
Microbiology and Parasitology Laboratory, Spain
Shigellosis is one of the leading causes of diarrhea worldwide. Each year,
160 million new cases of shigellosis are reported in the world, which
causes approximately 1.5 million deaths. Thus, the need of an effective
vaccine is still a priority. Previous studies showed the capacity of outer
membrane vesicles (OMVs) to protect mice against an experimental
infection with Shigella flexneri. Further studies, showed the capacity of the
antigenic complex to confer a long-term protection by oral or nasal routes
when encapsulated into nanoparticles. Daisy worked in the Microbiology
and Parasitology lab of Universidad de Navarra in the synthesis of an Ipa-
enriched antigenic extract. Ipa proteins are adhesin proteins known to be
involved in bacterial invasion of intestinal epithelial cells. Secretion of
these proteins in the extract was stimulated by the presence of bile salt
deoxycholate (DOC) and Congo Red (RC) dye to simulate physiological
conditions. The RC/DOC extract was characterized by SDS-PAGE,
Western blot, KDO and Lowry tests. Data generated by Daisy suggest the presence of various adhesin
proteins such as IpaB, iPaD, OspG, OspE in the RC/DOC extract that could enhance the interaction of the
antigen complex with the mucosa and trigger a higher immune response.
*Update: Daisy is currently a PhD student at Purdue University.
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