Piecing together the Plasmodium falciparum genome puzzle : characterization of genes/proteins, PFE0565w and PF11_0394

Title from PDF of title page (University of Missouri--Columbia, viewed on June 4, 2012).The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Dissertation advisor: Dr. Brenda T. BeerntsenVita.Ph. D. University of Missouri-Columbia 2011."December 2011"Malaria is still a significant problem around the world and, thus, better control methods are in great need. A key stage in the Plasmodium life cycle is the sporozoite because it exhibits dual infectivity in both the mosquito vector and vertebrate host and, therefore, is a promising target for discovering effective ways of controlling malaria. The P. falciparum genes, PFE0565w and PF11_0394, were chosen as candidates for study based on data available on PlasmoDB, the Plasmodium database, indicating that they are expressed both at the transcriptional and protein levels in sporozoites and likely encode putative surface proteins. Transcripts of both PFE0565w and PF11_0394 are present in both mosquito and vertebrate host life cycle stages, but both of their proteins are specific to salivary gland sporozoites as shown by immunofluorescent assays and/or GFP-trafficking studies. Functional studies for PFE0565w are currently in progress to determine if it may play a role in parasite development and/or invasion of host tissues. Because PFE0565w and PF11_0394 do not have homology with any human proteins, they could be targets for new drugs and/or vaccines. Lastly, in addition to studies conducted with P. falciparum, a preliminary comparative study between the P. berghei orthologs of PFE0565w and PF11_0394, PBANKA_111090 and PBANKA_091050, respectively, was conducted.Includes bibliographical reference

Selective migration of neuralized embryonic stem cells to stem cell factor and media conditioned by glioma cell lines

BACKGROUND: Pluripotent mouse embryonic stem (ES) cells can be induced in vitro to become neural progenitors. Upon transplantation, neural progenitors migrate toward areas of damage and inflammation in the CNS. We tested whether undifferentiated and neuralized mouse ES cells migrate toward media conditioned by glioma cell lines (C6, U87 & N1321) or Stem Cell Factor (SCF). RESULTS: Cell migration assays revealed selective migration by neuralized ES cells to conditioned media as well as to synthetic SCF. Migration of undifferentiated ES cells was extensive, but not significantly different from that of controls (Unconditioned Medium). RT-PCR analysis revealed that all the three tumor cell lines tested synthesized SCF and that both undifferentiated and neuralized ES cells expressed c-kit, the receptor for SCF. CONCLUSION: Our results demonstrate that undifferentiated ES cells are highly mobile and that neural progenitors derived from ES cells are selectively attracted toward factors produced by gliomas. Given that the glioma cell lines synthesize SCF, SCF may be one of several factors that contribute to the selective migration observed

Transcript and protein expression profile of PF11_0394, a Plasmodium falciparum protein expressed in salivary gland sporozoites

<p>Abstract</p> <p>Background</p> <p><it>Plasmodium falciparum </it>malaria is a significant problem around the world today, thus there is still a need for new control methods to be developed. Because the sporozoite displays dual infectivity for both the mosquito salivary glands and vertebrate host tissue, it is a good target for vaccine development.</p> <p>Methods</p> <p>The <it>P. falciparum </it>gene, <it>PF11_0394</it>, was chosen as a candidate for study due to its potential role in the invasion of host tissues. This gene, which was selected using a data mining approach from PlasmoDB, is expressed both at the transcriptional and protein levels in sporozoites and likely encodes a putative surface protein. Using reverse transcription-polymerase chain reaction (RT-PCR) and green fluorescent protein (GFP)-trafficking studies, a transcript and protein expression profile of PF11_0394 was determined.</p> <p>Results</p> <p>The PF11_0394 protein has orthologs in other <it>Plasmodium </it>species and Apicomplexans, but none outside of the group Apicomplexa. <it>PF11_0394 </it>transcript was found to be present during both the sporozoite and erythrocytic stages of the parasite life cycle, but no transcript was detected during axenic exoerythrocytic stages. Despite the presence of transcript throughout several life cycle stages, the PF11_0394 protein was only detected in salivary gland sporozoites.</p> <p>Conclusions</p> <p>PF11_0394 appears to be a protein uniquely detected in salivary gland sporozoites. Even though a specific function of PF11_0394 has not been determined in <it>P. falciparum </it>biology, it could be another candidate for a new vaccine.</p