Cerebral Malaria Associated Neurological Disorders In India
Jonathan K Stiles, Associate Professor
Morehouse School Of Medicine 720 Westview Dr Sw Atlanta, Ga 30310
Grant 3R21TW006804-02S1 from Fogarty International Center IRG: ZNS1
Abstract: Plasmodium falciparum is the most common parasite to infect central nervous system and the leading cause of diffuse encephalopathy in young children. This encephalopathy is associated with 10-14% of mortality with an estimated annual death of 1-2.5 million annual deaths. P. falciparum is the most lethal species among the four human malaria parasites (P. falciparum, P. vivax, P. malariae, P. ovae) and it has been estimated that it infects 300-500 million people per year. About 1% of all cases of falciparum malaria results in cerebral malaria and thus affects central nervous system at least in 3 million people especially young children. In the absence of effective vaccine to protect against malaria coupled with the increasing anti-malaria drug resistance globally, malaria is re-emerging as a major public health threat in the tropics and subtropics. Most of the studies conducted to date to understand the long and short term effects of malaria on brain and brain function have focused largely on malaria-induced gross neurological defects but very little data is available on the impact of this disease on learning cognitive function and neuro-psychology. Previous studies in our laboratory using human post mortem brain and serum samples from West Africa indicated that RANTES and corresponding receptors CCR1, CCR3, and CCR5, play a very important role in brain immunopathogenesis that may result in neurological impairment or dysfunction. We hypothesize that cerebral malaria induces neurological impairment and reduces cognitive function. A corollary to this hypothesis is that this neurological impairment is mediated by immunopathogenesis. We propose a multidisciplinary international partnership involving Morehouse School of Medicine, Centers of Disease Control and the Medical Research Center (ICMR), Jabalpur, India to address the role of immunopathogenesis in malaria-induced neurological impairment following P. falciparum malaria in a population most affected by malaria in the sub-continent of India. The first specific aim will conduct preliminary retrospective and prospective epidemiological investigations to assess the extent of long-term neurological impairment associated with CM caused by P. falciparum in central India where falciparum malaria i s widespread. The second specific aim will conduct preliminary investigations to determine the potential immunopathological factors associated with neurological impairment after recovery from cerebral malaria. This proposal will pursue epidemiology and molecular immunology of cerebral malaria as well as capacity building in India. Data from the proposed research will reveal t he molecular basis of cerebral malaria induced neurological and cognitive impairment.
Keywords: India, central nervous system disorder, cerebral cortex, cognition disorder, encephalography, immunopathology, malaria, medical complication, arthropod borne communicable disease, chemokine, cooperative study, cytokine receptor, learning disorder, longitudinal human study, nervous system disorder epidemiology, neuropsychology, receptor expression, Plasmodium falciparum, blood chemistry, clinical research, enzyme linked immunosorbent assay, human subject, microarray technology, polymerase chain reaction, proteomics, statistics /biometry
Project start date: 2003-09-28
Project end date: 2008-02-28
3R21TW006804-02S1 (2005): $71000
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Jonathan K Stiles
CEREBRAL MALARIA-INDUCED APOPTOSIS AND BRAIN PATHOLOGY
Jonathan K Stiles, Dr
Morehouse School Of Medicine, 720 Westview Dr Sw, Atlanta, Ga 30310
Abstract: This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Malaria (P. falciparum) infects 200 to 300 million people globally and kills 2 million (mostly children) every year. 15% of fatal cases are due to cerebral malaria (CM) and other severe forms of malaria. A significant segment of CM patients die regardless of recommended treatment. A significant number of survivors develop neurological complications and cognition problems. The precise mechanisms responsible for CM induced brain damage and poor prognosis is unclear. The hypothesis is that Plasmodium apoptotic factor(s) (PAF) induce neuronal and microvascular endothelial cell apoptosis and that selectively blocking PAF mediated apoptosis will negate or significantly reduce apoptosis and CM-induced pathology. Our objective was to identify and characterize the role of PAF in CM-induced brain pathology using human brain endothelial (HBVEC), glial, and neuronal cell lines, as well as our established rodent CM model respectively. We utilized genomics, proteomics, immunological methods, imaging techniques, ultrastructural analysis, and targeted gene inactivation (RNA interference, RNAi) to pursue these goals
Keywords: 0-11 years old; Acquired brain injury; Apoptosis; Apoptosis Pathway; Apoptotic; Biomedical Research; Brain; Brain Injuries; Brain Pathology; CRISP; Cell Death, Programmed; Cell Line; Cell Lines, Strains; CellLine; Cerebral Malaria; Child; Child Youth; Children (0-21); Cognition; Computer Retrieval of Information on Scientific Projects Database; Encephalon; Encephalons; Endothelial Cells; Forecast of outcome; Funding; Gene Inactivation; Gene Silencing; Genomics; Goals; Grant; Human; Human, Child; Human, General; Imaging Procedures; Imaging Techniques; Institution; Investigators; Killings; Malaria; Mammals, Rodents; Man (Taxonomy); Man, Modern; Mediating; Methods; Modeling; NIH; National Institutes of Health; National Institutes of Health (U.S.); Nerve Cells; Nerve Unit; Nervous System, Brain; Neural Cell; Neurocyte; Neurologic; Neurological; Neurons; Paludism; Pathology; Patients; Plasmodium; Plasmodium Infections; Plasmodium falciparum; Post-Transcriptional Gene Silencing; Post-Transcriptional Gene Silencings; Posttranscriptional Gene Silencing; Posttranscriptional Gene Silencings; Prognosis; Proteomics; Quelling; RNA Interference; RNA Silencing; RNA Silencings; RNAi; Research; Research Personnel; Research Resources; Researchers; Resources; Rodent; Rodentia; Rodentias; Role; Sequence-Specific Posttranscriptional Gene Silencing; Source; Survivors; Technics, Imaging; United States National Institutes of Health; brain damage; brain lesion (from injury); children; cultured cell line; neuronal; outcome forecast; social role; youngster
Project start date: 2009-06-01
Project end date: 2010-05-31
Budget start date: 1-JUN-2009
Budget end date: 31-MAY-2010
5G12RR003034-24_5388 (2009): $112959
Cerebral Malaria Associated Neurological Disorders In India
Jonathan K Stiles, Associate Professor
Morehouse School Of Medicine 720 Westview Dr Sw Atlanta, Ga 30310
Grant 5R21TW006804-02 from Fogarty International Center IRG: ZNS1
Abstract: Plasmodium falciparum is the most common parasite to infect central nervous system and the leading cause of diffuse encephalopathy in young children. This encephalopathy is associated with 10-14% of mortality with an estimated annual death of 1-2.5 million annual deaths. P. falciparum is the most lethal species among the four human malaria parasites (P. falciparum, P. vivax, P. malariae, P. ovae) and it has been estimated that it infects 300-500 million people per year. About 1% of all cases of falciparum malaria results in cerebral malaria and thus affects central nervous system at least in 3 million people especially young children. In the absence of effective vaccine to protect against malaria coupled with the increasing anti-malaria drug resistance globally, malaria is re-emerging as a major public health threat in the tropics and subtropics. Most of the studies conducted to date to understand the long and short term effects of malaria on brain and brain function have focused largely on malaria-induced gross neurological defects but very little data is available on the impact of this disease on learning cognitive function and neuro-psychology. Previous studies in our laboratory using human post mortem brain and serum samples from West Africa indicated that RANTES and corresponding receptors CCR1, CCR3, and CCR5, play a very important role in brain immunopathogenesis that may result in neurological impairment or dysfunction. We hypothesize that cerebral malaria induces neurological impairment and reduces cognitive function. A corollary to this hypothesis is that this neurological impairment is mediated by immunopathogenesis. We propose a multidisciplinary international partnership involving Morehouse School of Medicine, Centers of Disease Control and the Medical Research Center (ICMR), Jabalpur, India to address the role of immunopathogenesis in malaria-induced neurological impairment following P. falciparum malaria in a population most affected by malaria in the sub-continent of India. The first specific aim will conduct preliminary retrospective and prospective epidemiological investigations to assess the extent of long-term neurological impairment associated with CM caused by P. falciparum in central India where falciparum malaria i s widespread. The second specific aim will conduct preliminary investigations to determine the potential immunopathological factors associated with neurological impairment after recovery from cerebral malaria. This proposal will pursue epidemiology and molecular immunology of cerebral malaria as well as capacity building in India. Data from the proposed research will reveal t he molecular basis of cerebral malaria induced neurological and cognitive impairment.
Keywords: India, central nervous system disorder, cerebral cortex, cognition disorder, encephalography, immunopathology, malaria, medical complication, arthropod borne communicable disease, chemokine, cooperative study, cytokine receptor, learning disorder, longitudinal human study, nervous system disorder epidemiology, neuropsychology, receptor expression, Plasmodium falciparum, blood chemistry, clinical research, enzyme linked immunosorbent assay, human subject, microarray technology, polymerase chain reaction, proteomics, statistics /biometry
Project start date: 2003-09-28
Project end date: 2008-02-28
5R21TW006804-02 (2004): $142000
Cerebral Malaria Neurological Disorders In India
Jonathan K Stiles, Associate Professor
Morehouse School Of Medicine 720 Westview Dr Sw Atlanta, Ga 30310
Grant 1R21TW006804-01 from Fogarty International Center IRG: ZNS1
Abstract: Plasmodium falciparum is the most common parasite to infect central nervous system and the leading cause of diffuse encephalopathy in young children. This encephalopathy is associated with 10-14% of mortality with an estimated annual death of 1-2.5 million annual deaths. P. falciparum is the most lethal species among the four human malaria parasites (P. falciparum, P. vivax, P. malariae, P. ovae) and it has been estimated that it infects 300-500 million people per year. About 1% of all cases of falciparum malaria results in cerebral malaria and thus affects central nervous system at least in 3 million people especially young children. In the absence of effective vaccine to protect against malaria coupled with the increasing anti-malaria drug resistance globally, malaria is re-emerging as a major public health threat in the tropics and subtropics. Most of the studies conducted to date to understand the long and short term effects of malaria on brain and brain function have focused largely on malaria-induced gross neurological defects but very little data is available on the impact of this disease on learning cognitive function and neuro-psychology. Previous studies in our laboratory using human post mortem brain and serum samples from West Africa indicated that RANTES and corresponding receptors CCR1, CCR3, and CCR5, play a very important role in brain immunopathogenesis that may result in neurological impairment or dysfunction. We hypothesize that cerebral malaria induces neurological impairment and reduces cognitive function. A corollary to this hypothesis is that this neurological impairment is mediated by immunopathogenesis. We propose a multidisciplinary international partnership involving Morehouse School of Medicine, Centers of Disease Control and the Medical Research Center (ICMR), Jabalpur, India to address the role of immunopathogenesis in malaria-induced neurological impairment following P. falciparum malaria in a population most affected by malaria in the sub-continent of India. The first specific aim will conduct preliminary retrospective and prospective epidemiological investigations to assess the extent of long-term neurological impairment associated with CM caused by P. falciparum in central India where falciparum malaria i s widespread. The second specific aim will conduct preliminary investigations to determine the potential immunopathological factors associated with neurological impairment after recovery from cerebral malaria. This proposal will pursue epidemiology and molecular immunology of cerebral malaria as well as capacity building in India. Data from the proposed research will reveal t he molecular basis of cerebral malaria induced neurological and cognitive impairment.
Keywords: India, central nervous system disorder, cerebral cortex, cognition disorder, encephalography, immunopathology, malaria, medical complication, arthropod borne communicable disease, chemokine, cooperative study, cytokine receptor, learning disorder, longitudinal human study, nervous system disorder epidemiology, neuropsychology, receptor expression, Plasmodium falciparum, blood chemistry, clinical research, enzyme linked immunosorbent assay, human subject, microarray technology, polymerase chain reaction, proteomics, statistics /biometry
Project start date: 2003-09-28
Project end date: 2005-02-28
1R21TW006804-01 (2003): $142000
Targeting Trypanosome Cation Pumps And Channels
Jonathan K Stiles, Associate Professor
Morehouse School Of Medicine 720 Westview Dr Sw Atlanta, Ga 30310
Grant 2S06GM008248-200063 from National Institute Of General Medical Sciences IRG: MPRC
Abstract: Human African Trypanosomiasis (HAT, sleeping sickness) is a neglected but fatal vector borne disease caused by Trypanosoma brucei ssp. (T. brucei). Sixty million people are at risk of infection with HAT, and 50,000 new case s and an equal number of deaths are reported annually in subsaharan Africa. The only available anti-trypanosomal drugs on the market are extremely toxic, and result in post-treatment encephalopathy in treated patients. The ideal anti-trypanosomal agents will target vital physiological processes and/or non-variant parasite-derived molecules without adversely affecting the human host. We and others have shown that that cytosolic calcium ion concentration [Ca2+ ]i in blood stages of T. brucei is 4- 10 orders of magnitude below that encountered in host extracellular milieu and that parasites require effective mechanisms to maintain [Ca2+ ] homeostasis, survival, and proliferation in their host. In our previous grant, we identified and characterized two key plasma-membrane-like cation pumps (ATPases; TBCA1 and TBCA2) utilized by T. brucei for survival and generated antibodies to immunolocalize them in bloodstage and insect stage parasites. We determined their functional role in insect and bloodstage parasites using transient RNAi inhibition technology and synthetic inhibitor assays. We subsequently constructed recombinant anti-pump vaccines based on a novel bacterial ghost vaccine delivery technology, developed at Morehouse School of Medicine, which partially protected against parasite challenge in mice. Our results revealed that TBCA1 resembled a fungal K+/Na+-ATPase while TBCA2 was a plasma-membrane-like Ca2+ ATPase. RNAi inhibition of these targets resulted in increased parasite mortality. Furthermore, we determined by inhibition studies that Ca2+ homeostasis in T. brucei is not only regulated by the Ca2+ ATPases but also by L-type calcium ion channels. Since targeting the Ca2+ pumps by RNAi inhibition increased parasite mortality and vaccination with TBCA2 significantly reduced parasitemia and survival of infected mice, we propose that targeting the key cation pumps (TBCA1 and TBCA2) as well as L-type Ca2+ channels together with either synthetic inhibitor drugs or vaccines, will be sufficient to inhibit proliferation of T. brucei and provide complete protection against T. brucei infection. In this competitive renewal proposal, we have gone a step further to hypothesize that trypanosomes utilize cation pumps and channels to mediate establishment in mammalian host blood and that simultaneous inhibition by target specific drugs and blocking by vaccination will prevent T. brucei proliferation and development. Two specific aims are proposed In Specific aim 1. we will functionally characterize and localize the L-type Ca2+ channel in T. brucei and determine its role in Ca2+ homeostasis. In Specific aim 2. we will construct and test various Ca2+ pump/channel gene constructs as antigens in a novel bacterial ghost based vaccine system against infections by T. brucei and determine their levels of protection against T. brucei infection. Our longterm goal is to build on our established proof of principle to develop and deliver a novel class of small molecule drugs and/or immunotherapeutics capable of inhibiting the essential Ca2+ pumps and channels of T. brucei during development. We also plan to generate enough data, through this application, to apply for an RQ-1 type grant to fund future studies on anti-trypanosome drugs.
Keywords: Trypanosoma brucei, antiprotozoal agent, calcium channel, cation, drug design /synthesis /production, host organism interaction, membrane transport protein, trypanosomiasis, vaccine development, communicable disease control, drug screening /evaluation, immunotherapy, inhibitor /antagonist, parasitism, vaccine evaluation, laboratory mouse
Project start date: 2006-08-01
Project end date: 2010-07-31
TARGETING TRYPANOSOME CATION PUMPS AND CHANNELS IN TRYPANOSOMIASIS CONTROL
Jonathan K Stiles, Dr
Morehouse School Of Medicine, 720 Westview Dr Sw, Atlanta, Ga 30310
Grant 5S06GM008248-23_0063 from National Institute Of General Medical Sciences
Abstract: Human African Trypanosomiasis (HAT, sleeping sickness) is a neglected but fatal vector borne disease caused by Trypanosoma brucei ssp. (T. brucei). Sixty million people are at risk of infection with HAT, and 50,000 new case´s and an equal number of deaths are reported annually in subsaharan Africa. The only available anti-trypanosomal drugs on the market are extremely toxic, and result in post-treatment encephalopathy in treated patients. The ideal anti-trypanosomal agents will target vital physiological processes and/or non-variant parasite-derived molecules without adversely affecting the human host. We and others have shown that that cytosolic calcium ion concentration [Ca2+ ]i in blood stages of T. brucei is 4- 10 orders of magnitude below that encountered in host extracellular milieu and that parasites require effective mechanisms to maintain [Ca2+ ] homeostasis, survival, and proliferation in their host. In our previous grant, we identified and characterized two key plasma-membrane-like cation pumps (ATPases; TBCA1 and TBCA2) utilized by T. brucei for survival and generated antibodies to immunolocalize them in bloodstage and insect stage parasites. We determined their functional role in insect and bloodstage parasites using transient RNAi inhibition technology and synthetic inhibitor assays. We subsequently constructed recombinant anti-pump vaccines based on a novel bacterial ghost vaccine delivery technology, developed at Morehouse School of Medicine, which partially protected against parasite challenge in mice. Our results revealed that TBCA1 resembled a fungal K+/Na+-ATPase while TBCA2 was a plasma-membrane-like Ca2+ ATPase. RNAi inhibition of these targets resulted in increased parasite mortality. Furthermore, we determined by inhibition studies that Ca2+ homeostasis in T. brucei is not only regulated by the Ca2+ ATPases but also by L-type calcium ion channels. Since targeting the Ca2+ pumps by RNAi inhibition increased parasite mortality and vaccination with TBCA2 significantly reduced parasitemia and survival of infected mice, we propose that targeting the key cation pumps (TBCA1 and TBCA2) as well as L-type Ca2+ channels together with either synthetic inhibitor drugs or vaccines, will be sufficient to inhibit proliferation of T. brucei and provide complete protection against T. brucei infection. In this competitive renewal proposal, we have gone a step further to hypothesize that trypanosomes utilize cation pumps and channels to mediate establishment in mammalian host blood and that simultaneous inhibition by target specific drugs and blocking by vaccination will prevent T. brucei proliferation and development. Two specific aims are proposed In Specific aim 1. we will functionally characterize and localize the L-type Ca2+ channel in T. brucei and determine its role in Ca2+ homeostasis. In Specific aim 2. we will construct and test various Ca2+ pump/channel gene constructs as antigens in a novel bacterial ghost based vaccine system against infections by T. brucei and determine their levels of protection against T. brucei infection. Our longterm goal is to build on our established proof of principle to develop and deliver a novel class of small molecule drugs and/or immunotherapeutics capable of inhibiting the essential Ca2+ pumps and channels of T. brucei during development. We also plan to generate enough data, through this application, to apply for an RQ-1 type grant to fund future studies on anti-trypanosome drugs
Keywords: 3, 5-Pyridinedicarboxylic acid, 1, 4-dihydro-2, 6-dimethyl-4-(2-nitrophenyl)-, dimethyl ester; 3, 5-Pyridinedicarboxylic acid, 1, 4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl)-, 2-methoxyethyl 1-methylethyl ester; ATGN; ATP phosphohydrolase; ATP phosphohydrolase (Ca(2+)-transporting); ATP phosphohydrolase (Na+ K+ transporting); ATPase; Acocantherin; Acolongifloroside K; Adalat; Adenosine Triphosphatase; Adenosine Triphosphatase, Calcium; Adenosinetriphosphatase; Affect; Africa South of the Sahara; African Sleeping Sickness; African Trypanosomiasis; After Care; After-Treatment; Aftercare; Amino Acids; Anti-Malarials; Antibodies; Antigen Variation; Antigenic Variability; Antigenic Variation; Antigens; Antimalarial Agents; Antimalarial Drugs; Antimalarials; Architecture; Artemisinins; Assay; Autoregulation; Bacteria; Bayer Brand of Nimodipine; Benzeneacetonitrile, alpha-(3-((2-(3, 4-dimethoxyphenyl)ethyl)methylamino)propyl)-3, 4-dimethoxy-alpha-(1-methylethyl)-; Bioassay; Biologic Assays; Biological Assay; Blood; Blood Coagulation Factor IV; Ca(2+)-Transporting ATPase; Ca++ element; Ca2+ ATPase; Ca2+ transporting ATPase; Calcium; Calcium ATPase; Calcium Adenosinetriphosphatase; Calcium Channel; Calcium Channel Antagonist Receptor; Calcium Pump; Calcium ion; Cancer of Prostate; Card-20(22)-enolide, 3-((6-deoxy-alpha-L-mannopyranosyl)oxy)-1, 5, 11, 14, 19-pentahydroxy-, (1beta, 3beta, 5beta, 11alpha)-; Cation Pumps; Cations; Cell membrane; Cessation of life; Coagulation Factor IV; Cytoplasmic Membrane; Data; Death; Development; Drugs; Encephalopathies; Engineering / Architecture; Factor IV; Funding; Future; G-Strophanthin; Generalized Growth; Genes; Genome; Goals; Grant; Growth; Homeostasis; Human; Human, General; ITX; Immune system; Immunologically Directed Therapy; Immunotherapeutic agent; Immunotherapy; In Vitro; Infection; Insecta; Insects; Intermediary Metabolism; Invertebrates, Insects; Ion Channels, Calcium; Ion Pumps; Iproveratril; Laboratories; Location; METBL; Malignant Cell; Malignant Tumor of the Prostate; Malignant neoplasm of prostate; Malignant prostatic tumor; Mammals, Mice; Man (Taxonomy); Man, Modern; Marketing; Mediating; Medication; Membrane; Membrane Proteins; Membrane-Associated Proteins; Messenger RNA; Metabolic Processes; Metabolism; Mice; Morphology; Mortality; Mortality Vital Statistics; Murine; Mus; Na(+)-K(+)-Exchanging ATPase; Na(+)-K(+)-Transporting ATPase; Na+ K+ ATPase; Nifedipine; Nimodipine; Nimotop; Nucleotides; Organism-Level Process; Organismal Process; Ortholog; Orthologous Gene; Ouabain; Parasitemia; Parasites; Patients; Pharmaceutic Preparations; Pharmaceutical Preparations; Physiologic Processes; Physiological Homeostasis; Physiological Processes; Plasma Membrane; Plasmodium falciparum; Post-Transcriptional Gene Silencing; Post-Transcriptional Gene Silencings; Posttranscriptional Gene Silencing; Posttranscriptional Gene Silencings; Potassium Pump; Predisposition; Procardia; Programs (PT); Programs [Publication Type]; Prostate CA; Prostate Cancer; Prostatic Cancer; Proteins; Pump; Quelling; RNA Interference; RNA Silencing; RNA Silencings; RNA, Messenger; RNAi; Receptors, Calcium Channel Blocker; Recombinants; Reporting; Reticuloendothelial System, Blood; Risk; Role; Schools, Medical; Sequence-Specific Posttranscriptional Gene Silencing; Sodium Pump; Sodium, Potassium ATPase; Sodium, Potassium Adenosine Triphosphatase; Sodium, Potassium Adenosinetriphosphatase; Sodium-Potassium Pump; Staging; Stomach; Sub-Saharan Africa; Subsaharan Africa; Surface Proteins; Susceptibility; System; System, LOINC Axis 4; T. brucei; Technology; Testing; Thapsigargin; Tissue Growth; Trypanosoma; Trypanosoma brucei; Trypanosoma brucei brucei; Trypanosomatidae; Trypanosomatina; Trypanosome; Trypanosomiasis; Trypanosomiasis, African; VDCC; Vaccinated; Vaccination; Vaccines; Vanadates; Variant; Variation; Vector-borne disease; Vector-borne infectious disease; Vector-transmitted disease; Vector-transmitted infectious disease; Verapamil; Voltage-Dependent Calcium Channels; Work; aminoacid; arteannuin; artemisinin; artemisinine; base; body system, allergic/immunologic; calcium transporting ATPase; cancer cell; channel blockers; disease control; disorder control; drug/agent; extracellular; fungus; gastric; gene product; immune therapy; immunogen; immunologic preparation; immunotherapeutics; inhibitor; inhibitor/antagonist; mRNA; medical schools; member; membrane structure; neglect; novel; ontogeny; organ system, allergic/immunologic; overexpression; parasaetemia; plasmalemma; prevent; preventing; programs; qinghaosu; quing hau sau; quinghaosu; sleeping sickness; small molecule; social role; sodium potassium exchanging ATPase; stem; vaccine delivery; vaccine development
Budget start date: 1-AUG-2009
Budget end date: 31-JUL-2010
5S06GM008248-23_0063 (2009): $152603
Targeting Trypanosome Cation Pumps And Channels
Jonathan K Stiles, Associate Professor
Morehouse School Of Medicine
720 Westview Dr Sw
atlanta, Ga 30310
Grant 5S06GM008248-210063 from National Institute Of General Medical Sciences IRG: MPRC
Abstract: Human African Trypanosomiasis (HAT, sleeping sickness) is a neglected but fatal vector borne disease caused by Trypanosoma brucei ssp. (T. brucei). Sixty million people are at risk of infection with HAT, and 50,000 new case´s and an equal number of deaths are reported annually in subsaharan Africa. The only available anti-trypanosomal drugs on the market are extremely toxic, and result in post-treatment encephalopathy in treated patients. The ideal anti-trypanosomal agents will target vital physiological processes and/or non-variant parasite-derived molecules without adversely affecting the human host. We and others have shown that that cytosolic calcium ion concentration [Ca2+ ]i in blood stages of T. brucei is 4- 10 orders of magnitude below that encountered in host extracellular milieu and that parasites require effective mechanisms to maintain [Ca2+ ] homeostasis, survival, and proliferation in their host. In our previous grant, we identified and characterized two key plasma-membrane-like cation pumps (ATPases; TBCA1 and TBCA2) utilized by T. brucei for survival and generated antibodies to immunolocalize them in bloodstage and insect stage parasites. We determined their functional role in insect and bloodstage parasites using transient RNAi inhibition technology and synthetic inhibitor assays. We subsequently constructed recombinant anti-pump vaccines based on a novel bacterial ghost vaccine delivery technology, developed at Morehouse School of Medicine, which partially protected against parasite challenge in mice. Our results revealed that TBCA1 resembled a fungal K+/Na+-ATPase while TBCA2 was a plasma-membrane-like Ca2+ ATPase. RNAi inhibition of these targets resulted in increased parasite mortality. Furthermore, we determined by inhibition studies that Ca2+ homeostasis in T. brucei is not only regulated by the Ca2+ ATPases but also by L-type calcium ion channels. Since targeting the Ca2+ pumps by RNAi inhibition increased parasite mortality and vaccination with TBCA2 significantly reduced parasitemia and survival of infected mice, we propose that targeting the key cation pumps (TBCA1 and TBCA2) as well as L-type Ca2+ channels together with either synthetic inhibitor drugs or vaccines, will be sufficient to inhibit proliferation of T. brucei and provide complete protection against T. brucei infection. In this competitive renewal proposal, we have gone a step further to hypothesize that trypanosomes utilize cation pumps and channels to mediate establishment in mammalian host blood and that simultaneous inhibition by target specific drugs and blocking by vaccination will prevent T. brucei proliferation and development. Two specific aims are proposed In Specific aim 1. we will functionally characterize and localize the L-type Ca2+ channel in T. brucei and determine its role in Ca2+ homeostasis. In Specific aim 2. we will construct and test various Ca2+ pump/channel gene constructs as antigens in a novel bacterial ghost based vaccine system against infections by T. brucei and determine their levels of protection against T. brucei infection. Our longterm goal is to build on our established proof of principle to develop and deliver a novel class of small molecule drugs and/or immunotherapeutics capable of inhibiting the essential Ca2+ pumps and channels of T. brucei during development. We also plan to generate enough data, through this application, to apply for an RQ-1 type grant to fund future studies on anti-trypanosome drugs
Keywords: Trypanosoma brucei, antiprotozoal agent, calcium channel, cation, drug design /synthesis /production, host organism interaction, membrane transport protein, trypanosomiasis, vaccine development communicable disease control, drug screening /evaluation, immunotherapy, inhibitor /antagonist, parasitism, vaccine evaluation laboratory mouse
Morehouse School Of Medicine Training In Genomics And Hemoglobinopathies Program
Jonathan K Stiles, Associate Professor
Morehouse School Of Medicine 720 Westview Dr Sw Atlanta, Ga 30310
Grant 5T90HG004004-02 from National Human Genome Research Institute IRG: GNOM
Abstract: Hemoglobinopathies affect significant portions of the global population, mostly residing in countries with low incomes. The major goal of the Morehouse School of Medicine s Training in Genomics and Hemoglobinopathies Program (MSM TGHP) is to train outstanding researchers in this discipline while promoting the participation of trainees from underrepresented US minority populations, particularly those affected by hemoglobinopathies. The program will recruit and train 4 postdoctoral fellows over three years. This program will be conducted in collaboration with the excellent MSM Ph.D. in Biomedical Sciences and the Master of Clinical Research programs. The program covers travel, living and research expenses for trainees. Collaborators from University of Ghana Medical School in Accra, Ghana, Emory University and Medical College of Georgia will be included in this program. Once trainees arrive at MSM, they will engage in a research project guided by an MSM mentor, assisted by the directors of the program and program faculty. Didactic training topics will include an overview of hemoglobin, laboratory diagnosis and clinical aspects of hemoglobinopathies, including Sickle Cell Disease and Thalassemias. In the genomic course, trainees will be immersed in the application of molecular biology techniques (Genomics/Proteomics) and use of scientific equipment. Students will be trained in scientific methods such as experimental design, data collection, explore the molecular basis (genomics and proteomics) of the role of nutrition, infections/inflammatory response, vascular biology and other acquired versus inherited factors on the severity of hemoglobinopathies. Trainees will be matched with mentors at MSM and at collaborating institutions to conduct research in hematology, utilizing genomics techniques. Collaborative, multidisciplinary research will be fostered through the availability of faculty with diverse interests on an individual basis, regular program meetings with peers and faculty, as well as participation at local and national meetings and seminars. Trainees will be expected to produce a final paper based on their project, to be submitted for presentation at a national conference and for publication. Trainees will be mandated to write a re-entry grant proposal following their training using various funding agencies, including those available at the NIH and the Fogarty International Center. These proposals will form the foundation of their independent research careers after returning to their home country or institution. Each trainee will receive post-training follow-up from the MSM Faculty Mentor and the Program Directors. Trainees will gain experience by conducting research in a different cultural context, and will be encouraged to pursue research careers in the field of hemoglobinopathies research that involves the use of modern genomic tools. With hope, trainees will become future outstanding researchers who strive to improve care of individuals both burdened by hemoglobinopathies and resource disparities.
Project start date: 2006-05-01
Project end date: 2011-04-30
5T90HG004004-02 (2007): $1080
1T90HG004004-01 (2006): $60994
5T90HG004004-05 (2010): $124018
5T90HG004004-04 (2009): $120943
Sponsored Links Excellgen http://Excellgen.com
5R90HG004151-05 (2010): $16130
5R90HG004151-04 (2009): $15919
5R90HG004151-02 (2007): $148170
1R90HG004151-01 (2006): $89909