A5074927083- Research on Leishmaniasis Studies
- Trypanosoma species research and implications
- Entomological Studies and Ecology
- Lepidoptera: Biology and Taxonomy
- Insect-Plant Interactions and Control
- Hemiptera Insect Studies
- Forest Insect Ecology and Management
- Insect behavior and control techniques
- Plant and animal studies
- Insect and Pesticide Research
- Insect and Arachnid Ecology and Behavior
- Coleoptera Taxonomy and Distribution
- History and Developments in Astronomy
- Orthoptera Research and Taxonomy
- Invertebrate Taxonomy and Ecology
- Parasites and Host Interactions
- Fossil Insects in Amber
- Parasite Biology and Host Interactions
- Insect Utilization and Effects
- Extracellular vesicles in disease
- Mosquito-borne diseases and control
- Insects and Parasite Interactions
- Diptera species taxonomy and behavior
- Coleoptera: Cerambycidae studies
- Fish Biology and Ecology Studies
University of Florida
2014-2024
Larkin University
2024
Guangzhou Medical University
2022
Institute of Parasitology
2022
Sun Yat-sen University
2022
Yale University
1995-2003
Hahnemann University Hospital
1992
Baylor College of Medicine
1987
University of Maryland, Baltimore
1984
To study the role of CD40 ligand (CD40L) in host immune responses against intracellular pathogens, we infected CD40L knockout (CD40L−/−) mice with Leishmania amazonensis. Although wild-type were susceptible to infection and developed progressive ulcerative lesions, tissue parasite burdens CD40L−/− significantly higher. This heightened susceptibility was associated an impaired T cell macrophage activation altered inflammatory response, as reflected by low levels IFNγ, lymphotoxin–tumor...
We show here that maintenance of Leishmania infections with mexicana complex parasites (Leishmania amazonensis and pifanoi) is impaired in the absence circulating antibody. In these studies, we used mice genetically altered to contain no antibody, without functional B cells. This experimental design allowed us rule out a critical role for cell antigen presentation pathogenesis. addition, lacking common gamma chain Fc receptors (FcgammaRI, FcepsilonRI, FcgammaRIII) are similarly refractory...
Previous reports have shown that cells infected with promastigotes of some Leishmania species are resistant to the induction apoptosis. This would suggest either parasites elaborate factors block signalling from apoptosis inducers or engage endogenous host pathways To investigate latter scenario, we determined whether infection results in activation been mediate resistance other models. First, showed promastigote form major, pifanoi and amazonensis activates through p38 mitogen-activated...
Leishmaniasis is a complex disease that caused by parasites of the Leishmania genus. are further classified into several complexes, each which can engage in distinct interactions with mammalian hosts resulting differing presentations. It therefore not unexpected host immune responses to variable. The induction interferon gamma (IFN-γ) and response it these infections has received considerable attention. In this review, we summarize our current understanding some during regulated IFN-γ....
Extracellular vesicles (EVs) are membrane-enclosed packets that released from cells and subsequently transfer bioactive molecules between without directly contacting the target cells. This of can activate consequential processes in recipient cells, including cell differentiation migration, thus maintaining tissue homeostasis or promoting pathology. A controversial but therapeutically promising aspect EV biology is their ability to engage defined at specific sites. On one hand, persuasive...
In the search for a leishmaniasis vaccine, extensive studies have been carried out with promastigote (insect stage) molecules. Information in this regard on amastigote (mammalian host molecules is limited. To investigate immune responses to Leishmania antigens, we purified three stage-specific antigens (A2, P4, and P8) from vitro-cultivated amastigotes of pifanoi by using immunoaffinity chromatography. We found that Corynebacterium parvum as an adjuvant, intraperitoneal injections 5...
Macrophages that express representative endoplasmic reticulum (ER) molecules tagged with green fluorescence protein were generated to assess the recruitment of ER Leishmania parasitophorous vacuoles (PVs). More than 90% PVs harbouring pifanoi or donovani parasites recruited calnexin, their PV membrane. An equivalent proportion also membrane-associated soluble N-ethylmaleimide-sensitive factor attachment receptors (SNAREs), Sec22b. Both appeared be very early in formation nascent PVs....
Whereas infections of macrophages by promastigote forms Leishmania mexicana pifanoi induce the production superoxide, amastigotes barely superoxide production. Several approaches were employed to gain insight into mechanism which avoid eliciting First, in experiments with nitroblue tetrazolium, we found that 25% parasitophorous vacuoles (PVs) harbor promastigotes are positive for NADPH oxidase complex, contrast only 2% PVs amastigotes. Second, confocal microscope analyses infected cells...
Abstract CD4 + T cell lines raised against the protective leishmanial antigens GP46 and P8 were used to study presentation of endogenously synthesized Leishmania by infected cells. Using two different sources macrophages, 14.07 macrophage line (H‐2 k ) which constitutively expresses major histocompatibility complex (MHC) class II molecules, elicited peritoneal exudate cells, we found that cells with amastigotes presented little, if any parasite In contrast, promastigote‐infected macrophages...
ABSTRACT Previous studies have demonstrated that protection against New World leishmaniasis caused by Leishmania amazonensis can be elicited immunization with the developmentally regulated amastigote antigen, P-8. In this study, several independent experimental approaches were employed to investigate protective immunological mechanisms involved. T-cell subset depletion experiments clearly indicate elicitation of CD8 + (as well as CD4 ) effector responses is required for protection. Further,...
Leishmania donovani infection of macrophages results in quantitative and qualitative changes the protein profile extracellular vesicles (EVs) released by infected host cells. We confirmed mass spectrometry orthogonally performing Western blots for several -infected macrophage-enriched EVs (LieEVs) molecules. Several cell proteins LieEVs have been implicated promoting vascular other systems. also identified 59 parasite-derived LieEVs, including a putative L. homolog mammalian vasohibins...
Parasitophorous vacuoles (PV) that harbour Leishmania parasites acquire some characteristics from fusion with host cell vesicles. Recent studies have shown PVs and display resident endoplasmic reticulum (ER) molecules. We investigated the importance of ER molecules to PV biology by assessing consequence blocking vesicles originate early secretory pathway. This was achieved targeting N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) mediate In presence dominant negative...
Professional phagocytes generate a myriad of antimicrobial molecules to kill invading microorganisms, which nitrogen oxides are integral in controlling the obligate intracellular pathogen Leishmania. Although reactive species produced by inducible nitric oxide synthase (iNOS) can promote clearance parasites, some Leishmania species/stages relatively resistant iNOS-mediated activity. The underlying mechanism for this resistance remains largely uncharacterized. Here, we show that amastigote...
To gain entry into non-phagocytic cells, Trypanosoma cruzi trypomastigotes recruit lysosomes to the host cell surface. Lysosome fusion at site of parasite leads formation a parasitophorous vacuole with lysosomal properties. Here, we show that increased expression membrane glycoprotein Lamp-1 surface renders CHO cells more susceptible trypomastigote invasion in microtubule-dependent fashion. Mutation critical residues lysosome-targeting motif abolished enhancement T. invasion. This suggests...
Abstract CD8+ T cells play a protective role in immunity to cutaneous leishmaniasis. However, it has been unclear how these execute this function, since results from several investigations attempting demonstrate recognition of Leishmania-infected macrophages by have contradictory. In study, we report the generation cell lines specific for GP46/M-2, leishmanial Ag, previously shown protectively immunize mice against Leishmania amazonensis challenge. Using cytolysis and IFN-gamma production...
Miltefosine is an important drug for the treatment of leishmaniasis; however, its mechanism action still poorly understood. In these studies, we tested hypothesis that like in cancer cells, miltefosine's efficacy leishmaniasis due to inhibition Akt activation host cells. We show using pharmacologic agents block by different mechanisms and also inducible knockdown approach miltefosine loses when access Akt1 limited. Interestingly, limitation results clearance established Leishmania...
Leishmaniasis is amongst the most important neglected diseases, afflicting more than 12 million people in 88 countries. There an urgent need for safe orally bioavailable and cost-effective drugs treatment of leishmaniasis. It has recently been shown that Leishmania activates host macrophage serine/threonine kinase Akt, to promote survival both parasites infected cells. Here, we sought evaluate a compound, Miransertib (ARQ 092), selective allosteric Akt inhibitor currently clinical trials...
Amazonian localized cutaneous leishmaniasis (LCL) is caused by parasites of the subgenera Leishmania and Viannia . Respectively, these may cause diffuse (DCL) mucocutaneous (MCL). This, together with differing skin test responses, suggests some species‐specificity in cell mediated immunity. In this study, T responses (proliferative interferon‐γ) to crude defined antigens were examined paired samples pre post chemotherapy. Untreated L. (L.) amazonensis LCL patients showed lower leishmanial...