Immunogenicity and protective efficacy of three DNA vaccines encoding pre-erythrocytic- and erythrocytic-stage antigens of Plasmodium cynomolgi in rhesus monkeys

Although several malaria vaccine candidate antigens have been identified, the most suitable methods for their delivery are still being investigated. In this regard, direct immunization with DNA encoding these vaccine target antigens is an attractive alternative. Here, we have investigated the immune responses to DNA immunization with three major vaccine target antigens: the apical membrane antigen-1 and the 19-kDa C-terminal fragment of merozoite surface protein-1 from the erythrocytic stage, and the thrombospondin-related adhesive protein from the pre-erythrocytic stage of Plasmodium cynomolgi in rhesus monkeys. Antigen-specific antibodies were developed in all the immunized monkeys and peripheral blood mononuclear cells from all immunized monkeys proliferated to different extents upon in vitro stimulation with the corresponding recombinant proteins. The immunized monkeys were challenged with P. cynomolgi sporozoites. All of the immunized animals developed infection but although there was no significant difference between the control and vaccinated animals in terms of pre-patent period, total duration of patency and primary peak parasitemia, the vaccinated animals had significantly lower secondary peak parasitemia than the control animals.     

In vivo active antimalarial isonitriles

Building on the lead from antimalarial isonitriles 1-4 of marine origin, several easily accessible synthetic isonitriles were assessed for their antimalarial activity against Plasmodium falciparum (in vitro) and multidrug resistant Plasmodium yoelii in Swiss mice model (in vivo). Isonitrile 11 has shown promising activity in both these assays.     

Novel indolo[2,1-b]quinazoline analogues as cytostatic agents: synthesis,biological evaluation and structure-activity relationship

In our endeavor to design and synthesize novel anticancer agents, a new series of indoloquinazoline compounds were prepared and tested initially for anticancer activity in vitro against a panel of human cancer cell lines. Most of these compounds exhibited cytotoxic activity in in vitro screens. Compounds were selected and further evaluated using a modified Hollow Fiber Assay for their preliminary in vivo activity against 12 cell lines implanted in the subcutaneous and intraperitoneal compartments in mice. The results indicate that these compounds may constitute a new class of anticancer agents.     

An Hsp70 family chaperone,mortalin/mthsp70/PBP74/Grp75: what,when, and where?

Mortalin/mthsp70/PBP74/Grp75 (called mortalin hereafter), a member of the Hsp70 family of chaperones, was shown to have different subcellular localizations in normal and immortal cells. It has been assigned to multiple subcellular sites and implicated in multiple functions ranging from stress response, intracellular trafficking, antigen processing, control of cell proliferation, differentiation, and tumorigenesis. The present article compiles and reviews information on the multiple sites and functions of mortalin in different organisms. The relevance of its differential distributions and functions in normal and immortal cell phenotypes is discussed.     

Cytotoxic cell granule-mediated apoptosis. Characterization of the macromolecular complex of granzyme B with serglycin

We have recently shown that the physiological mediator of granule-mediated apoptosis is a macromolecular complex of granzymes and perforin complexed with the chondroitin-sulfate proteoglycan, serglycin (Metkar, S. S., Wang, B., Aguilar-Santelises, M., Raja, S. M., Uhlin-Hansen, L., Podack, E., Trapani, J. A., and Froelich, C. J. (2002) Immunity 16, 417-428). We now report our biophysical studies establishing the nature of granzyme B-serglycin (GrB.SG) complex. Dynamic laser light scattering studies establish that SG has a hydrodynamic radius of approximately 140 +/- 23 nm, comparable to some viral particles. Agarose mobility shift gels and surface plasmon resonance (SPR), show that SG binds tightly to GrB and has the capacity to hold 30-60 GrB molecules. SPR studies also indicate equivalent binding affinities (K(d) approximately 0.8 microm), under acidic (granule pH) and neutral isotonic conditions (extra-cytoplasmic pH), for GrB.SG interaction. Finally, characterization of GrB.SG interactions within granules revealed complexes of two distinct molecular sizes, one held approximately 4-8 molecules of GrB, whereas the other contained as many as 32 molecules of GrB or other granule proteins. These studies provide a firm biophysical basis for our earlier reported observations that the proapoptotic granzyme is exocytosed predominantly as a macromolecular complex with SG.     

Expression of hepatitis B surface antigen in tobacco cell suspension cultures

Hepatitis B virus ' s ' gene coding for surface antigen was cloned into plant transformation vectors pHER100 and pHBs100 with and without endoplasmic reticulum retention signal, respectively. Transformed tobacco cell lines were analyzed for the integration of the transgene by PCR and Southern blot hybridization. Expression levels as determined by ELISA showed maximum expression levels of 2 microg HBsAg gm(-1) fresh weight and 10 ng mL(-1) of spent medium in pHER100 transformed cells. Western blot analysis confirmed the presence of 24 kDa band specific to HBsAg in the transformed cells. HBsAg was expressed both as intracellular and secreted forms in pHER100 transformed cells. The buoyant density in CsCl of HBsAg derived from pHBs100 transformed tobacco cells was determined and found to be 1.095 g mL(-1). HBsAg obtained from transformed tobacco cells is similar to the human serum derived one in buoyant density properties. This is the first report on the secretion of HBsAg particles by plant cells into the cell culture medium.     

Effect of non-linearity in predicting doppler waveforms through a novel model

Background  

In pregnancy, the uteroplacental vascular system develops de novo locally in utero and a systemic haemodynamic & bio-rheological alteration accompany it. Any abnormality in the non-linear vascular system is believed to trigger the onset of serious morbid conditions like pre-eclampsia and/or intrauterine growth restriction (IUGR). Exact Aetiopathogenesis is unknown. Advancement in the field of non-invasive doppler image analysis and simulation incorporating non-linearities may unfold the complexities associated with the inaccessible uteroplacental vessels. Earlier modeling approaches approximate it as a linear system.     

Selective toxicity of engineered lentivirus lytic peptides in a CF airway cell model

Lentivirus lytic peptides (LLPs) are derived from HIV-1 and have antibacterial properties. LLP derivatives (eLLPs) were engineered for greater potency against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA). Minimum bactericidal concentration (MBC) was determined in low and physiologic salt concentrations. MBC was decreased against SA and equivalent against PA in physiologic salt when compared to the parent compound LLP1. In a novel cystic fibrosis (CF) airway cell model, one derivative, WLSA5, reduced the number of adherent PA and only moderately affected CF cell viability. Overall, eLLPs are selectively toxic to bacteria and may be useful against CF airway infections.