Immunization with genetically attenuated P52-deficient Plasmodium berghei sporozoites induces a long-lasting effector memory CD8+ T cell response in the liver

Background

The induction of sterile immunity and long lasting protection against malaria has been effectively achieved by immunization with sporozoites attenuated by gamma-irradiation or through deletion of genes. For mice immunized with radiation attenuated sporozoites (RAS) it has been shown that intrahepatic effector memory CD8⁺ T cells are critical for protection. Recent studies have shown that immunization with genetically attenuated parasites (GAP) in mice is also conferred by liver effector memory CD8⁺ T cells.

Findings

In this study we analysed effector memory cell responses after immunization of GAP that lack the P52 protein. We demonstrate that immunization with p52 ^-GAP sporozoites also results in a strong increase of effector memory CD8⁺ T cells, even 6 months after immunization, whereas no specific CD4⁺ effector T cells response could be detected. In addition, we show that the increase of effector memory CD8⁺ T cells is specific for the liver and not for the spleen or lymph nodes.

Conclusions

These results indicate that immunization of mice with P. berghei p52 ^-GAP results in immune responses that are comparable to those induced by RAS or GAP lacking expression of UIS3 or UIS4, with an important role implicated for intrahepatic effector memory CD8⁺ T cells. The knowledge of the mediators of protective immunity after immunization with different GAP is important for the further development of vaccines consisting of genetically attenuated sporozoites.     

Mycobacterial immune reconstitution inflammatory syndrome in HIV-1 infection after antiretroviral therapy is associated with deregulated specific T-cell responses: Beneficial effect of IL-2 and GM-CSF immunotherapy

Background  

With the advent of antiretroviral therapy (ART) cases of immune reconstitution inflammatory syndrome (IRIS) have increasingly been reported. IRIS usually occurs in individuals with a rapidly rising CD4 T-cell count or percentage upon initiation of ART, who develop a deregulated immune response to infection with or without reactivation of opportunistic organisms. Here, we evaluated rises in absolute CD4 T-cells, and specific CD4 T-cell responses in 4 HIV-1⁺ individuals presenting with mycobacterial associated IRIS who received in conjunction with ART, IL-2 plus GM-CSF immunotherapy.     

Evaluation of the impact of chitosan/DNA nanoparticles on the differentiation of human naive CD4+ T cells

Chitosan (CS) is one of the most widely studied polymers in non-viral gene delivery since it is a cationic polysaccharide that forms nanoparticles with DNA and hence protects the DNA against digestion by DNase. However, the impact of CS/DNA nanoparticle on the immune system still remains poorly understood. Previous investigations did not found CS/DNA nanoparticles had any significant impact on the function of human and murine macrophages. To date, little is known about the interaction between CS/DNA nanoparticles and naive CD4⁺ T cells. This study was designed to investigate whether CS/DNA nanoparticles affect the initial differentiation direction of human naive CD4⁺ T cells. The indirect impact of CS/DNA nanoparticles on naive CD4⁺ T cell differentiation was investigated by incubating the nanoparticles with human macrophage THP-1 cells in one chamber of a transwell co-incubation system, with the enriched human naive CD4⁺ T cells being placed in the other chamber of the transwell. The nanoparticles were also co-incubated with the naive CD4⁺ T cells to explore their direct impact on naive CD4⁺ T cell differentiation by measuring the release of IL-4 and IFN-?? from the cells. It was demonstrated that CS/DNA nanoparticles induced slightly elevated production of IL-12 by THP-1 cells, possibly owing to the presence of CpG motifs in the plasmid. However, this macrophage stimulating activity was much less significant as compared with lipopolysaccharide and did not impact on the differentiation of the naive CD4⁺ T cells. It was also demonstrated that, when directly exposed to the naive CD4⁺ T cells, the nanoparticles induced neither the activation of the naive CD4⁺ T cells in the absence of recombinant cytokines (recombinant human IL-4 or IFN-??) that induce naive CD4⁺ T cell polarization, nor any changes in the differentiation direction of naive CD4⁺ T cells in the presence of the corresponding cytokines.     

Radiosensitivity of CD3−CD8+CD56+ NK cells

The effect of lower doses (0.5–3.0 Gy) of gamma radiation on radiosensitivity of CD3?/CD8+ NK cells subpopulation isolated from the peripheral blood of healthy volunteers was studied 48 h after the irradiation. Only a subtle increase in terms of induction of apoptosis (A+ cells), was observed in Annexin positive CD3?/CD8+ NK cells. The assessment of the relative presence of CD3^?/CD8⁺ NK cells in Annexin negative populations of lymphocytes considerably contributes to the elimination of individual variability and could be useful in biodosimetry.Living CD3?/CD8+; Annexin negative NK cells were analyzed using five-color flow cytometry 16 h after irradiation by the doses of 1–10 Gy. The study was carried out on NK cells subsets CD3?/CD8? CD16+, CD56 (dim) and CD56 (bright). NK cells characterized with their low-density expression of CD56 (dim) are more cytotoxic and express CD16. Those with high-density expression of CD56 (bright) are known for their capacity to produce cytokines following activation of monocytes but their natural cytotoxicity is low; they are classified as CD16? or CD16 (dim). A dose-depending decrease in the relative presence of CD3?/CD8+ NK cells was observed 16 h after ionizing radiation (1–10 Gy). The decrease was highly pronounced in CD56 (bright) subset of NK cells and this subpopulation was considered as the most radiosensitive one. Unfortunately, the most radiosensitive subpopulation of NK cells – CD56bright cannot be used as a biodosimetric marker due to its insufficient amount in peripheral blood.     

Spatial distribution of Na<Superscript>+</Superscript>-K<Superscript>+</Superscript>-ATPase in dendritic spines dissected by nanoscale superresolution STED microscopy

Background  

The Na⁺,K⁺-ATPase plays an important role for ion homeostasis in virtually all mammalian cells, including neurons. Despite this, there is as yet little known about the isoform specific distribution in neurons.     

Dynamics of the HIV infection under antiretroviral therapy: A cellular automata approach

The dynamics of human immunodeficiency virus infection under antiretroviral therapy is investigated using a cellular automata model where the effectiveness of each drug is self-adjusted by the concentration of CD4⁺  T infected cells present at each time step. The effectiveness of the drugs and the infected cell concentration at the beginning of treatment are the control parameters of the cell population’s dynamics during therapy. The model allows describing processes of mono and combined therapies. The dynamics that emerges from this model when considering combined antiretroviral therapies reproduces with fair qualitative agreement the phases and different time scales of the process. As observed in clinical data, the results reproduce the significant decrease in the population of infected cells and a concomitant increase of the population of healthy cells in a short timescale (weeks) after the initiation of treatment. Over long time scales, early treatment with potent drugs may lead to undetectable levels of infection. For late treatment or treatments starting with a low density of CD4⁺  T healthy cells it was observed that the treatment may lead to a steady state in which the T cell counts are above the threshold associated with the onset of AIDS. The results obtained are validated through comparison to available clinical trial data.     

Effects of dietary Na+ deprivation on epithelial Na+ channel (ENaC), BDNF, and TrkB mRNA expression in the rat tongue

Background  

In rodents, dietary Na⁺ deprivation reduces gustatory responses of primary taste fibers and central taste neurons to lingual Na⁺ stimulation. However, in the rat taste bud cells Na⁺ deprivation increases the number of amiloride sensitive epithelial Na⁺ channels (ENaC), which are considered as the "receptor" of the Na⁺ component of salt taste. To explore the mechanisms, the expression of the three ENaC subunits (α, β and γ) in taste buds were observed from rats fed with diets containing either 0.03% (Na⁺ deprivation) or 1% (control) NaCl for 15 days, by using in situ hybridization and real-time quantitative RT-PCR (qRT-PCR). Since BDNF/TrkB signaling is involved in the neural innervation of taste buds, the effects of Na⁺ deprivation on BDNF and its receptor TrkB expression in the rat taste buds were also examined.     

Serotonin-mediated modulation of Na<Superscript>+</Superscript>/K<Superscript>+</Superscript> pump current in rat hippocampal CA1 pyramidal neurons

Background  

The aim of this study was to investigate whether serotonin (5-hydroxytryptamine, 5-HT) can modulate Na⁺/K⁺ pump in rat hippocampal CA1 pyramidal neurons.     

Amiloride-sensitive channels in type I fungiform taste cells in mouse

Background  

Taste buds are the sensory organs of taste perception. Three types of taste cells have been described. Type I cells have voltage-gated outward currents, but lack voltage-gated inward currents. These cells have been presumed to play only a support role in the taste bud. Type II cells have voltage-gated Na⁺ and K⁺ current, and the receptors and transduction machinery for bitter, sweet, and umami taste stimuli. Type III cells have voltage-gated Na⁺, K⁺, and Ca²⁺ currents, and make prominent synapses with afferent nerve fibers. Na⁺ salt transduction in part involves amiloride-sensitive epithelial sodium channels (ENaCs). In rodents, these channels are located in taste cells of fungiform papillae on the anterior part of the tongue innervated by the chorda tympani nerve. However, the taste cell type that expresses ENaCs is not known. This study used whole cell recordings of single fungiform taste cells of transgenic mice expressing GFP in Type II taste cells to identify the taste cells responding to amiloride. We also used immunocytochemistry to further define and compare cell types in fungiform and circumvallate taste buds of these mice.     

Improved generation of anti-tumor immunity by antigen dose limitation

Background  

The malignant cells of cutaneous T cell lymphoma (CTCL) display immunogenic peptides derived from the clonal T cell receptor (TCR) providing an attractive model for refinement of anti-tumor immunization methodology. To produce a clinically meaningful anti-tumor response, induction of cytotoxic anti-CTCL cells must be maximized while suppressive T regulatory cells (Treg) should be minimized. We have demonstrated that engulfment of apoptotic CTCL cells by dendritic cells (DC) can lead to either CD8 anti-CTCL responses or immunosuppressive Treg induction. Treg generation is favored when the number of apoptotic cells available for ingestion is high.     

Elevated intracellular chloride level in albino visual cortex neurons is mediated by Na-K-Cl co-transporter

Background  

During development the switch from a depolarizing to a hyperpolarizing action of GABA is a consequence of a decrease of the Na⁺-K⁺-2Cl^- co-transporter (NKCC1, Cl^--uptake) and increase of the K⁺-Cl^- co-transporter (KCC2, Cl^--extrusion) expression. However albino visual cortex neurons don't show a corresponding decrease in intracellular chloride concentration during development of the visual system as compared to pigmented animals.     

A Comparison of Complexation of Li<Superscript>+</Superscript> Ion with Macrocyclic Ligands 15-Crown-5 and Benzo-derivatives in Binary Nitromethane–Acetonitrile Mixtures by Using Lithium-7 NMR Technique and Ab Initio Calculation

Abstract  

Lithium-7 nuclear magnetic resonance (NMR) measurements were used to investigate the stoichiometry and stability of Li⁺ complexes with 15-crown-5 (15C5), benzo-15-crown-5 (B15C5) and dibenzo-15-crown-5 (DB15C5) in a number of nitromethane (NM)–acetonitrile (AN) binary mixtures. In all cases, the exchange between the free and complexed lithium ion was fast on the NMR time scale and a single population average resonance was observed. While all crown ethers form 1:1 complexes with Li⁺ ion in the binary mixtures used, stepwise formation constants of the 1:1 (ligand/metal) complexes were evaluated from computer fitting of the NMR-mole ratio data to equations which relate the observed metal ion chemical shifts to formation constants. There is an inverse linear relationship between the logarithms of the stability constants and the mole fraction of AN in the solvent mixtures. The stability order of the 1:1 complexes was observed to be 15C5.Li⁺ > B15C5.Li⁺ > DB15C5.Li⁺. The optimized structures of the free ligands and their 1:1 complexes with the Li⁺ ion were predicted by ab initio theoretical calculations using the Gaussian 98 software. The results of calculations are discussed.     

Downregulation of calcium-dependent NMDA receptor desensitization by sodium-calcium exchangers: a role of membrane cholesterol

Background

The plasma membrane Na⁺/Ca²⁺-exchanger (NCX) has recently been shown to regulate Ca²⁺-dependent N-methyl-d-aspartate receptor (NMDAR) desensitization, suggesting a tight interaction of NCXs and NMDARs in lipid nanoclasters or “rafts”. To evaluate possible role of this interaction we studied effects of Li⁺ on NMDA-elicited whole-cell currents and Ca²⁺ responses of rat cortical neurons in vitro before and after cholesterol extraction by methyl-β-cyclodextrin (MβCD).

Results

Substitution Li⁺ for Na⁺ in the external solution caused a concentration-dependent decrease of steady-state NMDAR currents from 440?±?71 pA to 111?±?29 pA in 140 mM Na⁺ and 140 mM Li⁺, respectively. The Li⁺ inhibition of NMDAR currents disappeared in the absence of Ca²⁺ in the external solution (Ca²⁺-free), suggesting that Li⁺ enhanced Ca²⁺-dependent NMDAR desensitization. Whereas the cholesterol extraction with MβCD induced a decrease of NMDAR currents to 136?±?32 pA in 140 mM Na⁺ and 46?±?15 pA in 140 mM Li⁺, the IC₅₀ values for the Li⁺ inhibition were similar (about 44 mM Li⁺) before and after this procedure. In the Ca²⁺-free Na⁺ solution the steady-state NMDAR currents after the cholesterol extraction were 47?±?6% of control values. Apparently this amplitude decrease was not Ca²⁺-dependent. In the Na⁺ solution containing 1 mM Ca²⁺ the Ca²⁺-dependent NMDAR desensitization was greater when cholesterol was extracted. Obviously, this procedure promoted its development. In agreement, Li⁺ and KB-R7943, an inhibitor of NCX, both considerably reduced NMDA-activated Ca²⁺ responses. The cholesterol extraction itself caused a decrease of NMDA-activated Ca²⁺ responses and, in addition, abolished the effects of Li⁺ and KB-R7943. The cholesterol loading into the plasma membrane caused a recovery of the KB-R7943 effects.

Conclusions

Taken together our data suggest that NCXs downregulate the Ca²⁺-dependent NMDAR desensitization. Most likely, this is determined by a tight functional interaction of NCX and NMDAR molecules because of their co-localization in membrane lipid rafts. The destruction of these rafts is accompanied by an enhancement of NMDAR desensitization and a loss of NCX-selective agent effects on NMDARs.

     

Ultrasmall superparamagnetic iron oxides enhanced MR imaging in rats with experimentally induced endometriosis

Purpose

The purpose of our study was to evaluate the feasibility of magnetic resonance imaging (MRI) using ultrasmall superparamagnetic iron oxides (USPIO) in the detection of experimentally induced endometriosis.

Materials and methods

Endometriosis was surgically induced in rats by transplanting an autologous fragment of uterine tissue onto the inner surface of the abdominal wall, the posterior surface of the uterine body and the arterial cascades of the small intestines adjacent to mesenteric blood vessels. Six weeks later, MRI using Gd-DTPA and USPIO was performed for the evaluation of the ectopic uterine tissue (EUT). A scoring system was developed for image interpretation (0=absence, 1=probably absence, 2=probably presence and 3=presence). We defined MR index (MRIx) as the sum of T1-weighted and enhanced T1-weighted and T2-weighted image scores, and USPIO MRIx (MRIx^+USPIO) as the MRIx score plus the score of USPIO-enhanced T2-weighted image.

Results

The MRIx^+USPIO was also higher in the successfully autotransplanted group than in the failed group (6.19±1.72 versus 3.94±1.20, P<.001). There was also a significant linear relationship between MRIx^+USPIO and pathologic status (R²=0.494, P<.001). Thirty-one (64.6%) of the 48 implanted uterine tissues were histologically confirmed on pathologic review. The area of MRIx and MRIx^+USPIO in the detection of EUT more than 3 mm in size was 0.739 and 0.913, respectively.

Conclusion

Our results suggest that USPIO-enhanced MRI could be a novel diagnostic tool for diagnosis in experimentally induced peritoneal endometriosis.     

Expression of Galpha14 in sweet-transducing taste cells of the posterior tongue

Background  

"Type II"/Receptor cells express G protein-coupled receptors (GPCRs) for sweet, umami (T1Rs and mGluRs) or bitter (T2Rs), as well as the proteins for downstream signalling cascades. Transduction downstream of T1Rs and T2Rs relies on G-protein and PLCβ2-mediated release of stored Ca²⁺. Whereas Gαgus (gustducin) couples to the T2R (bitter) receptors, which Gα-subunit couples to the sweet (T1R2 + T1R3) receptor is presently not known. We utilized RT-PCR, immunocytochemistry and single-cell gene expression profiling to examine the expression of the Gαq family (q, 11, 14) in mouse taste buds.     

Targeted radiofrequency field mapping using 3D reduced field-of-view-catalyzed double-angle method

Purpose

The aim of this study was to develop a targeted volumetric radiofrequency field (B₁⁺) mapping technique to provide region-of-interest B₁⁺ information.

Materials and Methods

Targeted B₁⁺ maps were acquired using three-dimensional (3D) reduced field-of-view (FOV) inner-volume turbo spin echo-catalyzed double-angle method (DAM). Targeted B₁⁺ maps were compared with full-FOV B₁⁺ maps acquired using 3D catalyzed DAM in a phantom and in the brain of a healthy volunteer. In addition, targeted volumetric abdomeninal B₁⁺ mapping was demonstrated in the abdomen of another healthy volunteer.

Results

The targeted reduced-FOV images demonstrated no aliasing artifacts in all experiments. Close match between targeted B₁⁺ map and reference full-FOV B₁⁺ map in the same region was observed, with percentage root-mean-squared error <0.4% in the phantom and <0.8% in the healthy volunteer brain. The abdominal B₁⁺ maps showed small B₁⁺ variation in the kidneys and liver from the healthy volunteer.

Conclusion

The proposed 3D reduced-FOV catalyzed DAM provides a rapid, simple and accurate method for targeted volumetric B₁⁺ mapping and can be easily implemented for applications related to radiofrequency field mapping in small targeted regions.     

The Kv2.1 K<Superscript>+</Superscript> channel targets to the axon initial segment of hippocampal and cortical neurons in culture and <Emphasis Type="Italic">in situ</Emphasis>

Background  

The Kv2.1 delayed-rectifier K⁺ channel regulates membrane excitability in hippocampal neurons where it targets to dynamic cell surface clusters on the soma and proximal dendrites. In the past, Kv2.1 has been assumed to be absent from the axon initial segment.     

Tumor-infiltrating effector cells of α-galactosylceramide-induced antitumor immunity in metastatic liver tumor

Background  

α-Galactosylceramide (α-GalCer) can be presented by CD1d molecules of antigen-presenting cells, and is known to induce a potent NKT cell-dependent cytotoxic response against tumor cells. However, the main effector cells in α-GalCer-induced antitumor immunity are still controversial.     

IMP321 (sLAG-3), an immunopotentiator for T cell responses against a HBsAg antigen in healthy adults: a single blind randomised controlled phase I study

Background  

LAG-3 (CD223) is a natural high affinity ligand for MHC class II. The soluble form (sLAG-3) induces maturation of monocyte-derived dendritic cells in vitro and is used as a potent Th1-like immune enhancer with many antigens in animal models. To extend this observation to human, a proof of concept study was conducted with a clinical-grade sLAG-3, termed IMP321, coinjected with alum-non-absorbed recombinant hepatitis B surface antigen.     

Preparation of immunomagnetic nanoparticles and their application in the separation of mouse CD34 hematopoietic stem cells

The magnetic nanoparticles with a diameter of about 60 nm were synthesized by coprecipitation from ferrous and ferric iron solutions and coated with silica. Then the nanoparticles were modified with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPS) in order to immobilize anti-CD34⁺ monoclonal antibodies to the surface of modified magnetic particles. The results of transmission electron microscope (TEM) and Fourier transformed infrared (FT-IR) indicated that the nanoparticles were successfully prepared. Scanning electron microscope (SEM) photo confirmed that the mouse CD34⁺ cells (cells expressing CD34) were separated by the immunomagnetic nanoparticles. The viability of the separated cells was studied by hematopoietic colony-forming assay, the result of which showed that the target cells still had an ability of proliferation and differentiation. The application of the separated CD34⁺ cells was in testing the pharmacological effect of three samples isolated from enzyme-digested traditional Chinese medicine Colla corii asini.