Targeted anti-cancer therapy: Co-delivery of VEGF siRNA and Phenethyl isothiocyanate (PEITC) via cRGD-modified lipid nanoparticles for enhanced anti-angiogenic efficacy

Anti-tumor angiogenesis therapy, targeting the suppression of blood vessel growth in tumors, presents a potent approach in the battle against cancer. Traditional therapies have primarily concentrated on single-target techniques, with a specific emphasis on targeting the vascular endothelial growth factor, but have not reached ideal therapeutic efficacy. In response to this issue, our study introduced a novel nanoparticle system known as CS-siRNA/PEITC&L-cRGD NPs. These chitosan-based nanoparticles have been recognized for their excellent biocompatibility and ability to deliver genes. To enhance their targeted delivery capability, they were combined with a cyclic RGD peptide (cRGD). Targeted co-delivery of gene and chemotherapeutic agents was achieved through the use of a negatively charged lipid shell and cRGD, which possesses high affinity for integrin αvβ3 overexpressed in tumor cells and neovasculature. In this multifaceted approach, co-delivery of VEGF siRNA and phenethyl isothiocyanate (PEITC) was employed to target both tumor vascular endothelial cells and tumor cells simultaneously. The co-delivery of VEGF siRNA and PEITC could achieve precise silencing of VEGF, inhibit the accumulation of HIF-1α under hypoxic conditions, and induce apoptosis in tumor cells. In summary, we have successfully developed a nanoparticle delivery platform that utilizes a dual mechanism of action of anti-tumor angiogenesis and pro-tumor apoptosis, which provides a robust and potent strategy for the delivery of anti-cancer therapeutics.

Linkages of microbial community structure and root exudates: Evidence from microbial nitrogen limitation in soils of crop families

Rhizosphere microorganisms are critical for crop nutrient cycling and soil ecological functions in agroecosystem soils; however, there is limited information regarding the role of root exudates in determining soil microbial communities and functions in plant-soil systems, especially for microbial nutrient limitations. In the present study, rhizosphere soil samples were collected from the main food crop families, including maize, soybean, potato, and buckwheat, representing the cereals, Leguminosae, Solanaceae, and Polygonaceae families, in the northern Loess Plateau, China, to investigate soil microbial co-occurrences and assembly processes and the relationship between soil microbes and root exudates. The results showed that the crop families greatly regulated the soil microbial community composition and assembly, and all microorganisms of the four species were subjected to N limitation via the vector analysis. The topological properties of the soil microbial networks varied with the crop family, demonstrating that the ecological relationships of bacterial taxa are more complex than those of fungi. Stochastic processes were more important in stimulating assembly across the four crop families; the non-dominated process governed >60 % of the critical ecological turnover in community assembly, whereas dispersal limitation was the key factor influencing fungal community assembly. Furthermore, the metabolic profiles of root exudates in response to microbial N limitation varied by family. Microbial function and metabolic limitations were strongly associated with variations in root exudates, especially amino acids and organic acids, which were directly facilitated by crop families. Our results highlight the key roles of root exudates in stimulating microbial community structure and ecological functions from the perspective of microbial nutrient limitation and improve our understanding of plant-microbe interactions in agricultural ecosystems.

Phosphorous fertilization alleviates shading stress by regulating leaf photosynthesis and the antioxidant system in mung bean (Vigna radiata L.)

Shading can limit photosynthesis and plant growth. Understanding how phosphorus (P) application mitigates the effects of shading stress on morphology and physiology of mung beans (Vigna radiata L.) is of great significance for the establishment of efficient planting structures and optimizing P-use management. The effects of various light environments (non-shading stress, S0; low light stress, S1; severe shading stress, S2) on the growth of two mung bean cultivars (Xilv1 and Yulv1) and the role of P application (0 kg ha^-1, P0; 90 kg ha^-1, P1; 150 kg ha^-1, P2) in such responses were investigated in a field experiment. Our results demonstrated that shading decreased the dry matter accumulation of mung bean markedly by limiting photosynthesis capacity and disrupting agronomic traits. For the leaf areas of the two cultivars, chlorophyll a+b, the net photosynthetic and electron transport rates were increased by 16.8%, 20.0%, 15.5%, and 12.5% under P1 treatment, and by 32.4%, 40.3%, 16.3% and 12.8% under P2 treatment, respectively, when compared to those for the non-fertilized plants under shading stress. These responses resulted in increased light capture and weak light utilization. Moreover, the activities of superoxide dismutase and peroxidase were enhanced by 20.9% and 43.7%, respectively; malondialdehyde and superoxide anion contents were reduced by 18.6% and 14.1%, respectively, under P application. These findings suggest that P application moderately mitigates the damage caused by shading stress and enhances tolerance by regulating mung bean growth. In addition, Xilv1 was more sensitive to P under shading stress than Yulv1.

Cultivar sensitivity of broomcorn millet (Panicum miliaceum L.) to nitrogen availability is associated with differences in photosynthetic physiology and nitrogen uptake

In order to explore the influences of low nitrogen (N) fertilizer on the growth performances of two broomcorn millet (Panicum miliaceum L.) cultivars with different N tolerances, the field experiment was carried out with a low-N-tolerant cultivar (BM 184) and a low-N-sensitive cultivar (BM 230) under three N levels (0, 75 and 150 kg N ha^-1) in the Loess Plateau, China. 150 kg N ha^-1 was conventional N application rate and considered as the control. Compared to typical N supply, low N fertilizer significantly weakened the photosynthetic capacity by increasing the light transmission ratio and decreasing leaf area index, resulting in reduced biomass accumulation. BM 184 held the longer duration of the biomass increase phase and larger relative growth rate than BM 230 as well as higher photosynthetic parameters (i.e., relative chlorophyll content, net photosynthetic rate, and transpiration rate) did under low N treatments. Such optimized physiological characteristics contributed to more effective N uptake and transportation from the stems, leaves, and sheaths to grains in the BM 184. Furthermore, compared with BM 230, BM 184 had higher rhizosphere soil fertility and soil enzyme activity under low N conditions; consequently, combined with the physiological characteristics for aboveground and soil nutrient status for belowground, higher productivity was obtained in BM 184 than that in BM 230 over the two years study. Overall, our results demonstrated that low-N-tolerant cultivar achieved reduced N fertilizer input with increased efficiency by optimizing growth performances in semi-arid cultivation areas.

Endogenous bioactive gibberellin/abscisic acids and enzyme activity synergistically promote the phytoremediation of alkaline soil by broomcorn millet (Panicum miliaceum L.)

Broomcorn millet (Panicum miliaceum L.), an important food crop, grows in arid and semi-arid areas that face soil saline-alkalization. To date, no studies have investigated the mechanisms by which broomcorn millet seeds respond to and tolerate alkali stress. In this study, six broomcorn millet genotypes (B102, B220, B269, B279, B289, and B297) were selected to explore the physiological and molecular mechanisms of alkali stress at the germination stage. The results showed that alkali stress delayed the germination of broomcorn millet, and α-amylase activity was positively correlated with the germination rate. After alkali stress, the genotypes with lower alkali damage rates exhibited stronger antioxidant defenses. Real-time polymerase chain reaction analysis showed that alkali stress downregulated gibberellic acid (GA) synthesis genes but upregulated GA inactivation and abscisic acid (ABA) synthesis genes. Similarly, seeds displayed lower GA concentrations and higher ABA concentrations after alkali stress. Therefore, the ratios of various GAs/ABA decreased within the range of 35.77% to approximately 96.45%. Additionally, genotypes associated with lower alkali damage rates had higher GA/ABA ratios. These findings indicate that the alkali tolerance of broomcorn millet at the germination stage may be attributed to higher GA/ABA ratios, higher α-amylase activity, and stronger antioxidant defense, which synergistically resist alkali stress. This study will contribute to molecular breeding aiming to enhance alkali-tolerance and restoration of alkaline soils.

Mung Bean (Vigna radiata L.) Source Leaf Adaptation to Shading Stress Affects Not Only Photosynthetic Physiology Metabolism but Also Control of Key Gene Expression

Shading stress strongly limits the effective growth of plants. Understanding how plant morphogenesis and physiological adaptation are generated in response to the reduced low light conditions is important for food crop development. In this study, two mung bean (Vigna radiata L.) cultivars, namely, Xilv 1 and Yulv 1, were grown in the field to explore the effects of shading stress on their growth. The results of morphology, physiology, and biochemistry analyses showed that the shading stress significantly weakened the leaf photosynthetic capacity as measured by the decreased net photosynthetic rate, stomatal conductance, and transpiration rate and increased intercellular CO₂ concentration. These responses resulted in plant morphological characteristics that increased the light energy absorption in low light conditions. Such variations occurred due to the leaf anatomical structure with destroyed palisade tissues and spongy tissues. Under shading stress, Yulv 1 showed higher physiological metabolic intensity than Xilv 1, which was related to changes in chlorophyll (Chl), such as Chl a and b, and Chl a/b ratio. Compared with normal light conditions, the Chl fluorescence values, photosynthetic assimilation substances, and enzyme activities in mung bean plants under shading stress were reduced to different extent. In addition, the relative expression levels of VrGA2ox, VrGA20ox1, VrGA3ox1, VrROT3, and VrBZR1, which are related to endogenous hormone in mung bean leaves, were upregulated by shading stress, further leading to the improvements in the concentrations of auxin, gibberellins (GAs), and brassinolide (BR). Combined with the morphological, physiological, and molecular responses, Yulv 1 has stronger tolerance and ecological adaptability to shading stress than Xilv 1. Therefore, our study provides insights into the agronomic traits and gene expressions of mung bean cultivars to enhance their adaptability to the shading stress.

Identifying the primary meteorological factors affecting the growth and development of Tartary buckwheat and a comprehensive landrace evaluation using a multi-environment phenotypic investigation

BACKGROUND

Tartary buckwheat (Fagopyrum tataricum) is a traditional edible and medicinal crop and has been praised as one of the green foods for humans in the 21st century. However, its production and promotion are restricted by the low yields of current varieties. The interaction of genotype and environment could lead to inconsistent phenotypic performance of genotypes across different environments. Climate change has intensified these effects and poses a substantial threat to crop production.

RESULTS

In the present study, the effects of meteorological factors on the phenotypic traits of 200 Tartary buckwheat landraces across four macro-environments were investigated. Overall, the phenotypic performance of these Tartary buckwheat landraces was markedly varied across the different environments. Also, the average daily temperature and precipitation had relatively higher impacts on phenotypic performance. The results also revealed the negative impacts of relative humidity on the yield-related traits. Twenty-five Tartary buckwheat landraces were ultimately identified as having good overall phenotypic performance and high yield stability.

CONCLUSION

Understanding the impacts of meteorological factors on the phenotypic performance of crops can guide appropriate measures and facilitate germplasm selection for yield enhancement in the context of climate change. The landraces selected comprehensively in this study could be used as parents or intermediate materials for breeding high-quality Tartary buckwheat varieties in the future. The methods used could also be extended to other crops for breeding and germplasm innovation. © 2021 Society of Chemical Industry.

Transcriptome analysis reveals the mechanism associated with dynamic changes in fatty acid and phytosterol content in foxtail millet (Setaria italica) during seed development

Foxtail millet (Setaria italica) is an excellent source of beneficial natural fatty acids and phytosterols. However, the mechanisms underlying the dynamic changes of fatty acids and phytosterols during seed development are unknown. In this study, a comprehensive dynamic change analysis of the bioactive compounds during seed development was conducted in two cultivars with different crude fat content (high-fat, JG 35 [5.40%]; and low-fat, JG 39 [2.90%]). GC-FID/MS analysis showed that the proportion of unsaturated fatty acids (UFAs) were higher than the saturated fatty acids (SFAs). UFA content first increased, then decreased during seed development, while SFA content showed the opposite trend. Oil contents continuously increased with seed development, especially at the S2 stage. Phytosterol contents initially increased, then decreased with seed development. Transcriptome analysis revealed that 152 genes were associated with fatty acid metabolism and phytosterol biosynthesis, of which 46 and 62 were related to UFA and phytosterol biosynthesis, respectively. Furthermore, the key genes involved in fatty acid synthesis (ACCase and FATA/B), triacylglycerol biosynthesis (LACS, GPAT, and DGAT), and phytosterols synthesis (CAS1, STM1, EGR6, and DWF1) were overexpressed. This led to maximum UFA, oil, and phytosterol accumulation in JG 35 at the S2 stage. This study reveals the mechanism behind the dynamic changes of fatty acid and phytosterol contents in foxtail millet during seed development.

Intercropping Alters the Soil Microbial Diversity and Community to Facilitate Nitrogen Assimilation: A Potential Mechanism for Increasing Proso Millet Grain Yield

Intercropping of cereals and legumes has been used in modern agricultural systems, and the soil microorganisms associated with legumes play a vital role in organic matter decomposition and nitrogen (N) fixation. This study investigated the effect of intercropping on the rhizosphere soil microbial composition and structure and how this interaction affects N absorption and utilization by plants to improve crop productivity. Experiments were conducted to analyze the rhizosphere soil microbial diversity and the relationship between microbial composition and N assimilation by proso millet (Panicum miliaceum L.) and mung bean (Vigna radiata L.) from 2017 to 2019. Four different intercropping row arrangements were evaluated, and individual plantings of proso millet and mung bean were used as controls. Microbial diversity and community composition were determined through Illumina sequencing of 16S rRNA and internal transcribed spacer (ITS) genes. The results indicated that intercropping increased N levels in the soil-plant system and this alteration was strongly dependent on changes in the microbial (bacterial and fungal) diversities and communities. The increase in bacterial alpha diversity and changes in unique operational taxonomic unit (OTU) numbers increased the soil N availability and plant N accumulation. Certain bacterial taxa (such as Proteobacteria) and fungal taxa (such as Ascomycota) were significantly altered under intercropping and showed positive responses to increased N assimilation. The average grain yield of intercropped proso millet increased by 13.9-50.1% compared to that of monoculture proso millet. Our data clearly showed that intercropping proso millet with mung bean altered the rhizosphere soil microbial diversity and community composition; thus, this intercropping system represents a potential mechanism for promoting N assimilation and increasing grain yield.

Low-nitrogen tolerance comprehensive evaluation and physiological response to nitrogen stress in broomcorn millet (Panicum miliaceum L.) seedling

Developing the new crop varieties with high productivity under low nitrogen (N) input is an important access to facilitate modern agricultural sustainability. In the present study, 20 broomcorn millet (Panicum miliaceum L.) varieties were characterized for their morphological and nutrient parameters to different low N levels in seedling. The results showed that 0.25 mM NH₄NO₃ was the standard concentration for the evaluation and identification of low-N tolerance. Through pearson's correlation analysis, principal component analysis, and subordinate function analysis, the tolerance of 20 varieties under N stress was evaluated and plant height, root length, shoot biomass, and shoot and root N content were considered as the evaluation system of low-N tolerance. Although leaves photosynthetic capacities and activities of N metabolism related enzymes showed the decreasing tendency to N stress, low-N tolerant varieties had higher activities in both leaves and roots as compared to low-N sensitive varieties. The work provides a reliable and comprehensive method for evaluating low-N tolerance in broomcorn millet and our data elucidate possible physiological adaptive mechanisms by which broomcorn millet tolerates N stress.

Linkages between nutrient ratio and the microbial community in rhizosphere soil following fertilizer management

To unravel the linkages between ecological ratios (C:N:P) and the microbial community in rhizosphere soil in response to fertilizer management, soil samples were collected from a proso millet (Panicum miliaceum L.) field under different fertilizer management systems, including nitrogen fertilizer (NF), phosphorus fertilizer (PF), combined N and P (NP) fertilizer, and organic fertilizer (OF); no fertilizer (CK) was used as a control. Furthermore, 16S rRNA and ITS gene sequencing were applied to represent the bacterial and fungal diversity in the soil. Moreover, the elemental properties, including the carbon (C), nitrogen (N), and phosphorus (P) contents, in the microbial biomass and rhizosphere soil were evaluated. The results showed that the C, N, and P contents and microbial biomass (MBC, MBN and MBP, respectively) in the rhizosphere soil were augmented following fertilizer management. Increases in the alpha diversity indices (Shannon and Chao 1) of soil bacteria and fungi were observed in response to the fertilizers, and the responses were more closely related to the soil C:N and N:P ratios than to the C:P ratio. Additionally, with high relative abundances (>1%) across all soil samples, the composition of soil microbial phyla levels revealed different trends following fertilizer management. The abundances of Actinobacteria and Gemmatimonadetes increased, while the abundances of Acidobacteria and Nitrospirae decreased (P < 0.05) following fertilizer management. Among the fungal taxa, the abundances of Ascomycota and Mortierellomycota responded positively to fertilizer. These results were largely influenced by changes in the C:N and N:P ratios in both the soil and microbial biomass. Overall, significantly increased C:N and decreased N:P ratios in the soil reflected the N deficiency that would limit increased microbial biomass and diversity. Together, all of these results indicated that interactions between ecological ratios (C:N:P) and microbial community composition play vital roles in resource imbalance in dynamic environments. Thus, N status should be an important factor for sustainable agricultural management. Moreover, the synergistic effects were better with the combination of C, N, and P or with organic fertilizer than with C, N and P separately.

Enhancement of photoelectrochemical oxidation by an amorphous nickel boride catalyst on porous BiVO4

This paper describes an amorphous nickel boride (NiB) electrocatalyst loaded on porous bismuth vanadate (BiVO₄) with high activity for oxygen evolution in photoelectrochemical water oxidation. The NiB-decorated BiVO₄ photoanode exhibits an onset potential of 0.25 V versus the reversible hydrogen electrode (vs. RHE) and a photocurrent of 3.47 mA cm^-2 at 1.23 V vs. RHE under simulated 100 mW cm^-2 irradiation.

Improvement of attention span and reaction time with hyperbaric oxygen treatment in patients with toxic injury due to mold exposure

It is, by now, well established that mold toxins (mycotoxins) can cause significant adverse health effects. In this study, 15 subjects who developed an attention deficit disorder (ADD) and slowing of reaction time at the time of exposure to mold toxins were identified. Deficits in attention span and reaction time were documented not only by taking a careful history, but also by performing a Test of Variables of Attention (TOVA). The TOVA test provides an objective measure of these two variables. It was found that mold-exposed subjects show statistically significant decreases in attention span and significant increases in reaction time to stimuli compared to controls. After ten sessions of hyperbaric oxygen treatment (HBOT), a statistically significant improvement was seen in both measures. This preliminary study suggests promising outcomes in treating mold-exposed patients with hyperbaric oxygen.

Gastric ulcers evoke hyperexcitability and enhance P2X receptor function in rat gastric sensory neurons

Tissue inflammation contributes to the development of hyperalgesia, which is at least in part due to altered properties of primary afferent neurons. We hypothesized that gastric ulcers enhance the excitability of gastric sensory neurons and increase their response to purinergic agonists. The rat stomach was surgically exposed, and a retrograde tracer [1.1'-dioctadecyl-3,3,3,'3-tetramethylindocarbocyanine methanesulfonate (DiI)] was injected into the wall of the distal stomach. Kissing ulcers (KUs) were produced by a single injection of acetic acid (0.1 ml for 45 s; 60%) into the clamped gastric lumen. Saline injection served as control. Gastric nodose ganglion (NG) or dorsal root ganglion (DRG) cells were harvested 7 days later and acutely dissociated for whole cell recordings. Based on whole cell capacitance, gastric DRG neurons exhibited larger cell size than NG neurons. Significantly more control gastric DRG neurons compared with NG counterparts had TTX-resistant action potentials. Almost all control NG neurons (90%) compared with significantly less DRG neurons (< or =38%) responded to ATP or alpha,beta-metATP. Whereas none of the control cells exhibited spontaneous activity, about 20% of the neurons from KU animals generated spontaneous action potentials. KUs enhanced excitability as shown by a decrease in threshold for action potential generation, which was in part due to an increased input resistance. This was associated with an increase in the fraction of neurons with TTX-resistant action potentials and cells responding to capsaicin and purinergic agonists. KU doubled the current density evoked by the P2X receptor agonist alpha,beta-metATP and slowed decay of the slowly desensitizing component of the current without affecting the concentration dependence of the response. These data show that KU sensitizes vagal and spinal gastric afferents by affecting both voltage- and ligand-gated channels, thereby potentially contributing to the development of dyspeptic symptoms.

Interaction of γ-aminobutyric acid receptor type B receptors and calcium channels in nociceptive transmission studied in the mouse hemisected spinal cord in vitro: withdrawal symptoms related to baclofen treatment

An in vitro mouse hemisected spinal cord was used to characterize the gamma-aminobutyric acid receptor type B (GABA(B)) modulation of the ventral root potential (VRP) in response to electrical stimulation of the dorsal root (DR). Low-intensity (LI) and high-intensity (HI) stimulation induced VRPs with progressively higher amplitude and duration. Repetitive HI-stimulation of the DR (1-10 Hz) produced windup. The selective GABA(B) receptor agonist, CGP35024, inhibited the VRPs in a dose-dependent manner. The inhibitory action of CGP35024 was blocked by CGP52432, a potent GABA(B) receptor antagonist. Following washout of the GABA(B) receptor agonist, VRPs and windup were significantly enhanced. The rebound increase of the VRP following removal of CGP35024 was also blocked by the GABA(B) receptor antagonist, CGP52432. This phenomenon is not linked to receptor desensitization, but rather due to GABA(B) receptor-induced hyperactivity of N-, P/Q-type Ca(2+) channels, as omega-CgTx GVIA and MVIIC abolished/prevented the increase. The 'rebound' enhancement of the spinal transmission after exposure to GABA(B) agonists sheds light on the possible mechanism of the severe withdrawal effects after abrupt termination of baclofen treatment in patients suffering from multiple sclerosis.

Gastric ulcers reduce A-type potassium currents in rat gastric sensory ganglion neurons

Voltage-dependent potassium currents are important contributors to neuron excitability and thus also to hypersensitivity after tissue insult. We hypothesized that gastric ulcers would alter K(+) current properties in primary sensory neurons. The rat stomach was surgically exposed, and a retrograde tracer (1,1'-dioctadecyl-3,3,3,3'-tetramethylindocarbocyanine methanesulfonate) was injected into multiple sites in the stomach wall. Inflammation and ulcers were produced by 10 injections of 20% acetic acid (HAc) in the gastric wall. Saline (Sal) injections served as control. Nodose or T9-10 dorsal root ganglia (DRG) cells were harvested and cultured 7 days later to record whole cell K(+) currents. Gastric sensory neurons expressed transient and sustained outward currents. Gastric inflammation significantly decreased the A-type K(+) current density in DRG and nodose neurons (Sal vs. HAc-DRG: 82.9 +/- 7.9 vs. 46.5 +/- 6.1 pA/pF; nodose: 149.2 +/- 10.9 vs. 71.4 +/- 11.8 pA/pF), whereas the sustained current was not altered. In addition, there was a significant shift in the steady-state inactivation to more hyperpolarized potentials in nodose neurons (Sal vs. HAc: -76.3 +/- 1.0 vs. -83.6 +/- 2.2 mV) associated with an acceleration of inactivation kinetics. These data suggest that a reduction in K(+) currents contributes, in part, to increased neuron excitability that may lead to development of dyspeptic symptoms.

Interaction of group I mGlu and NMDA receptor agonists within the dorsal horn of the spinal cord of the juvenile rat

1. The modulatory effects of mGlu receptors on NMDA-induced potential changes in spinal motoneurones were studied in vitro. 2. Selective activation of mGlu5 receptors by 10 microM (RS)-2-Chloro-5-hydroxyphenylglycine (CHPG; EC(50)=280 +/- 24 microM) did not produce any change in the ventral root potential. However, the same concentration of CHPG (10 min perfusion) significantly attenuated the NMDA-induced ventral root depolarization (VRD). The effect persisted for 10 min after washout. NMDA-induced responses returned to control in 30 min. Brief co-application of CHPG and NMDA did not alter the NMDA-induced response indicating lack of direct receptor interaction. 3. The attenuating effect of CHPG on the NMDA-induced VRD was inhibited by the mGluR5 receptor antagonist, 2-methyl-6-phenyl-ethynylpyridine (MPEP). 4. In the presence of CGP56433A, a GABA(B) receptor antagonist, the NMDA-induced VRD was unchanged. However, NMDA-induced responses were potentiated after 10 min co-application of CHPG and CGP56433A. 5. (2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate ((2R,4R)-APDC), a group II mGlu receptor agonist did not attenuate the NMDA-induced response. 6. Under normal physiological conditions group I mGlu receptor agonists activate at least two populations of neurones: (1) GABA-ergic cells, which could release GABA and inhibit dorsal horn neurones, and (2) deep dorsal horn neurones/motoneurones which express NMDA receptors. Therefore, activation of mGlu5 receptors located on GABA-ergic interneurones could influence any direct potentiating interaction between mGlu5 and NMDA receptors in spinal cord and result in depression of the VRD. In the presence of a GABA(B) receptor antagonist, the direct synergistic interaction is unmasked. These data suggest that group I mGlu receptors provide a complex modulation of spinal synaptic processes.

Induction of potent Th1-type immune responses from a novel DNA vaccine for West Nile virus New York isolate (WNV-NY1999)

West Nile virus (WNV) is a vectorborne pathogen that induces brain inflammation and death. Recently, confirmed cases of infection and deaths have occurred in the United States Mid-Atlantic region. In this study, a DNA vaccine encoding the WNV capsid protein was constructed, and the in vivo immune responses generated were investigated in DNA vaccine-immunized mice. Antigen-specific humoral and cellular immune responses were observed, including a potent induction of antigen-specific Th1 and cytotoxic T lymphocyte responses. Strong induction of Th1-type immune responses included high levels of antigen-specific elaboration of the Th1-type cytokines interferon-gamma and interleukin-2 and beta-chemokines RANTES (regulated upon activation, normal T cell-expressed and secreted) and macrophage inflammatory protein-1beta. Dramatic infiltration of CD4 and CD8 T cells and macrophages also was observed at the muscle injection site. These results support the potential utility of this method as a tool for developing immunization strategies for WNV and other emerging pathogens.

Induction of immune responses and safety profiles in rhesus macaques immunized with a DNA vaccine expressing human prostate specific antigen

Prostate specific antigen (PSA) is a widely used marker for prostate cancer, which is secreted by normal prostate cells at low levels, but is produced more substantially by cancer cells. We have previously reported on the use of a DNA vaccine construct that encodes for human PSA gene to elicit host immune responses against cells producing PSA. DNA immunization strategy delivers DNA constructs encoding for a specific immunogen into the host, who becomes the in vivo protein source for the production of antigen. This antigen then is the focus of the resulting immune response. In this study, we examine the induction of immune responses and safety profiles in rhesus macaques immunized with DNA-based PSA vaccine. We observed induction of PSA-specific humoral response as well as positive PSA-specific lymphoproliferative (LPA) response in the vaccinated macaques. We also observed that the stimulated T cells from the PSA-immunized rhesus macaques produced higher levels of Th1 type cytokine IFN-gamma than the control vector immunized animals. On the other hand, DNA immunization did not result in any adverse effects in the immunized macaques, as indicated by complete blood counts, leukocyte differentials and hepatic and renal chemistries. The macaques appeared healthy, without any physical signs of toxicity throughout the observation period. In addition, we did not observe any adverse effect on the vaccination site. The apparent safety and immunogenecity of DNA immunization in this study suggest that further evaluation of this vaccination strategy is warranted.

Engineering enhancement of immune responses to DNA-based vaccines in a prostate cancer model in rhesus macaques through the use of cytokine gene adjuvants

DNA immunization is an important vaccination technique that is being explored as an immunotherapeutic strategy against a variety of infectious diseases as well as cancer. We have been investigating the utility of DNA-based vaccine strategy against prostate cancer. We have developed a DNA vaccine construct that encodes for the human prostate specific antigen (PSA) gene. PSA expression is limited to prostate cells, and the level of PSA expression is substantially increased in prostate cancer cells. This tissue specificity makes PSA a potential target for the development of immunotherapies against prostate cancer. A DNA-based PSA vaccine was used to elicit PSA-specific host immune responses in rodent and nonhuman primate models. In an effort to enhance the clinical utility of the DNA-based PSA vaccine, we also examined the use of cytokine gene adjuvants to modulate vaccine-induced immune responses in these animal models. We observed that pCPSA vaccine-induced humoral and cellular immune responses can be modulated through the coimmunization with cytokine genes in mice, and these enhancement effects on the PSA-specific cellular responses were extended in macaques. More specifically, coimmunization with interleukin (IL)-2 cDNA construct resulted in a significant enhancement of PSA-specific antibody responses in both mice and macaque models. In contrast, coinjection of IL-12 resulted in reduction of antibody responses in both models. In mice, the groups coimmunized with IL-2, IL-12, or IL-18 showed a dramatic increase in T helper cell proliferation over the results with pCPSA alone. These results support that further evaluation of this vaccination strategy to treat prostate cancer is warranted.

Involvement of G protein-coupled receptor kinase-6 in desensitization of CGRP receptors

This investigation was undertaken to study the mechanisms of calcitonin gene-related peptide (CGRP)-mediated desensitization using recombinant porcine CGRP receptors stably expressed in human embryonic kidney (HEK-293) cells. Pretreatment of these cells with human alphaCGRP resulted in an approximately 60% decrease in CGRP-stimulated adenylyl cyclase activity and an approximately 10-fold rightward shift in the dose-response curve of CGRP. This effect was rapid (t(1/2) approximately 5 min) and was accompanied by a significant decrease in [125I]CGRP binding to membrane preparations from CGRP-pretreated cells. In contrast, CGRP pretreatment had no effect on isoproterenol- or forskolin-stimulated adenylyl cyclase activity in these cells. The potential involvement of protein kinase A or protein kinase C in CGRP-mediated desensitization was studied using selective inhibitors or activators of these kinases. Pretreatment of the cells with forskolin (adenylyl cyclase activator) or phorbol dibutyrate (protein kinase C activator) had no effect on CGRP-mediated adenylyl cyclase activity and did not influence CGRP-mediated desensitization. However, pretreatment of the cells with 2-(8-[(dimethylamino)methyl]-6,7,8, 9-tetrahydropyrido[1,2-a]indol-3-yl]-3-(1-methylindol-3-yl)m aleimide hydrochloride (Ro 32-0432) (a potent inhibitor of protein kinase C) resulted in significant attenuation of CGRP-mediated desensitization with an IC(50) approximately 3 microM. To establish whether this effect might be due to inhibition of other protein kinases by Ro 32-0432, its effect was tested against several G protein-coupled receptor kinases (GRKs). Ro 32-0432 was found to inhibit GRK2, GRK5, and GRK6 with IC(50) values of 29, 3.6, and 16 microM, respectively, suggesting that its effect on CGRP-mediated desensitization might be a result of GRK inhibition. To further test this hypothesis, as well as the potential GRK specificity, the cells were treated with antisense oligonucleotides to GRK2, GRK5, and GRK6. While GRK2 and GRK5 antisense nucleotides had no effect on CGRP-mediated desensitization, the GRK6 antisense nucleotide treatment significantly reversed CGRP-mediated desensitization. These results suggest the involvement of GRK6 in CGRP-mediated desensitization in HEK-293 cells.

LFA-3 plasmid DNA enhances Ag-specific humoral- and cellular-mediated protective immunity against herpes simplex virus-2 in vivo: involvement of CD4+ T cells in protection

Adhesion molecules are important for cell trafficking and delivery of secondary signals for stimulation of T cells and antigen-presenting cells (APCs) in a variety of immune and inflammatory responses. Adhesion molecules lymphocyte function-associated antigen (LFA)-1 and CD2 on T cells recognize intercellular adhesion molecule (ICAM)-1 and LFA-3 on APCs, respectively. Recent studies have suggested that these molecules might play a regulatory role in antigen-specific immune responses. To investigate specific roles of adhesion molecules in immune induction we coimmunized LFA-3 and ICAM-1 cDNAs with a gD plasmid vaccine and then analyzed immune modulatory effects and protection against lethal herpes simplex virus (HSV)-2 challenge. We observed that gD-specific IgG production was enhanced by LFA-3 coinjection. However, little change in IgG production was observed by ICAM-1 coinjection. Furthermore, both Th1 and Th2 IgG isotype production was driven by LFA-3. LFA-3 also enhanced Th cell proliferative responses and production of interleukin (IL)-2, interferon-gamma, IL-4, and IL-10 from splenocytes. In contrast, ICAM-1 showed slightly increasing effects on T-cell proliferation responses and cytokine production. beta-Chemokine production (RANTES, MIP-1alpha, and MCP-1) was also influenced by LFA-3 or ICAM-1. When animals were challenged with a lethal dose of HSV-2, LFA-3-coimmunized animals exhibited an enhanced survival rate, as compared to animals given ICAM-1 or gD DNA vaccine alone. This enhanced protection appears to be mediated by CD4+ T cells, as determined by in vitro and in vivo T-cell subset deletion. These studies demonstrate that adhesion molecule LFA-3 can play an important role in generating protective antigen-specific immunity in the HSV model system through increased induction of CD4+ Th1 T-cell subset.

Patients with an ultrasonographic cervical length < or =15 mm have nearly a 50% risk of early spontaneous preterm delivery

OBJECTIVE

The aim of this study was to determine the value in the prediction of spontaneous preterm delivery of ultrasonographically measured cervical length measured between 14 and 24 weeks' gestation.

STUDY DESIGN

A retrospective cohort study examined cervical length by means of a two-stage procedure, transabdominal ultrasonography followed by transvaginal ultrasonography if cervical length was <30 mm.

RESULTS

A total of 6877 patients met inclusion criteria. Mean cervical length was 37.5 mm. Odds ratios for early preterm delivery (< or =32 weeks' gestation) for patients with cervical lengths < or =10, < or =15, < or = 20, < or =25, and < or =30 mm were, respectively, 29.3 (95% confidence interval, 11.3-75.8), 24.3 (95% confidence interval, 12. 9-45.9), 18.3 (95% confidence interval, 10.8-31.0), 13.4 (95% confidence interval, 8.8-20.6), and 3.2 (95% confidence interval, 2. 4-4.4). For early preterm delivery a cervical length of < or =15 mm had a positive predictive value of 47.6%, a negative predictive value of 96.7%, a sensitivity of 8.2%, and a specificity of 99.7%.

CONCLUSIONS

A short cervix seen on a second-trimester sonogram was a powerful predictor of early spontaneous preterm delivery (< or =32 weeks' gestation). Nearly 50% of patients with a cervical length < or =15 mm had an early spontaneous preterm delivery, which suggests that clinical trials of interventions (eg, cerclage) in this population are urgently needed.

Chemokine gene adjuvants can modulate immune responses induced by DNA vaccines

Nucleic acid immunization has been shown to induce both antigen-specific cellular and humoral immune responses in vivo. Moreover, immune responses induced by DNA immunization can be enhanced by the use of molecular adjuvants. For example, coadministration of costimulatory molecules (CD80 and CD86), proinflammatory cytokines (interleukin-1alpha [IL-1alpha], tumor necrosis factor-alpha [TNF-alpha, and TNF-beta), Th1 cytokines (interleukin-2 [IL-2], IL-12, IL-15, and IL-18), Th2 cytokines (IL-4, IL-5, and IL-10), and granulocytes-macrophage colony-stimulating factor (GM-CSF) with DNA vaccine constructs leads to modulation of the magnitude and direction (humoral or cellular) of the immune responses. To further engineer the immune response in vivo, we compared the induction and regulation of immune responses from the codelivery of chemokine (IL-8, interferon-gamma-inducible protein-10 [gammaIP-10], macrophage inhibitory protein-1alpha [MIP-1alpha], and RANTES) genes with codelivery of cytokine genes. We found that as in cytokine gene codelivery, coimmunization with chemokine genes along with DNA immunogen constructs can modulate the direction and magnitude of induced immune responses. We observed that coimmunization with IL-8, gammaIP-10, and MIP-1alpha genes increased the antibody response. We also found that coinjection with IL-8, gammaIP-10, and RANTES resulted in a dramatic enhancement of T helper (Th) proliferation response. Furthermore, among all coinjection combinations, we found that RANTES coinjection caused a high level of cytotoxic lymphocyte (CTL) enhancement. This enhancement of CTL responses observed from the coinjection with RANTES was CD8+ T cell dependent. Together with earlier reports on the utility of coimmunizing immunologically important molecules with DNA immunogens, we demonstrate the potential of this strategy as an important tool for the development of more rationally designed vaccines.

Factors associated with fetal macrosomia in offspring of gestational diabetic women

OBJECTIVE

To determine whether there is a relationship between birthweight and interval between 1-h and 3-h glucose tolerance test (GTT) as well as other factors.

METHODS

We performed a retrospective analysis of our computerized diabetes database for the years 1992-1997. Ninety-four women with gestational diabetes fulfilled the inclusion criteria (i.e., singleton gestation, term delivery, absence of medical conditions, and known interval between 1-h and 3-h GTT). They were evaluated based on prepregnancy body mass index (BMI), mean glucose values, interval between diagnostic testing, and gestational age of 3-h GTT.

RESULTS

Subjects with GDM had a mean glucose value of 96.8 mg/dl and average prepregnancy BMI of 29.3 kg/m2. When GDM subjects with and without macrosomic infants were compared, mean glucose values (97.4 vs. 96.6 mg/dl) and mean interval (18.1 vs. 17.0 days) between diagnostic testing did not significantly differ. However, maternal prepregnancy BMI was higher in the group of women who gave birth to macrosomic infants (32.2 vs. 28.22 kg/m2, P = 0.008). Using stepwise multiple regression, maternal prepregnancy BMI was the only variable found to be predictive of macrosomia.

CONCLUSION

We were unable to show a statistical relationship between interval of diagnostic testing and rate of macrosomia. However, we demonstrated a clear relationship between maternal BMI and infant birthweight.

Macrophage colony-stimulating factor can modulate immune responses and attract dendritic cells in vivo

Studies have indicated that professional APCs in the periphery, such as dendritic cells and macrophages, play an important role in initiating DNA vaccine-specific immune responses. To engineer the immune response induced by DNA vaccines in vivo we investigated the modulatory effects of codelivering growth factor genes for the hematopoietic APCs along with DNA vaccines. Specifically, we examined the effects on the antigen-specific immune responses following the codelivery of the gene expression cassettes for M-CSF, G-CSF, and GM-CSF along with HIV-1 DNA immunogen constructs. We observed that coimmunization with GM-CSF increased the antibody response and resulted in a significant enhancement of lymphoproliferative response. Furthermore, among all coinjection combinations, we found that M-CSF coinjections resulted in a high level of CTL enhancement. This enhancement of CTL responses observed from the coinjection with M-CSF was CD8+ T cell dependent and was associated with the presence of CD11c+ cells at the site of injection and with the antigen-specific induction of the beta-chemokine MIP-1beta, suggesting a role for this chemokine in CTL induction. These results suggest that hematopoietic growth factors should be further studied as potential adjuvants for in vivo modulators of immune responses.

Comparative affinities of adrenomedullin (AM) and calcitonin gene-related peptide (CGRP) for [125I] AM and [125I] CGRP specific binding sites in porcine tissues

We have investigated the binding characteristics of rat [125I] adrenomedullin (AM) and human [125I] calcitonin gene-related peptide (CGRP) to membranes prepared from a number of porcine tissues including atrium, ventricle, lung, spleen, liver, renal cortex and medulla. These membranes displayed specific, high affinity binding for [125I] rat AM and [125I] human CGRP. Porcine lung displayed the highest density of binding sites for radiolabeled AM and CGRP followed by porcine renal cortex. Competition experiments performed with [125I] rat AM indicated that the rank order of potencies of various peptides for inhibiting [125I] rat AM binding to various tissues were rat AM > or = human AM > or = human AM(22-52) > h alpha CGRP > or = h alpha CGRP(8-37) >>>> sCT except spleen, atrium, renal cortex and renal medulla where rAM and hAM were 20-300 fold more potent than hAM (22-52). When the same experiments were performed using [125I] h alpha CGRP as the radioligand, the rank order potencies for various peptides were rAM = hAM > h alpha CGRP > h alpha CGRP(8-37) in most of the tissues except in spleen and liver where h alpha CGRP was the most potent ligand. In lung, h alpha CGRP was almost as potent as rAM and hAM in displacing [125I] h alpha CGRP binding. These data suggest the existence of distinct CGRP and AM specific binding sites in contrast to previous reports that showed that both peptides interact differently in rat tissues.

CD86 (B7-2) can function to drive MHC-restricted antigen-specific CTL responses in vivo

Activation of T cells requires both TCR-specific ligation by direct contact with peptide Ag-MHC complexes and coligation of the B7 family of ligands through CD28/CTLA-4 on the T cell surface. We recently reported that coadministration of CD86 cDNA along with DNA encoding HIV-1 Ags i.m. dramatically increased Ag-specific CTL responses. We investigated whether the bone marrow-derived professional APCs or muscle cells were responsible for the enhancement of CTL responses following CD86 coadministration. Accordingly, we analyzed CTL induction in bone marrow chimeras. These chimeras are capable of generating functional viral-specific CTLs against vaccinia virus and therefore represent a useful model system to study APC/T cell function in vivo. In vaccinated chimeras, we observed that only CD86 + Ag + MHC class I results in 1) detectable CTLs following in vitro restimulation, 2) detectable direct CTLs, 3) enhanced IFN-gamma production in an Ag-specific manner, and 4) dramatic tissue invasion of T cells. These results support that CD86 plays a central role in CTL induction in vivo, enabling non-bone marrow-derived cells to prime CTLs, a property previously associated solely with bone marrow-derived APCs.

Intracellular adhesion molecule-1 modulates beta-chemokines and directly costimulates T cells in vivo

The potential roles of adhesion molecules in the expansion of T cell-mediated immune responses in the periphery were examined using DNA immunogen constructs as model antigens. We coimmunized cDNA expression cassettes encoding the adhesion molecules intracellular adhesion molecule-1 (ICAM-1), lymphocyte function associated-3 (LFA-3), and vascular cell adhesion molecule-1 (VCAM-1) along with DNA immunogens, and we analyzed the resulting antigen-specific immune responses. We observed that antigen-specific T-cell responses can be enhanced by the coexpression of DNA immunogen and adhesion molecules ICAM-1 and LFA-3. Coexpression of ICAM-1 or LFA-3 molecules along with DNA immunogens resulted in a significant enhancement of T-helper cell proliferative responses. In addition, coimmunization with pCICAM-1 (and more moderately with pCLFA-3) resulted in a dramatic enhancement of CD8-restricted cytotoxic T-lymphocyte responses. Although VCAM-1 and ICAM-1 are similar in size, VCAM-1 coimmunization did not have any measurable effect on cell-mediated responses. These results suggest that ICAM-1 and LFA-3 provide direct T-cell costimulation. These observations are further supported by the finding that coinjection with ICAM-1 dramatically enhanced the level of interferon-gamma (IFN-gamma) and beta-chemokines macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and regulated on activation normal T-cell expression and secreted (RANTES) produced by stimulated T cells. Through comparative studies, we observed that ICAM-1/LFA-1 T-cell costimulatory pathways are independent of CD86/CD28 pathways and that they may synergistically expand T-cell responses in vivo.

Cytokine molecular adjuvants modulate immune responses induced by DNA vaccine constructs for HIV-1 and SIV

DNA or nucleic acid immunization has been shown to induce both antigen-specific cellular and humoral immune responses in vivo. Moreover, immune responses induced by DNA immunization can be enhanced and modulated by the use of molecular adjuvants. To further engineer the immune response in vivo, we investigated the induction and regulation of immune responses from the codelivery of Thl cytokines (interleukin-2 [IL-2] and IL-12), Th2 cytokines (IL-4 and IL-10), and granulocyte-macrophage colony-stimulating factor (GM-CSF) genes along with a DNA vaccine construct encoding for simian immunodeficiency virus (SIV) gag/pol proteins. We observed that coinjection with IL-2, IL-4, IL-10, and GM-CSF resulted in increased levels of antigen-specific antibodies. In addition, we found that coinjection with cytokine genes drove the immune responses toward a more Thl or Th2 phenotype. We also observed that coadministration of IL-2, IL-12, and GM-CSF genes resulted in a dramatic enhancement of Th proliferation responses. Moreover, coimmunization with IL-12 genes resulted in a dramatic enhancement of antigen-specific cytotoxic T lymphocyte (CTL) responses. These results support the potential utility of molecular adjuvants in DNA vaccine regimens.

Volume-length impact of lateral jaw resections on complication rates

OBJECTIVE

To study the relationship between soft tissue volume loss and bone resection length following lateral segmental mandibulectomy with plate reconstruction and complication rates.

DESIGN

Retrospective case review of 31 patients (1989-1996), with average follow-up of 37.2 months, who were treated by lateral composite resection for oral cavity and/or oropharyngeal malignancy with primary reconstruction by defect-bridging plates.

SETTING

Academic tertiary care referral center.

INTERVENTIONS

Thirty patients had stainless steel and 1 patient a vitallium reconstruction plate to restore mandibular continuity. Soft tissue defects were repaired with pectoralis myocutaneous flaps (n = 25), skin grafts (n = 4), a radial forearm free flap (n = 1), or primary closure (n = 1). All patients received preoperative (n = 6) or postoperative (n = 25) radiation therapy.

MAIN OUTCOME MEASURES

Overall and hardware-related complications.

RESULTS

All 31 initial soft tissue repairs were successful. Subsequent complications occurred in 14 patients (45%), which included plate exposure (29%), loosened screws requiring hardware removal (29%), fistula (14%), local wound infection (14%), osteomyelitis (7%), and plate fracture (7%). Average time to complication was 7.7 months. Complication rates were 81% for bone defects greater than 5.0 cm, and 7% for those less than 5.0 cm. Bivariate analysis indicated bone resection lengths greater than 5.0 cm to be a significant predictor of both hardware-related (P = .02) and overall complications (P = .005), whereas soft tissue volume resections greater than 240 cm3 were found only to be marginally significant (P = .04) for overall complications.

CONCLUSION

Extirpative losses involving more than 5 cm of bone, or tissue volume greater than 240 cm3, are associated with unacceptably high complication rates when reconstructed with solid screw stainless steel plates and this warrants consideration of alternative techniques for long-term stability.

Molecular and immunological analysis of genetic prostate specific antigen (PSA) vaccine

Nucleic acid immunization has been investigated as immunotherapy for infectious diseases as well as for treating specific types of cancers. In this approach, nucleic acid expression cassettes are directly inoculated into the host, whose transfected cells become the production source of novel and possibly immunologically foreign protein. We have developed a DNA vaccine construct which encodes for PSA by cloning a cDNA for PSA into a mammalian expression vector under control of a CMV promoter. We investigated and characterized the immunogenicity of PSA DNA expression cassettes in mice. PSA-specific immune responses induced in vivo by immunization were characterized by enzyme-linked immunosorbent assay (ELISA), T helper proliferation cytotoxic T lymphocyte (CTL), and flow cytometry assays. We observed a strong and persistent antibody response against PSA for at least 180 days following immunization. In addition, a significant T helper cell proliferation was observed against PSA protein. Using synthetic peptides spanning the PSA open frame, we identified four dominant T helper epitopes of PSA. Furthermore, immunization with PSA plasmid induced MHC Class I CD8+ T cell-restricted cytotoxic T lymphocyte response against tumor cell targets expressing PSA. The prostate represents a very specific functional organ critical for reproduction but not for the health and survival of the individual. Understanding the immunogenicity of PSA DNA immunization cassettes offers insight into the possible use of this tumor-associated antigen as a target for immunotherapy. These results demonstrate the ability of the genetic PSA to serve as a specific immune target capable of generating both humoral and cellular immune responses in vivo.

CD8 positive T cells influence antigen-specific immune responses through the expression of chemokines

The potential roles of CD8(+) T-cell-induced chemokines in the expansion of immune responses were examined using DNA immunogen constructs as model antigens. We coimmunized cDNA expression cassettes encoding the alpha-chemokines IL-8 and SDF-1alpha and the beta-chemokines MIP-1alpha, RANTES, and MCP-1 along with DNA immunogens and analyzed the resulting antigen-specific immune responses. In a manner more similar to the traditional immune modulatory role of CD4(+) T cells via the expression of Th1 or Th2 cytokines, CD8(+) T cells appeared to play an important role in immune expansion and effector function by producing chemokines. For instance, IL-8 was a strong inducer of CD4(+) T cells, indicated by strong T helper proliferative responses as well as an enhancement of antibody responses. MIP-1alpha had a dramatic effect on antibody responses and modulated the shift of immune responses to a Th2-type response. RANTES coimmunization enhanced the levels of antigen-specific Th1 and cytotoxic T lymphocyte (CTL) responses. Among the chemokines examined, MCP-1 was the most potent activator of CD8(+) CTL activity. The enhanced CTL results are supported by the increased expression of Th1 cytokines IFN-gamma and TNF-alpha and the reduction of IgG1/IgG2a ratio. Our results support that CD8(+) T cells may expand both humoral and cellular responses in vivo through the elaboration of specific chemokines at the peripheral site of infection during the effector stage of the immune response.

Modulation of amplitude and direction of in vivo immune responses by co-administration of cytokine gene expression cassettes with DNA immunogens

Immunization with nucleic acids has been shown to induce both antigen-specific cellular and humoral immune responses in vivo. We hypothesize that immunization with DNA could be enhanced by directing specific immune responses induced by the vaccine based on the differential correlates of protection known for a particular pathogen. Recently we and others reported that specific immune responses generated by DNA vaccine could be modulated by co-delivery of gene expression cassettes encoding for IL-12, granulocyte-macrophage colony-stimulating factor and the co-stimulatory molecule CD86. To further engineer the immune response in vivo, we investigated the induction and regulation of immune responses following the co-delivery of pro-inflammatory cytokine (IL-1 alpha, TNF-alpha, and TNF-beta), Th1 cytokine (IL-2, IL-12, IL-15, and IL-18), and Th2 cytokine (IL-4, IL-5 and IL-10) genes. We observed enhancement of antigen-specific humoral response with the co-delivery of Th2 cytokine genes IL-4, IL-5, and IL-10 as well as those of IL-2 and IL-18. A dramatic increase in antigen-specific T helper cell proliferation was seen with IL-2 and TNF-alpha gene co-injections. In addition, we observed a significant enhancement of the cytotoxic response with the co-administration of TNF-alpha and IL-15 genes with HIV-1 DNA immunogens. These increases in CTL response were both MHC class I restricted and CD8+ T cell dependent. Together with earlier reports on the utility of co-immunizing using immunologically important molecules together with DNA immunogens, we demonstrate the potential of this strategy as an important tool for the development of more rationally designed vaccines.

Modulation of amplitude and direction of in vivo immune responses by co-administration of cytokine gene expression cassettes with DNA immunogens

Immunization with nucleic acids has been shown to induce both antigen-specific cellular and humoral immune responses in vivo. We hypothesize that immunization with DNA could be enhanced by directing specific immune responses induced by the vaccine based on the differential correlates of protection known for a particular pathogen. Recently we and others reported that specific immune responses generated by DNA vaccine could be modulated by co-delivery of gene expression cassettes encoding for IL-12, granulocyte-macrophage colony-stimulating factor and the co-stimulatory molecule CD86. To further engineer the immune response in vivo, we investigated the induction and regulation of immune responses following the co-delivery of pro-inflammatory cytokine (IL-1 alpha, TNF-alpha, and TNF-beta), Th1 cytokine (IL-2, IL-12, IL-15, and IL-18), and Th2 cytokine (IL-4, IL-5 and IL-10) genes. We observed enhancement of antigen-specific humoral response with the co-delivery of Th2 cytokine genes IL-4, IL-5, and IL-10 as well as those of IL-2 and IL-18. A dramatic increase in antigen-specific T helper cell proliferation was seen with IL-2 and TNF-alpha gene co-injections. In addition, we observed a significant enhancement of the cytotoxic response with the co-administration of TNF-alpha and IL-15 genes with HIV-1 DNA immunogens. These increases in CTL response were both MHC class I restricted and CD8+ T cell dependent. Together with earlier reports on the utility of co-immunizing using immunologically important molecules together with DNA immunogens, we demonstrate the potential of this strategy as an important tool for the development of more rationally designed vaccines.

Interaction of adrenomedullin with calcitonin receptor in cultured human breast cancer cells, T 47D

Human adrenomedullin (hADM), human calcitonin gene-related peptide (hCGRP), and salmon calcitonin (sCT)-activated adenylyl cyclase with EC50 values of 132, 764, and 0.5 nM, respectively, in human breast cancer cell line, T 47D. Treatment of T 47D cell membranes with near maximal concentrations of sCT, hADM and hCGRP had no additive effect on adenylyl cyclase activity. Salmon calcitonin (8-32)[sCT (8-32)], selective antagonist of calcitonin receptor, inhibited the activation of adenylyl cyclase by these three peptides. On the other hand, the putative ADM receptor antagonist, ADM (22-52), and CGRP receptor antagonist, CGRP (8-37), failed to inhibit ADM-, CGRP- or sCT-activated adenylyl cyclase. These results suggest that in T47D cells, both ADM and CGRP activated adenylyl cyclase through sCT receptors.

Evidence for histamine involvement in the effect of histidine loads on food and water intake in rats

We examined the hypothesis that histidine is a regulator of short-term food and water intake in rats and that this control is through histidine's action as a precursor for histamine. The primary objectives were to measure food and water intake after histidine monohydrochloride monohydrate (His-HCl) given by intragastric (IG) and intraperitoneal (IP) routes of administration and to measure feeding and drinking responses to histidine when given after blockade of the histaminergic pathway by chlorpheniramine (CPA) and alpha-fluoromethylhistidine (FMH). Eight experiments were conducted using a back-to-back design. Rats were given treatment by IP or IG administration, and food and water intake was measured during time periods of 0-1, 1-2, 2-3 and 3-14 h. Histidine consistently reduced food intake with the sensitivity to IP much greater than to the IG route. The effect of histidine given by IP or IG on water intake was similar, generally causing an increase at least in the first hour. Histidine's action was not accounted for by its energy, pH or nitrogen content. Because FMH, which blocks the enzyme converting histidine to histamine, partially reversed the effect of histidine on food and water intake, these results support the hypothesis that histidine regulates food and water intake, at least in part, through its precursor control of histamine.

Engineering of in vivo immune responses to DNA immunization via codelivery of costimulatory molecule genes

Nucleic acid immunization is a novel vaccination technique to induce antigen-specific immune responses. We have developed expression cassettes for cell surface markers CD80 and CD86, two functionally related costimulatory molecules that play an important role in the induction of T cell-mediated immune responses. Coimmunization of these expression plasmids, along with plasmid DNA encoding for HIV-1 antigens, did not result in any significant change in the humoral response; however, we observed a dramatic increase in cytotoxic T-lymphocyte (CTL) induction as well as T-helper cell proliferation after the coadministration of CD86 genes. In contrast, coimmunization with a CD80 expression cassette resulted in a minor, but positive increase in T-helper cell or CTL responses. This strategy may be of value for the generation of rationally designed vaccines and immune therapeutics.

Mucosal immunization with a DNA vaccine induces immune responses against HIV-1 at a mucosal site

Mucosal immunity is the first defense system in protection against mucosal infection by sexually transmitted diseases and subsequent systemic dissemination of infection. Development of vaccines which can induce protective mucosal immunity would have great promise for preventing sexually transmitted diseases including AIDS. DNA vaccines have recently shown certain advantages over other types of vaccines in safety and elicitation of specific immune responses. We have hypothesized that direct delivery of a DNA plasmid coding the HIV-1 envelope (pcMN160) via mucosal routes will stimulate mucosal immunity against HIV-1. The expression of DNA plasmid inoculated intravaginally was detected in various tissues. Intravaginal inoculation of pcMN160 elicits production of vaginal immunoglobulins which specifically bind to the HIV-1 envelope and neutralize HIV-1 infectivity in vitro. These results indicate the feasibility of inducing mucosal immunity following mucosal inoculation of DNA vaccines. When coupled with systemic inoculation of appropriate DNA constructs, effective mucosal and systemic immunity may be generated.

Safety and immunogenicity of intramuscular and intravaginal delivery of HIV-1 DNA constructs to infant chimpanzees

Any global strategy for controlling the human immunodeficiency virus (HIV) epidemic is likely to rely heavily on immunization of infants and children. Given the well-documented differences in children's responses to traditional vaccines, we initiated this study to extend our findings on DNA vaccination of adult chimpanzees to immunologically immature infant chimpanzees. Our findings were consistent with our previous work in adults as we observed that the DNA vaccines used here were both well tolerated and immunogenic within weeks of the initial vaccination.

In vivo engineering of a cellular immune response by coadministration of IL-12 expression vector with a DNA immunogen

Recent studies support the importance of investigating a DNA vaccination approach for the immunologic control of HIV-1. In this regard, it may be important to specifically engineer immune responses in order to improve on first generation vaccine attempts. Especially for HIV, induction of cell-mediated immunity may be an important feature for any candidate vaccine. In an attempt to engineer in vivo the enhancement of cellular immune response and to direct Ag-dependent immune response from Th2 to Th1 type, we investigated the role of codelivery of genes for IL-12 and granulocyte-macrophage-CSF along with DNA vaccine formulations for HIV-1 Ag. We found that codelivery of IL-12 expression cassettes with DNA vaccines for HIV-1 in mice resulted in splenomegaly as well as a shift in the specific immune responses induced. The codelivery of IL-12 genes resulted in the reduction of specific Ab response, while the coinjection of granulocyte-macrophage-CSF genes resulted in the enhancement of specific Ab response. In addition, we observed a significant Ag-specific stimulation of T cells with codelivery of both cytokines. Most importantly, we observed a dramatic increase in specific CTL response from the group coimmunized with the HIV-1 DNA vaccine and IL-12 genes. This work demonstrates the power of DNA delivery in vivo for both the production of a new generation of more effective and targeted vaccines or immunotherapies as well as an analytic tool for the molecular dissection of the mechanisms of immune function.

In vivo engineering of a cellular immune response by coadministration of IL-12 expression vector with a DNA immunogen

Recent studies support the importance of investigating a DNA vaccination approach for the immunologic control of HIV-1. In this regard, it may be important to specifically engineer immune responses in order to improve on first generation vaccine attempts. Especially for HIV, induction of cell-mediated immunity may be an important feature for any candidate vaccine. In an attempt to engineer in vivo the enhancement of cellular immune response and to direct Ag-dependent immune response from Th2 to Th1 type, we investigated the role of codelivery of genes for IL-12 and granulocyte-macrophage-CSF along with DNA vaccine formulations for HIV-1 Ag. We found that codelivery of IL-12 expression cassettes with DNA vaccines for HIV-1 in mice resulted in splenomegaly as well as a shift in the specific immune responses induced. The codelivery of IL-12 genes resulted in the reduction of specific Ab response, while the coinjection of granulocyte-macrophage-CSF genes resulted in the enhancement of specific Ab response. In addition, we observed a significant Ag-specific stimulation of T cells with codelivery of both cytokines. Most importantly, we observed a dramatic increase in specific CTL response from the group coimmunized with the HIV-1 DNA vaccine and IL-12 genes. This work demonstrates the power of DNA delivery in vivo for both the production of a new generation of more effective and targeted vaccines or immunotherapies as well as an analytic tool for the molecular dissection of the mechanisms of immune function.

In vivo protective anti-HIV immune responses in non-human primates through DNA immunization

An effective immune response involves the specific recognition of and elimination of an infectious organism at multiple levels. In this context DNA immunization can present functional antigenic proteins to the host for recognition by all arms of the immune system, yet provides the opportunity to delete any genes of the infectious organism which code for antigens or pieces of antigens that may have deleterious effects. Our group has developed the use of nucleic acid immunization as a possible method of vaccination against Human immunodeficiency virus type 1 (HIV-1) [1,2,3,10,11,12]. Sera from non-human primates immunized with DNA vectors that express the envelope proteins from HIV-1 contain antibodies specific to the HIV-1 envelope. These sera also neutralize HIV-1 infection in vitro and inhibit cell to cell infection in tissue culture. Analysis of cellular responses is equally encouraging. T cell proliferation as well as cytotoxic T cell lysis of relevant env expressing target cells were observed. In addition, evidence that DNA vaccines are capable of inducing a protective response against live virus was demonstrated using a chimeric SIV/HIV (SHIV) challenge in vaccinated cynomologous macaques. We found that nucleic acid vaccination induced protection from challenge in one out of four immunized cynomolgus macaques and viral load was lower in the vaccinated group of animals versus the control group of animals. These data encouraged us to analyze this vaccination technique in chimpanzees, the most closely related animal species to man. We observed the induction of both cellular and humoral immune responses with a DNA vaccine in chimpanzees. These studies demonstrate the utility of this technology to induce relevant immune responses in primates which may ultimately lead to effective vaccines.

DNA inoculation induces cross clade anti-HIV-1 responses

Nucleic acid or DNA immunization represents a novel approach to vaccine and immune therapeutic development. The direct injection of expression cassettes into a living host results in in vivo gene expression and immune activation. In the case of HIV-1 it has been shown by our laboratory that facilitated injection mimicks aspects of live attenuated vaccines and that both humoral and cellular responses can be induced upon injection of a nucleic acid sequence directly into a host target tissue. Antisera from HIV-1 plasmid expression cassette-immunized animals contain anti-HIV envelope glycoprotein immune responses. The antiserum neutralizes HIV-1 infection and inhibits cell to cell infection in vitro. Cellular immune responses have also been evaluated. We observed both T cell proliferation and isotype switching consistent with the production of relevant T helper immune responses in immunized animals. Furthermore it was demonstrated that CTL lysis of relevant env-expressing targets was similarly induced. These studies further define the importance of evaluating this new technology for vaccine and immune therapeutic development for HIV-1 as well as for other human viral pathogens.