Conserved molecular chaperone PrsA stimulates protective immunity against group A Streptococcus

Group A Streptococcus (GAS) is a significant human pathogen that poses a global health concern. However, the development of a GAS vaccine has been challenging due to the multitude of diverse M-types and the risk of triggering cross-reactive immune responses. Our previous research has identified a critical role of PrsA1 and PrsA2, surface post-translational molecular chaperone proteins, in maintaining GAS proteome homeostasis and virulence traits. In this study, we aimed to further explore the potential of PrsA1 and PrsA2 as vaccine candidates for preventing GAS infection. We found that PrsA1 and PrsA2 are highly conserved among GAS isolates, demonstrating minimal amino acid variation. Antibodies specifically targeting PrsA1/A2 showed no cross-reactivity with human heart proteins and effectively enhanced neutrophil opsonophagocytic killing of various GAS serotypes. Additionally, passive transfer of PrsA1/A2-specific antibodies conferred protective immunity in infected mice. Compared to alum, immunization with CFA-adjuvanted PrsA1/A2 induced higher levels of Th1-associated IgG isotypes and complement activation and provided approximately 70% protection against invasive GAS challenge. These findings highlight the potential of PrsA1 and PrsA2 as universal vaccine candidates for the development of an effective GAS vaccine.

Subunit vaccines with a saponin-based adjuvant boost humoral and cellular immunity to MERS coronavirus

Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks have constituted a public health issue with drastic mortality higher than 34%, necessitating the development of an effective vaccine. During MERS-CoV infection, the trimeric spike protein on the viral envelope is primarily responsible for attachment to host cellular receptor, dipeptidyl peptidase 4 (DPP4). With the goal of generating a protein-based prophylactic, we designed a subunit vaccine comprising the recombinant S1 protein with a trimerization motif (S1-Fd) and examined its immunogenicity and protective immune responses in combination with various adjuvants. We found that sera from immunized wild-type and human DPP4 transgenic mice contained S1-specific antibodies that can neutralize MERS-CoV infection in susceptible cells. Vaccination with S1-Fd protein in combination with a saponin-based QS-21 adjuvant provided long-term humoral as well as cellular immunity in mice. Our findings highlight the significance of the trimeric S1 protein in the development of MERS-CoV vaccines and offer a suitable adjuvant, QS-21, to induce robust and prolonged memory T cell response.

[Spatiotemporal changes of COVID-19 outbreak in Shanghai]

Objective: To clarify the epidemiological characteristics and spatiotemporal clustering dynamics of COVID-19 in Shanghai in 2022. Methods: The COVID-19 data presented on the official websites of Municipal Health Commissions of Shanghai during March 1, 2022 and May 31, 2022 were collected for a spatial autocorrelation analysis by GeoDa software. A logistic growth model was used to fit the epidemic situation and make a comparison with the actual infection situation. Results: Pudong district had the highest number of symptomatic and asymptomatic infectants, accounting for 29.30% and 35.58% of the total infectants. Differences in cumulative attack rates and infection rates among 16 districts (P<0.001) were significant. The rates were significantly higher in Huangpu district than in other districts. The attack rate of COVID-19 from March 1, 2022 to May 31, 2022 had a global spatial positive correlation (P<0.05). Spatial distribution of COVID-19 attack rate was different at different periods. The global autocorrelation coefficient from March 16 to March 29, April 6 to April 12 and May 18 to May 24 had no statistical significance (P>0.05). Our local autocorrelation analysis showed that 22 high-high clustering areas were detected in eight periods.The high-risk hot-spot areas have experienced a "less-more-less" change process. The growth model fitting results were consistent with the actual infection situation. Conclusion: There was a clear spatiotemporal correlation in the distribution of COVID-19 in Shanghai. The comprehensive prevention and control measures of COVID-19 epidemic in Shanghai have effectively prohibited the growth of the epidemic, not only curbing the spatially spread of high-risk epidemic areas, but also reducing the risk of transmission to other cities.

Estimating Local Cellular Density in Glioma Using MR Imaging Data

BACKGROUND AND PURPOSE

Increased cellular density is a hallmark of gliomas, both in the bulk of the tumor and in areas of tumor infiltration into surrounding brain. Altered cellular density causes altered imaging findings, but the degree to which cellular density can be quantitatively estimated from imaging is unknown. The purpose of this study was to discover the best MR imaging and processing techniques to make quantitative and spatially specific estimates of cellular density.

MATERIALS AND METHODS

We collected stereotactic biopsies in a prospective imaging clinical trial targeting untreated patients with gliomas at our institution undergoing their first resection. The data included preoperative MR imaging with conventional anatomic, diffusion, perfusion, and permeability sequences and quantitative histopathology on biopsy samples. We then used multiple machine learning methodologies to estimate cellular density using local intensity information from the MR images and quantitative cellular density measurements at the biopsy coordinates as the criterion standard.

RESULTS

The random forest methodology estimated cellular density with R 2 = 0.59 between predicted and observed values using 4 input imaging sequences chosen from our full set of imaging data (T2, fractional anisotropy, CBF, and area under the curve from permeability imaging). Limiting input to conventional MR images (T1 pre- and postcontrast, T2, and FLAIR) yielded slightly degraded performance (R2 = 0.52). Outputs were also reported as graphic maps.

CONCLUSIONS

Cellular density can be estimated with moderate-to-strong correlations using MR imaging inputs. The random forest machine learning model provided the best estimates. These spatially specific estimates of cellular density will likely be useful in guiding both diagnosis and treatment.

Imaging-Based Algorithm for the Local Grading of Glioma

BACKGROUND AND PURPOSE

Gliomas are highly heterogeneous tumors, and optimal treatment depends on identifying and locating the highest grade disease present. Imaging techniques for doing so are generally not validated against the histopathologic criterion standard. The purpose of this work was to estimate the local glioma grade using a machine learning model trained on preoperative image data and spatially specific tumor samples. The value of imaging in patients with brain tumor can be enhanced if pathologic data can be estimated from imaging input using predictive models.

MATERIALS AND METHODS

Patients with gliomas were enrolled in a prospective clinical imaging trial between 2013 and 2016. MR imaging was performed with anatomic, diffusion, permeability, and perfusion sequences, followed by image-guided stereotactic biopsy before resection. An imaging description was developed for each biopsy, and multiclass machine learning models were built to predict the World Health Organization grade. Models were assessed on classification accuracy, Cohen κ, precision, and recall.

RESULTS

Twenty-three patients (with 7/9/7 grade II/III/IV gliomas) had analyzable imaging-pathologic pairs, yielding 52 biopsy sites. The random forest method was the best algorithm tested. Tumor grade was predicted at 96% accuracy (κ = 0.93) using 4 inputs (T2, ADC, CBV, and transfer constant from dynamic contrast-enhanced imaging). By means of the conventional imaging only, the overall accuracy decreased (89% overall, κ = 0.79) and 43% of high-grade samples were misclassified as lower-grade disease.

CONCLUSIONS

We found that local pathologic grade can be predicted with a high accuracy using clinical imaging data. Advanced imaging data improved this accuracy, adding value to conventional imaging. Confirmatory imaging trials are justified.

Challenges of Vaccine Development for Zika Virus

The emergence of outbreaks of Zika virus (ZIKV) in Brazil in 2015 was associated with devastating effects on fetal development and prompted a world health emergency and multiple efforts to generate an effective vaccine against infection. There are now more than 40 vaccine candidates in preclinical development and six in clinical trials. Despite similarities with other flaviviruses to which successful vaccines have been developed, such as yellow fever virus and Japanese Encephalitis virus, there are unique challenges to the development and clinical trials of a vaccine for ZIKV.

[Enhancing Soft-tissue Reattachment with Artificial Mesh in Joint Endoprosthetic Reconstruction for Bone Tumors]

Objective: To investigate the operative method and clinical application of the BARD(®) Mesh in enhancing joint stability and function of endoprosthetic reconstruction for bone tumors. Methods: From Jan 2013 to Jun 2015, the clinical data of 51 patients aged (44.75±23.18) years underwent wide resection of tumor and endoprosthetic reconstruction using the BARD(®) Mesh were collected. Among them, 27 were male and 24 were female. The surgical treatments received by these patients included 5 shoulder arthroplasties, 12 elbow replacements, 12 hip replacements and 32 knee replacements (including 24 femoral tumors and 8 tibial tumors). According to the pathologic type, there were 12 metastatic tumors, 20 osteosarcomas, 7 chondrosarcomas, 5 malignant fibrous histiocytomas, 4 giant cell tumors of bone, 1 Ewing sarcoma, 1 leiomyosarcoma and 1 pigmented villonodular synovitis (pvns). These patients received extensive tumor resection, tumorous prosthesis replacement, preserved articular capsule and muscles repair with artificial mesh and endoprosthesis wrapping. The curative effect including joints range of motion and Musculoskeletal Tumour Society Scores (MSTS) were evaluated. Results: The median follow-up time was (19.75±8.17) months. The drainages were removed out on an average of 4 days after operation. The postoperative complications included 2 superficial incision infection, 1 deep incision infection and 1 osteofascial compartment syndrome, infection or dislocation of prosthesis wasn't observed. The mean active flexion of shoulder joint after replacement was (34.00±10.84)°, mean active abduction was (20.00±9.35)° and the mean MSTS was 19.80±9.54. The superior rate of shoulder flexion function was 0. The mean active flexion of elbow joint after replacement was (75.00±7.07)°, mean active abduction was (-5.00±7.07)° and the mean MSTS was 25.00±2.83. The superior rate of elbow flexion function was 50.0% (1/2). The mean active flexion of hip joint after replacement was (86.67±20.60)°, mean active abduction was (2.08±4.98)° and the mean MSTS was 25.42±1.78. The superior rate of hip flexion function was 83.3% (10/12). The mean active flexion of knee joint after replacement was (89.69±22.39)°, mean active abduction was (-0.63±1.68)° and the mean MSTS was 23.31±2.09. The superior rate of knee flexion function was 50.0%(16/32). Among them, the superior rate of femoral flexion function was 66.7% (16/24), the superior rate of tibial flexion function was 0. All of patients were satisfied with the curative effect of operation at the end of follow-up time. Conclusions: The BARD(®) Mesh may enhance the attachment of soft-tissue to endoprosthesis, improve the joint stability, decrease the endoprosthetic infection and dislocation, facilitate the attachment of tendon to endoprosthesis and recover the muscular motivation after endoprosthetic reconstruction. This plays an important role in joint stability and motivation reconstruction of soft-tissue impairment, effectively prevents surgical complications.

Performance Assessment for Brain MR Imaging Registration Methods

BACKGROUND AND PURPOSE

Clinical brain MR imaging registration algorithms are often made available by commercial vendors without figures of merit. The purpose of this study was to suggest a rational performance comparison methodology for these products.

MATERIALS AND METHODS

Twenty patients were imaged on clinical 3T scanners by using 4 sequences: T2-weighted, FLAIR, susceptibility-weighted angiography, and T1 postcontrast. Fiducial landmark sites (n = 1175) were specified throughout these image volumes to define identical anatomic locations across sequences. Multiple registration algorithms were applied by using the T2 sequence as a fixed reference. Euclidean error was calculated before and after each registration and compared with a criterion standard landmark registration. The Euclidean effectiveness ratio is the fraction of Euclidean error remaining after registration, and the statistical effectiveness ratio is similar, but accounts for dispersion and noise.

RESULTS

Before registration, error values for FLAIR, susceptibility-weighted angiography, and T1 postcontrast were 2.07 ± 0.55 mm, 2.63 ± 0.62 mm, and 3.65 ± 2.00 mm, respectively. Postregistration, the best error values for FLAIR, susceptibility-weighted angiography, and T1 postcontrast were 1.55 ± 0.46 mm, 1.34 ± 0.23 mm, and 1.06 ± 0.16 mm, with Euclidean effectiveness ratio values of 0.493, 0.181, and 0.096 and statistical effectiveness ratio values of 0.573, 0.352, and 0.929 for rigid mutual information, affine mutual information, and a commercial GE registration, respectively.

CONCLUSIONS

We demonstrate a method for comparing the performance of registration algorithms and suggest the Euclidean error, Euclidean effectiveness ratio, and statistical effectiveness ratio as performance metrics for clinical registration algorithms. These figures of merit allow registration algorithms to be rationally compared.

Temperature-Dependent Development and Reproductive Traits of Tyrophagus putrescentiae (Sarcoptiformes: Acaridae) Reared on Different Edible Mushrooms

China is the largest producer, consumer, and exporter of mushrooms in the world. The storage mite, Tyrophagus putrescentiae Schrank, is one of the most important arthropod pests in mushroom cultivation. This study investigated the development and reproductive traits of this mite reared on four mushroom species: Agaricus bisporus Lange, Pleurotus ostreatus Kumm, Auricularia polytricha (Mont.) Sacc., and Flammulina velutipes (Fr.) Sing., at seven constant temperatures ranging from 16 to 34 °C at 80% relative humidity. Development time for the immature stages decreased with increasing temperature, and was also significantly affected by mushroom species. The shortest immature developmental period (7.0 ± 0.2 d) was observed at 31 °C when reared on F. velutipes, while the longest development was at 16 °C (36.0 ± 0.3 d) reared on P. ostreatus. The effects of temperature and mushroom hosts on the development, female longevity, and reproduction were also significant. The lower threshold temperatures from egg-to-adult for the four mushroom species were 11.97, 12.02, 10.80, and 11.57 °C, for A. bisporus, P. ostreatus, Au. polytricha, and F. velutipes, and the thermal constants were 133.3, 136.8, 165.2, and 135.9 degree days (°C d), for the same mushroom species, respectively. Life table parameters at 25 °C were estimated as follows: net reproductive rates (R0), 59.16, 28.94, 42.62, and 62.93, and intrinsic rate of natural increase (rm), 0.24, 0.13, 0.17, and 0.24, respectively. These results suggest that these mushrooms are suitable hosts for T. putrescentiae, and the storage mite may be able to adapt to higher temperatures.

Recombinant human kallistatin inhibits angiogenesis by blocking VEGF signaling pathway

Kallistatin has been recognized as an endogenous angiogenic inhibitor. However, the underlying molecular mechanism remains poorly understood. Taking it into account that vascular endothelial growth factor (VEGF) has been implicated in all aspects of normal and pathological vasculogenesis and angiogenesis. In this study, we investigated whether VEGF signaling pathway was impacted by the anti-angiogenic effect of recombinant human kallistatin (rhKal). We found that the rhKal inhibited proliferation as well as induced apoptosis of cultured human umbilical vein endothelial cells (HUVECs) in both concentration- and time-dependent manners. The rhKal also suppressed the VEGF-induced migration and tube formation of HUVECs. Furthermore, our data revealed that the rhKal suppressed the VEGF165-stimulated tyrosine phosphorylation of VEGFR-2 as well as its downstream signal molecular activation. The inhibition of receptor phosphorylation was correlated with a decrease in VEGF-triggered phosphorylation of angiogenesis signal molecules AKT and ERK, but not stress-related JNK. Taken together, these findings added the knowledge for us to understand the anti-angiogenic mechanism of kallistatin, which suggested that the rhKal could be worth as a candidate compound for further development for the purpose of anti-angiogenic therapies.

TNFα and IFNγ but not perforin are critical for CD8 T cell-mediated protection against pulmonary Yersinia pestis infection

Septic pneumonias resulting from bacterial infections of the lung are a leading cause of human death worldwide. Little is known about the capacity of CD8 T cell-mediated immunity to combat these infections and the types of effector functions that may be most effective. Pneumonic plague is an acutely lethal septic pneumonia caused by the Gram-negative bacterium Yersinia pestis. We recently identified a dominant and protective Y. pestis antigen, YopE69-77, recognized by CD8 T cells in C57BL/6 mice. Here, we use gene-deficient mice, Ab-mediated depletion, cell transfers, and bone marrow chimeric mice to investigate the effector functions of YopE69-77-specific CD8 T cells and their relative contributions during pulmonary Y. pestis infection. We demonstrate that YopE69-77-specific CD8 T cells exhibit perforin-dependent cytotoxicity in vivo; however, perforin is dispensable for YopE69-77-mediated protection. In contrast, YopE69-77-mediated protection is severely impaired when production of TNFα and IFNγ by CD8 T cells is simultaneously ablated. Interestingly, TNFα is absolutely required at the time of challenge infection and can be provided by either T cells or non-T cells, whereas IFNγ provided by T cells prior to challenge appears to facilitate the differentiation of optimally protective CD8 T cells. We conclude that cytokine production, not cytotoxicity, is essential for CD8 T cell-mediated control of pulmonary Y. pestis infection and we suggest that assays detecting Ag-specific TNFα production in addition to antibody titers may be useful correlates of vaccine efficacy against plague and other acutely lethal septic bacterial pneumonias.

Intranasal prophylaxis with CpG oligodeoxynucleotide can protect against Yersinia pestis infection

Immunomodulatory agents potentially represent a new class of broad-spectrum antimicrobials. Here, we demonstrate that prophylaxis with immunomodulatory cytosine-phosphate-guanidine (CpG) oligodeoxynucleotide (ODN), a toll-like receptor 9 (TLR9) agonist, confers protection against Yersinia pestis, the etiologic agent of plague. The data establish that intranasal administration of CpG ODN 1 day prior to lethal pulmonary exposure to Y. pestis strain KIM D27 significantly improves survival of C57BL/6 mice and reduces bacterial growth in hepatic tissue, despite paradoxically increasing bacterial growth in the lung. All of these CpG ODN-mediated impacts, including the increased pulmonary burden, are TLR9 dependent, as they are not observed in TLR9-deficient mice. The capacity of prophylactic intranasal CpG ODN to enhance survival does not require adaptive immunity, as it is evident in mice lacking B and/or T cells; however, the presence of T cells improves long-term survival. The prophylactic regimen also improves survival and reduces hepatic bacterial burden in mice challenged intraperitoneally with KIM D27, indicating that intranasal delivery of CpG ODN has systemic impacts. Indeed, intranasal prophylaxis with CpG ODN provides significant protection against subcutaneous challenge with Y. pestis strain CO92 even though it fails to protect mice from intranasal challenge with that fully virulent strain.

Fibrin facilitates both innate and T cell-mediated defense against Yersinia pestis

The Gram-negative bacterium Yersinia pestis causes plague, a rapidly progressing and often fatal disease. The formation of fibrin at sites of Y. pestis infection supports innate host defense against plague, perhaps by providing a nondiffusible spatial cue that promotes the accumulation of inflammatory cells expressing fibrin-binding integrins. This report demonstrates that fibrin is an essential component of T cell-mediated defense against plague but can be dispensable for Ab-mediated defense. Genetic or pharmacologic depletion of fibrin abrogated innate and T cell-mediated defense in mice challenged intranasally with Y. pestis. The fibrin-deficient mice displayed reduced survival, increased bacterial burden, and exacerbated hemorrhagic pathology. They also showed fewer neutrophils within infected lung tissue and reduced neutrophil viability at sites of liver infection. Depletion of neutrophils from wild-type mice weakened T cell-mediated defense against plague. The data suggest that T cells combat plague in conjunction with neutrophils, which require help from fibrin to withstand Y. pestis encounters and effectively clear bacteria.

Immunity to the conserved influenza nucleoprotein reduces susceptibility to secondary bacterial infections

Influenza causes >250,000 deaths annually in the industrialized world, and bacterial infections frequently cause secondary illnesses during influenza outbreaks, including pneumonia, bronchitis, sinusitis, and otitis media. In this study, we demonstrate that cross-reactive immunity to mismatched influenza strains can reduce susceptibility to secondary bacterial infections, even though this fails to prevent influenza infection. Specifically, infecting mice with H3N2 influenza before challenging with mismatched H1N1 influenza reduces susceptibility to either Gram-positive Streptococcus pneumoniae or Gram-negative Klebsiella pneumoniae. Vaccinating mice with the highly conserved nucleoprotein of influenza also reduces H1N1-induced susceptibility to lethal bacterial infections. Both T cells and Abs contribute to defense against influenza-induced bacterial diseases; influenza cross-reactive T cells reduce viral titers, whereas Abs to nucleoprotein suppress induction of inflammation in the lung. These findings suggest that nonneutralizing influenza vaccines that fail to prevent influenza infection may nevertheless protect the public from secondary bacterial diseases when neutralizing vaccines are not available.

The bile steroid chenodeoxycholate is a potent antagonist at NMDA and GABA(A) receptors

The bile steroids (BS) cholic acid and chenodeoxycholic acid are produced in hepatocytes and in the brain. Nothing is known about neuronal actions of BS. Deficiency in a 27-hydroxylase enzyme coincides with reduced production of chenodeoxycholic acid (CDCA) and a relative increase in cholic acid in an inherited lipid storage disease, cerebrotendinous xanthomatosis, characterized by neurological dysfunctions, which can be treated by dietary CDCA. We have examined the modulation of hypothalamic network activity by nine common BS. Cholate and CDCA significantly reduced the firing of hypothalamic neurons and synchronized network activity with CDCA being nearly 10 times more potent. The synthetic BS dehydrocholate synchronized the activity without affecting the firing rate. Gabazine, a GABA(A) receptor antagonist, occluded synchronization by BS. Whole-cell patch clamp recordings revealed a block of NMDA- and GABA(A)-receptors by BS. Potencies of nine common BS differed between NMDA and GABA(A) receptors, however in both cases they correlated with BS affinities for albumin but not with their lipophilicity, supporting a direct action at ligand gated ion channels. GABAergic synaptic currents displayed a faster decay under BS. Our data provide new insight into extrahepatic functions of BS revealing their neuroactive potential.

Yersinia pestis YopE contains a dominant CD8 T cell epitope that confers protection in a mouse model of pneumonic plague

Septic bacterial pneumonias are a major cause of death worldwide. Several of the highest priority bioterror concerns, including anthrax, tularemia, and plague, are caused by bacteria that acutely infect the lung. Bacterial resistance to multiple antibiotics is increasingly common. Although vaccines may be our best defense against antibiotic-resistant bacteria, there has been little progress in the development of safe and effective vaccines for pulmonary bacterial pathogens. The Gram-negative bacterium Yersinia pestis causes pneumonic plague, an acutely lethal septic pneumonia. Historic pandemics of plague caused millions of deaths, and the plague bacilli's potential for weaponization sustains an ongoing quest for effective countermeasures. Subunit vaccines have failed, to date, to fully protect nonhuman primates. In mice, they induce the production of Abs that act in concert with type 1 cytokines to deliver high-level protection; however, the Y. pestis Ags recognized by cytokine-producing T cells have yet to be defined. In this study, we report that Y. pestis YopE is a dominant Ag recognized by CD8 T cells in C57BL/6 mice. After vaccinating with live attenuated Y. pestis and challenging intranasally with virulent plague, nearly 20% of pulmonary CD8 T cells recognize this single, highly conserved Ag. Moreover, immunizing mice with a single peptide, YopE(69-77), suffices to confer significant protection from lethal pulmonary challenge. These findings suggest YopE could be a valuable addition to subunit plague vaccines and provide a new animal model in which sensitive, pathogen-specific assays can be used to study CD8 T cell-mediated defense against acutely lethal bacterial infections of the lung.

Sox11 regulates survival and axonal growth of embryonic sensory neurons

Sensory neurons transduce various stimuli including temperature, pain, and touch from the periphery to the central nervous system. Sensory neuron development is governed by a combination of extracellular cues and specific gene expression. We demonstrated that the transcription factor Sox11 was highly expressed in the developing sensory neurons. To test the function of Sox11, we used a knockin mouse model where the entire coding region of Sox11 was replaced by a LacZ reporter. The ablation of Sox11 caused severe reduction in sensory neuron survival in the trigeminal and dorsal root ganglia, although it did not affect migration of neural crest cells or acquisition of major sensory neuron subtypes. We further demonstrated that ablating Sox11 caused an arrest of axonal outgrowth in vivo and in vitro. This defect could not be fully rescued by blocking cell death. Our data suggest that Sox11 is a key regulator of sensory neuron development.

IL-17 contributes to cell-mediated defense against pulmonary Yersinia pestis infection

Pneumonic plague is one of the world's most deadly infectious diseases. The causative bacterium, Yersinia pestis, has the potential to be exploited as a biological weapon, and no vaccine is available. Vaccinating B cell-deficient mice with D27-pLpxL, a live attenuated Y. pestis strain, induces cell-mediated protection against lethal pulmonary Y. pestis challenge. In this article, we demonstrate that prime/boost vaccination with D27-pLpxL confers better protection than prime-only vaccination. The improved survival does not result from enhanced bacterial clearance but is associated with increased levels of IL-17 mRNA and protein in the lungs of challenged mice. The boost also increases pulmonary numbers of IL-17-producing CD4 T cells. Interestingly, most of these cells simultaneously produce canonical type 1 and type 17 cytokines; most produce IL-17 and TNF-α, and many produce IL-17, TNF-α, and IFN-γ. Neutralizing IL-17 counteracts the improved survival associated with prime/boost vaccination without significantly impacting bacterial burden. Thus, IL-17 appears to mediate the enhanced protection conferred by booster immunization. Although neutralizing IL-17 significantly reduces neutrophil recruitment to the lungs of mice challenged with Y. pestis, this impact is equally evident in mice that receive one or two immunizations with D27-pLpxL, suggesting it cannot suffice to account for the improved survival that results from booster immunization. We conclude that IL-17 plays a yet to be identified role in host defense that enhances protection against pulmonary Y. pestis challenge, and we suggest that pneumonic plague vaccines should aim to induce mixed type 1 and type 17 cellular responses.

TNFα and IFNγ contribute to F1/LcrV-targeted immune defense in mouse models of fully virulent pneumonic plague

Immunization with the Yersinia pestis F1 and LcrV proteins improves survival in mouse and non-human primate models of pneumonic plague. F1- and LcrV-specific antibodies contribute to protection, however, the mechanisms of antibody-mediated defense are incompletely understood and serum antibody titers do not suffice as quantitative correlates of protection. Previously we demonstrated roles for tumor necrosis factor-alpha (TNFα) and gamma-interferon (IFNγ) during defense against conditionally attenuated pigmentation (pgm) locus-negative Y. pestis. Here, using intranasal challenge with fully virulent pgm-positive Y. pestis strain CO92, we demonstrate that neutralizing TNFα and IFNγ interferes with the capacity of therapeutically administered F1- or LcrV-specific antibody to reduce bacterial burden and increase survival. Moreover, using Y. pestis strain CO92 in an aerosol challenge model, we demonstrate that neutralizing TNFα and IFNγ interferes with protection conferred by immunization with recombinant F1-LcrV fusion protein vaccine (p<0.0005). These findings establish that TNFα and IFNγ contribute to protection mediated by pneumonic plague countermeasures targeting F1 and LcrV, and suggest that an individual's capacity to produce these cytokines in response to Y. pestis challenge will be an important co-determinant of antibody-mediated defense against pneumonic plague.

Distinct roles of complement receptor 3, Dectin-1, and sialic acids in murine macrophage interaction with Histoplasma yeast

The yeast cells of dimorphic fungal pathogen Histoplasma reside primarily within the macrophages of an infected host; the interaction between the yeast and macrophage has a profound impact on host defense against the fungus. We used blocking antibodies and saccharides to identify the receptors that participate in the phagocytosis of and the cytokine response to Histoplasma. The phagocytosis and cytokine response results show that sialic acids on the macrophages were involved in the interaction between macrophages and Histoplasma. CR3, although not the only receptor involved, was responsible for phagocytosis and cytokine response. It is unclear which receptors other than CR3 are responsible for phagocytosis, but we did rule out the participation of TLR2, TLR4, MR, DC-SIGN/SIGNR1, FcgammaR, VLA-5, and Dectin-1. Even though Dectin-1 did not participate in phagocytosis, it collaborated with CR3 in the cytokine response to Histoplasma, suggesting that in the presence of phagocytic receptors, Histoplasma triggers cytokine signals through Dectin-1. Moreover, macrophage phagocytosis of and cytokine response to Histoplasma are Syk kinase-dependent. Our study delineated the distinct roles of CR3, Dectin-1, and sialic acids in the interaction with Histoplasma and suggested that multiple receptor use might be important to host defense against Histoplasma.

Differential effects of acute and repeat dosing with the H3 antagonist GSK189254 on the sleep-wake cycle and narcoleptic episodes in Ox-/- mice

BACKGROUND AND PURPOSE

Histamine H3 receptor antagonists are currently being evaluated in clinical trials for a number of central nervous system disorders including narcolepsy. These agents can increase wakefulness (W) in cats and rodents following acute administration, but their effects after repeat dosing have not been reported previously.

EXPERIMENTAL APPROACH

EEG and EMG recordings were used to investigate the effects of acute and repeat administration of the novel H3 antagonist GSK189254 on the sleep-wake cycle in wild-type (Ox+/+) and orexin knockout (Ox-/-) mice, the latter being genetically susceptible to narcoleptic episodes. In addition, we investigated H3 and H1 receptor expression in this model using radioligand binding and autoradiography.

KEY RESULTS

In Ox+/+ and Ox-/- mice, acute administration of GSK189254 (3 and 10 mg x kg(-1) p.o.) increased W and decreased slow wave and paradoxical sleep to a similar degree to modafinil (64 mg x kg(-1)), while it reduced narcoleptic episodes in Ox-/- mice. After twice daily dosing for 8 days, the effect of GSK189254 (10 mg x kg(-1)) on W in both Ox+/+ and Ox-/- mice was significantly reduced, while the effect on narcoleptic episodes in Ox-/- mice was significantly increased. Binding studies revealed no significant differences in H3 or H1 receptor expression between Ox+/+ and Ox-/- mice.

CONCLUSIONS AND IMPLICATIONS

These studies provide further evidence to support the potential use of H3 antagonists in the treatment of narcolepsy and excessive daytime sleepiness. Moreover, the differential effects observed on W and narcoleptic episodes following repeat dosing could have important implications in clinical studies.

A CMOS neuroelectronic interface based on two-dimensional transistor arrays with monolithically-integrated circuitry

The ability to monitor and to elicit neural activity with a high spatiotemporal resolution has grown essential for studying the functionality of neuronal networks. Although a variety of microelectrode arrays (MEAs) has been proposed, very few MEAs are integrated with signal-processing circuitry. As a result, the maximum number of electrodes is limited by routing complexity, and the signal-to-noise ratio is degraded by parasitics and noise interference. This paper presents a single-chip neuroelectronic interface integrating oxide-semiconductor field-effect transistors (OSFETs) with signal-processing circuitry. After the chip was fabricated with the standard complementary-metal-oxide-semiconductor (CMOS) process, polygates of specific transistors were etched at die-level to form OSFETs, while metal layers were retained to connect the OSFETs into two-dimensional arrays. The complete removal of polygates was confirmed by high-resolution image scanners, and the reliability of OSFETs was examined by measuring their electrical characteristics. Through a gate oxide of only 7nm thick, each OSFET can record and stimulate neural activity extracellularly by capacitive coupling. The capability of the full chip in neural recording and stimulation was further experimented using the well-characterised escape circuit of the crayfish. Experimental results indicate that the OSFET-based neuroelectronic interface can be used to study neuronal networks as faithfully as conventional electrophysiological tools. Moreover, the proposed simple, die-level fabrication process of the OSFETs underpins the development of various field-effect biosensors on a large scale with on-chip circuitry.

CMOS-micromachined, two-dimenisional transistor arrays for neural recording and stimulation

In-plane microelectrode arrays have proven to be useful tools for studying the connectivities and the functions of neural tissues. However, seldom microelectrode arrays are monolithically-integrated with signal-processing circuits, without which the maximum number of electrodes is limited by the compromise with routing complexity and interferences. This paper proposes a CMOS-compatible, two-dimensional array of oxide-semiconductor field-effect transistors(OSFETs), capable of both recording and stimulating neuronal activities. The fabrication of the OSFETs not only requires simply die-level, post-CMOS micromachining process, but also retains metal layers for monolithic integration with signal-processing circuits. A CMOS microsystem containing the OSFET arrays and gain-programmable recording circuits has been fabricated and tested. The preliminary testing results are presented and discussed.

Hair follicle: a reliable source of recipient origin after allogeneic hematopoietic stem cell transplantation

Blood, buccal swab and hair follicles are among the most commonly used sources for forensic science, parentage testing and personal identification. A total of 29 patients who have had a sustained engraftment from 15 months to 21.5 years after allogeneic hematopoietic stem cell transplantation (HSCT) without rejection, relapse or chronic GVHD involving oral mucosa were enrolled for a chimerism study. PCR-amplified short tandem repeat analyses were conducted per patient every 3 months for at least three consecutive times. The results for blood were all donor type except one who had a mixed chimerism, 14.5 years after receiving a transplant for lymphoma. As for buccal swab, mixed chimerism ranging from 10 to 96% donor origin was noted for 28 recipients except the one who had mixed chimerism of blood and retained total recipient type. In contrast, hair follicles were 100% recipient type for the entire group. It is concluded that the hair follicle is devoid of adult stem cell plasticity and may serve as a reliable source of recipient's origin when pre-transplant DNA fingerprinting or reference DNA is not available for people who have successfully received allogeneic HSCT while in need of a personal identification.