A Comparative Study on the Mechanism of Delayed-Type Hypersensitivity Mediated by the Recombinant Mycobacterium tuberculosis Fusion Protein ESAT6-CFP10 and Purified Protein Derivative.

While purified protein derivative (PPD) is commonly used as skin diagnostic reagent for tuberculosis (TB) infection, it cannot distinguish effectively Bacillus Calmette-Guérin (BCG) vaccination from Mycobacterium tuberculosis (MTB) complex and nontuberculous mycobacteria infection. The new skin reagent ESAT6-CFP10 (EC) has favorable sensitivity and specificity, which can overcome limitations associated with PPD. At present, EC skin test reactions are mainly characterized by erythema, while PPD mainly causes induration. We conducted a comparative study on the potential differences between EC-induced erythema and PPD-induced induration using a guinea pig model. The size of EC-dependent erythema was similar to that of PPD-induced induration, and an inflammatory response characterized by the infiltration of monocytes, macrophages and lymphocytes, as well as tissue damage, appeared at the injection site. The lymphocytes included CD4+ T and CD8+ T cells, which released IFN-γ as the main cytokine. Both EC erythema and PPD induration could lead to increased levels of acute-phase proteins, and the differential pathways were similar, thus indicating that the main induced immune pathways were similar. The above results indicated that erythema produced by EC could generate the main delayed-type hypersensitivity (DTH) response characteristic of PPD induration, thereby suggesting that erythema might also have a certain diagnostic significance and provide a possible theoretical basis for its use as a diagnostic indicator for detecting MTB infection.

Sensitivity, Specificity, and Safety of a Novel ESAT6-CFP10 Skin Test for Tuberculosis Infection in China: 2 Randomized, Self-Controlled, Parallel-Group Phase 2b Trials.

BACKGROUND: Diagnostics to identify tuberculosis infection are limited. We aimed to assess the diagnostic accuracy and safety of ESAT6-CFP10 (EC) skin test for tuberculosis infection in Chinese adults. METHODS: We conducted 2 randomized, parallel-group clinical trials in healthy participants and tuberculosis patients. All participants were tested with the T-SPOT.TB test, then received an EC skin test and tuberculin skin test (TST). The diameter of skin indurations and/or redness at injection sites were measured at different time periods. A bacillus Calmette Guerin (BCG) model was established to assess the diagnosis of tuberculosis infection using an EC skin test. RESULTS: In total, 777 healthy participants and 96 tuberculosis patients were allocated to receive EC skin test at 1.0 µg/0.1 mL or 0.5 µg/0.1 mL. The area under the curve was 0.95 (95% confidence interval [CI], .91-.97) for the EC skin test at 1.0 µg/0.1 mL at 24-72 hours. Compared with the T-SPOT.TB test, the EC skin test demonstrated similar sensitivity (87.5, 95% CI, 77.8-97.2 vs 86.5, 95% CI, 79.5-93.4) and specificity (98.9, 95% CI, 96.0-99.9 vs 96.1, 95% CI, 93.5-97.8). Among BCG vaccinated participants, the EC skin test had high consistency with the T-SPOT.TB test (96.3, 95% CI, 92.0-100.0). No serious adverse events related to the EC skin test were observed. CONCLUSIONS: The EC skin test demonstrated both high specificity and sensitivity at a dose of 1.0 µg/0.1 mL, comparable to the T-SPOT.TB test. The diagnostic accuracy of the EC skin test was not impacted by BCG vaccination. CLINICAL TRIALS REGISTRATION: NCT02389322 and NCT02336542.

Traffic Intersection Re-Identification Using Monocular Camera Sensors.

Perception of road structures especially the traffic intersections by visual sensors is an essential task for automated driving. However, compared with intersection detection or visual place recognition, intersection re-identification (intersection re-ID) strongly affects driving behavior decisions with given routes, yet has long been neglected by researchers. This paper strives to explore intersection re-ID by a monocular camera sensor. We propose a Hybrid Double-Level re-identification approach which exploits two branches of Deep Convolutional Neural Network to accomplish multi-task including classification of intersection and its fine attributes, and global localization in topological maps. Furthermore, we propose a mixed loss training for the network to learn the similarity of two intersection images. As no public datasets are available for the intersection re-ID task, based on the work of RobotCar, we propose a new dataset with carefully-labeled intersection attributes, which is called "RobotCar Intersection" and covers more than 30,000 images of eight intersections in different seasons and day time. Additionally, we provide another dataset, called "Campus Intersection" consisting of panoramic images of eight intersections in a university campus to verify our updating strategy of topology map. Experimental results demonstrate that our proposed approach can achieve promising results in re-ID of both coarse road intersections and its global pose, and is well suited for updating and completion of topological maps.

A safety and immunogenicity study of a novel subunit plague vaccine in cynomolgus macaques.

Plague has led to millions of deaths in history and outbreaks continue to the present day. The efficacy limitations and safety concerns of the existing killed whole cell and live-attenuated vaccines call for the development of new vaccines. In this study, we evaluated the immunogenicity and safety of a novel subunit plague vaccine, comprising native F1 antigen and recombinant V antigen. The cynomolgus macaques in low- and high-dose vaccine groups were vaccinated at weeks 0, 2, 4 and 6, at dose levels of 15 µg F1 + 15 µg rV and 30 µg F1 + 30 µg rV respectively. Specific antibodies and interferon-γ and interleukin-2 expression in lymphocytes were measured. For safety, except for the general toxicity and local irritation, we made a systematic immunotoxicity study on the vaccine including immunostimulation, autoimmunity and anaphylactic reaction. The vaccine induced high levels of serum anti-F1 and anti-rV antibodies, and caused small increases of interferon-γ and interleukin-2 in monkeys. The vaccination led to a reversible increase in the number of peripheral blood eosinophils, the increases in serum IgE level in a few animals and histopathological change of granulomas at injection sites. The vaccine had no impact on general conditions, most clinical pathology parameters, percentages of T-cell subsets, organ weights and gross pathology of treated monkeys and had passable local tolerance. The F1 + rV subunit plague vaccine can induce very strong humoral immunity and low level of cellular immunity in cynomolgus macaques and has a good safety profile.

[Utility value of a T-cell interferon-γ release assay based on recombinant Mycobacterium tuberculosis 11kD protein in the diagnosis of tuberculosis].

OBJECTIVE: To evaluate the diagnostic efficiency of a T-cell interferon-γ release assay based on recombinant Mycobacterium tuberculosis (MTB) 11kD protein for diagnosing tuberculosis. METHODS: This prospective study enrolled inpatients with suspected tuberculosis at PUMCH to examine the diagnostic sensitivity, specificity, predictive value (PV) and likelihood ratio (LR) of T-cell interferon-γ release assays based on recombinant MTB-11kD protein, early antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) peptides (T-SPOT. TB). Test results were compared with final clinical and microbiological diagnoses. RESULTS: Among 151 inpatients with suspected tuberculosis, 33 (21.9%) were microbiologically or clinically diagnosed as tuberculosis and 107 (70.9%) ruled out. And the remaining 11 (7.3%) patients were clinically indeterminate. The sensitivities of recombinant MTB-11kD-ELISPOT assay and T-SPOT. TB were 60.6%and 81.8%respectively (P = 0.057).Whereas, the specificity of recombinant MTB-11kD-ELISPOT assay was significantly higher than that of T-SPOT. TB (84.1%vs 72.9%, P = 0.046). The parallel testing increased the sensitivity to 84.9% and serial testing increased the specificity to 86.9%. CONCLUSION: The recombinant MTB-11kD-ELISPOT assay is more specific than T-SPOT. TB. And its combination with T-SPOT. TB may improve the diagnostic efficiency for tuberculosis.

Relationship between soil and species diversity in typical forest stands in Xianrendong, Liaoning Province based on plant-soil feedback.

Exploring the relationship between soil properties and species diversity in typical forest stands in Liaoning Xianrendong National Nature Reserve will help maintain the stability of forest communities in the transition zone between flora in Changbai and North China. Based on the plant-soil feedback theory, community sample data from nine typical forest stands in the study area and experimental test data from 54 soil samples, we selected indexes of soil physical and chemical properties based on the minimum data set (temperature, compactness, capillary pore space, bulk weight, capillary water holding capacity, drainage capacity, soil water storage, conductivity, pH, organic matter, Ca, Fe, K, N and P). We adopt the research method of classical statistical analysis. The soil properties of nine typical stands in Xianrendong National Nature Reserve of Liaoning Province were systematically analyzed. The relationship between soil properties and forest stands' species diversity was quantified using correlation and redundancy analyses. The Pearson correlation analysis results showed significant positive correlations between the Gleason abundance index (arbors) with conductivity, pH, organic matter, Ca, N and P; Pielou's evenness index (arbors) with bulk weight and Fe. Significant negative correlations between the Gleason abundance index (arbors) with capillary pore space, bulk weight, drainage capacity, soil water storage and capillary water holding capacity; Simpson dominance index and Shannon-Wiener diversity index with capillary water holding capacity, drainage capacity and soil water storage; Pielou's evenness index (arbors) with Ca and N. The natural moisture content and clay particles are neutral feedback. The results showed that the feedback mechanism of soil physicochemical properties on stand species diversity was complex, which was conducive to species coexistence and community stability.

A uranium-bridged dimeric Keggin-type polyoxometalate and its proton conductive properties.

A novel dimeric structure based on trilacunary Keggin-type [SbW9O33]9- was synthesized and comprehensively characterized. Different from the conventional dimeric structures, the compound (NH4)10[(SbW9O33)2(UO2)2(H2O)2(SbOH)2]·7H2O ({U2Sb4}) features two additional Sb3+ cations. The successful synthesis of {U2Sb4} reveals the significant role of heteroatoms in structural modulation. The dimer forms a hydrogen-bonded network with water molecules and NH4+ and is therefore expected to exhibit remarkable proton conductivity. Proton conduction studies revealed that {U2Sb4} was a temperature and humidity-dependent proton conductor with conductivity reaching up to 2.50 × 10-2 S cm-1 at 85 °C and 85% RH.

Efficacy and safety of recombinant Mycobacterium tuberculosis ESAT-6 protein for diagnosis of pulmonary tuberculosis: a phase II trial.

BACKGROUND: This study aimed to determine the efficacy and safety of recombinant Mycobacterium tuberculosis ESAT-6 protein for diagnosis of pulmonary tuberculosis (TB). MATERIAL AND METHODS: A phase II trial was performed in 158 patients with pulmonary TB (145 initially-treated and 13 re-treated) and 133 healthy subjects. Skin testing was carried out by injecting purified protein derivative (PPD) (on left forearm) or recombinant ESAT-6 protein at a dosage of 2, 5, or 10 µg/mL (on the right forearm) in each subject. Reaction activity and adverse events were monitored at 24, 48, and 72 h following the injection. Receiver operating characteristic curves were plotted to determine the areas under the curves (AUCs) and the cut-off induration diameters for the optimal diagnostic performance. RESULTS: The reaction activity was significantly increased upon recombinant ESAT-6 injection in pulmonary TB patients compared with healthy subjects. In pulmonary TB patients, the reaction was dose-dependent, and at 48 h, 10 µg/mL recombinant ESAT-6 produced a reaction similar to that produced by PPD. The AUCs for a 10 µg/mL dosage were 0.9823, 0.9552, and 0.9266 for 24 h, 48 h, and 72 h, respectively, and the induration diameters of 4.5-5.5 mm were the optimal trade-off values between true positive rates and false positive rates. No serious adverse events occurred in any subjects. CONCLUSIONS: Recombinant ESAT-6 protein is efficacious and safe for diagnosing pulmonary TB. Based on the reaction, performance, safety, and practicability, we recommend that 10 µg/mL at 48 h with an induration cut-off value of 5.0 mm be used.

"Brain age" predicts disability accumulation in multiple sclerosis.

OBJECTIVE: Neurodegenerative conditions often manifest radiologically with the appearance of premature aging. Multiple sclerosis (MS) biomarkers related to lesion burden are well developed, but measures of neurodegeneration are less well-developed. The appearance of premature aging quantified by machine learning applied to structural MRI assesses neurodegenerative pathology. We assess the explanatory and predictive power of "brain age" analysis on disability in MS using a large, real-world dataset. METHODS: Brain age analysis is predicated on the over-estimation of predicted brain age in patients with more advanced pathology. We compared the performance of three brain age algorithms in a large, longitudinal dataset (>13,000 imaging sessions from >6,000 individual MS patients). Effects of MS, MS disease course, disability, lesion burden, and DMT efficacy were assessed using linear mixed effects models. RESULTS: MS was associated with advanced predicted brain age cross-sectionally and accelerated brain aging longitudinally in all techniques. While MS disease course (relapsing vs. progressive) did contribute to advanced brain age, disability was the primary correlate of advanced brain age. We found that advanced brain age at study enrollment predicted more disability accumulation longitudinally. Lastly, a more youthful appearing brain (predicted brain age less than actual age) was associated with decreased disability. INTERPRETATION: Brain age is a technically tractable and clinically relevant biomarker of disease pathology that correlates with and predicts increasing disability in MS. Advanced brain age predicts future disability accumulation.

Three rare-earth incorporating 6-peroxotantalo-4-selenates and catalytic activities for imidation reaction.

Functionalization with belt lanthanide groups allows for the crystallization and structural characterization of homometallic selenotantalates, CsK[Ln(H2O)6Se4(TaO2)6(OH)3O18]·nH2O (Ln = Eu/Gd, n = 14 (STD-Eu, STD-Gd) and Ln = Lu, n = 12 (STD-Lu)). The basket-shaped {Se4(TaO2)6} archetype is assembled in a simple one-pot reaction of Na2SeO3 and K8[Ta6O19]·17H2O in acidic aqueous medium (pH 2) and in the presence of hydrogen peroxide. This unit has been proven to be an effective precursor for the preparation of a range of new POMs containing the {Se4(TaO2)6} unit. The lanthanide derivatives STD-Eu, STD-Gd and STD-Lu have been fully characterized with single-crystal X-ray diffraction, IR spectroscopy, TG analysis and PXRD in the solid state. The photoluminescence and lifetime decay behaviours of STD-Eu have been studied at room temperature, and the photoluminescence spectrum displays the characteristic emission of the Eu3+ cation. In addition, the catalytic activities of STD-Eu, STD-Gd and STD-Lu on the reaction of phthalic anhydride with phenylamines have been investigated. STD-Eu shows good catalytic activities for imidation reactions.

Therapeutic Effect of Subunit Vaccine AEC/BC02 on Mycobacterium tuberculosis Post-Chemotherapy Relapse Using a Latent Infection Murine Model.

Tuberculosis (TB), caused by the human pathogen Mycobacterium tuberculosis (Mtb), is an infectious disease that presents a major threat to human health. Bacillus Calmette-Guérin (BCG), the only licensed TB vaccine, is ineffective against latent TB infection, necessitating the development of further TB drugs or therapeutic vaccines. Herein, we evaluated the therapeutic effect of a novel subunit vaccine AEC/BC02 after chemotherapy in a spontaneous Mtb relapse model. Immunotherapy followed 4 weeks of treatment with isoniazid and rifapentine, and bacterial loads in organs, pathological changes, and adaptive immune characteristics were investigated. The results showed slowly increased bacterial loads in the spleen and lungs of mice inoculated with AEC/BC02 with significantly lower loads than those of the control groups. Pathological scores for the liver, spleen, and lungs decreased accordingly. Moreover, AEC/BC02 induced antigen-specific IFN-γ-secreting or IL-2-secreting cellular immune responses, which decreased with the number of immunizations and times. Obvious Ag85b- and EC-specific IgG were observed in mice following the treatment with AEC/BC02, indicating a significant Th1-biased response. Taken together, these data suggest that AEC/BC02 immunotherapy post-chemotherapy may shorten future TB treatment.

Two novel telluroniobates with efficient catalytic activity for the imidation/amidation reaction.

We present the synthesis and catalytic properties of two novel telluroniobates {Te15Nb21} and {Te10Nb14}. {Te15Nb21} is the first trimeric telluroniobate with the largest number of tellurium atoms in the Te-Nb system. Besides, both clusters exhibit excellent catalytic activity in the amidation reactions of anhydrides and amines, and cyclic imides and bi-amides can be controllably synthesized, which represents a breakthrough in the catalysis of polyoxoniobates.

The Subunit AEC/BC02 Vaccine Combined with Antibiotics Provides Protection in Mycobacterium tuberculosis-Infected Guinea Pigs.

A latent tuberculosis infection (LTBI) is a major source of active tuberculosis, and addressing an LTBI is crucial for the elimination of tuberculosis. The treatment of tuberculosis often requires a 6-month course of multidrug therapy, and for drug-resistant tuberculosis, a longer course of multidrug therapy is needed, which has many drawbacks. At present, vaccines are proposed as an adjunct to chemotherapy to protect populations with an LTBI and delay its recurrence. In this study, we analyzed the protective effect of a novel subunit vaccine, AEC/BC02, in a guinea pig latent infection model. Through the optimization of different chemotherapy durations and immunization times, it was found that 4 weeks of administration of isoniazid-rifampin tablets combined with three or six injections of the vaccine could significantly reduce the gross pathological score and bacterial load in organs and improve the pathological lesions. This treatment regimen had a better protective effect than the other administration methods. Furthermore, no drug resistance of Mycobacterium tuberculosis was detected after 2 or 4 weeks of administration of the isoniazid-rifampin tablets, indicating a low risk of developing drug-resistant bacteria during short-term chemotherapy. The above results provided the foundation for an AEC/BC02 clinical protocol.

[The effect of various antigen compounds of tuberculosis composite antigen vaccine on the immune function in mice].

OBJECTIVE: To study the immune function of mice immunized by different combinations of antigen 85b (Ag85b), fusion protein culture filtered protein 10 (CFP-10), early secreted antigenic target 6 kDa protein (ESAT-6) and heat shock protein X (Hsp X) with combined adjuvants of Bacille Calmette-Guerin (BCG) CpG and aluminum. METHODS: According to antigen combinations, 48 BALB/c mice were divided into 8 groups: (1) group A: Ag85b + CFP-10/ESAT-6 + HspX + adjuvant; (2) group B: CFP-10/ESAT-6 + HspX + adjuvant; (3) group C: Ag85b + HspX + adjuvant; (4) group D: Ag85b + CFP-10/ESAT-6 + adjuvant; (5) group E: Ag85b + adjuvant; (6) group F: CFP-10/ESAT-6 + adjuvant; (7) group G: HspX + adjuvants; (8) control group: saline (6 mice per group). The mice were subcutaneously immunized 3 times. One week after the third subcutaneous immunization, spleens were collected for enzyme-linked immunospot (ELISPOT) assay to detect IFN-γ and IL-4 secretion, and for the lymphocyte proliferation assay to observe antigen-specific lymphocyte proliferation. Serum samples were separated for enzyme-linked immunosorbent assay (ELISA) to detect the titers of antigen-specific IgG, IgG(1) and IgG(2a) antibodies. RESULTS: The amount of IFN-γ spots in Group E [median(quartile), 122.8 (78.4 - 184.4)] was significantly more than that in group C [14.3 (6.5 - 14.6)] and the control group [0.5 (0.5 - 1.3)] (u = 0.0, P < 0.01). The amount of IL-4 spots in Group D stimulated with Ag85b and CFP-10/ESAT-6 [173.5 (78.8 - 233.4), 132.8 (50.3 - 159.4)] were significantly more than those in the control group [0.5 (0.5 - 1.3), 5.3 (2.9 - 6.5)] (u = 0.0, P < 0.01). The level of stimulation index of lymphocyte proliferation in Group A, C, D, E (2.42 ± 0.50, 2.18 ± 0.37, 2.86 ± 0.51, 2.70 ± 0.15) was significantly higher than that of the control group (1.11 ± 0.13) (F = 20.96, P < 0.01). The level of antigen-specific IgG, IgG(1), IgG(2a) antibody titers induced by Hsp X [lg(antibody dilution degree), 3.90 - 5.21] was significantly higher than those induced by Ag85b (3.30 - 4.51) and CFP-10/ESAT-6 (3.10 - 4.05) (F = 63.8 - 70.4, P < 0.01). CONCLUSIONS: With the use of adjuvants, different antigen combinations showed different influences on the immune function in mice. A combination of 3 antigens did not elicit the best immune effect, suggesting that the interaction among antigens may affect their immunity.

[Preparation of two antigens--Ag85b and HspX of Mycobacterium tuberculosis H37Rv and the effects of their co-administration with adjuvants in mice].

OBJECTIVE: To synthesize two antigens-Ag85b and HspX of Mycobacterium tuberculosis H37Rv with molecular biological methods and to observe their biologic activity after co-administration of adjuvants (aluminum and/or CpG) in mice. METHODS: Recombinant expression plasmids pET30a-Ag85b and pET30a-HspX were constructed. The objective DNA fragments was characterized with restriction enzyme. Then the recombinant plasmids were transformed into E. coli BL-21, and two proteins were expressed by induction of isopropyl beta-D-1-thiogalactopyranoside. After purification with anion exchange column Source30, QHP, and hydrophobic chromatography column, two proteins were identified by amino acid sequencing. After the successful preparation of these two antigens, they were co-administered in mice with adjuvants of aluminum and/or CpG (Ag85b, Ag85b + Al, Ag85b + CpG, Ag85b + Al + CpG; HspX, HspX + Al, HspX + CpG, HspX + Al + CpG); one group received normal saline and served as the control. Splenic lymphocytes were isolated for enzyme-linked immunosorbent spot assay to detect the secreted specific interferon-gamma (IFN-gamma); in addition, lymphocytes proliferation test was performed to observe lymphocytes proliferation after in vitro stimulated with two antigens. RESULTS: The purity of two proteins reached 95% after purification. The N-terminal amino acid sequence (15 aa) of the purified proteins was same as the target sequence. For Ag85b, the secreted specific IFN-gamma from isolated splenic lymphocytes after having been stimulated in vitro with Ag85b (80 microg/ml) remarkably increased in Ag85b + CpG group, Ag85b + Al group, and Ag85b + CpG + Al group; the changes were significantly different between these three groups and control group (P < 0.05). For HspX, the changes were significantly different between HspX + Al + CpG group and normal sodium group, although remarked increase of IFN-gamma was also observed in HspX group, HspX + Al group, and HspX + CpG group. CONCLUSIONS: Ag85b and HspX were successfully expressed and purified. A cell-mediated immunity may be induced when the antigens are co-administered with adjuvants of aluminum and/or CpG in mice, indicating that the recombinant proteins are bioactive.

Ag85b/ESAT6-CFP10 adjuvanted with aluminum/poly-IC effectively protects guinea pigs from latent mycobacterium tuberculosis infection.

The high global burden of tuberculosis (TB) underscores the urgent need for an effective TB vaccine since the only licensed Bacillus Calmette-Guérin (BCG) vaccine is ineffective in preventing adult pulmonary TB and affords no protection against latent TB infection (LTBI). Herein we investigated the potential of Mycobacterium tuberculosis (Mtb) antigen proteins AEC comprised of Ag85b and ESAT6-CFP10 proteins in conjunction with aluminum (Al) and polyriboinosinic-polyribocytidylic acid (poly-IC) as a novel subunit vaccine against TB. The immunogenicity and protection induced by the adjuvanted vaccine were evaluated in two animal models. Mice vaccinated with AEC/Al/poly-IC exhibited significant antigen-specific humoral immune responses and cell-mediated immunity as determined by immunoassay and multicolor flow cytometric assay, and the protective effect of the vaccine was demonstrated in a guinea pig model of latent Mtb infection. Compared to the control group, the mean pathological scores and bacterial loads in lungs and spleens of AEC/Al/poly-IC-immunized guinea pigs were significantly reduced. These data indicate that the AEC/Al/poly-IC is highly immunogenic in mice and can effectively protect guinea pigs against latent Mtb infection; it may represent a promising candidate vaccine for the control of latent TB.

Recombinant tuberculosis vaccine AEC/BC02 induces antigen-specific cellular responses in mice and protects guinea pigs in a model of latent infection.

PURPOSE: To preliminarily evaluate the immunogenicity and efficacy of the recombinant tuberculosis vaccine AEC/BC02 in which Ag85b and fusion protein ESAT6-CFP10 were combined with bacillus Calmette-Guérin CpG and an aluminum salt-based adjuvant system. METHODS: Groups of BALB/c mice were immunized intramuscularly three times at 10-day intervals with AEC/BC02 or the adjuvant alone and the vaccine-induced cell-mediated immune responses were evaluated. The efficacy of AEC/BC02 was evaluated in two guinea pig models, one a model of prevention and the other a model of latent infection. RESULTS: The AEC/BC02 vaccine induced strong cellular immune responses characterized by a high frequency of antigen-specific interferon-γ-secreting T cells in mice at different time points after the last vaccination. In the preventive model of guinea pig, AEC/BC02 did not protect against Mycobacterium tuberculosis as a pre-exposure vaccine. However, in a latent infection model of guinea pig, it effectively controlled the reactivation of M. tuberculosis and lowered the bacterial load in the lung and spleen. CONCLUSION: These results indicate AEC/BC02 can protect against reactivation of latent infection and may function as a therapeutic vaccine.

The effect of bacille Calmette-Guérin vaccination at birth on immune response in China.

Bacille Calmette-Guérin (BCG) vaccine is still the most effective approach to prevent tuberculosis in childhood. In order to provide protection against severe forms of childhood tuberculosis, it is customary to give BCG vaccination at birth in China. Tuberculin skin testing after vaccination is usually used to evaluate the immunogenic activity and protective efficacy of the BCG. We report the results of a multi-site prospective cohort study to evaluate the immunological reactivity against BCG in four prefectural cities in China. A total of 59,022 newborn infants were vaccinated between January 2011 and March 2012, and follow-up data on 27,517 vaccinated infants were available for this study. Of these, 679 (2.5%) had PPD readings of 0-5mm, 17,072 (62.0%) had PPD readings of 5-10 mm of induration, 8864 (32.2%) had readings of 10-15 mm, 815 (3.0%) had readings of 15-20 mm, and 87 (0.3%) had readings of >20 mm of induration. The size of PPD reaction varied significantly with the geographic location, gender, season of vaccination, and grade of hospital administering the BCG vaccine (P<0.001). 97.8% of the infants with a BCG scar of >1mm had a positive TST reaction. However, only 56.9% of infants without a BCG scar had a positive PPD reaction. Our results demonstrate that the BCG immunization among newborn infants in China induces satisfactory immune response. In addition, BCG scars provide a useful indicator of vaccination response in Chinese infants.

Preclinical study and phase I clinical safety evaluation of recombinant Mycobacterium tuberculosis ESAT6 protein.

BACKGROUND: To investigate the ability of rESAT6 to identify different mycobacteria-sensitized guinea pigs and its safety in preclinical and phase I clinical study. MATERIAL AND METHODS: Guinea pigs were sensitized with different Mycobacteria. After sensitization, all animals were intradermally injected with rESAT6 and either PPD or PPD-B. At 24 h after the injection, the erythema of the injection sites were measured using a double-blind method. For the preclinical safety study, different doses of rESAT6 and BSA were given 3 times intramuscularly to guinea pigs. On day 14 after the final immunization, the guinea pigs were intravenously injected with the same reagents in the hind legs and the allergic reactions were observed. A single-center, randomized, open phase I clinical trial was employed. The skin test was conducted in 32 healthy volunteers aged 19-65 years with 0.1 µg, 0.5 µg, and 1 µg rESAT6. Physical examination and laboratory tests were performed before and after the skin test and adverse reactions were monitored. The volunteers' local and systemic adverse reactions and adverse events were recorded for 7 days. RESULTS: Positive PPD or PPD-B skin tests were observed in all Mycobacteria-sensitized guinea pigs; the diameters of erythema were all >10 mm. The rESAT6 protein induced a positive skin test result in the guinea pigs sensitized with MTB, M. bovis, M. africanum and M. kansasii; the diameters of erythema were 14.7±2.0, 9.3±3.8, 18.7±2.4, and 14.8±4.2 mm, respectively. A negative skin test result was detected in BCG-vaccinated and other NTM-sensitized guinea pigs. The rESAT6 caused no allergic symptoms, but many allergic reactions, such as cough, dyspnea, and even death, were observed in the guinea pigs who were administered BSA. During the phase I clinical trial, no adverse reactions were found in the 0.1 µg rESAT6 group, but in the 0.5 µg rESAT6 group 2 volunteers reported pain and 1 reported itching, and in the 1 µg rESAT6 group there was 1 case of pain, 1 case of itching, and 1 case of blister. No other local or systemic adverse reactions or events were reported. CONCLUSIONS: The rESAT6 can differentiate effectively among MTB infection, BCG vaccination, and NTM infection and is safe in healthy volunteers.

The development and preliminary evaluation of a new Mycobacterium tuberculosis vaccine comprising Ag85b, HspX and CFP-10:ESAT-6 fusion protein with CpG DNA and aluminum hydroxide adjuvants.

Ag85b and HspX of Mycobacterium tuberculosis (Mtb) (H37Rv) were expressed and purified in this study. These two proteins were combined with another fusion protein CFP-10:ESAT-6 (C/E) (Ag), then mixed with the adjuvants CpG DNA and aluminum hydroxide and used to vaccinate mice and guinea pigs challenged with Mtb (H37Rv). The number of spleen lymphocytes secreting Ag85b, HspX and C/E-specific interferon-gamma were significantly higher in the Ag+Al+CpG group than in the Ag and CpG groups. The combination of Ag, Al and CpG induced the highest concentrations of anti-Ag85b, anti-HspX and anti-C/E immunoglobulin G in mouse serum. Mouse peritoneal macrophages from the Ag+Al+CpG group secreted significantly higher levels of interleukin-12 compared with macrophages from the other groups. The total mean liver, lung and spleen lesion scores and bacterial loads in the spleen in guinea pigs vaccinated with Ag+Al+CpG were lower than those of the other groups, but no significant difference was found. These results show that the mixture of Ag85b, HspX and C/E with a combination of CpG and aluminum adjuvants can induce both humoral and cellular immune responses in mice, whereas it plays only a small role in the control of disease progression in guinea pigs challenged with Mtb.