Unraveling the Immune Regulatory Functions of USP5: Implications for Disease Therapy.

Ubiquitin-specific protease 5 (USP5) belongs to the ubiquitin-specific protease (USP) family, which uniquely recognizes unanchored polyubiquitin chains to maintain the homeostasis of monoubiquitin chains. USP5 participates in a wide range of cellular processes by specifically cleaving isopeptide bonds between ubiquitin and substrate proteins or ubiquitin itself. In the process of immune regulation, USP5 affects important cellular signaling pathways, such as NF-κB, Wnt/ß-catenin, and IFN, by regulating ubiquitin-dependent protein degradation. These pathways play important roles in immune regulation and inflammatory responses. In addition, USP5 regulates the activity and function of immunomodulatory signaling pathways via the deubiquitination of key proteins, thereby affecting the activity of immune cells and the regulation of immune responses. In the present review, the structure and function of USP5, its role in immune regulation, and the mechanism by which USP5 affects the development of diseases by regulating immune signaling pathways are comprehensively overviewed. In addition, we also introduce the latest research progress of targeting USP5 in the treatment of related diseases, calling for an interdisciplinary approach to explore the therapeutic potential of targeting USP5 in immune regulation.

Tuberculosis Vaccines and T Cell Immune Memory.

Tuberculosis (TB) remains a major infectious disease partly due to the lack of an effective vaccine. Therefore, developing new and more effective TB vaccines is crucial for controlling TB. Mycobacterium tuberculosis (M. tuberculosis) usually parasitizes in macrophages; therefore, cell-mediated immunity plays an important role. The maintenance of memory T cells following M. tuberculosis infection or vaccination is a hallmark of immune protection. This review analyzes the development of memory T cells during M. tuberculosis infection and vaccine immunization, especially on immune memory induced by BCG and subunit vaccines. Furthermore, the factors affecting the development of memory T cells are discussed in detail. The understanding of the development of memory T cells should contribute to designing more effective TB vaccines and optimizing vaccination strategies.

Rapamycin improves the long-term T-cell memory and protective efficacy of tuberculosis subunit vaccine.

The formation of long-lived T-cell memory is a critical goal of vaccines against intracellular pathogens like Mycobacterium tuberculosis (M. tuberculosis). In this study, to access the adjuvant effect of rapamycin on tuberculosis subunit vaccine, we treated mice with rapamycin during the course of vaccination and then monitored the vaccine-specific long-term memory T cell recall responses and protective ability against mycobacterial organisms. Compared with the mice that received vaccine alone, rapamycin treatment enhanced the vaccine induced long-term IFN-γ and IL-2 recall responses, promoted the development of TCM (central memory) like cells and improved the long-term proliferative ability of lymphocytes. Long-duration (total 53 days) of low-dose rapamycin (75 µg/kg/day) treatment generated stronger vaccine-specific memory T cell responses than short-duration treatment (total 25 days). Moreover, rapamycin improved the vaccine's long-term protective efficacy, which resulted in a better reduction of 0.89-log10 CFU of mycobacterial organisms in the lungs compared with control without rapamycin treatment. These findings suggest that rapamycin may be considered in designing TB subunit vaccine regimens or as potential adjuvant to enhance vaccine-induced T cell memory response and to prolong the longevity of vaccine's protective efficacy.

Construction and evaluation of a novel multi-antigenic Mycobacterium tuberculosis subunit vaccine candidate BfrB-GrpE/DPC.

Tuberculosis poses a significant threat to human health due to the lack of an effective vaccine. Although promising progress has been made in the development of tuberculosis vaccines, new vaccines that broaden the antigenic repertoire need to be developed to eradicate this illness. In this study, we used Mycobacterium tuberculosis ferritin BfrB and heat-shock protein GrpE to construct a novel multi-antigenic fusion protein, BfrB-GrpE (BG). BG protein was stably overexpressed in the soluble form in Escherichia coli at a high yield and purified via sequential salt fractionation and hydrophobic chromatography. Purified BG was emulsified in an adjuvant containing N, N'-dimethyl-N, N'-dioctadecylammonium bromide, polyinosinic-polycytidylic acid, and cholesterol (DPC) to construct the BG/DPC vaccine, which stimulated strong cellular and humoral immune responses in mice. Moreover, combination of BG with our previously developed vaccine, Mtb10.4-HspX (MH), containing antigens from both the proliferating and dormant stages, significantly reduced the bacterial counts in the lungs and spleens of M. tuberculosis-infected mice. Importantly, mice that received BG + MH/DPC after M. tuberculosis H37Rv infection survived slightly better (100% survival) than those that received the BCG vaccine (80% survival), although the difference was not statistically significant. Our findings can aid in the selection of antigens and optimization of vaccination regimens to improve the efficacy of tuberculosis vaccines.

Correction: Wang et al. A VLP-Based Vaccine Displaying HBHA and MTP Antigens of Mycobacterium tuberculosis Induces Potentially Protective Immune Responses in M. tuberculosis H37Ra Infected Mice. Vaccines 2023, 11, 941.

Concerns were brought to the attention of the journal's editorial office after the paper was published [...].

A VLP-Based Vaccine Displaying HBHA and MTP Antigens of Mycobacterium tuberculosis Induces Protective Immune Responses in M. tuberculosis H37Ra Infected Mice.

Heparin-binding hemagglutinin (HBHA) and M. tuberculosis pili (MTP) are important antigens on the surface of Mycobacterium tuberculosis. To display these antigens effectively, the fusion protein HBHA-MTP with a molecular weight of 20 kD (L20) was inserted into the receptor-binding hemagglutinin (HA) fragment of influenza virus and was expressed along with matrix protein M1 in Sf9 insect cells to generate influenza virus-like particles (LV20 in short). The results showed that the insertion of L20 into the envelope of the influenza virus did not affect the self-assembly and morphology of LV20 VLPs. The expression of L20 was successfully verified by transmission electron microscopy. Importantly, it did not interfere with the immunogenicity reactivity of LV20 VLPs. We demonstrated that LV20 combined with the adjuvant composed of DDA and Poly I: C (DP) elicited significantly higher antigen-specific antibodies and CD4+/CD8+ T cell responses than PBS and BCG vaccination in mice. It suggests that the insect cell expression system is an excellent protein production system, and LV20 VLPs could be a novel tuberculosis vaccine candidate for further evaluation.

Severe persistent mycobacteria antigen stimulation causes lymphopenia through impairing hematopoiesis.

Miliary tubersculosis (TB), an acute systemic blood disseminated tuberculosis mainly caused by Mycobacterium tuberculosis (M. tuberculosis), can cause signs of lymphopenia in clinical patients. To investigate whether/how persistent mycobacteria antigen stimulation impairs hematopoiesis and the therapeutic effect of interleukin-7 (IL-7), a mouse model of Mycobacterium Bovis Bacillus Calmette-Guérin (BCG) intravenous infection with/without an additional stimulation with M. tuberculosis multi-antigen cocktail containing ESAT6-CFP10 (EC) and Mtb10.4-HspX (MH) was established. Consistent with what happened in miliary TB, high dose of BCG intravenous infection with/without additional antigen stimulation caused lymphopenia in peripheral blood. In which, the levels of cytokines IFN-γ and TNF-α in serum increased, and consequently the expression levels of transcription factors Batf2 and IRF8 involved in myeloid differentiation were up-regulated, while the expression levels of transcription factors GATA2 and NOTCH1 involved in lymphoid commitment were down-regulated, and the proliferating activity of bone marrow (BM) lineage- c-Kit+ (LK) cells decreased. Furthermore, recombinant Adeno-Associated Virus 2-mediated IL-7 (rAAV2-IL-7) treatment could significantly promote the elevation of BM lymphoid progenitors. It suggests that persistent mycobacteria antigen stimulation impaired lymphopoiesis of BM hematopoiesis, which could be restored by complement of IL-7.

Polysaccharides and glycolipids of Mycobacterium tuberculosis and their induced immune responses.

Tuberculosis (TB) is a chronic infectious disease mainly caused by Mycobacterium tuberculosis (M. tuberculosis). The structures of polysaccharides and glycolipids at M. tuberculosis cell wall vary among different strains, which affect the physiology and pathogenesis of mycobacteria by activating or inhibiting innate and acquired immunity. Among them, some components such as lipomannan (LM) and lipoarabinomannan (LAM) activate innate immunity by recognizing some kinds of pattern recognition receptors (PRRs) like Toll-like receptors, while other components like mannose-capped lipoarabinomannan (ManLAM) could prevent innate immune responses by inhibiting the secretion of pro-inflammatory cytokines and maturation of phagosomes. In addition, many glycolipids can activate natural killer T (NKT) cells and CD1-restricted T cells to produce interferon-γ (IFN-γ). Furthermore, humoral immunity against cell wall components, such as antibodies against LAM, plays a role in immunity against M. tuberculosis infection. Cell wall polysaccharides and glycolipids of M. tuberculosis have potential applications as antigens and adjuvants for novel TB subunit vaccines.

Metabolic plasticity and regulation of T cell exhaustion.

The metabolic reprogramming during T cell activation and differentiation affects T cell fate and immune responses. Cell metabolism may serve as the driving force that induces epigenetic modifications, contributing to regulating T cell differentiation. Persistent pathogen infection leads to T cell exhaustion, which is composed of two main subsets and with distinct metabolic characteristics. The progenitor exhausted T cells utilize mitochondrial fatty acid oxidation (FAO) and oxidative phosphorylation (OXPHOS) for energy, while terminally exhausted T cells mainly rely on glycolytic metabolism with impaired glycolysis and OXPHOS. Here, we compiled the latest research on how T cell metabolism defines differentiation, focusing on T cell exhaustion during chronic infections. In addition, metabolic-related factors including antigen stimulation signals strength, cytokines and epigenetics affecting T cell exhaustion were also reviewed. Furthermore, the intervention strategies on metabolism and epigenetics to reverse T cell exhaustion were discussed in detail, which may contribute to achieving the goal of prevention and treatment of T cell exhaustion.

Pyrazinamide enhances persistence of T-cell memory induced by tuberculosis subunit vaccine LT70.

Repurposing anti-tuberculosis drugs with adjuvant properties in vaccination has double benefits for the control of tuberculosis. In this study, to verify the immunomodulatory effect of the tuberculosis drug pyrazinamide (PZA) on tuberculosis subunit vaccine-induced memory T cell response, we treated mice with PZA during the course of vaccination and then monitored the vaccine-specific T cell memory responses. Compared with the mice that received LT70 alone, we found that the mice co-administrated with PZA and LT70 did not produce a higher frequency of multifunctional CD4+ T lymphocytes at 8-week post-vaccination, but the T lymphocytes produced stronger long-term IL-2 response rather than IFN-γ recall response and had higher long-term proliferating potential upon antigen stimulation at 28-week post-vaccination. In addition, the memory T cells from PZA-treated mice showed superior IFN-γ recall response after twice antigen stimulations in vivo and in vitro respectively. Together, the findings show that PZA treatment during the course of vaccination contributes to inducing TCM-like cells and enhances vaccine-induced T-cell long-term immunological memory, which would be helpful for designing novel vaccination and therapeutic strategies for tuberculosis.

IL-7 promoted the development of thymic DN3 cells in aged mice via DNA demethylation of Bcl2 and c-Myc genes.

IL-7 promotes the development of thymic double negative (DN) T cells during ß-selection, which might contribute to the remission of aging-associated thymic involution. Methylation levels of CpG sites is correlated with aging and modulates the development. To determine the involvement of DNA methylation/demethylation instructed by IL-7 signaling during the expansion of double negative (DN) T cells, the aged mice were treated with recombinant Adeno-Associated Virus 2-mediated IL-7 (rAAV2-IL-7) and the DNA methylation/demethylation modifications in this process were analyzed. The results showed that rAAV2-IL-7 increased the number of thymocytes, especially the DN3 thymocytes during ß-selection in aged mice. With aging, the methylation levels of Bcl2 and c-Myc promoter regions were increased in DN3 cells. Following rAAV2-IL-7 treatment, DNA methyltransferase Dnmt3a and Dnmt3b decreased, DNA demethylation factors TET2 and TET3 increased, and the methylation levels of Bcl2 and c-Myc in DN3 cells were reduced during DN3 stage in aged mice, consequently, resulting in the upregulation of Bcl2 and c-Myc and the larger increase of DN3 cells in thymus. In conclusion, these findings showed that Bcl2 and c-Myc genes of DN3 cells had an increased DNA methylation levels in aged mice compared to the young, and the hypermethylation in aged mice could be restored following rAAV2-IL-7 treatment.

Optimizing the Boosting Schedule of Subunit Vaccines Consisting of BCG and "Non-BCG" Antigens to Induce Long-Term Immune Memory.

Boosting Bacillus Calmette-Guérin (BCG) with subunit vaccine is expected to induce long-term protection against tuberculosis (TB). However, it is urgently needed to optimize the boosting schedule of subunit vaccines, which consists of antigens from or not from BCG, to induce long-term immune memory. To address it two subunit vaccines, Mtb10.4-HspX (MH) consisting of BCG antigens and ESAT6-CFP10 (EC) consisting of antigens from the region of difference (RD) of Mycobacterium tuberculosis (M. tuberculosis), were applied to immunize BCG-primed C57BL/6 mice twice or thrice with different intervals, respectively. The long-term antigen-specific immune responses and protective efficacy against M. tuberculosis H37Ra were determined. The results showed that following BCG priming, MH boosting twice at 12-24 weeks or EC immunizations thrice at 12-16-24 weeks enhanced the number and function of long-lived memory T cells with improved protection against H37Ra, while MH boosting thrice at 12-16-24 weeks or twice at 8-14 weeks and EC immunizations twice at 12-24 weeks or thrice at 8-10-14 weeks didn't induce long-term immunity. It suggests that following BCG priming, both BCG antigens MH boosting twice and "non-BCG" antigens EC immunizations thrice at suitable intervals induce long-lived memory T cell-mediated immunity.

A new poly(I:C)-decorated PLGA-PEG nanoparticle promotes Mycobacterium tuberculosis fusion protein to induce comprehensive immune responses in mice intranasally.

Protein-based subunit vaccine against tuberculosis (TB) is regarded as safer but with lower immunogenicity. To investigate effective adjuvant to improve the immunogenicity of TB subunit vaccine, we modified ploy(I:C) onto PLGA-PEG copolymer nanoparticle with polydopamine to produce a new nanoparticle adjuvant named "PLGA-PEG-poly(I:C)" (NP). M. tuberculosis fusion proteins Mtb10.4-HspX and ESAT-6-Rv2626c (M4) were encapsulated in the nanoparticles to produce the NP/M4 subunit vaccine. The PLGA-PEG/M4 nanoparticle was 200.21 ± 1.07 nm in diameter, and the polydispersity index (PDI) was 0.127 ± 0.02. Following modification with poly(I:C) by polydopamine, the NP/M4 was administered to C57BL/6 female mice intranasally and the immune responses were evaluated. The NP/M4 significantly induced antigen-specific CD4+ T cells proliferation, IL-2 and IFN-γ production. In addition, the NP/M4 could promote the production of antigen-specific IgG, IgG1, IgG2c in serum, and sIgA in lung washings. Overall, our results indicated that the NP would be a potential TB subunit vaccine adjuvant with the ability to induce strong Th1-type cell-mediated immunity and humoral immune responses.

ENO1 monoclonal antibody inhibits invasion, proliferation and clone formation of cervical cancer cells.

α-enolase (ENO1), highly expressing in cell membranes, cytoplasm and nuclei of cervical cancer and other tumors, acts as a plasminogen receptor and a glycolytic enzyme. ENO1 is found to be associated with tumorigenesis, invasion and migration, and proves to be an ideal target of tumor therapy. In this study, ENO1 monoclonal antibodies (ENO1mAb) was prepared to blockade ENO1 and the therapeutic role was observed in cervical cancer cells. First, ENO1mAb was prepared and screened by evaluating the inhibitory effect on migration and invasion of cervical cancer cells, which is supposed to block ENO1 expressed on cell membrane. Second, folic acid (FA) conjugated PLGA nanoparticles (FA-SS-PLGA) targeting tumor cells were prepared to mediate ENO1mAb entry into cells and its anti-tumor effects were investigated in vitro. We found that PLGA/FA-SS-PLGA nanoparticles-mediated ENO1mAb could antagonize the activity of ENO1 enzyme, significantly decreased the contents of lactic acid and pyruvate, and inhibited the proliferation, migration and clone formation of cervical cancer cells compared with the sham control (P < 0.05). In summary, ENO1mAb could specifically block ENO1 expressed on cell membrane and inhibit ENO1 glycolysis enzyme activity inside tumor cells, and plays a therapeutic role against cervical cancer cells. It suggests that ENO1mAb has promising anti-tumor effects.

Production of SARS-CoV-2 Virus-Like Particles in Insect Cells.

Coronavirus disease (COVID-19) causes a serious threat to human health. Virus-like particles (VLPs) constitute a promising platform in SARS-CoV-2 vaccine development. In this study, the E, M, and S genes were cloned into multiple cloning sites of a new triple expression plasmid with one p10 promoter, two pPH promoters, and three multiple cloning sites. The plasmid was transformed into DH10 BacTMEscherichia coli competent cells to obtain recombinant bacmid. Then the recombinant bacmid was transfected in ExpiSf9TM insect cells to generate recombinant baculovirus. After ExpiSf9TM cells infection with the recombinant baculovirus, the E, M, and S proteins were expressed in insect cells. Finally, SARS-CoV-2 VLPs were self-assembled in insect cells after infection. The morphology and the size of SARS-CoV-2 VLPs are similar to the native virions.

Id3 and Bcl6 Promote the Development of Long-Term Immune Memory Induced by Tuberculosis Subunit Vaccine.

Long-lived memory cell formation and maintenance are usually regulated by cytokines and transcriptional factors. Adjuvant effects of IL-7 have been studied in the vaccines of influenza and other pathogens. However, few studies investigated the adjuvant effects of cytokines and transcriptional factors in prolonging the immune memory induced by a tuberculosis (TB) subunit vaccine. To address this research gap, mice were treated with the Mycobacterium tuberculosis (M. tuberculosis) subunit vaccine Mtb10.4-HspX (MH) plus ESAT6-Ag85B-MPT64<190-198>-Mtb8.4-Rv2626c (LT70), together with adeno-associated virus-mediated IL-7 or lentivirus-mediated transcriptional factor Id3, Bcl6, Bach2, and Blimp1 at 0, 2, and 4 weeks, respectively. Immune responses induced by the vaccine were examined at 25 weeks after last immunization. The results showed that adeno-associated virus-mediated IL-7 allowed the TB subunit vaccine to induce the formation of long-lived memory T cells. Meanwhile, IL-7 increased the expression of Id3, Bcl6, and bach2-the three key transcription factors for the generation of long-lived memory T cells. The adjuvant effects of transcriptional factors, together with TB fusion protein MH/LT70 vaccination, showed that both Bcl6 and Id3 increased the production of antigen-specific antibodies and long-lived memory T cells, characterized by high proliferative potential of antigen-specific CD4+ and CD8+ T cells, and IFN-γ secretion in CD4+ and CD8+ T cells, respectively, after re-exposure to the same antigen. Overall, our study suggests that IL-7 and transcriptional factors Id3 and Bcl6 help the TB subunit vaccine to induce long-term immune memory, which contributes to providing immune protection against M. tuberculosis infection.

In silico analysis of epitope-based vaccine candidate against tuberculosis using reverse vaccinology.

Tuberculosis (TB) kills more individuals in the world than any other disease, and a threat made direr by the coverage of drug-resistant strains of Mycobacterium tuberculosis (Mtb). Bacillus Calmette-Guérin (BCG) is the single TB vaccine licensed for use in human beings and effectively protects infants and children against severe military and meningeal TB. We applied advanced computational techniques to develop a universal TB vaccine. In the current study, we select the very conserved, experimentally confirmed Mtb antigens, including Rv2608, Rv2684, Rv3804c (Ag85A), and Rv0125 (Mtb32A) to design a novel multi-epitope subunit vaccine. By using the Immune Epitopes Database (IEDB), we predicted different B-cell and T-cell epitopes. An adjuvant (Griselimycin) was also added to vaccine construct to improve its immunogenicity. Bioinformatics tools were used to predict, refined, and validate the 3D structure and then docked with toll-like-receptor (TLR-3) using different servers. The constructed vaccine was used for further processing based on allergenicity, antigenicity, solubility, different physiochemical properties, and molecular docking scores. The in silico immune simulation results showed significant response for immune cells. For successful expression of the vaccine in E. coli, in-silico cloning and codon optimization were performed. This research also sets out a good signal for the design of a peptide-based tuberculosis vaccine. In conclusion, our findings show that the known multi-epitope vaccine may activate humoral and cellular immune responses and maybe a possible tuberculosis vaccine candidate. Therefore, more experimental validations should be exposed to it.

Fusion Cytokines IL-7-Linker-IL-15 Promote Mycobacterium Tuberculosis Subunit Vaccine to Induce Central Memory like T Cell-Mediated Immunity.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tuberculosis), is among the most serious infectious diseases worldwide. Adjuvanted protein subunit vaccines have been demonstrated as a kind of promising novel vaccine. This study proposed to investigate whether cytokines interliukine-7 (IL-7) and interliukine-15 (IL-15) help TB subunit vaccines induce long-term cell-mediated immune responses, which are required for vaccination against TB. In this study, mice were immunized with the M. tuberculosis protein subunit vaccines combined with adnovirus-mediated cytokines IL-7, IL-15, IL-7-IL-15, and IL-7-Linker-IL-15 at 0, 2, and 4 weeks, respectively. Twenty weeks after the last immunization, the long-term immune responses, especially the central memory-like T cells (TCM like cell)-mediated immune responses, were determined with the methods of cultured IFN-γ-ELISPOT, expanded secondary immune responses, cell proliferation, and protective efficacy against Mycobacterium bovis Bacilli Calmette-Guerin (BCG) challenge, etc. The results showed that the group of vaccine + rAd-IL-7-Linker-IL-15 induced a stronger long-term antigen-specific TCM like cells-mediated immune responses and had higher protective efficacy against BCG challenge than the vaccine + rAd-vector control group, the vaccine + rAd-IL-7 and the vaccine + rAd-IL-15 groups. This study indicated that rAd-IL-7-Linker-IL-15 improved the TB subunit vaccine's efficacy by augmenting TCM like cells and provided long-term protective efficacy against Mycobacteria.

The Systematic Review and Meta-Analysis on the Immunogenicity and Safety of the Tuberculosis Subunit Vaccines M72/AS01E and MVA85A.

Background: Tuberculosis (TB) is a severe infectious disease with devastating effects on global public health. No TB vaccine has yet been approved for use on latent TB infections and healthy adults. In this study, we performed a systematic review and meta-analysis to evaluate the immunogenicity and safety of the M72/AS01E and MVA85A subunit vaccines. The M72/AS01E is a novel peptide-based vaccine currently in progress, which may increase the protection level against TB infection. The MVA85A was a viral vector-based TB subunit vaccine being used in the clinical trials. The vaccines mentioned above have been studied in various phase I/II clinical trials. Immunogenicity and safety is the first consideration for TB vaccine development. Methods: The PubMed, Embase, and Cochrane Library databases were searched for published studies (until October 2019) to find out information on the M72/AS01E and MVA85A candidate vaccines. The meta-analysis was conducted by applying the standard methods and processes established by the Cochrane Collaboration. Results: Five eligible randomized clinical trials (RCTs) were selected for the meta-analysis of M72/AS01E candidate vaccines. The analysis revealed that the M72/AS01E subunit vaccine had an abundance of polyfunctional M72-specific CD4+ T cells [standardized mean difference (SMD) = 2.37] in the vaccine group versus the control group, the highest seropositivity rate [relative risk (RR) = 5.09]. The M72/AS01E vaccinated group were found to be at high risk of local injection site redness (RR = 2.64), headache (RR = 1.59), malaise (RR = 3.55), myalgia (RR = 2.27), fatigue (RR = 2.16), pain (RR = 3.99), swelling (RR = 5.09), and fever (RR = 2.04) compared to the control groups. The incidences of common adverse events of M72/AS01E were local injection site redness, headache, malaise, myalgia, fatigue, pain, swelling, fever, etc. Six eligible RCTs were selected for the meta-analysis on MVA85A candidate vaccines. The analysis revealed that the subunit vaccine MVA85A had a higher abundance of overall pooled proportion polyfunctional MVA85A-specific CD4+ T cells SMD = 2.41 in the vaccine group vs. the control group, with the highest seropositivity rate [estimation rate (ER) = 0.55]. The MVA85A vaccinated group were found to be at high risk of local injection site redness (ER = 0.55), headache (ER = 0.40), malaise (ER = 0.29), pain (ER = 0.54), myalgia (ER = 0.31), and fever (ER = 0.20). The incidences of common adverse events of MVA85A were local injection site redness, headache, malaise, pain, myalgia, fever, etc. Conclusion: The M72/AS01E and MVA85A vaccines against TB are safe and had immunogenicity in diverse clinical trials. The M72/AS01E and MVA85A vaccines are associated with a mild adverse reaction. The meta-analysis on immunogenicity and safety of M72/AS01E and MVA85A vaccines provides useful information for the evaluation of available subunit vaccines in the clinic.

Identification of Novel Genes Involved in Escherichia coli Persistence to Tosufloxacin.

Persisters are metabolically quiescent phenotypic variants of the wild type that are tolerant to cidal antibiotics, and the mechanisms of persister formation and survival are complex and not completely understood. To identify genes involved in persistence to tosufloxacin, which has higher activity against persisters than most other quinolones, we screened the E. coli KEIO mutant library using a different condition from most persister mutant screens (6 h) with a longer exposure of 18 h with tosufloxacin. We identified 18 mutants (acrA, acrB, ddlB, dnaG, gltI, hlpA, lpcA, recG, recN, rfaH, ruvC, surA, tatC, tolQ, uvrD, xseA, and ydfI) that failed to form tosufloxacin tolerant persisters. Among them, gltI, hlpA, ruvC, ddlB, ydfI, and tatC are unique genes involved in E. coli persistence to tosufloxacin which have not been reported before. Furthermore, deletion mutants in genes coding periplasmic proteins (surA, lpcA, hlpA, and gltI) had more defect in persistence to tosufloxacin than the other identified mutants, with surA and lpcA mutants being the most prominent. The "deep" persister phenotype of surA and lpcA mutants was further confirmed both in vitro and in vivo. Compared with the wild type strain E. coli BW25113 in vitro, the persister phenotype of the surA and lpcA mutants was decreased more than 100-1,000-fold in persistence to various antibiotics, acidic, hyperosmotic and heat conditions. In addition, in both stationary phase bacteria and biofilm bacteria infection mouse models, the surA and lpcA mutants had lower survival and persistence than the parent uropathogenic strain UTI89, suggesting that the in vitro identified persister mechanisms (surA and lpcA) are operative and valid for in vivo persistence. Our findings provide new insight into the mechanisms of persister formation and maintenance under tosufloxacin and will likely provide novel therapeutic and vaccine targets for developing more effective treatment and prevention of persistent E. coli infections.