Strategy to develop broadly effective multivalent COVID-19 vaccines against emerging variants based on Ad5/35 platform

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron strain has evolved into highly divergent variants with several sub-lineages. These newly emerging variants threaten the efficacy of available COVID-19 vaccines. To mitigate the occurrence of breakthrough infections and re-infections, and more importantly, to reduce the disease burden, it is essential to develop a strategy for producing updated multivalent vaccines that can provide broad neutralization against both currently circulating and emerging variants. We developed bivalent vaccine AdCLD-CoV19-1 BA.5/BA.2.75 and trivalent vaccines AdCLD-CoV19-1 XBB/BN.1/BQ.1.1 and AdCLD-CoV19-1 XBB.1.5/BN.1/BQ.1.1 using an Ad5/35 platform-based non-replicating recombinant adenoviral vector. We compared immune responses elicited by the monovalent and multivalent vaccines in mice and macaques. We found that the BA.5/BA.2.75 bivalent and the XBB/BN.1/BQ.1.1 and XBB.1.5/BN.1/BQ.1.1 trivalent vaccines exhibited improved cross-neutralization ability compared to their respective monovalent vaccines. These data suggest that the developed multivalent vaccines enhance immunity against circulating Omicron subvariants and effectively elicit neutralizing antibodies across a broad spectrum of SARS-CoV-2 variants.

Boosting with variant-matched adenovirus-based vaccines promotes neutralizing antibody responses against SARS-CoV-2 Omicron sublineages in mice

Global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) Omicron subvariants, such as BA.4, BA.5 and XBB.1.5, has been leading the recent wave of coronavirus disease 2019 (COVID-19). Unique mutations in the spike proteins of these emerging Omicron subvariants caused immune evasion from the pre-existing protective immunity induced by vaccination or natural infection. Previously, we developed AdCLD-CoV19-1, a non-replicating recombinant adenoviral vector that encodes the receptor binding domain of the spike protein of the ancestral SARS-CoV-2 strain. Based on the same recombinant adenoviral vector platform, updated vaccines that cover unique mutations found in each Omicron subvariant, including BA.1, BA.2, BA.4.1 and BA.5, were constructed. Preclinical studies revealed that each updated vaccine as a booster shot following primary vaccination targeting the ancestral strain improved neutralizing antibody responses against the pseudovirus of its respective strain most effectively. Of note, boosting with a vaccine targeting the BA.1 or BA.2 Omicron subvariant was most effective in neutralization against the pseudovirus of the BA.2.75 strain, whereas BA.4.1/5-adapted booster shots were most effective in neutralization against the BQ.1, BQ1.1 and BF.7 strains. Therefore, it is imperative to develop a vaccination strategy that can cover the unique spike mutations of currently circulating Omicron subvariants in order to prevent the next wave of COVID-19.

One-year antibody durability induced by EuCorVac-19, a liposome-displayed COVID-19 receptor binding domain subunit vaccine, in healthy Korean subjects

OBJECTIVE

EuCorVac-19 (ECV-19), an adjuvanted liposome-displayed receptor binding domain (RBD) COVID-19 vaccine, previously reported interim Phase 2 trial results showing induction of neutralizing antibodies 3 weeks after prime-boost immunization. The objective of this study was to determine the longer-term antibody response of the vaccine.

METHODS

To assess immunogenicity 6 and 12 months after vaccination, participants in the Phase 2 trial (NCT04783311) were excluded if they: 1) withdrew, 2) reported COVID-19 infection or additional vaccination, or 3) exhibited increasing Spike (S) antibodies (representing possible non-reported infection). Following exclusions, of the 197 initial subjects, anti-S IgG antibodies and neutralizing antibodies were further assessed in 124 subjects at the 6-month timepoint, and 36 subjects at the 12-month timepoint.

RESULTS

Median anti-S antibody half-life was 52 days (interquartile range [IQR]:42-70), in the "early" period from 3 weeks to 6 months, and 130 days (IQR:97-169) in the "late" period from 6 to 12 months. There was a negative correlation between initial antibody titer and half-life. Anti-S and neutralizing antibody responses were correlated. Neutralizing antibody responses showed longer half-lives; the early period had a median half-life of 120 days (IQR:81-207), and the late period had a median half-life of 214 days (IQR:140-550).

CONCLUSION

These data establish antibody durability of ECV-19, using a framework to analyze COVID-19 vaccine-induced antibodies during periods of high infection.

Recombinant measles virus encoding the spike protein of SARS-CoV-2 efficiently induces Th1 responses and neutralizing antibodies that block SARS-CoV-2 variants

Owing to the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants, the development of effective and safe vaccines has become a priority. The measles virus (MeV) vaccine is an attractive vaccine platform as it has been administered to children for more than 40 years in over 100 countries. In this study, we developed a recombinant MeV expressing the full-length SARS-CoV-2 spike protein (rMeV-S) and tested its efficacy using mouse and hamster models. In hCD46Tg mice, two-dose rMeV-S vaccination induced higher Th1 secretion and humoral responses than one-dose vaccination. Interestingly, neutralizing antibodies induced by one-dose and two-dose rMeV-S immunization effectively blocked the entry of the α, β, γ, and δ variants of SARS-CoV-2. Furthermore, two-dose rMeV-S immunization provided complete protection against SARS-CoV-2 in the hamster model. These results suggest the potential of rMeV-S as a vaccine candidate for targeting SARS-CoV-2 and its variants.

Interim analysis from a phase 2 randomized trial of EuCorVac-19: a recombinant protein SARS-CoV-2 RBD nanoliposome vaccine

BACKGROUND

Numerous vaccine strategies are being advanced to control SARS-CoV-2, the cause of the COVID-19 pandemic. EuCorVac-19 (ECV19) is a recombinant protein nanoparticle vaccine that displays the SARS-CoV-2 receptor-binding domain (RBD) on immunogenic nanoliposomes.

METHODS

Initial study of a phase 2 randomized, observer-blind, placebo-controlled trial to assess the immunogenicity, safety, and tolerance of ECV19 was carried out between July and October 2021. Two hundred twenty-nine participants were enrolled at 5 hospital sites in South Korea. Healthy adults aged 19-75 without prior known exposure to COVID-19 were vaccinated intramuscularly on day 0 and day 21. Of the participants who received two vaccine doses according to protocol, 100 received high-dose ECV19 (20 μg RBD), 96 received low-dose ECV19 (10 μg RBD), and 27 received placebo. Local and systemic adverse events were monitored. Serum was assessed on days 0, 21, and 42 for immunogenicity analysis by ELISA and neutralizing antibody response by focus reduction neutralization test (FRNT).

RESULTS

Low-grade injection site tenderness and pain were observed in most participants. Solicited systemic adverse events were less frequent, and mostly involved low-grade fatigue/malaise, myalgia, and headache. No clinical laboratory abnormalities were observed. Adverse events did not increase with the second injection and no serious adverse events were solicited by ECV19. On day 42, Spike IgG geometric mean ELISA titers were 0.8, 211, and 590 Spike binding antibody units (BAU/mL) for placebo, low-dose and high-dose ECV19, respectively (p < 0.001 between groups). Neutralizing antibodies levels of the low-dose and high-dose ECV19 groups had FRNT₅₀ geometric mean values of 129 and 316, respectively. Boosting responses and dose responses were observed. Antibodies against the RBD correlated with antibodies against the Spike and with virus neutralization.

CONCLUSIONS

ECV19 was generally well-tolerated and induced antibodies in a dose-dependent manner that neutralized SARS-CoV-2. The unique liposome display approach of ECV19, which lacks any immunogenic protein components besides the antigen itself, coupled with the lack of increased adverse events during boosting suggest the vaccine platform may be amenable to multiple boosting regimes in the future. Taken together, these findings motivate further investigation of ECV19 in larger scale clinical testing that is underway.

TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov as # NCT04783311.

Amelioration of SARS-CoV-2 infection by ANO6 phospholipid scramblase inhibition

As an enveloped virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) delivers its viral genome into host cells via fusion of the viral and cell membranes. Here, we show that ANO6/TMEM16F-mediated cell surface exposure of phosphatidylserine is critical for SARS-CoV-2 entry and that ANO6-selective inhibitors are effective against SARS-CoV-2 infections. Application of the SARS-CoV-2 Spike pseudotyped virus (SARS2-PsV) evokes a cytosolic Ca2+ elevation and ANO6-dependent phosphatidylserine externalization in ACE2/TMPRSS2-positive mammalian cells. A high-throughput screening of drug-like chemical libraries identifies three different structural classes of chemicals showing ANO6 inhibitory effects. Among them, A6-001 displays the highest potency and ANO6 selectivity and it inhibits the single-round infection of SARS2-PsV in ACE2/TMPRSS2-positive HEK 293T cells. More importantly, A6-001 strongly inhibits authentic SARS-CoV-2-induced phosphatidylserine scrambling and SARS-CoV-2 viral replications in Vero, Calu-3, and primarily cultured human nasal epithelial cells. These results provide mechanistic insights into the viral entry process and offer a potential target for pharmacological intervention to protect against coronavirus disease 2019 (COVID-19).

The Chimeric Adenovirus (Ad5/35) Expressing Engineered Spike Protein Confers Immunity against SARS-CoV-2 in Mice and Non-Human Primates

Several COVID-19 platforms have been licensed across the world thus far, but vaccine platform research that can lead to effective antigen delivery is still ongoing. Here, we constructed AdCLD-CoV19 that could modulate humoral immunity by harboring SARS-CoV-2 antigens onto a chimeric adenovirus 5/35 platform that was effective in cellular immunity. By replacing the S1/S2 furin cleavage sequence of the SARS-CoV-2 Spike (S) protein mounted on AdCLD-CoV19 with the linker sequence, high antigen expression was confirmed in various cell lines. The high levels of antigen expression contributed to antigen-specific antibody activity in mice and non-human primates (NHPs) with a single vaccination of AdCLD-CoV19. Furthermore, the adenovirus-induced Th1 immune response was specifically raised for the S protein, and these immune responses protected the NHP against live viruses. While AdCLD-CoV19 maintained neutralizing antibody activity against various SARS-CoV-2 variants, it was reduced to single vaccination for β and ο variants, and the reduced neutralizing antibody activity was restored with booster shots. Hence, AdCLD-CoV19 can prevent SARS-CoV-2 with a single vaccination, and the new vaccine administration strategy that responds to various variants can maintain the efficacy of the vaccine.

Does dissemination of guidelines alone increase the use of palliative single-fraction radiotherapy? Initial report of a longitudinal change management campaign at a provincial cancer program

Background

Despite level 1 evidence demonstrating the equivalence of single-fraction radiotherapy (sfrt) and multiple-fraction radiotherapy (mfrt) for the palliation of painful bone metastases, sfrt remains underused. In 2015, to encourage the sustainable use of palliative radiation oncology resources, CancerCare Manitoba disseminated, to each radiation oncologist in Manitoba, guidelines from Choosing Wisely Canada (cwc) that recommend sfrt. We assessed whether dissemination of the guidelines influenced sfrt use in Manitoba in 2016, and we identified factors associated with mfrt.

Methods

All patients treated with palliative radiotherapy for bone metastasis in Manitoba from 1 January 2016 to 31 December 2016 were identified from the provincial radiotherapy database. Patient, treatment, and disease characteristics were extracted from the electronic medical record and tabulated by fractionation schedule. Univariable and multivariable logistic regression analyses were performed to identify risk factors associated with mfrt.

Results

In 2016, 807 patients (mean age: 70 years; range: 35-96 years) received palliative radiotherapy for bone metastasis, with 69% of the patients having uncomplicated bone metastasis. The most common primary malignancies were prostate (27.1%), lung (20.6%), and breast cancer (15.9%). In 62% of cases, mfrt was used-a proportion that was unchanged from 2015. On multivariable analysis, a gastrointestinal [odds ratio (or): 5.3] or lung primary (or: 3.3), complicated bone metastasis (or: 4.3), and treatment at a subsidiary site (or: 4.4) increased the odds of mfrt use.

Conclusions

Dissemination of cwc recommendations alone did not increase sfrt use by radiation oncologists in 2016. A more comprehensive knowledge translation effort is therefore warranted and is now underway to encourage increased uptake of sfrt in Manitoba.

Nanoformulated Single-Stranded RNA-Based Adjuvant with a Coordinative Amphiphile as an Effective Stabilizer: Inducing Humoral Immune Response by Activation of Antigen-Presenting Cells

As agonists of TLR7/8, single-stranded RNAs (ssRNAs) are safe and promising adjuvants that do not cause off-target effects or innate immune overactivation. However, low stability prevents them from mounting sufficient immune responses. This study evaluates the adjuvant effects of ssRNA derived from the cricket paralysis virus intergenic region internal ribosome entry site, formulated as nanoparticles with a coordinative amphiphile, containing a zinc/dipicolylamine complex moiety as a coordinative phosphate binder, as a stabilizer for RNA-based adjuvants. The nanoformulated ssRNA adjuvant was resistant to enzymatic degradation in vitro and in vivo, and that with a coordinative amphiphile bearing an oleyl group (CA-O) was approximately 100 nm, promoted effective recognition, and improved activation of antigen-presenting cells, leading to better induction of neutralizing antibodies following single immunization. Hence, CA-O may increase the efficacy of ssRNA-based adjuvants, proving useful to meet the urgent need for vaccines during pathogen outbreaks.

Safety and immunogenicity of a candidate Middle East respiratory syndrome coronavirus viral-vectored vaccine: a dose-escalation, open-label, non-randomised, uncontrolled, phase 1 trial

BACKGROUND

Cases of Middle East respiratory syndrome coronavirus (MERS-CoV) infection continue to rise in the Arabian Peninsula 7 years after it was first described in Saudi Arabia. MERS-CoV poses a significant risk to public health security because of an absence of currently available effective countermeasures. We aimed to assess the safety and immunogenicity of the candidate simian adenovirus-vectored vaccine expressing the full-length spike surface glycoprotein, ChAdOx1 MERS, in humans.

METHODS

This dose-escalation, open-label, non-randomised, uncontrolled, phase 1 trial was done at the Centre for Clinical Vaccinology and Tropical Medicine (Oxford, UK) and included healthy people aged 18-50 years with negative pre-vaccination tests for HIV antibodies, hepatitis B surface antigen, and hepatitis C antibodies (and a negative urinary pregnancy test for women). Participants received a single intramuscular injection of ChAdOx1 MERS at three different doses: the low-dose group received 5 × 10⁹ viral particles, the intermediate-dose group received 2·5 × 10¹⁰ viral particles, and the high-dose group received 5 × 10¹⁰ viral particles. The primary objective was to assess safety and tolerability of ChAdOx1 MERS, measured by the occurrence of solicited, unsolicited, and serious adverse events after vaccination. The secondary objective was to assess the cellular and humoral immunogenicity of ChAdOx1 MERS, measured by interferon-γ-linked enzyme-linked immunospot, ELISA, and virus neutralising assays after vaccination. Participants were followed up for up to 12 months. This study is registered with ClinicalTrials.gov, NCT03399578.

FINDINGS

Between March 14 and Aug 15, 2018, 24 participants were enrolled: six were assigned to the low-dose group, nine to the intermediate-dose group, and nine to the high-dose group. All participants were available for follow-up at 6 months, but five (one in the low-dose group, one in the intermediate-dose group, and three in the high-dose group) were lost to follow-up at 12 months. A single dose of ChAdOx1 MERS was safe at doses up to 5 × 10¹⁰ viral particles with no vaccine-related serious adverse events reported by 12 months. One serious adverse event reported was deemed to be not related to ChAdOx1 MERS. 92 (74% [95% CI 66-81]) of 124 solicited adverse events were mild, 31 (25% [18-33]) were moderate, and all were self-limiting. Unsolicited adverse events in the 28 days following vaccination considered to be possibly, probably, or definitely related to ChAdOx1 MERS were predominantly mild in nature and resolved within the follow-up period of 12 months. The proportion of moderate and severe adverse events was significantly higher in the high-dose group than in the intermediate-dose group (relative risk 5·83 [95% CI 2·11-17·42], p<0·0001) Laboratory adverse events considered to be at least possibly related to the study intervention were self-limiting and predominantly mild in severity. A significant increase from baseline in T-cell (p<0·003) and IgG (p<0·0001) responses to the MERS-CoV spike antigen was observed at all doses. Neutralising antibodies against live MERS-CoV were observed in four (44% [95% CI 19-73]) of nine participants in the high-dose group 28 days after vaccination, and 19 (79% [58-93]) of 24 participants had antibodies capable of neutralisation in a pseudotyped virus neutralisation assay.

INTERPRETATION

ChAdOx1 MERS was safe and well tolerated at all tested doses. A single dose was able to elicit both humoral and cellular responses against MERS-CoV. The results of this first-in-human clinical trial support clinical development progression into field phase 1b and 2 trials.

FUNDING

UK Department of Health and Social Care, using UK Aid funding, managed by the UK National Institute for Health Research.

Characterization of novel monoclonal antibodies against MERS-coronavirus spike protein

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Identification of neutralizing mAbs using MERS-CoV spike-pseudotyped virus.

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Transmembrane domain-deleted spike subunit protein induced neutralizing antibodies.

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Neutralizing antibodies could bind to RBD of MERS-CoV spike, but not vice versa.

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Mutation in residue 506–509 or 529 of S elicits neutralization escape of MERS-CoV.

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Our mAbs can be utilized for identification of specific mutation of MERS-CoV.

Middle East Respiratory Syndrome coronavirus (MERS-CoV) causes severe pulmonary infection, with ∼35 % mortality. Spike glycoprotein (S) of MERS-CoV is a key target for vaccines and therapeutics because S mediates viral entry and membrane-fusion to host cells. Here, four different S subunit proteins, receptor-binding domain (RBD; 358–606 aa), S1 (1–751 aa), S2 (752–1296 aa), and SΔTM (1–1296 aa), were generated using the baculoviral system and immunized in mice to develop neutralizing antibodies. We developed 77 hybridomas and selected five neutralizing mAbs by immunization with SΔTM against MERS-CoV EMC/2012 strain S-pseudotyped lentivirus. However, all five monoclonal antibodies (mAb) did not neutralize the pseudotyped V534A mutation. Additionally, one mAb RBD-14F8 did not show neutralizing activity against pseudoviruses with amino acid substitution of L506 F or D509 G (England1 strain, EMC/2012 L506 F, and EMC/2012 D509 G), and RBD-43E4 mAb could not neutralize the pseudotyped I529 T mutation, while three other neutralizing mAbs showed broad neutralizing activity. This implies that the mutation in residue 506–509, 529, and 534 of S is critical to generate neutralization escape variants of MERS-CoV. Interestingly, all five neutralizing mAbs have binding affinity to RBD, although most mAbs generated by RBD did not have neutralizing activity. Additionally, chimeric antibodies of RBD-14F8 and RBD-43E4 with human Fc and light chain showed neutralizing effect against wild type MERS-CoV KOR/KNIH/002, similar to the original mouse mAbs. Thus, our mAbs can be utilized for the identification of specific mutations of MERS-CoV.

Effect of Scapular Stabilization Exercise during Standing on Upper Limb Function and Gait Ability of Stroke Patients

Background

The purpose of this study was to determine the effect of scapular stabilization exercise during standing on a paretic side on upper limb function and gait ability of stroke patients.

Methods

This study was a hospital-based, randomized controlled trial with a blinded assessor. A total of 17 patients with hemiplegic diagnosis after stroke were divided into two groups (9 patients in a study group and 8 patients in a control group). The study group received physical therapy and scapular stabilization exercise on a paretic side. Participants were subjected to initial evaluation before the treatment. Subjects were subsequently re-evaluated 4 and 8 weeks later to compare the changes. Measurements of hand function and gait ability were performed.

Results

Based on multivariate analysis of variance for repeated-measures, there was a significant time effect for Timed Up and Go test (TUG) (F = 13.816, P = 0.000), Functional Gait Assessment (FGA) (F = 18.613, P = 0.000), and manual function test (MFT) (F = 16.777, P = 0.000). The group × time interaction effect was also significant for FGA (F = 4.966, P = 0.024) and MFT (F = 6.946, P = 0.003), but not for TUG test (F = 3.343, P = 0.069).

Conclusion

Results of the present study indicated that scapular stabilization exercise during standing on a paretic side for 8 weeks had an effect on hand function and gait ability of hemiplegic patients after stroke. Further studies are needed to find the most proper exercise for stroke patients who have gait disability and upper limb dysfunction.

Cricket paralysis virus internal ribosome entry site-derived RNA promotes conventional vaccine efficacy by enhancing a balanced Th1/Th2 response

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RNA adjuvant was developed from the CrPV intergenic region IRES.

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The RNA adjuvant functioned as an adjuvant with protein-based vaccines.

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The RNA adjuvant increased vaccine efficacy and induced balanced Th1/Th2 response.

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The RNA adjuvant enhanced APC chemotaxis.

An ideal adjuvant should increase vaccine efficacy through balanced Th1/Th2 responses and be safe to use. Recombinant protein-based vaccines are usually formulated with aluminum (alum)-based adjuvants to ensure an adequate immune response. However, use of alum triggers a Th2-biased immune induction, and hence is not optimal. Although the adjuvanticity of RNA has been reported, a systematic and overall investigation on its efficacy is lacking. We found that single strand RNA (termed RNA adjuvant) derived from cricket paralysis virus intergenic region internal ribosome entry site induced the expression of various adjuvant-function-related genes, such as type 1 and 2 interferon (IFN) and toll-like receptor (TLR), T cell activation, and leukocyte chemotaxis in human peripheral blood mononuclear cells; furthermore, its innate and IFN transcriptome profile patterns were similar to those of a live-attenuated yellow fever vaccine. This suggests that protein-based vaccines formulated using RNA adjuvant function as live-attenuated vaccines. Application of the RNA adjuvant in mouse enhanced the efficacy of Middle East respiratory syndrome spike protein, a protein-subunit vaccine and human papillomavirus L1 protein, a virus-like particle vaccine, by activating innate immune response through TLR7 and enhancing pAPC chemotaxis, leading to a balanced Th1/Th2 responses. Moreover, the combination of alum and the RNA adjuvant synergistically induced humoral and cellular immune responses and endowed long-term immunity. Therefore, RNA adjuvants have broad applicability and can be used with all conventional vaccines to improve vaccine efficacy qualitatively and quantitively.

Sublingual Immunization With an RSV G Glycoprotein Fragment Primes IL-17-Mediated Immunopathology Upon Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) is the leading cause of serious respiratory tract disease but there is no licensed RSV vaccine. Immunopathological mechanisms have long been suspected as operating in the development of severe RSV disease and have hampered the development of safe and effective vaccines. Here, we show that unlike intranasal immunization, sublingual immunization with RSV glycoprotein fragment containing the central conserved region (Gcf) primes the host for severe disease upon RSV challenge. This increased pathology does not require replication by the challenge virus and is associated with massive infiltration of inflammatory cells, extensive cell death, and excessive mucus production in the airway and lungs. This exacerbated RSV disease primed by sublingual Gcf immunization is distinct from the immunopathology by G-expressing vaccinia virus or formalin-inactivated RSV, and preceded by prominent IL-17 production. IL-17 deficiency abolished the enhanced disease. Our results suggest a novel mechanism of RSV vaccine-induced immunopathology by IL-17, and highlights the importance of vaccination site.

Cross-Protective Shigella Whole-Cell Vaccine With a Truncated O-Polysaccharide Chain

Shigella is a highly prevalent bacterium causing acute diarrhea and dysentery in developing countries. Shigella infections are treated with antibiotics but Shigellae are increasingly resistant to these drugs. Vaccination can be a countermeasure against emerging antibiotic-resistant shigellosis. Because of the structural variability in Shigellae O-antigen polysaccharides (Oag), cross-protective Shigella vaccines cannot be derived from single serotype-specific Oag. We created an attenuated Shigella flexneri 2a strain with one rather than multiple Oag units by disrupting the Oag polymerase gene (Δwzy), which broadened protective immunogenicity by exposing conserved surface proteins. Inactivated Δwzy mutant cells combined with Escherichia coli double mutant LT(R192G/L211A) as adjuvant, induced potent antibody responses to outer membrane protein PSSP-1, and type III secretion system proteins IpaB and IpaC. Intranasal immunization with the vaccine preparation elicited cross-protective immunity against S. flexneri 2a, S. flexneri 3a, S. flexneri 6, and Shigella sonnei in a mouse pneumonia model. Thus, S. flexneri 2a Δwzy represents a promising candidate strain for a universal Shigella vaccine.

Immunogenicity of a bivalent killed thimerosal-free oral cholera vaccine, Euvichol, in an animal model

PURPOSE

An oral cholera vaccine (OCV), Euvichol, with thimerosal (TM) as preservative, was prequalified by the World Health Organization (WHO) in 2015. In recent years, public health services and regulatory bodies recommended to eliminate TM in vaccines due to theoretical safety concerns. In this study, we examined whether TM-free Euvichol induces comparable immunogenicity to its TM-containing formulation in animal model.

MATERIALS AND METHODS

To evaluate and compare the immunogenicity of the two variations of OCV, mice were immunized with TM-free or TM-containing Euvichol twice at 2-week interval by intranasal or oral route. One week after the last immunization, mice were challenged with Vibrio cholerae O1 and daily monitored to examine the protective immunity against cholera infection. In addition, serum samples were obtained from mice to measure vibriocidal activity and vaccine-specific IgG, IgM, and IgA antibodies using vibriocidal assay and enzyme-linked immunosorbent assay, respectively.

RESULTS

No significant difference in immunogenicity, including vibriocidal activity and vaccine-specific IgG, IgM, and IgA in serum, was observed between mice groups administered with TM-free and -containing Euvichol, regardless of immunization route. However, intranasally immunized mice elicited higher levels of serum antibodies than those immunized via oral route. Moreover, intranasal immunization completely protected mice against V. cholerae challenge but not oral immunization. There was no significant difference in protection between two Euvichol variations.

CONCLUSION

These results suggested that TM-free Euvichol could provide comparable immunogenicity to the WHO prequalified Euvichol containing TM as it was later confirmed in a clinical study. The pulmonary mouse cholera model can be considered useful to examine in vivo the potency of OCVs.

Fibrinogen cleavage products and Toll-like receptor 4 promote the generation of programmed cell death 1 ligand 2-positive dendritic cells in allergic asthma

BACKGROUND

Inhaled protease allergens preferentially trigger T_H2-mediated inflammation in allergic asthma. The role of dendritic cells (DCs) on induction of T_H2 cell responses in allergic asthma has been well documented; however, the mechanism by which protease allergens induce T_H2-favorable DCs in the airway remains unclear.

OBJECTIVE

We sought to determine a subset of DCs responsible for T_H2 cell responses in allergic asthma and the mechanism by which protease allergens induce the DC subset in the airway.

METHODS

Mice were challenged intranasally with protease allergens or fibrinogen cleavage products (FCPs) to induce allergic airway inflammation. DCs isolated from mediastinal lymph nodes were analyzed for surface phenotype and T-cell stimulatory function. Anti-Thy1.2 and Mas-TRECK mice were used to deplete innate lymphoid cells and mast cells, respectively. Adoptive cell transfer, bone marrow DC culture, anti-IL-13, and Toll-like receptor (TLR) 4-deficient mice were used for further mechanistic studies.

RESULTS

Protease allergens induced a remarkable accumulation of T_H2-favorable programmed cell death 1 ligand 2 (PD-L2)⁺ DCs in mediastinal lymph nodes, which was significantly abolished in mice depleted of mast cells and, to a lesser extent, innate lymphoid cells. Mechanistically, FCPs generated by protease allergens triggered IL-13 production from wild-type mast cells but not from TLR4-deficient mast cells, which resulted in an increase in the number of PD-L2⁺ DCs. Intranasal administration of FCPs induced an increase in numbers of PD-L2⁺ DCs in the airway, which was significantly abolished in TLR4- and mast cell-deficient mice. Injection of IL-13 restored the PD-L2⁺ DC population in mice lacking mast cells.

CONCLUSION

Our findings unveil the "protease-FCP-TLR4-mast cell-IL-13" axis as a molecular mechanism for generation of T_H2-favorable PD-L2⁺ DCs in allergic asthma and suggest that targeting the PD-L2⁺ DC pathway might be effective in suppressing allergic T-cell responses in the airway.

Natural killer T cell sensitization during neonatal respiratory syncytial virus infection induces eosinophilic lung disease in re-infected adult mice

Respiratory syncytial virus (RSV) is a major viral pathogen that causes severe lower respiratory tract infections in infants and the elderly worldwide. Infants with severe RSV bronchiolitis tend to experience more wheezing and asthma in later childhood. Because invariant natural killer T (iNKT) cells are associated with the asthma pathology, we investigated whether neonatal iNKT cells are involved in the aggravation of pulmonary diseases following RSV infection in mice. Intranasal exposure to the iNKT cell ligand α-galactosylceramide (α-GC) with RSV primary infection in neonatal mice elicited neither cytokine production (except for a slight increase of IL-5) nor pulmonary eosinophilia, despite the presence of both CD1d⁺ cells and NKT cells. Interestingly, in adult mice re-infected with RSV, neonatal iNKT cell sensitization by α-GC during RSV primary infection resulted in much higher levels of pulmonary Th2 cytokines and elevated eosinophilia with airway hyperresponsiveness, whereas this was not observed in cd1d knockout mice. In contrast, α-GC priming of adults during RSV re-infection did not induce more severe airway symptoms than RSV re-infection in the absence of α-GC. α-GC co-administration during RSV primary infection facilitated RSV clearance regardless of age, but viral clearance following re-infection was not iNKT cell-dependent. This study clearly demonstrates that RSV-induced immune responses can be altered by iNKT cells, suggesting that neonatal iNKT cell sensitization during RSV primary infection is associated with exacerbation of pulmonary diseases following RSV re-infection in adulthood.

MicroRNA expression profiling of sputum for the detection of early and locally advanced non-small-cell lung cancer: a prospective case-control study

BACKGROUND

Non-small-cell lung cancer (nsclc) is associated with very poor overall survival because 70% of patients present with locally advanced or metastatic disease at the time of diagnosis. Micrornas (mirnas) are a class of short, noncoding rna molecules whose presence in samples of biologic fluids such as sputum has demonstrated promise as a potential means of detecting nsclc. We investigated the stage-specific nsclc detection potential of an efficient panel of 3 mirnas (mir-21, mir-210, mir-372) using a single sputum sample.

METHODS

A single spontaneously expectorated sputum sample was prospectively collected from 21 early nsclc (≤stage ii) patients, 22 advanced nsclc (≥stage iii) patients, and 10 control subjects. Mirna expression profiles were determined by quantitative real-time polymerase chain reaction and were analyzed by unsupervised hierarchical cluster analysis.

RESULTS

Mean tumour size (±95% confidence interval) in the early and advanced nsclc patients was 3.3 cm ± 0.9 cm and 4.8 cm ± 0.7 cm respectively. Adenocarcinoma constituted 61.9% of the early and 45.5% of the advanced nsclc cases respectively. In comparing the early nsclc group with the control group, the mirna panel yielded a diagnostic sensitivity of 67% and a specificity of 90.0%. For the advanced nsclc group, the mirna panel detected nsclc with a sensitivity and specificity of 64% and 100% respectively.

CONCLUSIONS

A sputum mir-21, mir-210, and mir-372 expression profile might provide a sensitive and highly specific means for detecting nsclc. Sputum mirna analysis demonstrates promise as a potential complementary screening tool.

Discovery of a Small Molecule that Enhances Astrocytogenesis by Activation of STAT3, SMAD1/5/8, and ERK1/2 via Induction of Cytokines in Neural Stem Cells

Identification of small molecules that direct neural stem cells (NSCs) into specific cell types would be helpful to understand the molecular mechanisms involved in regulation of NSC fate, and facilitate the development of therapeutic applications. In the current study, we developed and screened small molecules that can modulate the fate of NSCs that are derived from rat fetal cortex. Among these compounds, compounds 5 and 6 successfully differentiated NSCs into astrocytes and neurons, respectively. Compound 5 induced astrocytogenesis by increasing expression of interleukin-6, bone morphogenetic protein 2 and leukemia inhibitory factor and through consequent phosphorylation of signal transducer and activator of transcription 3 and Sma- and Mad-related protein 1/5/8 in NSCs. In addition, compound 5 increased the expression of fibroblast growth factor (FGF) 2 and FGF8 which may regulate the branching and morphology of astrocytes. Taken together, our results suggest that these small molecules can serve as a useful tool to study cell fate determination in NSCs and be used as an inexpensive alternative to cytokines to study mechanisms of astrocytogenesis.

Effects of water temperature on mortality in Megalocytivirus-infected rock bream Oplegnathus fasciatus (Temminck et Schlegel) and development of protective immunity

Rock bream iridovirus (RBIV) causes huge losses, especially in rock bream Oplegnathus fasciatus. Rock bream injected with RBIV and held at 29, 26, 23 or 20 °C had 100% mortality. Conversely, all infected fish held at 17 °C survived even after the temperature was progressively increased to 26 °C at 100 dpi. Rock bream exposed to virus and held for 2, 4 and 7 days at 23/26 °C before the temperature was reduced to 17 °C had mortality rates of 26.6/73.2%, 66.6/100% and 93.4/100%, respectively, through 100 dpi. When surviving fish had the water temperature increased from 17 to 26 °C at 100 dpi, they did not exhibit signs of disease and had low virus copy numbers (below 10(3)). To investigate the development of a protective immune, rock bream were infected with RBIV and held at 23 °C before shifting the water temperature to 17 °C at 4 dpi. All injected fish survived until 120 dpi. While 100% of the previously unexposed fish died, 80.2% of the previously infected fish survived. When the survivors were rechallenged again at 160 dpi, no further mortality occurred. The high survival rate of fish following rechallenge with RBIV indicates that protective immunity was established in the surviving rock bream.

Immunogenicity of inactivated polio vaccine, given with or without mucosal adjuvants dmLT and TCTA1T in rat model (VAC9P.1102)

To eradicate polio, the use of oral polio vaccine (OPV) should be stopped to avoid circulation of vaccine-derived polioviruses (VDPVs). After OPV cessation, transition to inactivated polio vaccine (IPV) is recommended. This can only be accomplished when IPV induce better mucosal protection. This can be achieved by adding mucosal adjuvant to the IPV formulation. In the present study we used wistar rats to elucidate the adjuvant effect of double mutant heat-labile toxin (dmLT) of E. coli and recombinant cholera toxin (TCTA1T) on IPV. Rats were administered by intramuscular injection of 1.0-0.6-1.0 D-antigen units (DU) of Inactivated Polio type 1, 2 and 3 /rat. The E. coli dmLT and TCTA1T was used as adjuvant and was administered subcutaneously along with IPV. The control groups received IPV alone or PBS. Rats were immunized on days 0, 14 and 28 days. After last vaccination mice were sacrificed and spleen cells and blood were collected. IgA secreting cells specific for Polio Type1, 2 and 3 were measured by ELISPOT. Intramuscular immunization results in robust mucosal response in inactivated polio antigens + dmLT group compared to other groups. Further measurement of antibodies in serum doesn’t show significant difference among IPV and adjuvanted IPV groups. Thus the present data suggest that vaccination with IPV and dmLT results in specific induction of mucosal immunity, which will provide barrier to infection from oral fecal route.

The influence of geometrical characteristics on the photocatalytic activity of TiO2 nanotube arrays for degradation of refractory organic pollutants in wastewater

The effects of geometrical characteristics such as surface area (SA) and porosity of TiO2 nanotube arrays (TNAs) on its photocatalytic activity were investigated by applying variable voltages and reaction times for the anodization of Ti substrates. While larger SA of nanotubes was observed under higher applied potential, the porosity of TNAs decreased by increasing anodizing voltage. Under applied potential of 80 V, the SA of TNAs increased from 0.164 to 0.471 m2/g as anodization time increased from 1 to 5 hours, respectively. However, no significant effect on the porosity of TNAs was observed. On the other hand, both SA and porosity of TNAs, synthesized at 60 V, increased by augmenting the anodization time from 1 to 3 hours. But further increasing of anodization time to 5 hours resulted in a decreased SA of TNAs with no effect on their porosity. Accordingly, the TNAs with SA of 0.368 m2/g and porosity of 47% showed the highest photocatalytic activity for degradation of 4-chlorobenzoic acid (4CBA). Finally, the degradation of refractory model compounds such as carbamazepine and bisphenol-A was tested and more than 50% of both compounds could be degraded under UV-A irradiation (λmax=365 nm).

Development of safe and effective RSV vaccine by modified CD4 epitope in G protein core fragment (Gcf)

Respiratory syncytial virus (RSV) is a major cause of respiratory tract infection in infants and young children worldwide, but currently no safe and effective vaccine is available. The RSV G glycoprotein (RSVG), a major attachment protein, is an important target for the induction of protective immune responses during RSV infection. However, it has been thought that a CD4⁺ T cell epitope (a.a. 183–195) within RSVG is associated with pathogenic pulmonary eosinophilia. To develop safe and effective RSV vaccine using RSV G protein core fragment (Gcf), several Gcf variants resulting from modification to CD4⁺ T cell epitope were constructed. Mice were immunized with each variant Gcf, and the levels of RSV-specific serum IgG were measured. At day 4 post-challenge with RSV subtype A or B, lung viral titers and pulmonary eosinophilia were determined and changes in body weight were monitored. With wild type Gcf derived from RSV A2 (wtAGcf), although RSV A subtype-specific immune responses were induced, vaccine-enhanced disease characterized by excessive pulmonary eosinophil recruitment and body weight loss were evident, whereas wtGcf from RSV B1 (wtBGcf) induced RSV B subtype-specific immune responses without the signs of vaccine-enhanced disease. Mice immunized with Th-mGcf, a fusion protein consisting CD4⁺ T cell epitope from RSV F (F_51–66) conjugated to mGcf that contains alanine substitutions at a.a. position 185 and 188, showed higher levels of RSV-specific IgG response than mice immunized with mGcf. Both wtAGcf and Th-mGcf provided complete protection against RSV A2 and partial protection against RSV B. Importantly, mice immunized with Th-mGcf did not develop vaccine-enhanced disease following RSV challenge. Immunization of Th-mGcf provided protection against RSV infection without the symptom of vaccine-enhanced disease. Our study provides a novel strategy to develop a safe and effective mucosal RSV vaccine by manipulating the CD4⁺ T cell epitope within RSV G protein.

Neonatal immunization with respiratory syncytial virus glycoprotein fragment induces protective immunity in the presence of maternal antibodies in mice

Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infections in infants and the elderly worldwide. The significant morbidity and mortality associated with this infection underscores the urgent need for development of RSV vaccine. In this study, we first show that intranasal administration of RSV glycoprotein core fragment (Gcf) to neonatal mice can induce systemic humoral immune responses and protective immunity against RSV without causing lung eosinophilia, although antibody response was shifted to a Th2 response. Next, we examined whether the presence of maternal anti-RSV antibodies would affect the responsiveness and protection efficacy of Gcf in newborn mice, since infants can possess RSV-specific maternal antibodies due to frequent RSV re-infections to adults. Intranasal administration of Gcf induced antibody response and increased IFNγ secretion and protected mice against RSV challenge without severe lung eosinophilia, even in the presence of high levels of RSV-specific maternal antibodies. Thus, our findings suggest that Gcf may be an effective and safe RSV vaccine during the neonatal period.

Tumor microenvironmental conversion of natural killer cells into myeloid-derived suppressor cells

How myeloid-derived suppressor cells (MDSC) emerge in the tumor environment remains unclear. Here, we report that GM-CSF can convert natural killer (NK) cells into MDSCs. When transferred into tumor-bearing mice, adoptively transferred NK cells lost their NK phenotype and were converted into Ly6C(high)Ly6G(high) MDSC. This conversion was abolished by exposure to IL-2 either in vitro or in vivo. Notably, we found that of the 4 maturation stages based on CD11b/CD27 expression levels, only the CD11b(high)CD27(high) NK cells could be converted into CD11b(+)Gr1(+) MDSC ex vivo. Transfer of CD27(high) NK cells from tumor-bearing mice into tumor-bearing recipients was associated with conversion to MDSC in a manner associated with reduced numbers of CD11b(high)CD27(high) and CD11b(high)CD27(low) NK cell populations in the recipients. Our results identify a pathway of MDSC development from immature NK cells in tumor-bearing hosts, providing new insights into how tumor cells modulate their host immune microenvironment to escape immune surveillance.

Pan-Shigella Surface Protein antigen 1 as potential cross-protective antigen for Shigella vaccine development. (P4286)

Shigellosis is a disease characterized by the destruction of the colonic epithelium in humans and one of the most severe diarrheal diseases, especially in children under 5 years of age in developing countries. We have identified several protein antigens that are shared by different shigella serotypes and species. Among these, one antigen, PSSP-1, induces cross-protection against experimental shigellosis induced by different species and serotypes. PSSP-1-induced protection requires (i) a mucosal route of administration; and (ii) the co-administration of a mucosal adjuvant (cholera toxin, mutant thermolabile enterotoxin (dmLT). When PSSP-1was formulated with dmLT, an adjuvant that has undergone human clinical testing, it induced cross-protection against S. flexneri 2a, 3a, 5a, 6, S. boydii and importantly also S. dysenteriae 1. While intradermally administered PSSP-1 adjuvanted with dmLT induced strong serum antibody responses, it failed to induce protection in the mouse lung pneumonia model (consisting of administering Shigella intranasally). In contrast, intranasal PSSP-1 + dmLT elicited efficient local (lung) and peripheral (spleen) antibody responses and regional and systemic IL-17 and IFNγ production. Interestingly, patients with recent onset shigellosis showed variable but significant antibody responses to most conserved Shigella protein antigens but not to PSSP-1. Although the above results are promising, these will have to be validated in humans.

Neonatal immunization with respiratory syncytial virus glycoprotein fragment induces protective immunity in the presence of maternal antibodies in mice (P4277)

Respiratory syncytial virus (RSV) is the major cause of severe lower respiratory tract infections in infants and the elderly worldwide. The significant morbidity and mortality associated with this infection underscores the urgent need for development of an RSV vaccine. In this study, we first show that intranasal administration of RSV glycoprotein core fragment (Gcf) to neonatal mice can induce systemic humoral immune responses and protective immunity against RSV without causing lung eosinophilia, although antibody response was shifted to a Th2 response. Next, we examined whether the presence of maternal anti-RSV antibodies affects the responsiveness and protection efficacy of Gcf in newborn mice, since infants can have RSV-specific maternal antibodies since adults are frequently reinfected with RSV. Intranasal administration of Gcf induced antibody response and IFNγ secretion and protected mice against RSV challenge without lung eosinophilia even in the presence of high levels of RSV-specific maternal antibodies. Thus, our findings suggest that Gcf may be an effective and safe RSV vaccine during the neonatal period.

Sublingual administration of bacteria-expressed influenza virus hemagglutinin 1 (HA1) induces protection against infection with 2009 pandemic H1N1 influenza virus

Influenza viruses are respiratory pathogens that continue to pose a significantly high risk of morbidity and mortality of humans worldwide. Vaccination is one of the most effective strategies for minimizing damages by influenza outbreaks. In addition, rapid development and production of efficient vaccine with convenient administration is required in case of influenza pandemic. In this study, we generated recombinant influenza virus hemagglutinin protein 1 (sHA1) of 2009 pandemic influenza virus as a vaccine candidate using a well-established bacterial expression system and administered it into mice via sublingual (s.l.) route. We found that s.l. immunization with the recombinant sHA1 plus cholera toxin (CT) induced mucosal antibodies as well as systemic antibodies including neutralizing Abs and provided complete protection against infection with pandemic influenza virus A/CA/04/09 (H1N1) in mice. Indeed, the protection efficacy was comparable with that induced by intramuscular (i.m.) immunization route utilized as general administration route of influenza vaccine. These results suggest that s.l. vaccination with the recombinant non-glycosylated HA1 protein offers an alternative strategy to control influenza outbreaks including pandemics.

Environmental implications and applications of carbon nanomaterials in water treatment

Carbon nanomaterials have been proposed as a basis for developing new technologies for photocatalytic oxidation and disinfection, improved membrane processes, adsorbents, and biofilm-resistant surfaces. This study details recent progress towards the development of these proposed applications. We explored the use of carbon nanomaterials such as fullerene C60, single-wall carbon nanotubes (SWCNTs), and multi-wall carbon nanotubes (MWCNTs) for a range of new technologies including, degradation of a probe organic compound by in situ generation of reactive oxygen species (ROS), new strategies for microbial disinfection, and the inhibition of biofilm development on membrane surfaces. The results show that the degradation of 2-chlorophenol by ROS produced microbial inactivation, and the mobility of the nanoparticle aggregates of the carbon nanomaterials all increased as suspensions were fractionated to enrich with smaller aggregates with sonication followed by successive membrane filtration.

Effect of maternal immune status on responsiveness of bacillus calmette-gurin vaccination in mouse neonates

OBJECTIVES

Bacillus Calmette-Guérin (BCG) vaccination has proven to be efficient in immunologically naïve infants; however, it has not been investigated that maternal natural exposure to Mycobacterium and/or BCG vaccine could influence the characteristics of immune responses to BCG in newborns. In this study, we analyzed whether the maternal immune status to M tuberculosis (M tb) can affect neonatal immunity to BCG using a mouse model.

METHODS

Neonates were obtained from mice that were previously exposed to live BCG, to live M avium, or to heat-killed M tb H37Rv, and from naïve control mothers. One week after birth, the neonates were divided into two subgroups: one group immunized with live BCG via the subcutaneous route and the other group of neonates sham-treated. Interferon-gamma (IFNγ) secretion in response to in vitro stimulation with heat-killed BCG or purified protein derivative (PPD) was examined. Protection against M tb infection was evaluated by challenging mice nasally with live M tb H37Rv followed by counting colonies from spleen and lung homogenates.

RESULTS

BCG-immunized neonates showed increased IFNγ secretion in response to heat-killed BCG or PPD. All mice in BCG-immunized neonates subgroups showed reduced bacterial burden (colony forming unit) in the lungs when compared with control naive neonate mice. However, no statistically significant difference was observed when comparing BCG-immunized mice born from mothers previously exposed to M avium or immunized with either heat-killed H37Rv or live BCG and mice born from naïve mothers.

CONCLUSION

The maternal immune status to M tb does not appear to impact on the immunogenicity of BCG vaccine in their progeny in our experimental conditions.

Myeloid derived suppressor cells(MDSCs) emergence from distinct splenic precursors (162.28)

Myeloid derived suppressor cells(MDSCs) are a heterogenous population of immature myeloid cells, which accumulate in various pathological conditions, especially in tumor. In mice, MDSCs are characterized by the co-expression of Gr1 and CD11b molecules, and these cells could be classified into two subsets, CD11b+Ly6G+Ly6Clow polymorphonuclear neutrophil-like(PMN) MDSCs and CD11b+Ly6G-Ly6Chigh monocytic(Mo) MDSCs, by their expression of Ly6C and Ly6G molecules. Functional characteristics and fate of MDSCs are defined quite well. On the other hands, accumulation mechanism and origins of MDSC need to be more elucidated, and have not been fully understood whether MDSC could be generated in the periphery from distinct precursors in tumor microenvironment. For the first time, we identified the presence of splenic MDSC precursors in tumor bearing mice, characterized by CD11b+Ly6G-Ly6Cneg/low. We demonstrated that cytokines related to MDSC accumulation convert CD11b+Ly6G-Ly6Cneg/low cells into CD11b+Ly6G+Ly6Clow PMN-MDSC and/or CD11b+Ly6G-Ly6Chigh Mo-MDSC. These converted cells exerted strong suppressive activity on DO11.10 Tg splenocytes proliferation. Thus, these data suggest that there are peripheral distinct precursors, CD11b+Ly6Cneg/low cells, from which immunosuppressive MDSC could be generated.

Criteria for decision making after endoscopic resection of well-differentiated rectal carcinoids with regard to potential lymphatic spread

BACKGROUND AND STUDY AIM

Rectal carcinoids are low-grade malignancies that are usually treated by endoscopic resection. However, on pathologic examination, resection margins that are positive for carcinoid cells are frequently found. Patient outcomes were reviewed after endoscopic resection of rectal carcinoids and the clinical significance of possible residual disease, as defined by pathologic and endoscopic examination, was evaluated.

PATIENTS AND METHODS

The medical records and endoscopic findings of 347 patients presenting with rectal carcinoids to 14 university hospitals in Korea between January 1999 and June 2007 were retrospectively analyzed.

RESULTS

A total of 304 patients were treated with endoscopic resection, and 43 patents were treated with surgery. In the endoscopic resection group, the complete resection rate was 88.2% based on endoscopic appearance (CR-E) and 60.2% based on pathologic evaluation (CR-P). The agreement between CR-E and CR-P was low (κ=0.192). No residual tumors were found in 77 of 85 patients (90.6%) who were CR-E but not CR-P and who had endoscopic biopsy taken at 24-month follow-up. The receiver-operating characteristic curve identified an optimal cut-off value of 10.5 mm, at which the sensitivity and the specificity for metastasis were 100% and 89%, respectively. The risk factors for metastasis by multivariate analysis were tumor size, increased mitotic rate, and lymphovascular invasion.

CONCLUSIONS

Endoscopic resection is a safe and effective modality for treating well-differentiated rectal carcinoids smaller than 10 mm in diameter. Discrepancies were observed between CR-E and CR-P. The risk factors for metastasis were tumor size, increased mitotic rate, and lymphovascular invasion.

Borderline mucinous tumor arising in a paratubal cyst: a case report

BACKGROUND

Paratubal borderline tumors (PBTs) are found incidentally at frozen section or permanant pathology, and are extremely rare. We describe the first case of a paratubal borderline mucinous tumor (PBMT).

CASE REPORT

A 20-year-old woman was referred with a complex right adnexal mass on pelvic sonogram. She underwent laparoscopic paratubal cyst enucleation. We used an endobag for cyst extraction. Cyst rupture or tearing of the endobag in the laparoscopic field was absent. Frozen section analysis was reported as a borderline mucinous tumor of low malignant potential. Currently, she has had no evidence of disease recurrence after a laparoscopic fertility-sparing staging procedure.

CONCLUSION

A proper preoperative differential diagnosis of an adnexal mass is difficult. Thus, laparoscopy is needed in large or symptomatic cysts. Although growth, torsion and malignancy are rare in paratubal cysts, the possibility of tumor seeding should be excluded with use of an endobag.

A case of primary ovarian adenomyoma mimicking ovarian malignancy

Adenomyoma is a benign tumor composed of smooth muscle and benign endometrium. These tumors typically originate within the uterus. An extrauterine adenomyoma is an extremely rare entity. After an extensive literature search, only four cases of primary ovarian adenomyoma appear to have thus far been reported. Here, we report a case of ovarian adenomyoma in a 39-year-old woman mimicking malignant neoplasma of the ovary, along with a brief literature review.

Ancient schwannoma of the thigh mimicking a malignant tumour: a report of two cases, with emphasis on MRI findings

Ancient schwannomas are rare, encapsulated tumours of long duration and are benign in nature. The tumour is solitary and may grow to a large size before detection of notable degenerative changes. The term "ancient schwannoma" is used to describe a tumour that has undergone such changes, typified by relative loss of Antoni type A tissue, perivascular hyalinisation, calcification, cystic necrosis, haemorrhage and the presence of degenerative nuclei that may be misinterpreted as sarcomatous pleomorphism. We report two cases of ancient schwannoma in the thigh mimicking malignancies. Identifying the fibrous capsule of the mass and a split fat sign using MRI is important for differentiating ancient schwannoma from other malignant tumours.

Downregulation of Th17 cells in the small intestine by disruption of gut flora in the absence of retinoic acid

Retinoic acid (RA), a well-known vitamin A metabolite, mediates inhibition of the IL-6-driven induction of proinflammatory Th17 cells and promotes anti-inflammatory regulatory T cell generation in the presence of TGF-beta, which is mainly regulated by dendritic cells. To directly address the role of RA in Th17/regulatory T cell generation in vivo, we generated vitamin A-deficient (VAD) mice by continuous feeding of a VAD diet beginning in gestation. We found that a VAD diet resulted in significant inhibition of Th17 cell differentiation in the small intestine lamina propria by as early as age 5 wk. Furthermore, this diet resulted in low mRNA expression levels of IL-17, IFN regulatory factor 4, IL-21, IL-22, and IL-23 without alteration of other genes, such as RORgammat, TGF-beta, IL-6, IL-25, and IL-27 in the small intestine ileum. In vitro results of enhanced Th17 induction by VAD dendritic cells did not mirror in vivo results, suggesting the existence of other regulation factors. Interestingly, the VAD diet elicited high levels of mucin MUC2 by goblet cell hyperplasia and subsequently reduced gut microbiome, including segmented filamentous bacteria. Much like wild-type mice, the VAD diet-fed MyD88-/-TRIF-/- mice had significantly fewer IL-17-secreting CD4+ T cells than the control diet-fed MyD88-/-TRIF-/- mice. The results strongly suggest that RA deficiency altered gut microbiome, which in turn inhibited Th17 differentiation in the small intestine lamina propria.

A case of small cell lung cancer treated with chemoradiotherapy followed by photodynamic therapy

Here, we present the case of a 51-year-old man with limited-stage small cell lung cancer (LS-SCLC) who received concurrent chemoradiotherapy and photodynamic therapy (PDT). The patient was diagnosed as having LS-SCLC with an endobronchial mass in the left main bronchus. Following concurrent chemoradiotherapy, a mass remaining in the left lingular division was treated with PDT. Clinical and histological data indicate that the patient has remained in complete response for 2 years without further treatment. This patient represents a rare case of complete response in LS-SCLC treated with PDT.

Effect of drug-eluting metal stents in benign esophageal stricture: an in vivo animal study

BACKGROUND AND STUDY AIMS

The aim of this study in canines was to investigate the effectiveness and safety of self-expandable metal stents, which were coated with paclitaxel to minimize the tissue response.

MATERIALS AND METHODS

14 dogs (5-10 kg) were randomly allocated to two groups. Drug-eluting stents (DES, n = 7) or nondrug-eluting stents (non-DES, n = 7) were endoscopically inserted and fixed in the esophagus of healthy dogs. Every 2 weeks, for a maximum period of 8 weeks, an endoscopic examination was performed to evaluate the status of stent insertion, the grade of tissue hyperplasia, and mucosal change at both ends of the stent.

RESULTS

One case of stent migration was observed after 4 weeks in the non-DES group. In this group, tissue reaction and hyperplasia remained for more than 4 weeks after stent insertion. By contrast, an endoscopic examination of the surrounding esophageal mucosa in the DES group showed very little tissue reaction, and the stent was easily separated from the esophageal tissue.

CONCLUSION

Although further studies are required to confirm our results, we suggest that these newly designed DES may provide an alternative tool to manage refractory benign esophageal stricture.

Endoscopic evaluation of significant gastrointestinal lesions in patients with iron deficiency with and without anaemia: a Korean Association for the Study of Intestinal Disease study

BACKGROUND

Although endoscopy is recommended for patients with iron deficiency anaemia, there is, currently, no consensus on the role of endoscopy for iron-deficient patients without anaemia. The goal of this study was to determine the prevalence of serious gastrointestinal (GI) lesions, identified by endoscopy in patients with iron deficiency and anaemia compared with patients with iron deficiency without anaemia.

METHODS

One thousand five hundred and eighteen patients with a ferritin value of <or=50 ng/mL and a total iron-binding capacity >or=300 mg/dL were retrospectively investigated using oesophagogastroduodenoscopy and colonoscopy between January 2005 and September 2006. The lesions identified were classified as clinically important according to standard predetermined criteria.

RESULTS

Among the 1518 cases, 749 patients had anaemia and 769 had normal haemoglobin levels. Clinically important lesions were identified in 24.6% of the patients with anaemia and in 22.8% of the patients without anaemia (P > 0.05). The frequency of lower GI tract lesions (13.6 vs 11.4%, P > 0.05) and upper GI tract lesions (11.9 vs 12.5%, P > 0.05) was similar in the comparisons between the two groups. However, the frequency of malignant GI lesions was higher in the patients with anaemia (5.1 vs 0.7%, P < 0.01). In addition, the patients without anaemia were significantly more likely to have early-stage neoplasia (adenoma, early gastric cancer and Dukes' A and B colon cancer) than were the patients with anaemia (98.4 vs 52.5%, P < 0.01).

CONCLUSION

The results of this study suggest that patients with iron deficiency should undergo endoscopic evaluation of the GI tract, irrespective of whether they have anaemia. The endoscopic evaluation of the GI tract in patients with iron deficiency without anaemia could provide an opportunity for the detection of early-stage neoplasia at a curable stage.

HIV-1 assembly: viral glycoproteins segregate quantally to lipid rafts that associate individually with HIV-1 capsids and virions

HIV-1 assembly depends on its structural protein, Gag, which after synthesis on ribosomes, traffics to the late endosome/plasma membrane, associates with HIV Env glycoprotein, and forms infectious virions. While Env and Gag migrate to lipid microdomains, their stoichiometry and specificity of interaction are unknown. Pseudotyped viral particles can be made with one viral core surrounded by heterologous envelope proteins. Taking advantage of this property, we analyzed the association of HIV Env and Ebola glycoprotein (GP), with HIV-1 Gag coexpressed in the same cell. Though both viral glycoproteins were expressed, each associated independently with Gag, giving rise to distinct virion populations, each with a single glycoprotein type. Confocal imaging demonstrated that Env and GP localized to distinct lipid raft microdomains within the same cell where they associated with different virions. Thus, a single Gag particle associates “quantally” with one lipid raft, containing homogeneous trimeric viral envelope proteins, to assemble functional virions.

Potent cross-reactive neutralization of SARS coronavirus isolates by human monoclonal antibodies

The severe acute respiratory syndrome coronavirus (SARS-CoV) caused a worldwide epidemic in late 2002/early 2003 and a second outbreak in the winter of 2003/2004 by an independent animal-to-human transmission. The GD03 strain, which was isolated from an index patient of the second outbreak, was reported to resist neutralization by the human monoclonal antibodies (hmAbs) 80R and S3.1, which can potently neutralize isolates from the first outbreak. Here we report that two hmAbs, m396 and S230.15, potently neutralized GD03 and representative isolates from the first SARS outbreak (Urbani, Tor2) and from palm civets (SZ3, SZ16). These antibodies also protected mice challenged with the Urbani or recombinant viruses bearing the GD03 and SZ16 spike (S) glycoproteins. Both antibodies competed with the SARS-CoV receptor, ACE2, for binding to the receptor-binding domain (RBD), suggesting a mechanism of neutralization that involves interference with the SARS-CoV-ACE2 interaction. Two putative hot-spot residues in the RBD (Ile-489 and Tyr-491) were identified within the SARS-CoV spike that likely contribute to most of the m396-binding energy. Residues Ile-489 and Tyr-491 are highly conserved within the SARS-CoV spike, indicating a possible mechanism of the m396 cross-reactivity. Sequence analysis and mutagenesis data show that m396 might neutralize all zoonotic and epidemic SARS-CoV isolates with known sequences, except strains derived from bats. These antibodies exhibit cross-reactivity against isolates from the two SARS outbreaks and palm civets and could have potential applications for diagnosis, prophylaxis, and treatment of SARS-CoV infections.

Lysis of human immunodeficiency virus type 1 by a specific secreted human phospholipase A2

Phospholipase A2 (PLA2) proteins affect cellular activation, signal transduction, and possibly innate immunity. A specific secretory PLA2, sPLA2-X, is shown here to neutralize human immunodeficiency virus type 1 (HIV-1) through degradation of the viral membrane. Catalytic function was required for antiviral activity, and the target cells of infection were unaffected. sPLA2-X potently reduced gene transfer of HIV-1 Env-pseudotyped lentivirus vectors and inhibited the replication of both CCR5- and CXCR4-tropic HIV-1 in human CD4+ T cells. Virions resistant to damage by antibody and complement were sensitive to lysis by sPLA2-X, suggesting a novel mechanism of antiviral surveillance independent of the acquired immune system.

Primary colon lymphoma in Korea: a KASID (Korean Association for the Study of Intestinal Diseases) Study

Although almost all primary colorectal lymphomas are of B-cell lineage in Western countries, primary colorectal T-cell lymphomas are not uncommon in the East. The aim of this study was to review the clinical characteristics and treatment outcomes of primary colorectal lymphomas, with special emphasis on the differences between T-cell and B-cell lymphomas. Ninety-five cases of primary colorectal lymphomas that satisfied Dawson's criteria were identified from the clinical databases of 13 university hospitals in Korea. The mean age at the time of presentation was 51.1 years and the male:female ratio was 64:31. The clinical information, including endoscopic and histological characteristics, was retrospectively analyzed. Of the primary colorectal lymphomas, 78 cases (82.1%) were of B-lineage and 17 cases (17.9%) were of T-cell lineage. Patients with T-cell lymphomas presented at a younger age than patients with B-cell lymphomas (42.8 vs 52.9 years, respectively; P = 0.016). The most common presenting symptom was abdominal pain (87.1%) for B-cell lymphomas, whereas hematochezia or night fever was more common for T-cell lymphomas (52.9% and 35.3%, respectively). The most common endoscopic type was fungating mass (54.0%) for B-cell lymphomas and ulcerative/ulcero-infiltrative lesions (80.0%) for T-cell lymphomas. Intussusception was more common in B-cell lymphomas than in T-cell lymphomas (30.8% vs 5.9%, respectively; P = 0.035), but perforation was more common in T-cell lymphomas than in B-cell lymphomas (23.5% vs 3.8%, respectively; P = 0.005). The prognosis was significantly worse for T-cell lymphomas than for B-cell lymphomas (P = 0.002). Primary colorectal T-cell lymphomas are characterized by multifocal ulcerative lesions in relatively young patients, a high rate of hematochezia, fever, or perforation, and a poor prognosis even for cases of localized disease.

Management of malignant stricture of the esophagogastric junction with a newly designed self-expanding metal stent with an antireflux mechanism

BACKGROUND AND STUDY AIMS

When stents are placed across the esophagogastric junction for palliative treatment of malignant strictures, they may lead to esophagogastric reflux. The aim of this study was to compare the effectiveness of a newly designed antireflux stent with that of a standard open stent and a currently available antireflux stent (Dostent) in preventing gastroesophageal reflux symptoms in patients with inoperable cancer at the esophagogastric junction.

PATIENTS AND METHODS

Thirty-six consecutive patients with cancer at the esophagogastric junction were randomly assigned to undergo placement of a newly designed antireflux stent (n = 12), a Dostent (n = 12), or a standard open stent (n = 12). Technical and clinical success, dysphagia score, reflux symptoms, complications and ambulatory 24-h esophageal pH monitoring were assessed.

RESULTS

The technical success rates were 100 %. After 1 week, dysphagia had improved in all patient groups ( P < 0.05), but the degree of improvement did not differ between the three groups. The DeMeester score was significantly lower in the group with the newly designed antireflux stent than in the other groups. The fraction of the total recording time during which esophageal pH was below 4 was 3.14 +/- 5.78 % using the newly designed antireflux stent, in comparison with 29.25 +/- 15.41 % in the Dostent group and 15.01 +/- 11.72 % in the standard open stent group ( P < 0.001). Fewer reflux episodes occurred with the newly designed antireflux stent than with the Dostent or standard open stent. There were no complications with any of the three stents.

CONCLUSIONS

The newly designed antireflux stent is effective in relieving dysphagia caused by malignant cancer at the esophagogastric junction. The newly designed antireflux stent is significantly more effective in preventing gastroesophageal reflux than currently available antireflux stents.