Radiation-induced pneumonitis and fibrosis - Defining the role of immune cells and regulatory molecules

Radiation-induced pneumonitis and fibrosis still constitute a major complication in the treatment of patients with thorax-associated neoplasms. To date, the molecular mechanisms governing the onset and progression of these injuries are not entirely understood and no effective therapies are available. Aim of the present study was to gain more insight into the pathogenesis of radiation-induced pneumonitis and fibrosis, with the ultimate goal to provide a molecular basis for the development of novel and effective strategies for prevention or treatment of these pathologies. At this purpose, investigations on immune cells and on immunomodulatory molecules have been performed in vivo in a C57BL/6 mouse model of whole thorax irradiation with 15 Gray (Gy). In the present work, a novel immunoregulatory molecule was identified as a key mediator of radiation-induced fibrosis, in that mice deficient in this molecule showed no or minimal fibrosis at 30 weeks post irradiation (p.i.), while wild type (WT) mice showed extensive collagen deposition, and fibrotic areas positive for α-SMA and TGF-β at this time point. Thus, lack of this molecule seems to exert a radioprotective effect. Of note, the progression to a more pronounced fibrosis in WT mice was associated with altered expression of this molecule on immune cells during the pneumonitic phase, and with early and late changes in the composition and phenotype of immune cells, both locally and systemically. Thus, endogenous presence or absence of this immunoregulatory molecule results in distinct responses within the lung tissue, determining the progression and the final outcome of radiation-induced side effects. Remarkably, complete absence of mature B and T cells led to an increased sensitivity to radiation-induced fibrosis. This model provided evidence for a direct involvement of the immune system in the pathogenesis of lung radiation-induced pneumopathy. Regulation of the immune system during lung responses to ionizing radiation might therefore represent a good target for future treatments

Targeting Antigen to the Surface of EVs Improves the In Vivo Immunogenicity of Human and Non-human Adenoviral Vaccines in Mice

Adenoviral (Ad) vectors represent promising vaccine platforms for infectious disease. To overcome pre-existing immunity to commonly used human adenovirus serotype 5 (Ad5), vectors based on rare species or non-human Ads are being developed. However, these vectors often exhibit reduced potency compared with Ad5, necessitating the use of innovative approaches to augment the immunogenicity of the encoded antigen (Ag). To achieve this, we engineered model Ag, enhanced green fluorescent protein (EGFP), for targeting to the surface of host-derived extracellular vesicles (EVs), namely exosomes. Exosomes are nano-sized EVs that play important roles in cell-to-cell communication and in regulating immune responses. Directed targeting of Ag to the surface of EVs/exosomes is achieved by “exosome display,” through fusion of Ag to the C1C2 domain of lactadherin, a protein highly enriched in exosomes. Herein, we engineered chimpanzee adenovirus ChAdOx1 and Ad5-based vaccines encoding EGFP, or EGFP targeted to EVs (EGFP_C1C2), and compared vaccine immunogenicity in mice. We determined that exosome display substantially increases Ag-specific humoral immunity following intramuscular and intranasal vaccination, improving the immunological potency of both ChAdOx1 and Ad5. We propose that this Ag-engineering approach could increase the immunogenicity of diverse Ad vectors that exhibit desirable manufacturing characteristics, but currently lack the potency of Ad5

Safety and immunogenicity of the ChAdOx1 nCoV-19 (AZD1222) vaccine in children aged 6-17 years: a preliminary report of COV006, a phase 2 single-blind, randomised, controlled trial.

BACKGROUND: Vaccination of children and young people against SARS-CoV-2 is recommended in some countries. Scarce data have been published on immune responses induced by COVID-19 vaccines in people younger than 18 years compared with the same data that are available in adults. METHODS: COV006 is a phase 2, single-blind, randomised, controlled trial of ChAdOx1 nCoV-19 (AZD1222) in children and adolescents at four trial sites in the UK. Healthy participants aged 6-17 years, who did not have a history of chronic respiratory conditions, laboratory-confirmed COVID-19, or previously received capsular group B meningococcal vaccine (the control), were randomly assigned to four groups (4:1:4:1) to receive two intramuscular doses of 5 × 1010 viral particles of ChAdOx1 nCoV-19 or control, 28 days or 84 days apart. Participants, clinical investigators, and the laboratory team were masked to treatment allocation. Study groups were stratified by age, and participants aged 12-17 years were enrolled before those aged 6-11 years. Due to the restrictions in the use of ChAdOx1 nCoV-19 in people younger than 30 years that were introduced during the study, only participants aged 12-17 years who were randomly assigned to the 28-day interval group had received their vaccinations at the intended interval (day 28). The remaining participants received their second dose at day 112. The primary outcome was assessment of safety and tolerability in the safety population, which included all participants who received at least one dose of the study drug. The secondary outcome was immunogenicity, which was assessed in participants who were seronegative to the nucleocapsid protein at baseline and received both prime and boost vaccine. This study is registered with ISRCTN (15638344). FINDINGS: Between Feb 15 and April 2, 2021, 262 participants (150 [57%] participants aged 12-17 years and 112 [43%] aged 6-11 years; due to the change in the UK vaccination policy, the study terminated recruitment of the younger age group before the planned number of participants had been enrolled) were randomly assigned to receive vaccination with two doses of either ChAdOx1 nCoV-19 (n=211 [n=105 at day 28 and n=106 at day 84]) or control (n=51 [n=26 at day 28 and n=25 at day 84]). One participant in the ChAdOx1 nCoV-19 day 28 group in the younger age bracket withdrew their consent before receiving a first dose. Of the participants who received ChAdOx1 nCoV-19, 169 (80%) of 210 participants reported at least one solicited local or systemic adverse event up to 7 days following the first dose, and 146 (76%) of 193 participants following the second dose. No serious adverse events related to ChAdOx1 nCoV-19 administration were recorded by the data cutoff date on Oct 28, 2021. Of the participants who received at least one dose of ChAdOx1 nCoV-19, there were 128 unsolicited adverse events up to 28 days after vaccination reported by 83 (40%) of 210 participants. One participant aged 6-11 years receiving ChAdOx1 nCoV-19 reported a grade 4 fever of 40·2°C on day 1 following first vaccination, which resolved within 24 h. Pain and tenderness were the most common local solicited adverse events for all the ChAdOx1 nCoV-19 and capsular group B meningococcal groups following both doses. Of the 242 participants with available serostatus data, 14 (6%) were seropositive at baseline. Serostatus data were not available for 20 (8%) of 262 participants. Among seronegative participants who received ChAdOx1 nCoV-19, anti-SARS-CoV-2 IgG and pseudoneutralising antibody titres at day 28 after the second dose were higher in participants aged 12-17 years with a longer interval between doses (geometric means of 73 371 arbitrary units [AU]/mL [95% CI 58 685-91 733] and 299 half-maximal inhibitory concentration [IC50; 95% CI 230-390]) compared with those aged 12-17 years who received their vaccines 28 days apart (43 280 AU/mL [95% CI 35 852-52 246] and 150 IC50 [95% CI 116-194]). Humoral responses were higher in those aged 6-11 years than in those aged 12-17 years receiving their second dose at the same 112-day interval (geometric mean ratios 1·48 [95% CI 1·07-2·07] for anti-SARS-CoV-2 IgG and 2·96 [1·89-4·62] for pseudoneutralising antibody titres). Cellular responses peaked after a first dose of ChAdOx1 nCoV-19 across all age and interval groups and remained above baseline after a second vaccination. INTERPRETATION: ChAdOx1 nCoV-19 is well tolerated and immunogenic in children aged 6-17 years, inducing concentrations of antibody that are similar to those associated with high efficacy in phase 3 studies in adults. No safety concerns were raised in this trial. FUNDING: AstraZeneca and the UK Department of Health and Social Care through the UK National Institute for Health and Care Research

Efficacy of a low-dose candidate malaria vaccine, R21 in adjuvant Matrix-M, with seasonal administration to children in Burkina Faso: a randomised controlled trial.

BACKGROUND: Stalled progress in controlling Plasmodium falciparum malaria highlights the need for an effective and deployable vaccine. RTS,S/AS01, the most effective malaria vaccine candidate to date, demonstrated 56% efficacy over 12 months in African children. We therefore assessed a new candidate vaccine for safety and efficacy. METHODS: In this double-blind, randomised, controlled, phase 2b trial, the low-dose circumsporozoite protein-based vaccine R21, with two different doses of adjuvant Matrix-M (MM), was given to children aged 5-17 months in Nanoro, Burkina Faso-a highly seasonal malaria transmission setting. Three vaccinations were administered at 4-week intervals before the malaria season, with a fourth dose 1 year later. All vaccines were administered intramuscularly into the thigh. Group 1 received 5 μg R21 plus 25 μg MM, group 2 received 5 μg R21 plus 50 μg MM, and group 3, the control group, received rabies vaccinations. Children were randomly assigned (1:1:1) to groups 1-3. An independent statistician generated a random allocation list, using block randomisation with variable block sizes, which was used to assign participants. Participants, their families, and the local study team were all masked to group allocation. Only the pharmacists preparing the vaccine were unmasked to group allocation. Vaccine safety, immunogenicity, and efficacy were evaluated over 1 year. The primary objective assessed protective efficacy of R21 plus MM (R21/MM) from 14 days after the third vaccination to 6 months. Primary analyses of vaccine efficacy were based on a modified intention-to-treat population, which included all participants who received three vaccinations, allowing for inclusion of participants who received the wrong vaccine at any timepoint. This trial is registered with ClinicalTrials.gov, NCT03896724. FINDINGS: From May 7 to June 13, 2019, 498 children aged 5-17 months were screened, and 48 were excluded. 450 children were enrolled and received at least one vaccination. 150 children were allocated to group 1, 150 children were allocated to group 2, and 150 children were allocated to group 3. The final vaccination of the primary series was administered on Aug 7, 2019. R21/MM had a favourable safety profile and was well tolerated. The majority of adverse events were mild, with the most common event being fever. None of the seven serious adverse events were attributed to the vaccine. At the 6-month primary efficacy analysis, 43 (29%) of 146 participants in group 1, 38 (26%) of 146 participants in group 2, and 105 (71%) of 147 participants in group 3 developed clinical malaria. Vaccine efficacy was 74% (95% CI 63-82) in group 1 and 77% (67-84) in group 2 at 6 months. At 1 year, vaccine efficacy remained high, at 77% (67-84) in group 1. Participants vaccinated with R21/MM showed high titres of malaria-specific anti-Asn-Ala-Asn-Pro (NANP) antibodies 28 days after the third vaccination, which were almost doubled with the higher adjuvant dose. Titres waned but were boosted to levels similar to peak titres after the primary series of vaccinations after a fourth dose administered 1 year later. INTERPRETATION: R21/MM appears safe and very immunogenic in African children, and shows promising high-level efficacy. FUNDING: The European & Developing Countries Clinical Trials Partnership, Wellcome Trust, and National Institute for Health Research Oxford Biomedical Research Centre

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Background A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. Methods This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. Findings Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. Interpretation ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

The Membrane-targeted Alkylphosphocholine Erufosine Interferes with Survival Signals from the Extracellular Matrix

Integrin-dependent adhesion of tumor cells to extracellular matrix proteins provides anchorage-dependent protection from cell death. In the present investigation we aimed to understand whether and how the paradigmatic membrane-targeted synthetic phospholipid analog erufosine is relevant for tumor cell adhesion to extracellular matrix proteins, cell survival and migration. The antineoplastic action of erufosine was analyzed with glioblastoma and prostate cancer cells adhering to fibronectin or collagen I using proliferation, adhesion and migration assays. The composition of adhesion contacts containing activated beta 1 integrins was studied using immunofluorescence. The importance of beta 1 integrins for the observed effects was analyzed in fibroblasts proficient or deficient in beta 1 integrin expression. Adhesion to collagen I and fibronectin increased the death threshold in serum-deprived tumor cells. Moreover, beta 1 integrin-deficient cells were more sensitive to erufosine-treatment compared to beta 1 integrin proficient cells suggesting a role of beta 1 integrins for matrix-mediated death resistance. Most importantly, erufosine disturbed the maturation of the cell adhesion complexes containing paxillin, activated beta 1 integrins and phosphorylated FAK, leading to a reduction of survival signals and inhibition of tumor cell adhesion and migration. These findings suggest that membrane-targeted synthetic phospholipids analogs may be of value for counteracting matrix-mediated treatment resistance in combined treatment approaches with radiotherapy or chemotherapy

Metropolitan Governance: Which Policies for Globalizing Cities?

Urbanization, Metropolitan areas, Governance, Water management, ICTs, R50, H70, Q25, O30,