Explore the vast range of titles available.

Despite the success of the BNT162b2 mRNA vaccine, the immunological mechanisms that underlie its efficacy are poorly understood. Here we analyzed the innate and adaptive responses to BNT162b2 in mice, and show that immunization stimulated potent antibody and antigen-specific T cell responses, as well as strikingly enhanced innate responses after secondary immunization, which was concurrent with enhanced serum interferon (IFN)-γ levels 1 d following secondary immunization. Notably, we found that natural killer cells and CD8+ T cells in the draining lymph nodes are the major producers of this circulating IFN-γ. Analysis of knockout mice revealed that induction of antibody and T cell responses to BNT162b2 was not dependent on signaling via Toll-like receptors 2, 3, 4, 5 and 7 nor inflammasome activation, nor the necroptosis or pyroptosis cell death pathways. Rather, the CD8+ T cell response induced by BNT162b2 was dependent on type I interferon-dependent MDA5 signaling. These results provide insights into the molecular mechanisms by which the BNT162b2 vaccine stimulates immune responses.How mRNA-based coronavirus disease 2019 vaccines drive immune responses is not clear. Here the authors characterize immune responses to the BNT162b2 vaccine in mice, and show how it stimulates innate immunity, with antigen-specific CD8+ T cell responses dependent on the RNA sensor MDA5.

Sentinel lymph node imaging and biopsy is important to clinical assessment of cancer metastasis, and novel non-radioactive lymphographic tracers have been actively pursued over the years. Here, we develop gold molecular clusters (Au 25 ) functionalized by phosphorylcholine (PC) ligands for NIR-II (1000–3000 nm) fluorescence imaging of draining lymph nodes in 4T1 murine breast cancer and CT26 colon cancer tumor mouse models. The Au-phosphorylcholine (Au-PC) probes exhibit ‘super-stealth’ behavior with little interactions with serum proteins, cells and tissues in vivo, which differs from the indocyanine green (ICG) dye. Subcutaneous injection of Au-PC allows lymph node mapping by NIR-II fluorescence imaging at an optimal time of ~ 0.5 − 1 hour postinjection followed by rapid renal clearance. Preclinical NIR-II fluorescence LN imaging with Au-PC affords high signal to background ratios and high safety and biocompatibility, promising for future clinical translation. Fluorescent tracers facilitate the identification and subsequent collection of tumour draining lymph node biopsies, enabling important clinical assessment. Here, the authors present a molecular gold nanocluster NIR-II fluorescent imaging probe and demonstrate its utility to visualise draining lymph nodes in breast and colon cancer mouse models.

The squalene-based oil-in-water emulsion (SE) vaccine adjuvant MF59 has been administered to more than 100 million people in more than 30 countries, in both seasonal and pandemic influenza vaccines. Despite its wide use and efficacy, its mechanisms of action remain unclear. In this study we demonstrate that immunization of mice with MF59 or its mimetic AddaVax (AV) plus soluble antigen results in robust antigen-specific antibody and CD8 T cell responses in lymph nodes and non-lymphoid tissues. Immunization triggered rapid RIPK3-kinase dependent necroptosis in the lymph node which peaked at 6 hr, followed by a sequential wave of apoptosis. Immunization with alum plus antigen did not induce RIPK3-dependent signaling. RIPK3-dependent signaling induced by MF59 or AV was essential for cross-presentation of antigen to CD8 T cells by Batf3-dependent CD8 + DCs. Consistent with this, RIPK3 deficient or Batf3 deficient mice were impaired in their ability to mount adjuvant-enhanced CD8 T cell responses. However, CD8 T cell responses were unaffected in mice deficient in MLKL, a downstream mediator of necroptosis. Surprisingly, antibody responses were unaffected in RIPK3-kinase or Batf3 deficient mice. In contrast, antibody responses were impaired by in vivo administration of the pan-caspase inhibitor Z-VAD-FMK, but normal in caspase-1 deficient mice, suggesting a contribution from apoptotic caspases, in the induction of antibody responses. These results demonstrate that squalene emulsion-based vaccine adjuvants induce antigen-specific CD8 T cell and antibody responses, through RIPK3-dependent and-independent pathways, respectively.

This work aimed to study the genome organization and the metabolic potential of Streptomyces carpaticus strain SCPM-O-B-9993, a promising plant-protecting and plant-stimulating strain isolated from brown semi-desert soils with very high salinity. The strain genome contains a linear chromosome 5,968,715 bp long and has no plasmids. The genome contains 5331 coding sequences among which 2139 (40.1%) are functionally annotated. Biosynthetic gene clusters (BGCs) of secondary metabolites exhibiting antimicrobial properties (ohmyungsamycin, pellasoren, naringenin, and ansamycin) were identified in the genome. The most efficient period of SCPM-O-B-9993 strain cultivation was 72 h: during this period, the culture went from the exponential to the stationary growth phase as well as exhibited excellent phytostimulatory properties and antiviral activity against the cucumber mosaic virus in tomatoes under laboratory conditions. The Streptomyces carpaticus SCPM-OB-9993 strain is a biotechnologically promising producer of secondary metabolites exhibiting antiviral and phytostimulatory properties.

Effective models for aligning public health and civil society at the local level have the potential to impact various global health issues, including tobacco. Georgia and Armenia Teams for Healthy Environments and Research (GATHER) is a collaboration between Armenia, Georgia and U.S. researchers involving a community randomized trial testing the impact of community coalitions to promote smoke-free policy adoption and compliance in various settings. Community Coalition Action Theory (CCAT) was used to guide and describe coalition formation, implementation and effectiveness. Mixed methods were used to evaluate 14 municipality-based coalitions in Georgia and Armenia, including semi-structured interviews (n = 42) with coalition leaders and active members, coalition member surveys at two timepoints (n = 85 and n = 83), and review of action plans and progress reports. Results indicated successful creation of 14 multi-sectoral coalitions, most commonly representing education, public health, health care, and municipal administration. Half of the coalitions created at least one smoke-free policy in specific settings (e.g., factories, parks), and all 14 promoted compliance with existing policies through no-smoking signage and stickers. The majority also conducted awareness events in school, health care, and community settings, in addition to educating the public about COVID and the dangers of tobacco use. Consistent with CCAT, coalition processes (e.g., communication) were associated with member engagement and collaborative synergy which, in turn, correlated with perceived community impact, skills gained by coalition members, and interest in sustainability. Findings suggest that community coalitions can be formed in varied sociopolitical contexts and facilitate locally-driven, multi-sectoral collaborations to promote health. Despite major contextual challenges (e.g., national legislation, global pandemic, war), coalitions were resilient, nimble and remained active. Additionally, CCAT propositions appear to be generalizable, suggesting that coalition-building guidance may be relevant for local public health in at least some global contexts.

Adjuvants enhance the magnitude and the durability of the immune response to vaccines. However, there is a paucity of comparative studies on the nature of the immune responses stimulated by leading adjuvant candidates. In this study, we compared five clinically relevant adjuvants in mice—alum, AS03 (a squalene-based adjuvant supplemented with α-tocopherol), AS37 (a TLR7 ligand emulsified in alum), CpG1018 (a TLR9 ligand emulsified in alum), O/W 1849101 (a squalene-based adjuvant)—for their capacity to stimulate immune responses when combined with a subunit vaccine under clinical development. We found that all four of the adjuvant candidates surpassed alum with respect to their capacity to induce enhanced and durable antigen-specific antibody responses. The TLR-agonist-based adjuvants CpG1018 (TLR9) and AS37 (TLR7) induced Th1-skewed CD4+ T cell responses, while alum, O/W, and AS03 induced a balanced Th1/Th2 response. Consistent with this, adjuvants induced distinct patterns of early innate responses. Finally, vaccines adjuvanted with AS03, AS37, and CpG1018/alum-induced durable neutralizing-antibody responses and significant protection against the B.1.351 variant 7 months following immunization. These results, together with our recent results from an identical study in non-human primates (NHPs), provide a comparative benchmarking of five clinically relevant vaccine adjuvants for their capacity to stimulate immunity to a subunit vaccine, demonstrating the capacity of adjuvanted SARS-CoV-2 subunit vaccines to provide durable protection against the B.1.351 variant. Furthermore, these results reveal differences between the widely-used C57BL/6 mouse strain and NHP animal models, highlighting the importance of species selection for future vaccine and adjuvant studies.

ObjectivesGiven high prevalence of smoking and secondhand smoke exposure in Armenia and Georgia and quicker implementation of tobacco legislation in Georgia versus Armenia, we examined correlates of having no/partial versus complete smoke-free home (SFH) restrictions across countries, particularly smoking characteristics, risk perceptions, social influences and public smoking restrictions.DesignCross-sectional survey study design.Setting28 communities in Armenia and Georgia surveyed in 2018.Participants1456 adults ages 18–64 in Armenia (n=705) and Georgia (n=751).MeasurementsWe used binary logistic regression to examine aforementioned correlates of no/partial versus complete SFH among non-smokers and smokers in Armenia and Georgia, respectively.ResultsParticipants were an average age of 43.35, 60.5% women and 27.3% smokers. In Armenia, among non-smokers, having no/partial SFHs correlated with being men (OR=2.63, p=0.001) and having more friend smokers (OR=1.23, p=0.002); among smokers, having no/partial SFHs correlated with being unmarried (OR=10.00, p=0.001), lower quitting importance (OR=0.82, p=0.010) and less favourable smoking attitudes among friends/family/public (OR=0.48, p=0.034). In Georgia, among non-smokers, having no/partial SFHs correlated with older age (OR=1.04, p=0.002), being men (OR=5.56, p<0.001), lower SHS risk perception (OR=0.43, p<0.001), more friend smokers (OR=1.49, p=0.002) and fewer workplace (indoor) restrictions (OR=0.51, p=0.026); among smokers, having no/partial SFHs correlated with being men (OR=50.00, p<0.001), without children (OR=5.88, p<0.001), daily smoking (OR=4.30, p=0.050), lower quitting confidence (OR=0.81, p=0.004), more friend smokers (OR=1.62, p=0.038) and fewer community restrictions (OR=0.68, p=0.026).ConclusionsPrivate settings continue to lack smoking restrictions in Armenia and Georgia. Findings highlight the importance of social influences and comprehensive tobacco legislation, particularly smoke-free policies, in changing household smoking restrictions and behaviours.Trial registration numberNCT03447912.

IntroductionLocal coalitions can advance public health initiatives such as smoke-free air but have not been widely used or well-studied in low-income and middle-income countries.MethodsWe conducted a matched-pairs community-randomised controlled trial in 28 communities in Armenia and Georgia (N=14/country) in which we helped establish local coalitions in 2019 and provided training and technical assistance for coalition activity promoting smoke-free policy development and enforcement (2019–2021). Surveys of ~1450 households (Fall 2018, May–June 2022) were conducted to evaluate coalition impact on smoke-free policy support, smoke-free home adoption, secondhand smoke exposure (SHSe), and coalition awareness and activity exposure, using multivariable mixed modelling.ResultsBivariate analyses indicated that, at follow-up versus baseline, both conditions reported greater smoke-free home rates (53.6% vs 38.5%) and fewer days of SHSe on average (~11 vs ~12 days), and that intervention versus control condition communities reported greater coalition awareness (24.3% vs 12.2%) and activity exposure (71.2% vs 64.5%). Multivariable modelling indicated that intervention (vs control) communities reported greater rates of complete smoke-free homes (adjusted Odds Ratio [aOR] 1.55, 95% confiedence interval [CI] 1.11 to 2.18, p=0.011) and coalition awareness (aOR 2.89, 95% CI 1.44 to 8.05, p=0.043) at follow-up. However, there were no intervention effects on policy support, SHSe or community-based activity exposure.ConclusionsFindings must be considered alongside several sociopolitical factors during the study, including national smoke-free policies implementation (Georgia, 2018; Armenia, 2022), these countries’ participation in an international tobacco legislation initiative, the COVID-19 pandemic and regional/local war). The intervention effect on smoke-free homes is critical, as smoke-free policy implementation provides opportunities to accelerate smoke-free home adoption via local coalitions.Trial registration numberNCT03447912.

The emergency use authorization of two mRNA vaccines in less than a year from the emergence of SARS-CoV-2 represents a landmark in vaccinology 1 , 2 . Yet, how mRNA vaccines stimulate the immune system to elicit protective immune responses is unknown. Here we used a systems vaccinology approach to comprehensively profile the innate and adaptive immune responses of 56 healthy volunteers who were vaccinated with the Pfizer–BioNTech mRNA vaccine (BNT162b2). Vaccination resulted in the robust production of neutralizing antibodies against the wild-type SARS-CoV-2 (derived from 2019-nCOV/USA_WA1/2020) and, to a lesser extent, the B.1.351 strain, as well as significant increases in antigen-specific polyfunctional CD4 and CD8 T cells after the second dose. Booster vaccination stimulated a notably enhanced innate immune response as compared to primary vaccination, evidenced by (1) a greater frequency of CD14 + CD16 + inflammatory monocytes; (2) a higher concentration of plasma IFNγ; and (3) a transcriptional signature of innate antiviral immunity. Consistent with these observations, our single-cell transcriptomics analysis demonstrated an approximately 100-fold increase in the frequency of a myeloid cell cluster enriched in interferon-response transcription factors and reduced in AP-1 transcription factors, after secondary immunization. Finally, we identified distinct innate pathways associated with CD8 T cell and neutralizing antibody responses, and show that a monocyte-related signature correlates with the neutralizing antibody response against the B.1.351 variant. Collectively, these data provide insights into the immune responses induced by mRNA vaccination and demonstrate its capacity to prime the innate immune system to mount a more potent response after booster immunization. Profiling the immune responses of 56 volunteers vaccinated with BNT162b2 reveals how this mRNA vaccine primes the innate immune system to mount a potent response to SARS-CoV-2 after booster immunization.

The fundamental goal of vaccinations is the induction of robust and durable protective immunity against pathogens. The emergence of the SARS-CoV-2 virus, and its rapid mutation into immune-evasive variants, underscored the necessity for vaccines to confer long-lasting and cross-protective memory responses. While current vaccination strategies for respiratory viruses such as SARS-CoV-2 and influenza virus provide moderate protection, achieving durable sterilizing immunity against these pathogens has remained a major challenge. This dissertation explores two vaccination strategies that have the potential to enhance current immunization approaches.First, we investigate the potential of vaccine adjuvants as a strategy to augment the magnitude, durability and breadth of vaccine-induced immunity. In Chapter 2, using mouse models, we perform a comparative evaluation of the immune responses induced by diverse vaccine adjuvants in combination with a candidate COVID-19 vaccine antigen. In Chapter 3, we delve deeper into the adaptive immune responses induced by an adjuvanted COVID-19 vaccine in humans, with a particular focus on the breadth of the antibody responses in the presence and absence of the adjuvant. Our findings presented in these two chapters highlight the crucial role of vaccine adjuvants in enhancing the immune response to vaccination, elucidate the diversity of different adjuvant formulations, and provide evidence for the enhancement of cross-reactive immunity by investigating the clonal dynamics of B cells over the course of vaccination in humans.Second, we examine the incorporation of T cell memory in addition to humoral immunity as a vaccination strategy to enhance protection against infection. In Chapter 4, using influenza as a model, we investigate the role of T cell memory and antibody responses in contributing to protection either individually or in combination. We find that combining T cell memory with humoral immunity provides with superior protection against infection, highlighting T cells as attractive targets of vaccination. In Chapter 5, using a novel vaccination platform utilizing circular RNA encoding antigenic sequences, we induce robust CD8 T cell responses in mice, elucidating a novel candidate platform for T cell vaccinesCollectively, the findings in this thesis significantly enhance our understanding of the adaptive immune responses induced by vaccination. Our results underscore the pivotal role of adjuvants in shaping the immune response to vaccination, and reveal the contribution of T cell memory to protection against infection, presenting two promising strategies to address current challenges in vaccinology.