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High-risk groups, including Indigenous people, are at risk of severe COVID-19. Here we found that Australian First Nations peoples elicit effective immune responses to COVID-19 BNT162b2 vaccination, including neutralizing antibodies, receptor-binding domain (RBD) antibodies, SARS-CoV-2 spike-specific B cells, and CD4+ and CD8+ T cells. In First Nations participants, RBD IgG antibody titers were correlated with body mass index and negatively correlated with age. Reduced RBD antibodies, spike-specific B cells and follicular helper T cells were found in vaccinated participants with chronic conditions (diabetes, renal disease) and were strongly associated with altered glycosylation of IgG and increased interleukin-18 levels in the plasma. These immune perturbations were also found in non-Indigenous people with comorbidities, indicating that they were related to comorbidities rather than ethnicity. However, our study is of a great importance to First Nations peoples who have disproportionate rates of chronic comorbidities and provides evidence of robust immune responses after COVID-19 vaccination in Indigenous people.

Circadian clocks govern temporal programs in the green lineage (Chloroplastida) as they do in other photosynthetic pro- and eukaryotes, bacteria, fungi, animals, and humans. Their physiological properties, including entrainment, phase responses, and temperature compensation, are well conserved. The involvement of transcriptional/translational feedback loops in the oscillatory machinery and reversible phosphorylation events are also maintained. Circadian clocks control a large variety of output rhythms in green algae and terrestrial plants, adjusting their metabolism and behavior to the day-night cycle. The angiosperm Arabidopsis (Arabidopsis thaliana) represents a well-studied circadian clock model. Several molecular components of its oscillatory machinery are conserved in other Chloroplastida, but their functions may differ. Conserved clock components include at least one member of the CIRCADIAN CLOCK ASSOCIATED1/REVEILLE and one of the PSEUDO RESPONSE REGULATOR family. The Arabidopsis evening complex members EARLY FLOWERING3 (ELF3), ELF4, and LUX ARRHYTHMO are found in the moss Physcomitrium patens and in the liverwort Marchantia polymorpha. In the flagellate chlorophyte alga Chlamydomonas reinhardtii, only homologs of ELF4 and LUX (named RHYTHM OF CHLOROPLAST ROC75) are present. Temporal ROC75 expression in C. reinhardtii is opposite to that of the angiosperm LUX, suggesting different clock mechanisms. In the picoalga Ostreococcus tauri, both ELF genes are missing, suggesting that it has a progenitor circadian “green” clock. Clock-relevant photoreceptors and thermosensors vary within the green lineage, except for the CRYPTOCHROMEs, whose variety and functions may differ. More genetically tractable models of Chloroplastida are needed to draw final conclusions about the gradual evolution of circadian clocks within the green lineage.

While the protective role of neutralising antibodies against COVID-19 is well-established, questions remain about the relative importance of cellular immunity. Using 6 pMHC-multimers in a cohort with early and frequent sampling we define the phenotype and kinetics of recalled and primary T cell responses following Delta or Omicron breakthrough infection. Recall of spike-specific CD4+T cells was rapid, with cellular proliferation and extensive activation evident as early as 1 day post-symptom onset. Similarly, spike-specific CD8+T cells were rapidly activated but showed variable levels of expansion. Strikingly, high levels of SARS-CoV-2-specific CD8+T cell activation at baseline and peak were strongly correlated with reduced peak SARS-CoV-2 RNA levels in nasal swabs and accelerated clearance of virus. Our study demonstrates rapid and extensive recall of memory T cell populations occurs early after breakthrough infection and suggests that CD8+T cells contribute to the control of viral replication in breakthrough SARS-CoV-2 infections.

The immune checkpoint receptor Lymphocyte activation gene-3 (LAG3) inhibits T cell function upon binding to Major Histocompatibility Complex Class II (MHCII) or Fibrinogen-like 1 (FGL1). Despite the emergence of LAG3 as a target for next-generation immunotherapies, we have little information describing the molecular structure of the LAG3 protein or how it engages cellular ligands. Here, we determined structures of human and murine LAG3 ectodomains, revealing a dimeric assembly mediated by immunoglobulin domain 2 (D2). Epitope mapping indicates that a potent LAG3 antagonist antibody blocks interactions with MHCII and FGL1 by binding to a flexible “Loop 2” region in LAG3 domain 1 (D1). We also defined the LAG3:FGL1 interface by mapping mutations onto structures of LAG3 and FGL1, and we established that FGL1 crosslinking induces the formation of higher-order LAG3 oligomers. These insights will guide LAG3-based drug development and implicate ligand-mediated LAG3 clustering as a mechanism for disrupting T cell activation.

Drosophila, Arabidopsis, Synechocystis, Homo (DASH) cryptochromes belong to the cryptochrome/photolyase family and can act as DNA repair enzymes. In bacteria and fungi, they also can play regulatory roles, but in plants their biological functions remain elusive. Here, we characterize CRY-DASH1 from the green alga Chlamydomonas reinhardtii. We perform biochemical and in vitro photochemical analysis. For functional characterization, a knock-out mutant of cry-dash1 is used. CRY-DASH1 protein is localized in the chloroplast and accumulates at midday. Although the photoautotrophic growth of the mutant is significantly reduced compared to the wild-type (WT), the mutant has increased levels of photosynthetic pigments and a higher maximum photochemical efficiency of photosystem II (PS II). Hyper-stacking of thylakoid membranes occurs together with an increase in proteins of the PS II reaction center, D1 and its antenna CP43, but not of their transcripts. CRY-DASH1 binds fully reduced flavin adenine dinucleotide and the antenna 5,10-methenyltetrahydrofolate, leading to an absorption peak in the UV-A range. Supplementation of white light with UV-A increases photoautotrophic growth of the WT but not of the cry-dash1 mutant. These results suggest a balancing function of CRY-DASH1 in the photosynthetic machinery and point to its role as a photoreceptor for the UV-A range separated from the absorption of photosynthetic pigments.

Today, aircraft composite structures are generally over-dimensioned to avoid catastrophic failure by unseen damages. This leads to a higher system weight and therefore an unwanted increase in greenhouse gas emissions. To reduce this parasitic mass, load monitoring can play an important role in damage detection. Additionally, the weight and volume of future aircraft structures can also be reduced by energy storing and load carrying structures: so-called power composites. In this study a novel method of combining both approaches for maximum weight reduction is shown. This is achieved by using power composites as load monitoring sensors and energy suppliers. Therefore, supercapacitors are integrated into fiber reinforced polymers and are then used to investigate the mechanical load influence. By using four-point bending experiments and in situ electrochemical impedance spectroscopy, a strong relation between the mechanical load and the electrochemical system is found and analyzed using a model. For the first time, it is possible to detect small strain values down to 0.2% with a power composite. This strain is considerably lower than the conventional system load. The developed model and the impedance data indicate the possibility of using the composite as an energy storage as well as a strain sensor.

Most human killer cell immunoglobulin-like receptors (KIR) are expressed by Natural Killer (NK) cells and recognize HLA class I molecules as ligands. Uniquely, KIR3DL3 is a conserved but polymorphic inhibitory KIR recognizing a B7 family ligand, HHLA2, and is implicated for immune checkpoint targeting. Because the expression profile and biological function of KIR3DL3 remained elusive, we searched extensively for KIR3DL3 transcripts, revealing expression is highly enriched in γδ and CD8+ T cells rather than NK cells. These KIR3DL3 expressing cells are rare in the blood and thymus, but more common in the lungs and digestive tract. High resolution flow cytometry and single cell transcriptomics showed that peripheral blood KIR3DL3+ T cells have an activated transitional memory phenotype and are hypofunctional. The TCR usage is biased towards genes from early rearranged TCR-α variable segments or Vδ1 chains. Whereas we detected no impact of KIR3DL3 polymorphism on ligand binding, variants in the proximal promoter and at residue 86 can reduce expression. Together, we demonstrate that KIR3DL3 is upregulated in response to unconventional T cell stimulation and that individuals may vary in their ability to express KIR3DL3. These results have implications for the personalized targeting of KIR3DL3/HHLA2 checkpoint inhibition.

In-depth understanding of human T-cell-mediated immunity in coronavirus disease 2019 (COVID-19) is needed if we are to optimize vaccine strategies and immunotherapies. Identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) T-cell epitopes and generation of peptide-human leukocyte antigen (peptide-HLA) tetramers facilitate direct ex vivo analyses of SARS-CoV-2-specific T cells and their T-cell receptor (TCR) repertoires. We utilized a combination of peptide prediction and in vitro peptide stimulation to validate novel SARS-CoV-2 epitopes restricted by HLA-A*24:02, one of the most prominent HLA class I alleles, especially in Indigenous and Asian populations. Of the peptides screened, three spike-derived peptides generated CD8+ IFNI³+ responses above background, S1208-1216 (QYIKWPWYI), S448-456 (NYNYLYRLF) and S193-201 (VFKNIDGYF), with S1208 generating immunodominant CD8+ IFNI³+ responses. Using peptide-HLA-I tetramers, we performed direct ex vivo tetramer enrichment for HLA-A*24:02-restricted CD8+ T cells in COVID-19 patients and prepandemic controls. The precursor frequencies for HLA-A*24:02-restricted epitopes were within the range previously observed for other SARS-CoV-2 epitopes for both COVID-19 patients and prepandemic individuals. Naive A24/SARS-CoV-2-specific CD8+ T cells increased nearly 7.5-fold above the average precursor frequency during COVID-19, gaining effector and memory phenotypes. Ex vivo single-cell analyses of TCRαs repertoires found that the A24/S448 + CD8+ T-cell TCRαs repertoire was driven by a common TCRs chain motif, whereas the A24/S1208 + CD8+ TCRαs repertoire was diverse across COVID-19 patients. Our study provides an in depth characterization and important insights into SARS-CoV-2-specific CD8+ T-cell responses associated with a prominent HLA-A*24:02 allomorph. This contributes to our knowledge on adaptive immune responses during primary COVID-19 and could be exploited in vaccine or immunotherapeutic approaches.

Plant cryptochromes are central blue light receptors in land plants and algae. Photoreduction of the flavin bound to the photolyase homology region (PHR) causes a dissociation of the C-terminal extension (CCT) as effector via an unclear pathway. We applied the recently developed in-cell infrared difference (ICIRD) spectroscopy to study the response of the full-length pCRY from Chlamydomonas reinhardtii in living bacterial cells, because the receptor degraded upon isolation. We demonstrate a stabilization of the flavin neutral radical as photoproduct and of the resulting β-sheet reorganization by binding of cellular ATP. Comparison between light-induced structural responses of full-length pCRY and PHR reveals a downshift in frequency of the β-sheet signal, implying an association of the CCT close to the only β-sheet of the PHR in the dark. We provide a missing link in activation of plant cryptochromes after flavin photoreduction by indicating that β-sheet reorganization causes the CCT release and restructuring.

The working group, “Clinical Tissue Regeneration” of the German Society of Orthopedics and Traumatology (DGOU) issues this paper to update their guidelines. Methods Peer-reviewed literature was analyzed regarding different topics relevant to osteochondral lesions of the talus (OLTs) treatment. This process concluded with a statement for each topic reflecting the best scientific evidence available for a particular diagnostic or therapeutic concept, including the grade of recommendation. Besides the scientific evidence, all group members rated the statements to identify possible gaps between literature and current clinical practice. Conclusion In patients with minimal symptoms, OLT progression to ankle osteoarthritis is unlikely. Risk factors for progression are the depth of the lesion on MRI, subchondral cyst formation, and the extent of bone marrow edema. Conservative management is the adaptation of activities to the performance of the ankle joint. A follow-up imaging after 12 months helps not to miss any progression. It is impossible to estimate the probability of success of conservative management from initial symptoms and imaging. Cast immobilization is an option in OLTs in children, with a success rate of approximately 50%, although complete healing, estimated from imaging, is rare. In adults, improvement by conservative management ranges between 45% and 59%. Rest and restrictions for sports activities seem to be more successful than immobilization. Intra-articular injections of hyaluronic acid and platelet-rich plasma can improve pain and functional scores for more than 6 months. If 3 months of conservative management does not improve symptoms, surgery can be recommended.

Echinochloa crus-galli (L.) Pal. Beauv. is one of the most noxious weeds in maize cultivation and has evolved target-site resistance to ALS-inhibiting herbicides. Due to the hexaploid nature of E. crus-galli, resistance inducing mutations can be harbored by multiple gene copies, but up to now, studies did not include an analysis of the ALS gene copies conferring resistance. Investigations on E. crus-galli populations from different countries in Central Europe revealed the presence of several point mutations conferring resistance and occurring independently at the positions Ala-122, Pro-197 and Trp-574. Moreover, an Asp-376-Glu mutation in the ALS gene in E. crus-galli and a Ser-653-Tyr amino acid change in the ALS protein of a weed were detected for the first time. Additionally, the study revealed the first case of an ALS-resistant population (Trp-574-Leu) in the Czech Republic. The detection of mutations is relevant to the evolution and management of herbicide resistance. Dose–response experiments showed different effects depending on the population and the individual active ingredients and mixtures. Due to the genetic variability of E. crus-galli, results were highly variable. Overall, the populations showed a high level of resistance. For the prevailing mutated positions, i.e., Ala-122, Pro-197 and Trp-574, gene copies were examined separately using molecular genetic methods. A single mutation in at least one out of three ALS gene copies was sufficient to confer resistance at the positions Pro-197 and Trp-574. At Ala-122, point mutations co-occurring in the ALS 1, ALS 2 and ALS 3 gene copy were identified. The study provides a starting point for differentiation of the resistance mechanisms in polyploid E. crus-galli.

Herbicide-tolerant winter oilseed rape (OSR) varieties offer the opportunity of using imazamox for weed control, an active ingredient belonging to the chemical group of acetolactate synthase (ALS-) inhibitors. However, ALS inhibitors are used in many different crops and are the most resistance-prone herbicide mode of action. Their frequent application in a crop rotation increases the selection pressure for ALS herbicide resistance in weeds, which has to be considered when designing resistance management strategies. Alopecurus myosuroides Huds. is a frequent and economically important grass weed in Northwestern Europe, which has evolved resistance to several herbicide modes of action. For the sustainable use of herbicide-tolerant OSR varieties, studies on the effects of the different intensities of ALS inhibitor use on A. myosuroides population dynamics and resistance development are required. Two field trials were conducted including susceptible and multiple resistant A. myosuroides individuals and four weed control strategies varying in their intensity of ALS inhibitor use over a three-year trial period. A. myosuroides head numbers, the presence of target-site mutations in surviving plants, and crop yields were assessed annually, and the amount of A. myosuroides seeds in the soil seed bank was determined at the end of the trial period. The results show that the intensity of ALS inhibitor use significantly influenced the density of A. myosuroides and the development of resistance. Under weed control strategy IV (no ALS inhibitors), an increase in A. myosuroides head number was observed due to multiple resistance in the A. myosuroides population employed in the field trial. None of the four weed control strategies was able to control A. myosuroides infestation to an acceptable level. The results on A. myosuroides densities in the soil seed bank were highly variable and inconsistent. Molecular analysis of surviving plants showed a selection of ALS-resistant biotypes depending on the ALS inhibitor selection pressure. This study did not reveal any specific deterioration of A. myosuroides infestation associated with the use of imidazolinone-tolerant OSR in a short-term crop rotation. However, this OSR production system should not be employed if ALS-resistant A. myosuroides plants are present in the field.

Significance As the recall of CD8+ T cell memory promotes rapid recovery in, for example, influenza, we investigated circulating SARS-CoV-2−specific CD8+ T cells from COVID-19 patients. For two HLA-A*02:01 SARS-CoV-2−specific CD8+ T cell epitopes, we found that, while ex vivo frequencies of responding T cells were approximately fivefold higher than for pre−COVID-19 samples, they were ∼10-fold lower than for influenza or EBV-specific memory CD8+ T cells. Additionally, SARS-CoV-2−specific CD8+ T cells recovered from convalescent COVID-19 patients had an atypically high prevalence of stem cell memory, central memory, and naïve phenotypes. Might this unexpectedly low prevalence of classical effector memory T cells be a negative consequence of the infectious process that could be avoided by prior priming with an appropriately constituted vaccine?, An improved understanding of human T cell-mediated immunity in COVID-19 is important for optimizing therapeutic and vaccine strategies. Experience with influenza shows that infection primes CD8+ T cell memory to peptides presented by common HLA types like HLA-A2, which enhances recovery and diminishes clinical severity upon reinfection. Stimulating peripheral blood mononuclear cells from COVID-19 convalescent patients with overlapping peptides from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the clonal expansion of SARS-CoV-2−specific CD8+ and CD4+ T cells in vitro, with CD4+ T cells being robust. We identified two HLA-A*02:01-restricted SARS-CoV-2-specfic CD8+ T cell epitopes, A2/S269–277 and A2/Orf1ab3183–3191. Using peptide−HLA tetramer enrichment, direct ex vivo assessment of A2/S269+CD8+ and A2/Orf1ab3183+CD8+ populations indicated that A2/S269+CD8+ T cells were detected at comparable frequencies (∼1.3 × 10−5) in acute and convalescent HLA-A*02:01+ patients. These frequencies were higher than those found in uninfected HLA-A*02:01+ donors (∼2.5 × 10−6), but low when compared to frequencies for influenza-specific (A2/M158) and Epstein–Barr virus (EBV)-specific (A2/BMLF1280) (∼1.38 × 10−4) populations. Phenotyping A2/S269+CD8+ T cells from COVID-19 convalescents ex vivo showed that A2/S269+CD8+ T cells were predominantly negative for CD38, HLA-DR, PD-1, and CD71 activation markers, although the majority of total CD8+ T cells expressed granzymes and/or perforin. Furthermore, the bias toward naïve, stem cell memory and central memory A2/S269+CD8+ T cells rather than effector memory populations suggests that SARS-CoV-2 infection may be compromising CD8+ T cell activation. Priming with appropriate vaccines may thus be beneficial for optimizing CD8+ T cell immunity in COVID-19.

Celiac disease is a T cell-mediated chronic inflammatory condition often characterized by human leukocyte antigen (HLA)-DQ2.5 molecules presenting gluten epitopes derived from wheat, barley, and rye. Although some T cells exhibit cross-reactivity toward distinct gluten epitopes, the structural basis underpinning such cross-reactivity is unclear. Here, we investigated the T-cell receptor specificity and cross-reactivity of two immunodominant wheat gluten epitopes, DQ2.5-glia-α1a (PFPQPELPY) and DQ2.5-glia-ω1 (PFPQPEQPF). We show by surface plasmon resonance that a T-cell receptor alpha variable (TRAV) 4+-T-cell receptor beta variable (TRBV) 29-1+ TCR bound to HLA-DQ2.5-glia-α1a and HLA-DQ2.5-glia-ω1 with similar affinity, whereas a TRAV4- (TRAV9-2+) TCR recognized HLA-DQ2.5-glia-ω1 only. We further determined the crystal structures of the TRAV4+-TRBV29-1+ TCR bound to HLA-DQ2.5-glia-α1a and HLA-DQ2.5-glia-ω1, as well as the structure of an epitope-specific TRAV9-2+-TRBV7-3+ TCR-HLA-DQ2.5-glia-ω1 complex. We found that position 7 (p7) of the DQ2.5-glia-α1a and DQ2.5-glia-ω1 epitopes made very limited contacts with the TRAV4+ TCR, thereby explaining the TCR cross-reactivity across these two epitopes. In contrast, within the TRAV9-2+ TCR-HLA-DQ2.5-glia-ω1 ternary complex, the p7-Gln was situated in an electrostatic pocket formed by the hypervariable CDR3β loop of the TCR and Arg70β from HLA-DQ2.5, a polar network which would not be supported by the p7-Leu residue of DQ2.5-glia-α1a. In conclusion, we provide additional insights into the molecular determinants of TCR specificity and cross-reactivity to two closely-related epitopes in celiac disease.

Throughout the integration of thin-film supercapacitors into composite structures, it is not only possible to store electric energy, but also to use them as sensor systems for strain detection. This paper describes the integration of thin-film supercapacitors into a glass-fiber composite structure, as well as their analyzation under mechanical load. The results are showing that there is a strong link between the mechanical load and the impedance spectra of the supercapacitor, enabling it to act as strain sensors. To characterize the samples, a four-point bending experiment is used, which features a well-defined constant load scenario with two interesting load states, a tensile and compression state, all in one sample. On each side one structural supercapacitor is integrated, placed far away from the neutral axis near to the outside layer, to be under the highest strain possible. Additionally, the device is placed in between the middle load entry points. During the four-point bending experiment the load is kept constant to run an electrochemical impedance spectroscopy to characterize the supercapacitor. This gives an inside view of what is happening in the supercapacitor. The experiments show a strong relation between the mechanical load and the electrochemical impedance measurements.

Stored energy is the decisive factor for almost all missions in transportation systems. Additionally, the energy devices must be powerful, and lightweight at the same time for efficient performance of the overall transportation system. Due to the advancing electrification, there is a huge demand for devices to store electrical energy. Aside from batteries, which receive a great deal of scientific attention, supercapacitors are a very promising technology. This system features several advantages such as short charging time, high energy density and cycle stability. Especially the latter advantage enables a further lightweight approach by integrating supercapacitors as a thin film into composite structures. Due to their cycle stability, supercapacitors are the ideal energy device for integration into hardly accessible positions such as mechanically loadable structures. This publication deals with the strategy of structurally compliant integration of pouch supercapacitor cells (structural power composites). The aim is to operate a peak power application needed for space positioning. However, there are several properties which have to be optimized during the development of structural power composites to achieve the best possible electromechanical performance. Furthermore, there are effects which have a positive influence on the specific performance by scaling up from laboratory scale to a full-size demonstrator. In this case, integration of energy storage devices into structures offers a volume and weight reduction of up to 80% compared to a structure with commercial supercapacitors.

SummarySARS-CoV-2 mRNA vaccines induce robust anti-spike (S) antibody and CD4+ T cell responses. It is not yet clear whether vaccine-induced follicular helper CD4+ T (TFH) cell responses contribute to this outstanding immunogenicity. Using fine needle aspiration of draining axillary lymph nodes from individuals who received the BNT162b2 mRNA vaccine, we show that frequency of TFH correlates with that of S-binding germinal center B cells. Mining of the responding TFH T cell receptor repertoire revealed a strikingly immunodominant HLADPB1* 04-restricted response to S167-180 in individuals with this allele, which is among the most common HLA alleles in humans. Paired blood and lymph node specimens show that while circulating S-specific TFH cells peak one week after the second immunization, S-specific TFH persist at nearly constant frequencies for at least six months. Collectively, our results underscore the key role that robust TFH cell responses play in establishing long-term immunity by this efficacious human vaccine.

Structural, biochemical and cellular analyses show that bacterial antigens can mimic gliadin epitopes involved in celiac disease being presented by HLA-DQ2.5 and recognized by T cells derived from patients.The human leukocyte antigen (HLA) locus is strongly associated with T cell-mediated autoimmune disorders. HLA-DQ2.5-mediated celiac disease (CeD) is triggered by the ingestion of gluten, although the relative roles of genetic and environmental risk factors in CeD is unclear. Here we identify microbially derived mimics of gliadin epitopes and a parental bacterial protein that is naturally processed by antigen-presenting cells and activated gliadin reactive HLA-DQ2.5-restricted T cells derived from CeD patients. Crystal structures of T cell receptors in complex with HLA-DQ2.5 bound to two distinct bacterial peptides demonstrate that molecular mimicry underpins cross-reactivity toward the gliadin epitopes. Accordingly, gliadin reactive T cells involved in CeD pathogenesis cross-react with ubiquitous bacterial peptides, thereby suggesting microbial exposure as a potential environmental factor in CeD.

Natural fibre based composites are being used more frequently in the automotive industry because of their positive characteristics. Fibres currently used and mostly imported to Europe do not sufficiently meet all the demands for natural fibres. As a new fibre plant velvetleaf (Abutilon theophrasti) has been taken into consideration. However, there is no knowledge about the cultivation of velvetleaf in Europe. Four field trials in southwest Germany were set up to investigate the potential of fibre yield in a temperate climate. The factors crop density, nitrogen fertilization, accessions, and different harvesting dates were tested. Across all experiments fibre yield ranged from 0.4 to 1.5 t ha-1 dry matter. The highest yields were achieved with a crop density of 30 plants m-2, and with N fertilization of 100-150 kg N ha-1 for the accession ‘Herbiseed’. For highest fibre yield, the date of harvest should be at the beginning of maturity. This study provides first insights into possibility and variation of cultivating velvetleaf and suggests adequate fibre yield when cultivated in proper plant density and appropriate accession. However, before the plant can be implemented as a new crop, more research on fibre quality and breeding activity to improve agronomic factors is required.

Speeding up stomatal responses A plant's cellular metabolism rapidly adjusts to changes in light conditions, but its stomata—pores that allow gas exchange in leaves—are slower to respond. Because of the lagging response, photosynthesis is less efficient, and excess water is lost through the open pores. Papanatsiou et al. introduced a blue light–responsive ion channel into stomata of the small mustard plant Arabidopsis. The channel increased the rate of stomata opening and closing in response to light. The engineered plants produced more biomass, especially in the fluctuating light conditions typical of outdoor growth. Science , this issue p. 1456

As establishment of SARS-CoV-2-specific T cell memory in children remains largely unexplored, we recruited convalescent COVID-19 children and adults to define their circulating memory SARS-CoV-2-specific CD4+ and CD8+ T cells prior to vaccination. We analysed epitope-specific T cells directly ex vivo using seven HLA class-I and class-II tetramers presenting SARS-CoV-2 epitopes, together with Spike-specific B cells. Unvaccinated children who seroconverted had comparable spike-specific, but lower ORF1a- and N-specific memory T cell responses compared to adults. This agreed with our TCR sequencing data showing reduced clonal expansion in children. A strong stem cell memory phenotype and common T cell receptor motifs were detected within tetramer-specific T cells in seroconverted children. Conversely, children who did not seroconvert had tetramer-specific T cells of predominantly naïve phenotypes and diverse TCRαβ repertoires. Our study demonstrates generation of SARS-CoV-2-specific T cell memory with common TCRαβ motifs in unvaccinated seroconverted children after their first virus encounter.

Children are at lower risk of developing severe COVID-19, yet the underlying immune mechanisms are understudied. While children’s innate immunity can drive rapid resolution of SARS-CoV-2 infection, the establishment of SARS-CoV-2-specific T-cell and B-cell memory in COVID-19 children remains unexplored. We recruited a household cohort to understand SARS-CoV-2-specific CD4+ and CD8+ T-cell immune responses at one month after mild or asymptomatic SARS-CoV-2 infection in PCR-positive children in comparison to those found in their mothers. We analysed SARS-CoV-2-specific T-cell responses, together with B-cells, directly ex vivo using six HLA class-I tetramers and one class-II tetramer presenting SARS57 CoV-2 T-cell epitopes (A1/ORF1a1637, A2/S269, A3/N361, A24/S1208, B7/N105, B40/N322 and DPB4/S167), and Spike- and Receptor Binding Domain (RBD)-specific B-cell probes. Our in depth profiling of epitope-specific T-cell responses at quantitative, phenotypic and clonal levels found that only children who seroconverted had prominent memory T-cell and B-cell profiles. These children had a high magnitude of SARS-CoV-2-specific T-cells displaying memory phenotypes and prevalent T-cell receptor motifs, which were not observed in PCR+ RBD but IgG-negative children. This suggests that seroconversion but not PCR-positivity defines establishment of adaptive SARS-CoV-2-specific immunological memory in children. Our study suggests that COVID-19 vaccination of children could be a major advantage in terms of establishing T-cell and B-cell immunological memory, especially in children who did not seroconvert after SARS-CoV-2 infection.

Antibodies specific for peptides bound to human leukocyte antigen (HLA) molecules are valuable tools for studies of antigen presentation and may have therapeutic potential. Here, we generated human T-cell receptor (TCR)-like antibodies towards the immunodominant signature gluten epitope DQ2.5-glia-α2 in celiac disease (CeD). Phage display selection combined with secondary targeted engineering was used to obtain highly specific antibodies with picomolar affinity. The crystal structure of a Fab fragment of the lead antibody 3.C11 in complex with HLA-DQ2.5:DQ2.5-glia-α2 revealed a binding geometry and interaction mode highly similar to prototypic TCRs specific for the same complex. Assessment of CeD biopsy material confirmed disease specificity and reinforced the notion that abundant plasma cells present antigen in the inflamed CeD gut. Further, 3.C11 specifically inhibited activation and proliferation of gluten-specific CD4(+) T cells in vitro and in HLA-DQ2.5 humanized mice, suggesting a potential for targeted intervention without compromising systemic immunity. ONE SENTENCE SUMMARY: A human TCR-like antibody blocks gluten-dependent activation of celiac disease T-cells in vitro and in HLA-DQ2.5 humanized mice.

Ti(1-x)AlxN hard coatings were prepared by reactive magnetron sputtering onto steel substrates (51CrV4 – 1.8159) and subsequently exposed for a short-time (~1 s) to high-flux electron beam (EB) treatment. Morphology, composition and the structure of as-deposited and EB treated coatings were investigated using transmission electron microscopy (TEM), secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD). It was found that the EB treatment had only a minor influence on the morphology and crystallinity of the Ti(1-x)AlxN phase, however, the stress-free lattice parameter and partly the compressive stress in the coatings were clearly reduced by the treatment. On the other hand, major changes of composition profiles and structure were observed in the metallic buffer layer between substrate and Ti(1-x)AlxN. The observed modifications in the coating-substrate system are explained by rapid heat up and radiation damage due to the fast electron exposure.

The focus of the work is on the evaluation, development and integration of a robust actuator system for three-dimensional flow control of a blown Coanda flap to improve the high lift system of commercial aircraft. As part of the research work presented, the system is integrated into a wind tunnel model in order to demonstrate its functionality under aerodynamic loads. The system is based on individual bending transducers that can vary the height of the blowing slot dynamically. There are 33 actuated segments to implement static and dynamic actuation along the wing span (3D-actuation). All segments can be controlled independently and thus offer great optimization potential for an effective flow control. The first aerodynamic results show an increase in lift of up to ∆Cl = 0.57. These aerodynamic gains are achieved at amplitudes that do not require the lip segments to completely close or open the blowing slot, which shows the advantage of the current lip design that enables activation with independently controlled stationary and unsteady components.

To better understand primary and recall T cell responses during COVID-19, it is important to examine unmanipulated SARS-CoV-2-specific T cells. Using peptide-HLA tetramers for direct ex vivo analysis, we characterized CD8+ T cells specific for SARS-CoV-2 epitopes in COVID-19 patients and unexposed individuals. Unlike CD8+ T cells directed towards subdominant epitopes – B7/N257, A2/S269 and A24/S1208 – CD8+ T cells specific for the immunodominant B7/N105 epitope were detected at high frequency in pre-pandemic samples, and at increased frequency during acute COVID-19 and convalescence. SARS-CoV-2-specific CD8+ T cells in pre-pandemic samples from children, adults and elderly individuals predominantly displayed a naïve phenotype, indicating a lack of previous cross-reactive exposures. T cell receptor (TCR) analyses revealed diverse TCRαβ repertoires and promiscuous αβ-TCR pairing within B7/N105+CD8+ T cells. Our study demonstrates high naive precursor frequency and TCRαβ diversity within immunodominant B7/N105-specific CD8+ T cells, and provides insight into SARS-CoV-2-specific T cell origins and subsequent responses., Graphical Abstract, Examining unmanipulated SARS-CoV-2-specific T cells is important for understanding primary and recall responses during COVID-19. Nguyen et al. analyze ex vivo CD8+ T cells specific for SARS-CoV-2 epitopes and find that immunodominant B7/N105-specific CD8+ T cells are present at high frequencies in blood samples from unexposed, acute COVID-19, and convalescence individuals, which is underpinned by diverse TCR repertoires.