V P Conforte, J Rinaldi, H R Bonomi, A Festa, D Garacoche, S Foscaldi, E Castagnaro, A A Vojnov, F Malamud
{"title":"Xanthomonas campestris pv. campestris regulates virulence mechanisms by sensing blue light.","authors":"V P Conforte, J Rinaldi, H R Bonomi, A Festa, D Garacoche, S Foscaldi, E Castagnaro, A A Vojnov, F Malamud","doi":"10.1007/s43630-025-00694-y","DOIUrl":"https://doi.org/10.1007/s43630-025-00694-y","url":null,"abstract":"<p><p>Light is an environmental stimulus to which all living organisms are exposed. Numerous studies have shown that bacteria can modulate virulence factors through photoreceptor proteins. Xanthomonas campestris pv. campestris (Xcc) is the causative agent of the systemic vascular disease black rot, which affects cruciferous crops worldwide. Typical symptoms include V-shaped yellow lesions emanating from the leaf margins and blackening of the leaf veins. In previous work, we have shown that Xcc possesses a functional bacteriophytochrome (XccBphP) that regulates its virulence in response to red and far-red light. In addition to the XccBphP protein the Xcc genome codes for a blue light photoreceptor, a Light Oxygen Voltage (LOV) domain-containing protein with a histidine kinase (HK) as the output module. Here, we show that both photoreceptors are able to sense blue light. We demonstrated that XccLOV is a functional photoreceptor by performing loss and gain of function experiments with a knock-out and a complemented strain for the lov gene. Blue light negatively affected swimming motility, whereas xanthan production was regulated by XccBphP, in a blue light independent manner. Additionally, our studies showed that blue light altered biofilm structure patterns and enhanced virulence. Overall, these results revealed that some Xcc virulence factors are blue light modulated via at least two photoreceptors.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sunscreens in pigmentary disorders: time to revise the message.","authors":"Sahngeun Jenny Mun, Vanessa Lee, Monisha Gupta","doi":"10.1007/s43630-025-00688-w","DOIUrl":"https://doi.org/10.1007/s43630-025-00688-w","url":null,"abstract":"<p><p>Current sunscreen messaging centres around skin cancer prevention, with an emphasis on mitigating the damaging effects of ultraviolet B (UVB) radiation. Darker skin is believed to be better protected against UVB owing to its higher melanin content, and therefore, this messaging has been largely targeted at people with lighter skin tones. This is reflected by low sunscreen use by people of darker skin types. However, visible light (VL) is now being appreciated as a culprit behind exacerbation of disorders of hyperpigmentation such as melasma and post-inflammatory hyperpigmentation (PIH) which is known to significantly impair quality of life (QoL) of those affected. The role of VL in melanogenesis is not well known to patients nor to dermatologists and is a missed opportunity in the management of pigmentary disorders. We propose that changing the terminology from 'sunscreen' to 'light protection' acknowledges the central role of VL in melanogenesis, underlining the importance of VL protection and making the messaging more inclusive for people of all skin colours.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143490181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marwa Moussa, Abdessalem Hamrouni, Nawres Lazaar, Mounir Ferhi, Ichraf Chérif, Hinda Lachheb, Cláudia G Silva, Maria J Sampaio, Joaquim L Faria
{"title":"Pt-doped g-C<sub>3</sub>N<sub>4</sub> photocatalyst for simultaneous hydrogen production and value-added chemical synthesis under visible light.","authors":"Marwa Moussa, Abdessalem Hamrouni, Nawres Lazaar, Mounir Ferhi, Ichraf Chérif, Hinda Lachheb, Cláudia G Silva, Maria J Sampaio, Joaquim L Faria","doi":"10.1007/s43630-025-00683-1","DOIUrl":"https://doi.org/10.1007/s43630-025-00683-1","url":null,"abstract":"<p><p>Metal-free photocatalysts, especially through the use of semi-conductors g-C<sub>3</sub>N<sub>4</sub> (graphitic carbon nitride, CN) have become a prominent topic due to their sustainable advantages and promising effectiveness in hydrogen (H<sub>2</sub>) production. However, CN material requires specific modifications, since its efficacy under visible light suffers from fast recombination of electron/hole pairs (e<sup>‒</sup>/h<sup>+</sup>), slow charge transfer and limited surface area. In this study, we present the synthesis of CN via the thermal treatment of urea and melamine mixture. To enhance its crystallinity and photocatalytic performance, Pt nanoparticles were loaded onto CN by simple incipient wetness impregnation method. The H<sub>2</sub> production was investigated through the potential application of aromatic alcohols including anisyl (AA), benzyl (BA), piperonol (PA), and methanol (M) alcohols, as sacrificial reagents. H<sub>2</sub> production was achieved using the hybrid Pt-CN system with the added benefit of value-added organic synthesis under visible light exposure. The Pt-CN photocatalyst exhibited varying H<sub>2</sub> evolution rates on the alcohol used as sacrificial reagent, with the PA yielding to the highest rate of 503.5 µmol·g<sup>-1</sup>·h<sup>-1</sup>. Stability assessments confirmed the robustness of the synthesized Pt-CN photocatalyst across three consecutive visible light driven experiments. Notably, piperonal (P) synthesis occurred along with H<sub>2</sub> production under visible light. Comprehensive structural, textural, morphologic, optoelectronic and electrochemical characterizations were performed correlating the Pt-CN's properties with its visible photocatalytic performance.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143456482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhancing antitumour immunity with photodynamic therapy.","authors":"Pål Kristian Selbo, Mladen Korbelik","doi":"10.1007/s43630-025-00690-2","DOIUrl":"https://doi.org/10.1007/s43630-025-00690-2","url":null,"abstract":"<p><p>In this perspective, we present and discuss pre-clinical and some clinical studies demonstrating that local photodynamic therapy (PDT) per se is a treatment modality that can induce systemic anti-tumour immunity, however, the anti-tumour efficacy is strongly enhanced when PDT is combined with other treatment modalities, e.g., vaccines or ICI therapy. PDT has been recognized for over 30 years as a modality inducing strong immune effects in treated tumours. More recently, PDT has become perceived as a distinct type of immunogenic antitumor modality with an attractive potential for use as unique form of clinical cancer immunotherapy. It can be argued that PDT-inflicted tumour tissue injury provokes in situ vaccination effect. In the end of this perspective paper, we express our opinion of challenges and future directions in the field of PDT and PDT + immunotherapy.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143456476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sadin Özdemir, Derya Güngördü Solğun, Gülay Giray, Mehmet Salih Ağırtaş
{"title":"Synthesis and biological activity, photophysical, photochemical properties of tetra substituted magnesium phthalocyanine.","authors":"Sadin Özdemir, Derya Güngördü Solğun, Gülay Giray, Mehmet Salih Ağırtaş","doi":"10.1007/s43630-025-00686-y","DOIUrl":"https://doi.org/10.1007/s43630-025-00686-y","url":null,"abstract":"<p><p>The compound 4-(2-((1H-benzo[d]imidazol-2-yl) thio) phenoxy) phthalonitrile was obtained from the reaction of 2-nitrophenol, 4-nitrophthalonitrile and 2-mercaptobenzimidazole. This compound was reacted with magnesium Chloride (MgCl<sub>2</sub>) to yield tetrakis-[(2-((1H-benzo[d]imidazol-2-yl) thio) phenoxy) phthalocyaninato] magnesium II. New compounds were characterized by UV-vis, <sup>1</sup>H NMR, <sup>13</sup>C NMR, FTIR and Mass spectra. Electronic spectra aggregation study of magnesium phthalocyanine compound in various concentrations and diverse solvents was performed. Photoluminescence spectra of magnesium phthalocyanine in different solvents were investigated. The biological activities of 3 and 4 compounds were investigated. The results showed that 4 had excellent antioxidant and antidiabetic activities as 75.71% and 81.83%, respectively. 3 and 4 had deoxyribonucleic acid (DNA) cleavage ability and 4 caused a double-strand fracture in plasmid DNA at 100 and 200 mg/L. Both compounds showed antimicrobial activity and also 4 was more effective against pathogenic microorganisms than 3. Photodynamic antimicrobial therapy of test compound was also more effective than without irradiation. The highest biofilm inhibition of 3 and 4 was 78.28% and 98.49% for S. aureus and also 73.95% and 91.13% for P. aeruginosa, respectively. Finally, both compounds demonstrated %100 microbial cell viability inhibition at 100 mg/L. Overall, the study suggests that both 3 and 4 have potential for further development as therapeutic agents.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nynne Johanne Sahl Frederiksen, Ida Schwarz Thorsteinsson, Catharina Margrethe Lerche, Jonatan Riber Granborg, Merete Hædersdal, Peter Dalum, Brian Køster
{"title":"Reactions to disclosed biofeedback information on skin DNA damage in individuals after a beach holiday: a mixed methods intervention study.","authors":"Nynne Johanne Sahl Frederiksen, Ida Schwarz Thorsteinsson, Catharina Margrethe Lerche, Jonatan Riber Granborg, Merete Hædersdal, Peter Dalum, Brian Køster","doi":"10.1007/s43630-024-00677-5","DOIUrl":"https://doi.org/10.1007/s43630-024-00677-5","url":null,"abstract":"<p><strong>Background: </strong>The incidence of skin cancer among Danes is one of the highest in the world. Most skin cancers are, however, avoidable with sun protection and reduction of exposure. One way to increase awareness could be through personal biofeedback information about skin DNA damage.</p><p><strong>Objective: </strong>This study investigates the influence of biofeedback information about skin DNA damage on Danish beach holiday travelers' perception of risk of developing skin cancer and motivations for behaviour change.</p><p><strong>Methods: </strong>The intervention experiment included 20 participants aged 36-56 years, travelling to destinations with a high UV-index in February/March 2023. A new technology for detecting skin DNA damage in urine was used. Each participant was required to provide urine samples before and after travelling on holiday and participate in an interview about risk perceptions. The interviews were semi-structured and included the disclosure of DNA damage obtained during the holiday. Risk perceptions were assessed using a scale before and after the disclosure of biofeedback information.</p><p><strong>Results: </strong>We identified key elements affecting perceived susceptibility of skin cancer as well as central barriers for behaviour change. The intervention increased risk perceptions for 35% of participants, and 30% expressed intentions to adopt more sun protective practices. However, most participants' perceived susceptibility to skin cancer did not change significantly, as the DNA damage still appeared too abstract.</p><p><strong>Conclusion: </strong>The findings suggest that biofeedback information can increase risk perceptions related to skin cancer and initiate intended behaviour change for some. Larger scale studies are needed and should include quantification of the individual DNA damage thereby making the assessed risk more relatable and personally relevant.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
İsa Sıdır, Yadigar Gülseven Sıdır, Halil Berber, Rui Fausto
{"title":"Solvatochromism and cis-trans isomerism in azobenzene-4-sulfonyl chloride.","authors":"İsa Sıdır, Yadigar Gülseven Sıdır, Halil Berber, Rui Fausto","doi":"10.1007/s43630-025-00684-0","DOIUrl":"https://doi.org/10.1007/s43630-025-00684-0","url":null,"abstract":"<p><p>Solvatochromism exhibited by azobenzene-4-sulfonyl chloride (here abbreviated as Azo-SCl) has been investigated in a series of non-polar, polar-aprotic and polar-protic solvents. The UV-vis spectra of Azo-SCl exhibit two long-wavelength bands, observed at 321-330 nm (band-I) and 435-461 nm (band-II), which are ascribed to the π*-π (S<sub>2</sub> ← S<sub>0</sub>) and π*-n (S<sub>1</sub> ← S<sub>0</sub>) transitions, respectively. The shorter wavelength band indicates a reversal in solvatochromism, from negative to positive solvatochromism, for a solvent with a dielectric constant of 32.66 (which is characteristic of methanol), while the longer wavelength band signposts negative solvatochromism in all range of solvent's dielectric constant investigated, demonstrating different interactions with the solvents in the S<sub>2</sub> and S<sub>1</sub> excited states. Using Catalán and Kamlet-Taft solvation energy models, we found that the shift in the solvatochromic behavior of band-I (S<sub>2</sub> ← S<sub>0</sub>) happens because solvent dipolarity/polarizability and hydrogen bonding affect the S<sub>2</sub> state in opposite ways. Dipolarity/polarizability stabilizes the S<sub>2</sub> state compared to the ground state, while hydrogen bonding destabilizes it. In contrast, for S<sub>1</sub>, both effects work together to destabilize the excited state. For all studied solvents, UV irradiation (λ ≥ 311 nm; room temperature) was found to lead to fast trans-cis azo photoisomerization. In the absence of light, the photogenerated cis form quickly converts back to the trans form. Interpretation of the experimental data is supported by quantum chemical calculations undertaken within the Density Functional Theory (DFT) framework, including Time Dependent DFT calculations for excited states.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Photophysical behavior of meso-N-butylcarbazole-substituted BODIPY in different nano-scale organized media.","authors":"E Anjana, Iti Gupta, Ashok Kumar Mishra","doi":"10.1007/s43630-024-00678-4","DOIUrl":"10.1007/s43630-024-00678-4","url":null,"abstract":"<p><p>The present work focuses on the photophysical behavior of meso-N-butylcarbazole-substituted BODIPY (CBZ-BDP) in different organized media towards exploring the possible use of the dye as a molecular sensor and imaging agent. The molecule shows an appreciable change in absorption and emission spectra at 75% water-acetonitrile mixture compared to pure acetonitrile. In water-acetonitrile mixture, it displays aggregate-induced emission (AIE) bands. New emission peaks are observed at 560 nm and 630 nm, corresponding to LE (locally excited) and ICT (intramolecular charge transfer) states of CBZ-BDP aggregates. The fluorescence anisotropy studies of CBZ-BDP in glycerol medium show its better sensitivity towards the microenvironment. CBZ-BDP was used to probe various microheterogeneous systems like bile salts, pluronics, and lipid bilayer systems in aqueous medium. The dye displays sensitive variation in emission intensity and fluorescence anisotropy in sodium cholate (NaC) bile salt in aqueous medium as a function of the bile salt concentration. The molecule detects the temperature-induced phase transitions in pluronic P123 and F127, as well as 1,2-dimyristoylphosphatidylcholine (DMPC) and 1,2-dipalmitoylphosphatidylcholine (DPPC) lipid bilayer systems in aqueous medium. These studies strongly suggest that CBZ-BDP can be used as an efficient fluorescent probe in sensing the micro-environmental changes in bile salts, pluronics, and lipid bilayers in aqueous medium. The imaging studies of CBZ-BDP-embedded Giant Unilamellar Vesicles (GUVs) were carried out. The molecule stains the lipid bilayers and displays bright-green fluorescent images, suggesting its potential in lipid bilayer imaging.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":"131-147"},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142870584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"21<sup>st</sup> century surface UV radiation changes deduced from CMIP6 models: part I-evolution of major influencing factors.","authors":"A Chatzopoulou, K Tourpali, A F Bais, P Braesicke","doi":"10.1007/s43630-024-00675-7","DOIUrl":"10.1007/s43630-024-00675-7","url":null,"abstract":"<p><p>For a given solar elevation, the levels of solar ultraviolet radiation at the Earth's surface are determined by the amounts of ozone, aerosols, and clouds, as well as by the reflectivity of the surface. Here, we study the evolution of these factors for three selected decades in the period 1950-2100 using results from simulations with Earth-System models (ESMs) participating in the 6<sup>th</sup> phase of the Coupled Model Intercomparison Project (CMIP6). The simulations for the future are based on three Shared Socioeconomic Pathways: SSP1-2.6, SSP3-7.0, and SSP5-8.5. The models were grouped according to whether they use prescribed ozone fields or interactive chemistry schemes for ozone, revealing significant differences in the absolute levels and variability of total ozone column between the two groups of models. From mid-twenty-first century onward, the ozone recovery is evident in both groups under SSP3-7.0 and SSP5-8.5, but not under SSP1-2.6. The changes in the aerosol optical depth show distinct geographical patterns that are related to their sources, either natural (i.e., dust, biomass burning) or anthropogenic (industrial activities). The aerosols are generally more abundant in 1990-2000 compared to 1950-1960, particularly over regions with industrial activity, with a reversal of this pattern in 2090-2100. Most of these patterns are present in all three pathways, but with different signs compared to 1990-2000 in some regions (i.e., Europe, North America). Over areas with strong natural sources, the aerosol optical depth (AOD) in 2090-2100 increases further under all pathways. The changes in surface reflectivity are important mainly at the end of the twenty-first century and occur predominantly at the high and polar latitudes of both hemispheres, with reductions relative to 1950-1960 of up to 45% due to sea ice retreat. The alterations in the attenuation of shortwave solar radiation by changing cloudiness (expressed in the form of the cloud modification factor, CMF) are more evident at high latitudes, with decreases in 2090-2100 over the Arctic ranging from -5% (SSP1-2.6) to -13% (SSP5-8.5) and smaller decreases of up to -5% in the vicinity of the Antarctic coast. The simulations of ozone, aerosols, surface reflectivity, and clouds for the recent past (2003-2012) were compared to the Copernicus Atmosphere Monitoring Service (CAMS) reanalysis data, showing for total ozone better agreement to models with interactive ozone chemistry. The model-derived AOD shows significant differences from CAMS in various regions worldwide, with up to 0.2 higher values across the northern hemisphere. Finally, the comparisons for surface reflectivity and cloud effects οn this decadal scale reveal a general agreement between models and observations over most of the globe. Thus, we conclude that the projected changes have a good basis in the recent past, suggesting they are realistic estimates of how factors influencing solar ultraviolet radiation may diffe","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":"89-109"},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142930005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Margaret S Clark, Michael Christie, Melinda Jones, Sarah Ashley, Mimi L K Tang
{"title":"Seasonal variation in sunlight exposure is differently associated with changes in T regulatory and T-helper 17 cell blood counts in adolescent and adults females: a pilot study.","authors":"Margaret S Clark, Michael Christie, Melinda Jones, Sarah Ashley, Mimi L K Tang","doi":"10.1007/s43630-024-00668-6","DOIUrl":"10.1007/s43630-024-00668-6","url":null,"abstract":"<p><p>Higher prevalence of multiple sclerosis at higher latitudes is associated with reduced sunlight during childhood. Alterations in inflammatory Th17 and regulatory T cells (Treg) are associated with autoimmunity. In Hobart, Australia (latitude 42.8° south), thirteen girls (aged 12-13) and sixteen women had blood collected in the evening in daylight in February/March, (post 15 h daylight) and at the same time in the dark in August/September (post 9 h daylight). Height and weight were measured. Participants completed online surveys prior around menstruation, sleep, exercise and time outside. Proportions of Th17 (CD4 + , CXCR3-, CCR4 + , CCR6 + , CD161 +), total Treg (CD4 + , CD25 + , CD127low), naïve Treg (CD45RA + , CD4 + , CD25 + , CD127low) and memory Treg (CD45RA low, CD4 + , CD25 + , CD127low) were enumerated by flow cytometry (Cytek Aurora). Hours spent outside was greater in summer than winter (12.5 v 10.5, p = 0.0003). The %Treg/CD4 + was higher in summer than winter (7.3% vs 7%, p = 0.004) including memory Treg (3.1% vs 2.9%, p = 0.02) for all females (n = 29), and naïve Treg were 13% higher in summer in women (3.2% vs 2.8%, p = 0.0009), whereas %Th17 remained unchanged. In women, a negative correlation between the number of hours spent outside in summer and %Th17 was observed (r = - 0.53, p = 0.035). The %Th17 cells were higher in women than girls (4.9% vs 3.1%, p = 0.001), whereas girls had a higher total %Treg (7.6% vs 6.7%, p = 0.005), consisting of a higher naïve Treg (5.5% vs 3.7%, p = 0.0001) while the women had a higher %memory Treg (3.4% vs 2.6%, p = 0.0001). These light-dependent seasonal differences may influence immune development in adolescents.</p>","PeriodicalId":98,"journal":{"name":"Photochemical & Photobiological Sciences","volume":" ","pages":"23-35"},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142794035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}