Assessing the impact of mRNA vaccination in chronic inflammatory murine model

Bruno A., Buttari F., Dolcetti E., Azzolini F., Borrelli A., Lauritano G., Di Caprio V., Rizzo F.R., Gilio L., Galifi G., Furlan R., Finardi A., Guadalupi L., Musella A., Mandolesi G., et. al.

Background: The role of vaccine-mediated inflammation in exacerbating multiple sclerosis (MS) is a matter of debate. Objective: In this cross-sectional study, we compared the cerebrospinal fluid (CSF) inflammation associated with MS relapses or anti-COVID-19 mRNA vaccinations in relapsing-remitting multiple sclerosis (RRMS). Methods: We dosed CSF cytokines in 97 unvaccinated RRMS patients with clinical relapse within the last 100 days. In addition, we enrolled 29 stable RRMS and 24 control patients receiving COVID-19 vaccine within the last 100 days. Results: In RRMS patients, a negative association was found between relapse distance and the CSF concentrations of the pro-inflammatory cytokines interleukin (IL)-2 (beta = −0.265, p = 0.016), IL-6 (beta = −0.284, p = 0.01), and IL-17 (beta = −0.224, p = 0.044). Conversely, vaccine distance positively correlated with a different set of cytokines including IL-12 (beta = 0.576, p = 0.002), IL-13 (beta = 0.432, p = 0.027), and IL-1ra (beta = 0.387, p = 0.05). These associations were significant also considering other clinical characteristics. No significant associations emerged between vaccine distance and CSF molecules in the control group. Conclusion: Vaccine for COVID-19 induces a central inflammatory response in RRMS patients that is qualitatively different from that associated with disease relapse.

Park H., Bang Y., Kwon S.P., Kwak W., Park S., Roh G., Bae S., Kim J., Kwak H.W., Kim Y., Yoo S., Kim D., Keum G., Bang E., Hong S., et. al.

AbstractIn response to the COVID-19 pandemic, different types of vaccines, such as inactive, live-attenuated, messenger RNA (mRNA), and protein subunit, have been developed against SARS-CoV-2. This has unintentionally created a unique scenario where heterologous prime-boost vaccination against a single virus has been administered to a large human population. Here, we aimed to analyze whether the immunization order of vaccine types influences the efficacy of heterologous prime-boost vaccination, especially mRNA and protein-based vaccines. We developed a new mRNA vaccine encoding the hemagglutinin (HA) glycoprotein of the influenza virus using the 3′-UTR and 5′-UTR of muscle cells (mRNA-HA) and tested its efficacy by heterologous immunization with an HA protein vaccine (protein-HA). The results demonstrated higher IgG2a levels and hemagglutination inhibition titers in the mRNA-HA priming/protein-HA boosting (R-P) regimen than those induced by reverse immunization (protein-HA priming/mRNA-HA boosting, P-R). After the viral challenge, the R-P group showed lower virus loads and less inflammation in the lungs than the P-R group did. Transcriptome analysis revealed that the heterologous prime-boost groups had differentially activated immune response pathways, according to the order of immunization. In summary, our results demonstrate that the sequence of vaccination is critical to direct desired immune responses. This study demonstrates the potential of a heterologous vaccination strategy using mRNA and protein vaccine platforms against viral infection.

Ong E.Z., Koh C.W., Tng D.J., Ooi J.S., Yee J.X., Chew V.S., Leong Y.S., Gunasegaran K., Yeo C.P., Oon L.L., Sim J.X., Chan K.R., Low J.G., Ooi E.E.

Post-mRNA vaccination-associated cardiac complication is a rare but life-threatening adverse event. Its risk has been well balanced by the benefit of vaccination-induced protection against severe COVID-19. As the rate of severe COVID-19 has consequently declined, future booster vaccination to sustain immunity, especially against infection with new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, may encounter benefit-risk ratios that are less favorable than at the start of the COVID-19 vaccination campaign. Understanding the pathogenesis of rare but severe vaccine-associated adverse events to minimize its risk is thus urgent.Here, we report a serendipitous finding of a case of cardiac complication following a third shot of COVID-19 mRNA vaccine. As this case was enrolled in a cohort study, pre-vaccination and pre-symptomatic blood samples were available for genomic and multiplex cytokine analyses.These analyses revealed the presence of subclinical chronic inflammation, with an elevated expression of RNASE2 at pre-booster baseline as a possible trigger of an acute-on-chronic inflammation that resulted in the cardiac complication. RNASE2 encodes for the ribonuclease RNase2, which cleaves RNA at the 3' side of uridine, which may thus remove the only Toll-like receptor (TLR)-avoidance safety feature of current mRNA vaccines.These pre-booster and pre-symptomatic gene and cytokine expression data provide unique insights into the possible pathogenesis of vaccine-associated cardiac complication and suggest the incorporation of additional nucleoside modification for an added safety margin.This work was funded by the NMRC Open Fund-Large Collaborative Grant on Integrated Innovations on Infectious Diseases (OFLCG19May-0034).

Yonker L.M., Swank Z., Bartsch Y.C., Burns M.D., Kane A., Boribong B.P., Davis J.P., Loiselle M., Novak T., Senussi Y., Cheng C., Burgess E., Edlow A.G., Chou J., Dionne A., et. al.

BACKGROUND: Cases of adolescents and young adults developing myocarditis after vaccination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–targeted mRNA vaccines have been reported globally, but the underlying immunoprofiles of these individuals have not been described in detail. METHODS: From January 2021 through February 2022, we prospectively collected blood from 16 patients who were hospitalized at Massachusetts General for Children or Boston Children’s Hospital for myocarditis, presenting with chest pain with elevated cardiac troponin T after SARS-CoV-2 vaccination. We performed extensive antibody profiling, including tests for SARS-CoV-2–specific humoral responses and assessment for autoantibodies or antibodies against the human-relevant virome, SARS-CoV-2–specific T-cell analysis, and cytokine and SARS-CoV-2 antigen profiling. Results were compared with those from 45 healthy, asymptomatic, age-matched vaccinated control subjects. RESULTS: Extensive antibody profiling and T-cell responses in the individuals who developed postvaccine myocarditis were essentially indistinguishable from those of vaccinated control subjects, despite a modest increase in cytokine production. A notable finding was that markedly elevated levels of full-length spike protein (33.9±22.4 pg/mL), unbound by antibodies, were detected in the plasma of individuals with postvaccine myocarditis, whereas no free spike was detected in asymptomatic vaccinated control subjects (unpaired t test; P <0.0001). CONCLUSIONS: Immunoprofiling of vaccinated adolescents and young adults revealed that the mRNA vaccine–induced immune responses did not differ between individuals who developed myocarditis and individuals who did not. However, free spike antigen was detected in the blood of adolescents and young adults who developed post-mRNA vaccine myocarditis, advancing insight into its potential underlying cause.

Zirkenbach V.A., Ignatz R.M., Öttl R., Cehreli Z., Stroikova V., Kaya M., Lehmann L.H., Preusch M.R., Frey N., Kaya Z.

In the course of the SARS-CoV-2 pandemic, vaccination safety and risk factors of SARS-CoV-2 mRNA-vaccines were under consideration after case reports of vaccine-related side effects, such as myocarditis, which were mostly described in young men. However, there is almost no data on the risk and safety of vaccination, especially in patients who are already diagnosed with acute/chronic (autoimmune) myocarditis from other causes, such as viral infections, or as a side effect of medication and treatment. Thus, the risk and safety of these vaccines, in combination with other therapies that could induce myocarditis (e.g., immune checkpoint inhibitor (ICI) therapy), are still poorly assessable. Therefore, vaccine safety, with respect to worsening myocardial inflammation and myocardial function, was studied in an animal model of experimentally induced autoimmune myocarditis. Furthermore, it is known that ICI treatment (e.g., antibodies (abs) against PD-1, PD-L1, and CTLA-4, or a combination of those) plays an important role in the treatment of oncological patients. However, it is also known that treatment with ICIs can induce severe, life-threatening myocarditis in some patients. Genetically different A/J (most susceptible strain) and C57BL/6 (resistant strain) mice, with diverse susceptibilities for induction of experimental autoimmune myocarditis (EAM) at various age and gender, were vaccinated twice with SARS-CoV-2 mRNA-vaccine. In an additional A/J group, an autoimmune myocarditis was induced. In regard to ICIs, we tested the safety of SARS-CoV-2 vaccination in PD-1−/− mice alone, and in combination with CTLA-4 abs. Our results showed no adverse effects related to inflammation and heart function after mRNA-vaccination, independent of age, gender, and in different mouse strains susceptible for induction of experimental myocarditis. Moreover, there was no worsening effect on inflammation and cardiac function when EAM in susceptible mice was induced. However, in the experiments with vaccination and ICI treatment, we observed, in some mice, low elevation of cardiac troponins in sera, and low scores of myocardial inflammation. In sum, mRNA-vaccines are safe in a model of experimentally induced autoimmune myocarditis, but patients undergoing ICI therapy should be closely monitored when vaccinated.

Mohammadian Khonsari N., Baygi F., Tabatabaei-Malazy O., Mohammadpoor Nami S., Ehsani A., Asadi S., Qorbani M.

BackgroundIndividuals with normal weight could suffer from obesity based on their body fat percentage (also known as normal weight obesity (NWO)), thus being at risk of significant morbidity and mortality compared to the general population. It seems that inflammatory pathways and chronic inflammation are significant contributors to the pathogenicity of NWO. This study aimed to assess and pool the association of proinflammatory and anti-inflammatory cytokines with NWO.MethodsIn this systematic review and meta-analysis, online international databases (PubMed, Scopus, EMBASE, Web of Science, and Google Scholar) were searched until August 2022. All observational studies with an English full text comparing the mean levels of proinflammatory and anti-inflammatory cytokines (e.g., C-reactive protein (CRP), various types of interleukins (IL) s, tumor necrosis factor-alpha (TNF)) and white blood cell (WBC) count, in subjects with NWO and “normal weight non-obese (NWNO)” were included. Two researchers independently screened, reviewed and assessed the quality of included studies. The remaining articles’ data were extracted post-screening. The heterogeneity between studies was assessed using the I2 and Cochran’s Q tests. A random effect model meta-analysis was used to pool the standardized mean difference (SMD) as an effect size.ResultsFrom the initial 559 studies, 21 and 19 were included in the qualitative and quantitative synthesis, respectively. In the systematic review, 8 studies reported a significant association between various proinflammatory cytokines (CRP, IL6, IL1β, and TNFα) and NWO. According to random-effect meta-analysis, the association between NWO with CRP (SMD: 0.60, 95% CI: 0.30, 0.91) and IL6 (SMD: 0.90, 95%CI: 0.14, 1.66) was statistically significant. Moreover, the mean level of TNFα in subjects with NWO and NWNO did not differ significantly (SMD: 0.67, 95% CI: -0.36, 1.70).ConclusionThe findings of this study show that NWO was associated with high levels of CRP and IL6. Therefore, inflammatory pathways may play a role in the pathogenicity of NWO.

Morikawa M.M., Harada M., Kishimoto E., Suzuki K., Nakagawa E., Hiramatsu T., Nakai S., Murakami Y., Nishimoto K., Matsushima S., Uto T., Imokawa S.

The relationship between rheumatoid arthritis (RA) and eosinophilic inflammation is unclear. According to recent studies, it has been suggested that T helper 2 cell responses play a role in the inhibition of RA. It is unclear how the immunological response after coronavirus disease-2019 (COVID-19) vaccination affects T cell immune reactions.Here, we report the case of an 88-year-old woman diagnosed with RA and chronic eosinophilic pneumonia (CEP). She was diagnosed with CEP about 20 years ago, and, through steroid treatment, she improved and had no relapse for 16 years. At the time of diagnosis of CEP, the rheumatoid factor (RF) was increased; however, there were no joint symptoms. After receiving the COVID-19 vaccine, joint and respiratory symptoms gradually worsened. Laboratory examinations showed increased RF, anti-cyclin citrullinated peptide antibody, and peripheral absolute eosinophil count. Musculoskeletal ultrasonography showed synovitis.Methylprednisolone pulse therapy improved respiratory and joint symptoms immediately; RA and CEP stabilized with no relapses.Eosinophilic and rheumatoid reactions following COVID-19 vaccination were an-reported adverse events. Eosinophilic inflammation might be reflected on an anti-inflammatory reaction in initial phase of RA.

Faizo A.A., Qashqari F.S., El‐Kafrawy S.A., Barasheed O., Almashjary M.N., Alfelali M., Bawazir A.A., Albarakati B.M., Khayyat S.A., Hassan A.M., Alandijany T.A., Azhar E.I.

Due to the adverse effects of obesity on host immunity, this study investigated the effectiveness of COVID-19 vaccines (BNT162b2, ChAdOx-nCov-2019, and mRNA-1273) in inducing anti-SARS-CoV-2 Spike (S) neutralizing antibodies among individuals with various obesity classes (class I, II, III, and super obesity). Sera from vaccinated obese individuals (n = 73) and normal BMI controls (n = 46) were subjected to S-based enzyme-linked immunosorbent assay (ELISA) and serum-neutralization test (SNT) to determine the prevalence and titer of anti-SARS-CoV-2 neutralizing antibodies. Nucleocapsid-ELISA was also utilized to distinguish between immunity acquired via vaccination only versus vaccination plus recovery from infection. Data were linked to participant demographics including age, gender, past COVID-19 diagnosis, and COVID-19 vaccination profile. S-based ELISA demonstrated high seroprevalence rates (>97%) in the study and control groups whether samples with evidence of past infection were included or excluded. Interestingly, however, SNT demonstrated a slightly significant reduction in both the rate and titer of anti-SARS-CoV-2 neutralizing antibodies among vaccinated obese individuals (60/73; 82.19%) compared to controls (45/46; 97.83%). The observed reduction in COVID-19 vaccine-induced neutralizing humoral immunity among obese individuals occurs independently of gender, recovery from past infection, and period from last vaccination. Our data suggest that COVID-19 vaccines are highly effective in inducing protective humoral immunity. This effectiveness, however, is potentially reduced among obese individuals which highlight the importance of booster doses to improve their neutralizing immunity. Further investigations on larger sample size remain necessary to comprehensively conclude about the effect of obesity on COVID-19 vaccine effectiveness on humoral immunity induction.

Yang M.M., Taylor K.E., Paez D., Carividi A., Demissie E., Pawar N., El‐Qunni A.A., McMorrow L.E., Schriefer R.E., Huang K., Kinnett B., Klebert M., Haile A., O'Halloran J.A., Presti R.M., et. al.

Objective Little is known regarding the reactogenicity and related SARS–CoV-2 vaccine response in patients with chronic inflammatory disease (CID). Our objective was to characterize the adverse event profile of CID patients following SARS–CoV-2 vaccination and understand the relationship between reactogenicity and immunogenicity of SARS–CoV-2 vaccines. Methods CID patients and healthy controls eligible to receive messenger RNA (mRNA) SARS–CoV-2 vaccines participated in 3 study visits (pre-vaccine, after dose 1, and after dose 2) in which blood and clinical data were collected. Assessment of adverse events were solicited within 7 days of receiving each dose. Serum anti–SARS–CoV-2 spike IgG ± antibody titers were quantified following vaccination. Statistical analysis was performed utilizing mixed models and tobit regressions, with adjustment for covariates. Results The present study included 441 participants (322 CID patients and 119 control subjects). Compared to controls, CID patients reported greater symptom severity after dose 1 (P = 0.0001), including more myalgia and fatigue (P < 0.05). For immunogenicity, a higher symptom severity after dose 1 and a higher number of symptoms after dose 2 was associated with higher antibody titers (P ≤ 0.05). Each increase of 1 symptom was associated with a 15.1% increase in antibody titer. Symptom association was strongest with site pain after dose 1 (105%; P = 0.03) and fatigue after dose 2 (113%; P = 0.004). Conclusion Patients with CID have a distinct reactogenicity profile following SARS–CoV-2 vaccination compared to controls. Furthermore, there is an association between increased reactogenicity and increased vaccine response. This finding may speak to the more variable immunogenicity in CID patients and may be an important indicator of vaccine response to the novel SARS–CoV-2 vaccines.

Zöphel D., Angenendt A., Kaschek L., Ravichandran K., Hof C., Janku S., Hoth M., Lis A.

A variety of intrinsic and extrinsic factors contribute to the altered efficiency of CTLs in elderly organisms. In particular, the efficacy of antiviral CD8+ T cells responses in the elderly has come back into focus since the COVID-19 pandemic outbreak. However, the exact molecular mechanisms leading to alterations in T cell function and the origin of the observed impairments have not been fully explored. Therefore, we investigated whether intrinsic changes affect the cytotoxic ability of CD8+ T cells in aging. We focused on the different subpopulations and time-resolved quantification of cytotoxicity during tumor cell elimination. We report a surprising result: Killing kinetics of CD8+ T cells from elderly mice are much faster than those of CD8+ T cells from adult mice. This is true not only in the total CD8+ T cell population but also for their effector (TEM) and central memory (TCM) T cell subpopulations. TIRF experiments reveal that CD8+ T cells from elderly mice possess comparable numbers of fusion events per cell, but significantly increased numbers of cells with granule fusion. Analysis of the cytotoxic granule (CG) content shows significantly increased perforin and granzyme levels and turns CD8+ T cells of elderly mice into very efficient killers. This highlights the importance of distinguishing between cell-intrinsic alterations and microenvironmental changes in elderly individuals. Our results also stress the importance of analyzing the dynamics of CTL cytotoxicity against cancer cells because, with a simple endpoint lysis analysis, cytotoxic differences could have easily been overlooked.

Esposito S., Caminiti C., Giordano R., Argentiero A., Ramundo G., Principi N.

Myocarditis (MYO) is a relatively uncommon inflammatory disease that involves the heart muscle. It can be a very severe disease as it can lead to the development of acute or chronic heart failure and, in a not marginal number of cases, to death. Most of the cases are diagnosed in healthy people younger than 30 years of age. Moreover, males are affected about twice as much as females. Viruses are among the most common causes of MYO, but how viral infection can lead to MYO development is not precisely defined. After COVID-19 pandemic declaration, incidence rate of MYO has significantly increased worldwide because of the SARS-CoV-2 infection. After the introduction of anti-COVID-19 vaccines, reports of post-immunization MYO have emerged, suggesting that a further cause of MYO together with the SARS-CoV-2 infection could increase the risk of heart damage during pandemic. Main aim of this study is to discuss present knowledge regarding etiopathogenesis and clinical findings of MYO associated with COVID-19 vaccine administration and whether the risk of this adverse events can modify the initially suggested recommendation for the use of COVID-19 vaccines in pediatric age. Literature analysis showed that MYO is an adverse event that can follow the COVID-19 immunization with mRNA vaccines in few persons, particularly young adults, adolescents, and older children. It is generally a mild disease that should not modify the present recommendations for immunization with the authorized COVID-19 mRNA vaccines. Despite this, further studies are needed to evaluate presently undefined aspects of MYO development after COVID-19 vaccine administration and reduce the risk of development of this kind of vaccine complication. Together with a better definition of the true incidence of MYO and the exact role of the various factors in conditioning incidence variations, it is essential to establish long-term evolution of acute COVID-19 related MYO.

Kimura M., Niwa J., Doyu M.

Rhabdomyolysis is a well-known clinical syndrome of muscle injury. Rhabdomyolysis following coronavirus disease 2019 (COVID-19) vaccination has recently been reported. The patients’ weakness gradually subsided and did not recur. Rhabdomyolysis associated with COVID-19 vaccination has not been assessed by repeated magnetic resonance imaging (MRI) within a short time. We report a rare case of an older woman who developed recurring weakness with rhabdomyolysis after COVID-19 vaccination. A 76-year-old woman presented with myalgia 2 days after receiving a third dose of the COVID-19 vaccine. A physical examination showed weakness of the bilateral iliopsoas muscles. Her creatine kinase concentration was 9816 U/L. MRI showed hyperintensity of multiple limb muscles. She was treated with intravenous normal saline. Her symptoms disappeared within 3 days. However, MRI on day 4 of hospitalization showed exacerbation of the hyperintensity in the left upper limb muscles. On day 5 of hospitalization, weakness of the left supraspinatus and deltoid muscles appeared. MRI on day 8 of hospitalization showed attenuation of the hyperintensity in all muscles. Her weakness and elevated creatine kinase concentration disappeared by day 10. Repeated MRI over a short time may be useful to predict potential weakness and monitor the course of COVID-19 vaccine-induced rhabdomyolysis.

Fraser M., Agdamag A.C., Maharaj V.R., Mutschler M., Charpentier V., Chowdhury M., Alexy T.

The direct and indirect adverse effects of SARS-CoV-2 infection on the cardiovascular system, including myocarditis, are of paramount importance. These not only affect the disease course but also determine clinical outcomes and recovery. In this review, the authors aimed at providing an update on the incidence of Coronavirus disease-2019 (COVID-19)-associated myocarditis. Our knowledge and experience relevant to this area continues to evolve rapidly since the beginning of the pandemic. It is crucial for the scientific and medical community to stay abreast of current information. Contrasting early reports, recent data suggest that the overall incidence of SARS-CoV-2-associated myocarditis is relatively low, yet infected individuals are at a substantially increased risk. Therefore, understanding the pathophysiology and diagnostic evaluation, including the use of serum biomarkers and imaging modalities, remain important. This review aims to summarize the most recent data in these areas as they relate to COVID-19-associated myocarditis. Given its increasing relevance, a brief update is included on the proposed mechanisms of myocarditis in COVID-19 vaccine recipients.

Baek M., Cho H., Min D.S., Choi C.S., Yoon M.

Muscle regeneration includes proliferation and differentiation of muscle satellite cells, which involves the mammalian target of rapamycin (mTOR). We identified the C-terminal unique attached sequence motif (UNE) domain of leucyl-tRNA synthetase (LRS-UNE-L) as an mTORC1 (mTOR complex1)-activating domain that acts through Vps34 and phospholipase D1 (PLD1) when introduced in the form of a muscle-enhancing peptide.In vitro Vps34 lipid kinase assay, phosphatidylinositol 3-phosphate (PI(3)P) measurement, in vivo PLD1 assay, and western blot assay were performed in HEK293 cells to test the effect of the LRS-UNE-L on the Vps34-PLD1-mTOR pathway. Adeno-associated virus (AAV)-LRS-UNE-L was transduced in C2C12 cells in vitro, in BaCl2 -injured tibialis anterior (TA) muscles, and in 18-month-old TA muscles to analyse its effect on myogenesis, muscle regeneration, and aged muscle, respectively. The muscle-specific cell-permeable peptide M12 was fused with LRS-UNE-L and tested for cell integration in C2C12 and HEK293 cells using FACS analysis and immunocytochemistry. Finally, M12-LRS-UNE-L was introduced into BaCl2 -injured TA muscles of 15-week-old Pld1+/+ or Pld1-/- mice, and its effect was analysed by measurement of cross-sectional area of regenerating muscle fibres.The LRS-UNE-L expression restored amino acid-induced S6K1 phosphorylation in LRS knockdown cells in a RagD GTPases-independent manner (421%, P = 0.007 vs. LRS knockdown control cells). The LRS-UNE-L domain was directly bound to Vps34; this interaction was accompanied by increases in Vps34 activity (166%, P = 0.0352), PI(3)P levels (146%, P = 0.0039), and PLD1 activity (228%, P = 0.0294) compared with amino acid-treated control cells, but it did not affect autophagic flux. AAV-delivered LRS-UNE-L domain augmented S6K1 phosphorylation (174%, P = 0.0013), mRNA levels of myosin heavy chain (MHC) (122%, P = 0.0282) and insulin-like growth factor 2 (IGF2) (146%, P = 0.008), and myogenic fusion (133%, P = 0.0479) in C2C12 myotubes. AAV-LRS-UNE-L increased the size of regenerating muscle fibres in BaCl2 -injured TA muscles (124%, P = 0.0279) (n = 9-10), but it did not change the muscle fibre size of TA muscles in old mice. M12-LRS-UNE-L was preferentially delivered into C2C12 cells compared with HEK293 cells and augmented regeneration of BaCl2 -injured TA muscles in a PLD1-dependent manner (116%, P = 0.0022) (n = 6).Our results provide compelling evidence that M12-LRS-UNE-L could be a muscle-enhancing protein targeting mTOR.

Rohm T.V., Meier D.T., Olefsky J.M., Donath M.Y.

Obesity leads to chronic, systemic inflammation and can lead to insulin resistance (IR), β-cell dysfunction, and ultimately type 2 diabetes (T2D). This chronic inflammatory state contributes to long-term complications of diabetes, including non-alcoholic fatty liver disease (NAFLD), retinopathy, cardiovascular disease, and nephropathy, and may underlie the association of type 2 diabetes with other conditions such as Alzheimer's disease, polycystic ovarian syndrome, gout, and rheumatoid arthritis. Here, we review the current understanding of the mechanisms underlying inflammation in obesity, T2D, and related disorders. We discuss how chronic tissue inflammation results in IR, impaired insulin secretion, glucose intolerance, and T2D and review the effect of inflammation on diabetic complications and on the relationship between T2D and other pathologies. In this context, we discuss current therapeutic options for the treatment of metabolic disease, advances in the clinic and the potential of immune-modulatory approaches.

Li H., Hu Y., Li J., He J., Yu G., Wang J., Lin X.

Abstract The rapid success of RNA vaccines in preventing SARS-CoV-2 has sparked interest in their use for cancer immunotherapy. Although many cancers originate in mucosal tissues, current RNA cancer vaccines are mainly administered non-mucosally. Here, we developed a non-invasive intranasal cancer vaccine utilizing circular RNA encapsulated in lipid nanoparticles to induce localized mucosal immune responses. This strategy elicited potent anti-tumor T cell responses in preclinical lung cancer models while mitigating the systemic adverse effects commonly associated with intravenous RNA vaccination. Specifically, type 1 conventional dendritic cells were indispensable for T cell priming post-vaccination, with both alveolar macrophages and type 1 conventional dendritic cells boosting antigen-specific T cell responses in lung tissues. Moreover, the vaccination facilitated the expansion of both endogenous and adoptive transferred antigen-specific T cells, resulting in robust anti-tumor efficacy. Single-cell RNA sequencing revealed that the vaccination reprograms endogenous T cells, enhancing their cytotoxicity and inducing a memory-like phenotype. Additionally, the intranasal vaccine can modulate the response of CAR-T cells to augment therapeutic efficacy against tumor cells expressing specific tumor-associated antigens. Collectively, the intranasal RNA vaccine strategy represents a novel and promising approach for developing RNA vaccines targeting mucosal malignancies.

Kawai A., Shimizu T., Tanaka H., Shichinohe S., Anindita J., Hirose M., Kawahara E., Senpuku K., Shimooka M., Quynh Mai L.T., Suzuki R., Nogimori T., Yamamoto T., Hirai T., Kato T., et. al.

Byun K., Seo S.B., Oh S., Jang J., Son K.H., Byun K.

Poly-D,L-lactic acid (PDLLA) filler, which increases volume and collagen synthesis, is used for skin rejuvenation. PDLLA filler also increases M2 macrophages and IL-10. Ultraviolet (UV) radiation induces dermal hyperpigmentation by disrupting the basement membrane (BM), allowing melanin to move into the dermis. Therefore, using UV-irradiated macrophages and animal skin, we determined whether PDLLA filler decreased M1 macrophages and skin inflammation, thereby reducing BM destruction and dermal hyperpigmentation. UV radiation increased the M1 macrophage marker CD86 and TNF-α expression, which was inhibited by the treatment of macrophages with PDLLA. In fibroblasts treated with conditioned medium from UV-irradiated macrophages, NF-κB activity, NLRP3 inflammasome components (NLRP3, ASC, and pro-caspase-1), IL-18, MMP2, and MMP9 increased, but all decreased after PDLLA treatment. Similar to the in vitro study, UV-irradiated mouse skin showed increased CD86, NLRP3, ASC, pro-caspase-1, MMP2, and MMP9, which decreased after PDLLA injection. Disruption of the lamina densa of the BM and dermal pigmentation increased after UV irradiation and decreased after PDLLA injection. In conclusion, PDLLA reduced dermal pigmentation by decreasing BM destruction in UV-irradiated skin. PDLLA has the potential to reduce dermal pigmentation by regenerating the BM.

Parvin N., Mandal T.K., Joo S.

The COVID-19 pandemic has significantly accelerated progress in RNA-based therapeutics, particularly through the successful development and global rollout of mRNA vaccines. This review delves into the transformative impact of the pandemic on RNA therapeutics, with a strong focus on lipid nanoparticles (LNPs) as a pivotal delivery platform. LNPs have proven to be critical in enhancing the stability, bioavailability, and targeted delivery of mRNA, facilitating the unprecedented success of vaccines like those developed by Pfizer-BioNTech and Moderna. Beyond vaccines, LNP technology is being explored for broader therapeutic applications, including treatments for cancer, rare genetic disorders, and infectious diseases. This review also discusses emerging RNA delivery systems, such as polymeric nanoparticles and viral vectors, which offer alternative strategies to overcome existing challenges related to stability, immune responses, and tissue-specific targeting. Additionally, we examine the pandemic’s influence on regulatory processes, including the fast-tracked approvals for RNA therapies, and the surge in research funding that has spurred further innovation in the field. Public acceptance of RNA-based treatments has also grown, laying the groundwork for future developments in personalized medicine. By providing an in-depth analysis of these advancements, this review highlights the long-term impact of COVID-19 on the evolution of RNA therapeutics and the future of precision drug delivery technologies.

Eens S., Van Hecke M., Van den Bogaert S., Favere K., Cools N., Fransen E., Roskams T., Heidbuchel H., Guns P.

Batsukh S., Oh S., Lee J.M., Joo J.H., Son K.H., Byun K.

Plant-derived extracellular vesicles (EVs) elicit diverse biological effects, including promoting skin health. EVs isolated from Ecklonia cava (EV-EC) carry heat shock protein 70 (HSP70), which inhibits key regulators such as TNF-α, MAPKs, and NF-κB, consequently downregulating matrix metalloproteinases (MMPs). Aging exacerbates oxidative stress, upregulating MAPK and NF-κB signaling and worsening extracellular matrix degradation in the skin. E. cava-derived phlorotannin (PT) mitigates MAPK and NF-κB signaling. We evaluated the impact of EV-EC and PT on skin rejuvenation using an in vitro keratinocyte senescence model and an in vivo aged-mouse model. Western blotting confirmed the presence of HSP70 in EV-EC. Treatment with EV-EC and PT in senescent keratinocytes increased HSP70 expression and decreased the expression of TNF-α, MAPK, NF-κB, activator protein-1 (AP-1), and MMPs. Oxidative stress was also reduced. Sequential treatment with PT and EV-EC (PT/EV-EC) yielded more significant results compared to individual treatments. The administration of PT/EV-EC to the back skin of aged mice mirrored the in vitro findings, resulting in increased collagen fiber accumulation and improved elasticity in the aged skin. Therefore, PT/EV-EC holds promise in promoting skin rejuvenation by increasing HSP70 expression, decreasing the expression of MMPs, and reducing oxidative stress in aged skin.

Byun K., Park Y., Oh S., Batsukh S., Son K.H., Byun K.

Hyperpigmentation due to ultraviolet (UV)-induced melanogenesis causes various esthetic problems. Phlorotannin (PT) and extracellular vesicles (EVs) derived from various plants suppress melanogenesis pathways. We used UV-exposed keratinocytes and animal skin to determine if co-treatment with PT and EVs from Ecklonia cava (EVE) could inhibit melanogenesis by reducing UV-induced oxidative stress and the expression of the thioredoxin-interacting protein (TXNIP)/nucleotide-binding oligomerization domain-like receptor family pyrin domain containing the 3 (NLRP3)/interleukin-18 (IL-18) pathway, which are upstream signals of the microphthalmia-associated transcription factor. UV exposure increased oxidative stress in keratinocytes and animal skin, as evaluated by 8-OHdG expression, and this effect was reduced by co-treatment with PT and EVE. UV also increased binding between NLRP3 and TXNIP, which increased NLRP3 inflammasome activation and IL-18 secretion, and this effect was reduced by co-treatment with PT and EVE in keratinocytes and animal skin. In melanocytes, conditioned media (CM) from UV-exposed keratinocytes increased the expression of melanogenesis-related pathways; however, these effects were reduced with CM from UV-exposed keratinocytes treated with PT and EVE. Similarly, PT and EVE treatment reduced melanogenesis-related signals, melanin content, and increased basement membrane (BM) components in UV-exposed animal skin. Thus, co-treatment with PT and EVE reduced melanogenesis and restored the BM structure by reducing oxidative stress and TXNIP/NLRP3/IL-18 pathway expression.