Biodegradable Lipid-Modified Poly(Guanidine Thioctic Acid)s: A Fortifier of Lipid Nanoparticles to Promote the Efficacy and Safety of mRNA Cancer Vaccines.

Lipid nanoparticles (LNPs)-based messenger RNA (mRNA) therapeutics have emerged with promising potentials in the fields of infectious diseases, cancer vaccines, and protein replacement therapies; however, their therapeutic efficacy and safety can still be promoted by the optimization of LNPs formulations. Unfortunately, current LNPs suffer from increased production of reactive oxygen species during translation, which leads to a decreased translation efficiency and the onset of inflammation and other side effects. Herein, we synthesize a lipid-modified poly(guanidine thioctic acid) polymer to fabricate novel LNPs for mRNA vaccines. The acquired G-LNPs significantly promote the translation efficiency of loaded mRNA and attenuate inflammation after vaccination through the elimination of reactive oxygen species that are responsible for translational inhibition and inflammatory responses. In vivo studies demonstrate the excellent antitumor efficacy of the G-LNPs@mRNA vaccine, and two-dose vaccination dramatically increases the population and infiltration of cytotoxic T cells due to the intense antitumor immune responses, thus generating superior antitumor outcomes compared with the mRNA vaccine prepared from traditional LNPs. By synergy with immune checkpoint blockade, the tumor inhibition of G-LNPs@mRNA is further boosted, indicating that G-LNPs-based mRNA vaccines will be powerful and versatile platforms to combat cancer.

Algorithm for optimized mRNA design improves stability and immunogenicity.

Messenger RNA (mRNA) vaccines are being used to combat the spread of COVID-19 (refs. 1-3), but they still exhibit critical limitations caused by mRNA instability and degradation, which are major obstacles for the storage, distribution and efficacy of the vaccine products4. Increasing secondary structure lengthens mRNA half-life, which, together with optimal codons, improves protein expression5. Therefore, a principled mRNA design algorithm must optimize both structural stability and codon usage. However, owing to synonymous codons, the mRNA design space is prohibitively large-for example, there are around 2.4 × 10632 candidate mRNA sequences for the SARS-CoV-2 spike protein. This poses insurmountable computational challenges. Here we provide a simple and unexpected solution using the classical concept of lattice parsing in computational linguistics, where finding the optimal mRNA sequence is analogous to identifying the most likely sentence among similar-sounding alternatives6. Our algorithm LinearDesign finds an optimal mRNA design for the spike protein in just 11 minutes, and can concurrently optimize stability and codon usage. LinearDesign substantially improves mRNA half-life and protein expression, and profoundly increases antibody titre by up to 128 times in mice compared to the codon-optimization benchmark on mRNA vaccines for COVID-19 and varicella-zoster virus. This result reveals the great potential of principled mRNA design and enables the exploration of previously unreachable but highly stable and efficient designs. Our work is a timely tool for vaccines and other mRNA-based medicines encoding therapeutic proteins such as monoclonal antibodies and anti-cancer drugs7,8.

Nonlysosomal Route of mRNA Delivery and Combining with Epigenetic Regulation Optimized Antitumor Immunoprophylactic Efficacy.

Currently, mRNA-based tumor therapies are in full flow because in vitro-transcribed (IVT) mRNA has the potential to express tumor antigens to initiate the adaptive immune responses. However, the efficacy of such therapy relies heavily on the delivery system. Here, a pardaxin-modified liposome loaded with tumor antigen-encoding mRNA and adjuvant (2',3'-cGAMP, (cyclic [G(2',5')pA(3',5')p])), termed P-Lipoplex-CDN is reported. Due to an nonlysosomal delivery route, the transfection efficiency on dendritic cells (DCs) is improved by reducing the lysosome disruption of cargos. The mRNA modified DCs efficiently induce tumor antigen-specific immune responses both in vitro and in vivo. As prophylactic vaccines, mRNA transfected DCs significantly delay the occurrence and development of tumors, and several immunized mice are even completely resistant to tumors. Interestingly, the efficacy depends on the major histocompatibility complex class I (MHC-I) expression level on tumor cells. Furthermore, epigenetic modification (decitabine, DAC) is applied as a combination strategy to deal with malignant tumor progression caused by deficient tumor MHC-I expression. This study highlights the close relationship between mRNA-DCs vaccine efficacy and the expression level of tumor cell MHC-I molecules. Moreover, a feasible strategy for tumor MHC-I expression deficiency is proposed, which may provide clinical guidance for the design and application of mRNA-based tumor therapies.

CD97 serves as a novel biomarker of immune cell infiltration in hepatocellular carcinoma.

BACKGROUND: CD97 is the most widely expressed G protein-coupled receptor in the epidermal growth factor seven-span transmembrane family. It plays a vital role in cell adhesion, migration, and cell connection regulation. We explored the role of CD97 in hepatocellular carcinoma (HCC). METHODS: We evaluated CD97 mRNA expression in HCC using TNMplot and the Gene Expression Omnibus database. The clinical prognostic significance of CD97 in HCC patients was evaluated by gene expression profiling interactive analysis, the Kaplan-Meier plotter, and the UALCAN database. The Tumor Immune Estimation Resource (TIMER) and CIBERSORT databases were used to analyze the relationships among CD97, genes positively related with CD97, and tumor-infiltrating immune cells. RESULTS: CD97 was highly expressed in HCC tissues and was associated with an adverse prognosis. CD97 and genes positively related with CD97 were positively correlated with the abundance of tumor-infiltrating immune cells and strongly correlated with tumor-infiltrating macrophages (all r ≥ 0.513, P < 0.001). CD97 was positively correlated with M2 macrophage and tumor-associated macrophage markers (both r ≥ 0.464, P < 0.001). CD97 was found to be an immune-related gene in HCC and positively correlated with the TOX, PD-L1, PD-L2, CTLA4, and PD-1 immune checkpoint genes. CD97 copy number alterations affect the level of immune cell infiltration and mRNA expression. CONCLUSIONS: CD97 can be used as a potential molecular marker of prognosis in HCC, which is associated with immune cell infiltration.

Long noncoding RNA uc.230/CUG-binding protein 1 axis sustains intestinal epithelial homeostasis and response to tissue injury.

Intestinal epithelial integrity is commonly disrupted in patients with critical disorders, but the exact underlying mechanisms are unclear. Long noncoding RNAs transcribed from ultraconserved regions (T-UCRs) control different cell functions and are involved in pathologies. Here, we investigated the role of T-UCRs in intestinal epithelial homeostasis and identified T-UCR uc.230 as a major regulator of epithelial renewal, apoptosis, and barrier function. Compared with controls, intestinal mucosal tissues from patients with ulcerative colitis and from mice with colitis or fasted for 48 hours had increased levels of uc.230. Silencing uc.230 inhibited the growth of intestinal epithelial cells (IECs) and organoids and caused epithelial barrier dysfunction. Silencing uc.230 also increased IEC vulnerability to apoptosis, whereas increasing uc.230 levels protected IECs against cell death. In mice with colitis, reduced uc.230 levels enhanced mucosal inflammatory injury and delayed recovery. Mechanistic studies revealed that uc.230 increased CUG-binding protein 1 (CUGBP1) by acting as a natural decoy RNA for miR-503, which interacts with Cugbp1 mRNA and represses its translation. These findings indicate that uc.230 sustains intestinal mucosal homeostasis by promoting epithelial renewal and barrier function and that it protects IECs against apoptosis by serving as a natural sponge for miR-503, thereby preserving CUGBP1 expression.

Soluble PD-L1 in blood correlates positively with neutrophil and negatively with lymphocyte mRNA markers and implies adverse sepsis outcome.

Sepsis causes a myriad of immunological reactions that result in life-threatening alterations in the human body. Immunosuppression in sepsis is partly attributed to the programmed death receptor (PD-1) and its associated ligand (PD-L1) via the regulation of lymphocytes and neutrophils. Although the soluble forms of these proteins (i.e., sPD-1 and sPD-L1, respectively) are recognized as possible sepsis biomarkers, their functional implications are yet to be elucidated. Our research assessed the correlation between sPD-1 and sPD-L1 and blood mRNA markers and sepsis outcome. Blood samples of septic patients of urogenital origin versus control patients (both groups: n = 18) were analyzed. Blood serum sPD-1 and sPD-L1 levels were determined using the enzyme-linked immunosorbent assay (ELISA). The whole blood mRNA concentrations of PD-1, PD-L1, neutrophil markers (CEACAM8 and MPO), and T-lymphocyte markers (TCRß, CD4 and CD8) were determined via reverse transcriptase quantitative PCR (RT-qPCR). sPD-L1 levels were significantly increased in septic patients when compared to the controls, whereas sPD-1 levels were unaltered. Patients with high sPD-L1 levels, as dichotomized to the median, had a significantly shorter survival rate than those with low sPD-L1 levels. The sensitivity/specificity characteristics of sPD-L1 proved significant for sepsis detection. Furthermore, sPD-L1 correlated with the mRNA concentrations of PD-L1, CEACAM, and MPO, as well as major inflammatory markers (C-reactive protein and procalcitonin). However, sPD-L1 negatively correlated with TCRß, CD4, and CD8 mRNAs. sPD-L1 was found to be significantly increased in septic patients. Notably, sPD-L1 correlated with PD-L1 mRNA and neutrophil markers and was indicative of adverse outcomes.

Increased expression of NOP14 is associated with improved prognosis due to immune regulation in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most common of cancer-related deaths. Nucleolar protein 14 (NOP14) is known to play different roles in diverse types of cancers. However, little is known about its roles in CRC. Here, we assessed the prognostic value and functions of NOP14 in CRC using the data from The Cancer Genome Atlas (TCGA) and validated them based on the data from Gene Expression Omnibus (GEO). METHODS: NOP14 mRNA and protein data in CRC was obtained from the TCGA, GEO, human protein atlas (HPA), and UALCAN databases. Survival and Cox regression analysis was performed to assess the prognostic value of NOP14 in CRC patients. Next, to evaluate the potential functions of NOP14, a protein-protein interaction (PPI) network was constructed and gene set enrichment analysis (GSEA) of differential expression genes (DEGs) associated with dysregulated NOP14 was performed. Finally, to investigate the immune response associated with NOP14 expression in CRC, we analyzed the correlations between immune cells infiltration and NOP14 expression level. Additionally, the correlations between immune molecule expression levels with NOP14 expression level were analyzed. RESULTS: High NOP14 mRNA expression was observed in CRC tissues based on the data from TCGA and GEO datasets. Similarly, high NOP14 protein levels were found in CRC tissues according to the immunohistochemical images from HPA. Interestingly, high NOP14 expression level was associated with an improved prognosis in CRC patients. Univariate and multivariate Cox regression analysis indicated that high NOP14 expression level was an independent protective factor for CRC patients. With the support of PPI network analysis, we found several risk genes interacted with NOP14. GSEA revealed that high NOP14 expression inhibited several signal pathways involved in tumor formation and development. Additionally, high NOP14 expression was positively associated with most kinds of immune cell infiltrations and the expression levels of some molecules related to immune activation. CONCLUSION: Altogether, these results indicated that high NOP14 expression leads to improved prognosis in CRC patients by inhibiting the signaling pathways involved in tumor growth and promoting the immune responses.

Decreased Expression of Programmed Death Ligand-L1 by Seven in Absentia Homolog 2 in Cholangiocarcinoma Enhances T-Cell-Mediated Antitumor Activity.

N6-methyladenosine (m6A) has been reported as an important mechanism of post-transcriptional regulation. Programmed death ligand 1 (PD-L1) is a primary immune inhibitory molecule expressed on tumor cells that promotes immune evasion. In addition, seven in absentia homolog 2 (Siah2), a RING E3 ubiquitin ligase, has been involved in tumorigenesis and cancer progression. However, the role of m6A-METTL14-Siah2-PD-L1 axis in immunotherapy remains to be elucidated. In this study, we showed that METTL14, a component of the m6A methyltransferase complex, induced Siah2 expression in cholangiocarcinoma (CCA). METTL14 was shown to enrich m6A modifications in the 3'UTR region of the Siah2 mRNA, thereby promoting its degradation in an YTHDF2-dependent manner. Furthermore, co-immunoprecipitation experiments demonstrated that Siah2 interacted with PD-L1 by promoting its K63-linked ubiquitination. We also observed that in vitro and in vivo Siah2 knockdown inhibited T cells expansion and cytotoxicity by sustaining tumor cell PD-L1 expression. The METTL14-Siah2-PD-L1-regulating axis was further confirmed in human CCA specimens. Analysis of specimens from patients receiving anti-PD1 immunotherapy suggested that tumors with low Siah2 levels were more sensitive to anti-PD1 immunotherapy. Taken together, our results evidenced a new regulatory mechanism of Siah2 by METTL14-induced mRNA epigenetic modification and the potential role of Siah2 in cancer immunotherapy.

Massive digital gene expression analysis reveals different predictive profiles for immune checkpoint inhibitor therapy between adenocarcinoma and squamous cell carcinoma of advanced lung cancer.

BACKGROUND: Immune checkpoint inhibitors prolong the survival of non-small cell lung cancer (NSCLC) patients. Although it has been acknowledged that there is some correlation between the efficacy of anti-programmed cell death-1 (PD-1) antibody therapy and immunohistochemical analysis, this technique is not yet considered foolproof for predicting a favorable outcome of PD-1 antibody therapy. We aimed to predict the efficacy of nivolumab based on a comprehensive analysis of RNA expression at the gene level in advanced NSCLC. METHODS: This was a retrospective study on patients with NSCLC who were administered nivolumab at the Kansai Medical University Hospital. To identify genes associated with response to anti-PD-1 antibodies, we grouped patients into responders (complete and partial response) and non-responders (stable and progressive disease) to nivolumab therapy. Significant genes were then identified for these groups using Welch's t-test. RESULTS: Among 42 analyzed cases (20 adenocarcinomas and 22 squamous cell carcinomas), enhanced expression of MAGE-A4, BBC3, and OTOA genes was observed in responders with adenocarcinoma, and enhanced expression of DAB2, HLA-DPB,1 and CDH2 genes was observed in responders with squamous cell carcinoma. CONCLUSIONS: This study predicted the efficacy of nivolumab based on a comprehensive analysis of mRNA expression at the gene level in advanced NSCLC. We also revealed different gene expression patterns as predictors of the effectiveness of anti PD-1 antibody therapy in adenocarcinoma and squamous cell carcinoma.

Estrogen enhanced the expression of IL-17 by tissue-resident memory γδT cells from uterus via interferon regulatory factor 4.

Tissue-resident memory γδT cells at mucosal and epithelial sites play an important role for pathogen clearance, immunosurveillance, and participating in physiological processes. Different from other barrier sites, the immune cells in uterus face the protection against infections and tolerate an allogeneic fetus during a successful pregnancy. In the previous study, we found that tissue-resident memory γδT cells were enriched both in human and murine uterus and highly expressed IL-17 that promoted the invasion of trophocytes in vitro. In the current study, we found that γδT cells in uterus but not in blood or spleens expressed higher levels of estrogen receptors. The injection of estrogen into mice increased the proportion of γδT cells in uterus but not in spleens in vivo via CXCR3-CXCL10 chemokine axis. In addition, we found that estrogen enhanced the production of IL-17 but not IFN-γ in vivo and in vitro via interferon regulatory factor 4 but not RORγt and pSTAT3 at mRNA and protein levels. The analysis of cell transcriptome sequence further identified multiple differentially expressed genes between estrogen and control γδT cells. Our study demonstrated that estrogen directly act on γδT cells in uterus to enhance the production of IL-17 that might promote the invasion of trophocytes. Furthermore, our study might provide a new idea that estrogen increased the prevalence of autoimmune diseases in women by enhancing γδT cell-derived IL-17 production in uterus and uncover the critical pathological roles for estrogen in the development of autoimmune diseases.

TREM2 is thyroid hormone regulated making the TREM2 pathway druggable with ligands for thyroid hormone receptor.

Triggering receptor expressed on myeloid cells-2 (TREM2) is a cell surface receptor on macrophages and microglia that senses and responds to disease-associated signals to regulate the phenotype of these innate immune cells. The TREM2 signaling pathway has been implicated in a variety of diseases ranging from neurodegeneration in the central nervous system to metabolic disease in the periphery. Here, we report that TREM2 is a thyroid hormone-regulated gene and its expression in macrophages and microglia is stimulated by thyroid hormone and synthetic thyroid hormone agonists (thyromimetics). Our findings report the endocrine regulation of TREM2 by thyroid hormone, and provide a unique opportunity to drug the TREM2 signaling pathway with orally active small-molecule therapeutic agents.

mRNA translation from an antigen presentation perspective: A tribute to the works of Nilabh Shastri.

The field of mRNA translation has witnessed an impressive expansion in the last decade. The once standard model of translation initiation has undergone, and is still undergoing, a major overhaul, partly due to more recent technical advancements detailing, for example, initiation at non-AUG codons. However, some of the pioneering works in this area have come from immunology and more precisely from the field of antigen presentation to the major histocompatibility class I (MHC-I) pathway. Despite early innovative studies from the lab of Nilabh Shastri demonstrating alternative mRNA translation initiation as a source for MHC-I peptide substrates, the mRNA translation field did not include these into their models. It was not until the introduction of the ribo-sequence technique that the extent of non-canonical translation initiation became widely acknowledged. The detection of peptides on MHC-I molecules by CD8 + T cells is extremely sensitive, making this a superior model system for studying alternative mRNA translation initiation from specific mRNAs. In view of this, we give a brief history on alternative initiation from an immunology perspective and its fundamental role in allowing the immune system to distinguish self from non-self and at the same time pay tribute to the works of Nilabh Shastri.

Antineoplastic treatment class modulates COVID-19 mRNA-BNT162b2 vaccine immunogenicity in cancer patients: a secondary analysis of the prospective Vax-On study.

BACKGROUND: Preliminary analysis from the Vax-On study did not find a correlation between cancer treatment type and antibody response to COVID-19 vaccination. We carried out a secondary subgroup analysis to verify the effects of comprehensive cancer treatment classification on vaccine immunogenicity. METHODS: The Vax-On study prospectively enrolled patients who started a two-dose messenger RNA-BNT162b2 vaccine schedule from 9 March 2021 to 12 April 2021 (timepoint-1). Those on active treatment within the previous 28 days accounted for the exposed cases. Patients who had discontinued such treatment by at least 28 days or received intravesical therapy represented the control cases. Quantification of immunoglobulin G (IgG) antibodies against the receptor binding domain of the S1 subunit of the SARS-CoV-2 spike protein was carried out before the second dose (timepoint-2) and 8 weeks thereafter (timepoint-3). Seroconversion response was defined at ≥50 arbitrary units/ml IgG titer. Classification of antineoplastic agents was based on their pharmacodynamic properties. RESULTS: Three hundred and sixty-six patients were enrolled (86 and 260 as control and exposed cases, respectively). Univariate analysis revealed a significantly lower IgG titer after both doses of vaccine in subgroups treated with tyrosine kinase inhibitors (TKIs), multiple cytotoxic agents, alkylating agents, and topoisomerase inhibitors. At timepoint-3, seroconversion response was significantly impaired in the topoisomerase inhibitors and mechanistic target of rapamycin (mTOR) inhibitors subgroups. After multivariate testing, treatment with alkylating agents and TKIs was significantly associated with a reduced change in IgG titer at timepoint-2. Treatment with mTOR inhibitors resulted in a similar interaction at each timepoint. Cyclin-dependent kinase 4/6 inhibitor treatment was independently correlated with an incremental variation in IgG titer at timepoint-3. Specific subgroups (TKIs, antimetabolites, alkylating agents, and multiple-agent chemotherapy) predicted lack of seroconversion at timepoint-2, but their effect was not retained at timepoint-3. Eastern Cooperative Oncology Group performance status 2, immunosuppressive corticosteroid dosing, and granulocyte colony-stimulating factor use were independently linked to lower IgG titer after either dose of vaccine. CONCLUSIONS: Drugs interfering with DNA synthesis, multiple-agent cytotoxic chemotherapy, TKIs, mTOR and cyclin-dependent kinase 4/6 inhibitors differentially modulate humoral response to messenger RNA-BNT162b2 vaccine.

Chemically modified mRNA beyond COVID-19: Potential preventive and therapeutic applications for targeting chronic diseases.

Chemically modified mRNA represents a unique, efficient, and straightforward approach to produce a class of biopharmaceutical agents. It has been already approved as a vaccination-based method for targeting SARS-CoV-2 virus. The COVID-19 pandemic has highlighted the prospect of synthetic modified mRNA to efficiently and safely combat various diseases. Recently, various optimization advances have been adopted to overcome the limitations associated with conventional gene therapeutics leading to wide-ranging applications in different disease conditions. This review sheds light on emerging directions of chemically modified mRNAs to prevent and treat widespread chronic diseases, including metabolic disorders, cancer vaccination and immunotherapy, musculoskeletal disorders, respiratory conditions, cardiovascular diseases, and liver diseases.

Identification of Novel Biomarkers for Predicting Prognosis and Immunotherapy Response in Head and Neck Squamous Cell Carcinoma Based on ceRNA Network and Immune Infiltration Analysis.

OBJECTIVES: Patients with head and neck squamous cell carcinoma (HNSCC) have poor prognosis and show poor responses to immune checkpoint (IC) inhibitor (ICI) therapy. Competing endogenous RNA (ceRNA) networks, tumor-infiltrating immune cells (TIICs), and ICIs may influence tumor prognosis and response rates to ICI therapy. This study is aimed at identifying prognostic and IC-related biomarkers and key TIIC signatures to improve prognosis and ICI therapy response in HNSCC patients. METHODS AND RESULTS: Ninety-five long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and 1746 mRNAs were identified using three independent methods. We constructed a ceRNA network and estimated the proportions of 22 immune cell subtypes. Ten ceRNAs were related to prognosis according to Kaplan-Meier analysis. Two risk signatures based, respectively, on nine ceRNAs (ANLN, CFL2, ITGA5, KDELC1, KIF23, NFIA, PTX3, RELT, and TMC7) and three immune cell types (naïve B cells, neutrophils, and regulatory T cells) via univariate Cox regression, least absolute shrinkage and selection operator, and multivariate Cox regression analyses could accurately and independently predict the prognosis of HNSCC patients. Key mRNAs in the ceRNA network were significantly correlated with naïve B cells and regulatory T cells and with stage, grade, and immune and molecular subtype. Eight IC genes exhibited higher expression in tumor tissues and were correlated with eight key mRNAs in the ceRNA network in HNSCC patients with different HPV statuses according to coexpression and TIMER 2.0 analyses. Most drugs were effective in association with expression of these key signatures (ANLN, CFL2, ITGA5, KIF23, NFIA, PTX3, RELT, and TMC7) based on GSCALite analysis. The prognostic value of key biomarkers and associations between key ceRNAs and IC genes were validated using online databases. Eight key ceRNAs were confirmed to predict response to ICI in other cancers based on TIDE analysis. CONCLUSIONS: We constructed two risk signatures to accurately predict prognosis in HNSCC. Key IC-related signatures may be associated with response to ICI therapy. Combinations of ICIs with inhibitors of eight key mRNAs may improve survival outcomes of HNSCC patients.

Immune responses to two and three doses of the BNT162b2 mRNA vaccine in adults with solid tumors.

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have shown high efficacy, but immunocompromised participants were excluded from controlled clinical trials. In this study, we compared immune responses to the BNT162b2 mRNA Coronavirus Disease 2019 vaccine in patients with solid tumors (n = 53) who were on active cytotoxic anti-cancer therapy to a control cohort of participants without cancer (n = 50). Neutralizing antibodies were detected in 67% of patients with cancer after the first immunization, followed by a threefold increase in median titers after the second dose. Similar patterns were observed for spike protein-specific serum antibodies and T cells, but the magnitude of each of these responses was diminished relative to the control cohort. In most patients with cancer, we detected spike receptor-binding domain and other S1-specific memory B cell subsets as potential predictors of anamnestic responses to additional immunizations. We therefore initiated a phase 1 trial for 20 cancer cohort participants of a third vaccine dose of BNT162b2 ( NCT04936997 ); primary outcomes were immune responses, with a secondary outcome of safety. At 1 week after a third immunization, 16 participants demonstrated a median threefold increase in neutralizing antibody responses, but no improvement was observed in T cell responses. Adverse events were mild. These results suggest that a third dose of BNT162b2 is safe, improves humoral immunity against SARS-CoV-2 and could be immunologically beneficial for patients with cancer on active chemotherapy.

High-affinity memory B cells induced by SARS-CoV-2 infection produce more plasmablasts and atypical memory B cells than those primed by mRNA vaccines.

Although both infections and vaccines induce memory B cell (MBC) populations that participate in secondary immune responses, the MBCs generated in each case can differ. Here, we compare SARS-CoV-2 spike receptor binding domain (S1-RBD)-specific primary MBCs that form in response to infection or a single mRNA vaccination. Both primary MBC populations have similar frequencies in the blood and respond to a second S1-RBD exposure by rapidly producing plasmablasts with an abundant immunoglobulin (Ig)A+ subset and secondary MBCs that are mostly IgG+ and cross-react with the B.1.351 variant. However, infection-induced primary MBCs have better antigen-binding capacity and generate more plasmablasts and secondary MBCs of the classical and atypical subsets than do vaccine-induced primary MBCs. Our results suggest that infection-induced primary MBCs have undergone more affinity maturation than vaccine-induced primary MBCs and produce more robust secondary responses.

Role of CXCL10 in the progression of in situ to invasive carcinoma of the breast.

Tumor immune microenvironment plays a crucial role in tumor progression. We performed immune profiling to compare immune-related gene expression between ductal carcinoma in situ (DCIS) and invasive carcinoma of the breast using nCounter PanCancer immune Profiling Panel and found that CXCL10 was the most significant gene that had the highest difference in expression between them. Effect of CXCL10 on breast cancer cell proliferation and invasion was examined in vitro, and expression of CXCL10 and its relationship with immune cell infiltration was assessed in breast cancer samples. CXCL10 induced cell proliferation, migration and epithelial-mesenchymal transition in MCF-7 and MDA-MB-231 breast cancer cell lines. We confirmed that CXCL10 mRNA expression was significantly higher in invasive carcinoma than in DCIS, especially in hormone receptor (HR)-negative tumors using a validation set. CXCL10 mRNA expression showed a positive correlation with tumor infiltrating lymphocyte (TIL) density in both DCIS and invasive carcinoma; CXCL10-positive tumors generally showed higher infiltration of CD8+ and FOXP3+TILs as well as PD-L1+ immune cells compared to CXCL10-negative tumors, albeit with different patterns according to HR status. In conclusion, our study showed that CXCL10 promotes tumor cell proliferation, invasion, and immune cell infiltration, implying its contribution in the progression of DCIS to invasive carcinoma of the breast.

Eficacia y seguridad de las vacunas de ARNm contra COVID-19 en adolescentes / Efficacy and security of vaccines of mRNA against COVID-19 in adolescents

INTRODUCCIÓN: La enfermedad por el coronavirus 2019 (COVID-19) causada por el coronavirus 2 del Síndrome respiratorio agudo grave o SARS-CoV-2 fue inicialmente reportada en Wuhan, China en diciembre de 2019. El 30 de enero de 2020 la OMS determinó que la COVID-19 representaba una emergencia de salud pública de importancia internacional y posteriormente el 11 de marzo del 2020 fue declarada como pandemia. A partir de diciembre de ese mismo año, se inició la vacunación contra la COVID-19 en el mundo. La Administración de Alimentos y Medicamentos (FDA) de los Estados Unidos, el 11 de diciembre de 2020, emitió una autorización de uso de emergencia (EUA) para la vacuna de tipo ARNm BNT162b2 desarrollada por Pfizer-BioNTech para su uso en personas a partir de los 16 años. En base a los resultados de un ensayo clínico de fase 3 (2), esta EUA se amplió para adolescentes de 12 a 15 años el 10 de mayo de 2021. En el Perú, el Ministerio de Salud (MINSA) aprobó la utilización de la vacuna BNT162b2/Pfizer-BioNTech en adolescente de 12 a 17 años con comorbilidades específicas a partir del mes de junio en base a la autorización de la Dirección General de Medicamentos (DIGEMID) (3). Hasta la fecha de la redacción de este informe, 17 de setiembre de 2021, en el Perú se habían administrado 18 953 dosis (1° dosis: 14 958 y 2° dosis: 3 995) de la vacuna de Pfizer-BioNTech en adolescentes de 12 a 16 años. OBJETIVO: Sintetizar la evidencia disponible sobre la eficacia, efectividad y seguridad de las vacunas contra COVID-19 basadas en ARN mensajero (ARNm) en adolescentes de 12 a 17 años. METODOLOGÍA: Pregunta PICO abordada: En adolescentes de 12 a 17 años ¿la administración de vacunas de ARNm contra COVID-19 es eficaz y segura? Criterios de elegibilidad: Los criterios de selección de los estudios fueron los siguientes: Estudios que corresponden a la pregunta PICO planteada y que reporten resultados para al menos uno de los desenlaces considerados. Los estudios que incluyeron adultos y adolescente fueron incluidos si reportaban resultados desagregados para la población de interés. Idioma: inglés, español y portugués. Se incluyeron estudios publicados y manuscritos sin revisión por pares (pre-print). Se excluyeron cartas al editor, revisiones narrativas, estudios preclínicos (estudios in vitro o en modelos animales) y artículos de opinión. Las cartas al editor, cartas de investigación y comentarios fueron incluidos sólo si brindaban datos suficientes sobre las características de los participantes, intervención y desenlaces. Las revisiones sistemáticas recuperadas y las referencias de las publicaciones relevantes fueron analizadas para identificar estudios adicionales que cumpliesen con los criterios de selección establecidos. Métodos de búsqueda: La búsqueda sistemática se realizó en MEDLINE/Pubmed, medRxiv (un servidor de distribución de manuscritos aún no publicados, sin revisión por pares) y en la Plataforma Living Overview of the Evidence (L·OVE) de la Fundación Epistemonikos, con fecha 15 y 16 de setiembre de 2021, incluyendo términos en lenguaje natural y lenguaje estructurado (Tesauros), según cada base de datos, para adolescentes y las vacunas de ARNm consideradas. Los resultados de las búsquedas fueron importados al gestor de referencias Zotero versión 5.0.96.3 para la identificación y eliminación de los artículos duplicados. Esta etapa fue realizada por una sola autora. Selección de evidencia y extracción de datos: La selección de estudios consideró una fase inicial de lectura de títulos y resúmenes, realizada de manera pareada e independiente por dos autoras utilizando el software Rayyan®, seguida de una fase de lectura del texto completo de las referencias potencialmente relevantes identificadas. Para la extracción de datos se utilizó una plantilla diseñada en Google Sheets. La selección por texto completo y la extracción de datos fue realizada de forma individual por cada autora. Análisis de los datos: Se realizó una síntesis narrativa de los datos extraídos. No se consideró la realización de un meta-análisis debido a la heterogeneidad de los estudios identificados (tipo de intervención y diseño de estudio). Evaluación de certeza de la evidencia: En un primer paso se realizó la evaluación de riesgo de sesgo de los estudios incluidos utilizando herramientas de acuerdo al diseño de investigación. Se empleó la Herramienta para evaluar riesgo de sesgo de ensayos clínicos aleatorizados de la Colaboración Cochrane versión 2 (RoB 2)(8) y para las series de caso, se empleó la lista de verificación para evaluación crítica de Joanna Briggs Institute para series de casos (9) (preguntas 1-8 y 10) y la herramienta para evaluar la calidad metodológica de reportes de caso y series de casos de Murad et al.(10) (ítems 4 y 8). En una segunda etapa, los estudios con mejor calidad metodológica o menor riesgo de sesgo fueron considerados para la evaluación de la certeza de la evidencia según la metodología GRADE, que toma en cuenta los siguientes criterios: diseño del estudio, riesgo de sesgo, inconsistencia en los resultados, ausencia de evidencia directa, imprecisión, sesgo de publicación, tamaño de efecto, gradiente dosis-respuesta, y efecto de los potenciales factores de confusión residual (los tres últimos aplicables en estudios observacionales)(11,12). RESULTADOS: Se identificaron 303 citaciones. Luego de la eliminación de duplicados, tamizaje de títulos y resúmenes y lectura de textos completos, se seleccionaron 13 estudios, reportados en 14 artículos (1 estudio con 2 reportes de diferentes periodos de seguimiento). Dos artículos estuvieron disponibles como pre-print. CONCLUSIONES: El objetivo del presente documento fue sintetizar la evidencia científica disponible respecto a la eficacia y seguridad de las vacunas basadas en ARNm en adolescentes de 12 a 17 años, específicamente para la vacuna BNT162b2 de Pfizer-BioNTech y la vacuna mRNA-1273 desarrolada por Moderna. Se identificaron 2 ensayos clínicos aleatorizados que evaluaron la eficacia y seguridad de estas vacunas, además de 11 series de caso que reportan la ocurrencia de miocarditis luego de la vacunación en adolescentes de 12 a 17 años. La eficacia de 2 dosis de BNT162b2 para prevenir COVID-19 (infección sintomática) en participantes de 12 a 15 años, se estimó en 100% (IC 95%: 75.3 ­ 100) (1983 participantes, con un seguimiento de al menos 2 meses en el 58% de ellos). Para el subgrupo de 16 a 17 años, esta eficacia se estimó en 100% (IC 95%: 58.2­100.0) (673 participantes, con un seguimiento de hasta 6 meses luego de la 2o dosis). La certeza de la evidencia es moderada debido a imprecisión. La eficacia del esquema de 2 dosis con la vacuna mRNA-1273 para prevenir COVID-19 en adolescentes de 12 a 17 años es de 93.3% (IC 95%: 47.9 - 99.9) (1 ensayo clínico aletorizado, 3181 participantes, seguimiento de 53 días luego de la 2o dosis). La certeza de evidencia es moderada debido a imprecisión. Se desconoce la eficacia de la vacunación con BNT162b2 ó mRNA-1273 para prevenir COVID-19 severo y mortalidad, ya que no se observaron estos eventos en los ensayos clínicos identificados. La incidencia de eventos adversos serios en el grupo de adolescentes de 12 a 15 años vacunados con BNT162b2, fue mayor a lo reportado en el grupo placebo (Incidencia de 0.4% versus 0.1%, riesgo relativo (RR): 3.99 (IC 95%: 0.45 a 35.67) (1 ensayo clínico, 2260 participantes). Ninguno de estos eventos fue catalogado como relacionado a la vacunación. La certeza de la evidencia es baja debido a imprecisión muy seria. La incidencia de eventos adversos serios, entre adolescentes de 12 a 17 años que recibieron la vacuna mRNA-1273 fue similar a lo reportado por el grupo placebo (Incidencia de 0.1% versus 0.1%, RR: 1.00 (IC 95%: 0.09 a 10.99) (1 ensayo clínico, 3276 participantes). Ninguno de estos eventos estuvo relacionado con la intervención recibida. La certeza de la evidencia es baja dado debido a imprecisión muy seria. El mayor número de casos de miocarditis reportados en las series fue de 397 y ocurrieron con mayor frecuencia en el sexo masculino y luego de la 2o dosis de la vacuna BNT162b2. El tiempo de inicio de síntomas fue de 2 días, rango de 1 a 7 días, luego de la 2o dosis. En su mayoría, los casos se caracterizaron por dolor torácico, elevación de troponinas, elevación del segmento ST e imágenes compatibles con miocarditis en la resonancia magnética cardiaca. El tiempo de hospitalización fue de 2 a 5 días (mediana). No se reportaron muertes durante la hospitalización y ninguno de los casos requirió soporte hemodinámico o respiratorio avanzado. No se cuenta con información suficiente respecto del seguimiento al alta que permita establecer su pronóstico a largo plazo. La tasa de ocurrencia de miocarditis en población adolescentes de Estados Unidos, a partir de los reportes disponibles en un sistema de notificación de reacciones adversas, estimada por CDC de Estados Unidos y autores independientes, osciló entre 43 a 162 y 72 a 94 casos por millón de segundas dosis administradas en adolescentes varones de 12 a 15 años y 16 a 17 años respectivamente. En mujeres, las tasas observadas fueron de 4 a 13 en el grupo de 12 a 15 años y de 0 a 8 en aquellas con 16 a 17 años. La certeza de la evidencia fue muy baja debido al diseño de estudio y riesgo de sesgo serio.