Immunological Memory Research Articles

Long non-coding RNAs: A trained immunity perspective

The conventional understanding of immunological memory within adaptive immunity has faced recent challenges, paving the way for a novel concept known as “trained immunity.” This phenomenon revolves around the epigenetic and metabolic reprogramming of cells as its central components. A growing body of evidence suggests that long non-coding RNAs (lncRNAs) play a crucial role in regulating immune cell development, function, and response to various diseases. Through intricate protein-protein interactions and interactions with DNA and RNA, lncRNAs significantly contribute to the modulation of immune processes. However, our comprehension of the involvement of lncRNAs in trained immunity is still in its early stages. This review delves into the recent advancements in lncRNA research, focusing on their diverse functions in immune cell development, host-pathogen interactions, potential processes, and their biological significance in trained immunity. Special attention is given to the role of lncRNAs in altering chromatin structure, orchestrating chromosomal looping, and driving metabolic reprogramming within cells.

Temporal Trends in SARS-CoV-2 Antibody Levels Among COVID-19 Patients in Kerala During the First Wave and Pre-vaccination Period.

The SARS-CoV-2 virus interacts with host cells through the S1 domain of its spike protein. This study measures the IgG immune response to this domain in COVID-19 patients from Kerala, India, and explores its association with various health factors. A cohort of 258 COVID-19 patients was analyzed for IgG antibodies targeting the S1 spike protein domain. The temporal pattern of the IgG response and its correlation with hospitalization needs, intensive care, and pre-existing conditions such as diabetes, hypertension, and coronary artery disease were assessed. A significant IgG response (76.4%) was detected, indicating robust immune activation post-infection. The IgG levels peaked between two tofour and four to eight weeks post-infection, with a notable increase at 12 weeks, hinting at possible secondary exposure or an immune memory response. No correlation was found between IgG levels and the presence of diabetes mellitus, hypertension, or coronary artery disease. However, higher IgG responses correlated with the severity of the infection, as seen in patients requiring hospitalization or intensive care. The IgG response to the S1 spike protein domain serves as a potential marker of immune activation in COVID-19. It reflects the body's defense mechanism against the virus and may predict disease severity and outcomes. The findings suggest that IgG levels could be indicative of the viral load, inflammatory response, and possibly the likelihood of protection against reinfection.

A guide to adaptive immune memory.

Immune memory - comprising T cells, B cells and plasma cells and their secreted antibodies - is crucial for human survival. It enables the rapid and effective clearance of a pathogen after re-exposure, to minimize damage to the host. When antigen-experienced, memory T cells become activated, they proliferate and produce effector molecules at faster rates and in greater magnitudes than antigen-inexperienced, naive cells. Similarly, memory B cells become activated and differentiate into antibody-secreting cells more rapidly than naive B cells, and they undergo processes that increase their affinity for antigen. The ability of T cells and B cells to form memory cells after antigen exposure is the rationale behind vaccination. Understanding immune memory not only is crucial for the design of more-efficacious vaccines but also has important implications for immunotherapies in infectious disease and cancer. This 'guide to' article provides an overview of the current understanding of the phenotype, function, location, and pathways for the generation, maintenance and protective capacity of memory T cells and memory B cells.

Immunogenicity, Immunological Memory and Monitoring of Disease Activity Following an Anamnestic Immunization With the 13-Valent Pneumococcal Conjugate Vaccine in Children With Idiopathic Nephrotic Syndrome.

Anamnestic 13-valent pneumococcal conjugate vaccine immunization did not affect the relapse risk in pediatric idiopathic nephrotic syndrome. Pneumococcal serotype (PS)-specific antibody titers increased significantly in all groups. Children receiving immunomodulatory treatments (IMTs) displayed significantly lower levels of PS-specific antibodies for 3/8 serotypes tested. PS-specific B-cell counts significantly increased only in healthy controls and patients receiving corticosteroids.

Intratumoral Fc-optimized agonistic CD40 antibody induces tumor rejection and systemic antitumor immunity in patients with metastatic cancer.

While CD40 agonism is an attractive approach for activating antigen-presenting cells and initiating antitumor responses, previous attempts have encountered limited clinical efficacy coupled with toxicity. We previously demonstrated that interactions between the antibody Fc domain and the inhibitory receptor FcγRIIB are critical for enhanced antitumor activity. Here, we present the results of a phase 1 study on intratumoral administration of an anti-CD40 agonistic antibody (2141-V11) Fc-engineered to enhance FcγRIIB binding. Primary endpoints included safety, maximum tolerated dose (MTD), and recommended phase 2 dose. Secondary objectives included preliminary clinical activity and correlative studies from biospecimens. 2141-V11 was well-tolerated without dose-limiting toxicities and MTD was not reached. In ten evaluable patients with metastatic cancer, the overall response rate was 20%, with complete responses in two patients (melanoma and breast carcinoma) and stable disease in six patients. 2141-V11 induced tumor regression in injected and non-injected lesions, with increased leukocyte infiltration and tertiary lymphoid structures (TLS) formation in post-treatment biopsies. In a humanized mouse model for CD40 and FcγRs, 2141-V11 induced TLS formation in mice bearing orthotopic breast carcinoma, correlating with local and abscopal antitumor effects, systemic immune activation, and immune memory. These findings support the safety and efficacy of 2141-V11, warranting phase 2 studies and suggesting a unique mechanism of action for this Fc-enhanced immunotherapy (NCT04059588).

A first-in-human phase 1 trial of T cell membrane-anchored tumor targeted IL12 (ATTIL12) -T cell therapy in advanced/metastatic soft tissue and bone sarcoma.

TPS11586 Background: Interleukin-12 (IL12) is a cytokine that induces antitumor immune response and immune memory by activation of NK cells, induction of IFNg, and maturation of DC cells in the tumor microenvironment (TME). However, prior clinical experience with IL12 has been limited by toxicities including cytokine release syndrome (CRS) and hepatotoxicity. We developed a novel tumor-targeted IL12 gene (ttIL12) that encodes the p35 and p40 VNTANST fusion subunits that targets cell surface vimentin (CSV). Vimentin is expressed intracellularly in many normal and neoplastic mesenchymal cells but our group discovered that intracellular vimentin is often flipped to the cell surface (referred to as CSV) across multiple tumor types.2 Preclinical studies demonstrated efficacy and induction of long-term memory of ttIL12 against metastatic osteosarcoma with reduced toxicity in immune competent models.3 However, ttIL12 had limited efficacy in treating large volume tumors and did not completely eliminate toxic peripheral cytokines. To address this, our team generated a membrane anchored ttIL12 to arm T cells known as attIL12-T cell therapy. We hypothesize attIL12 will minimize toxic cytokines in peripheral tissues but promote induction of INFg/TNFa in the TME to decrease the toxicity and boost efficacy. Methods: This is a phase 1 trial of attIL12-T cells in patients (pts) with locally advanced or metastatic soft tissue or bone sarcomas to assess safety, maximal tolerated dose (MTD) and recommended phase 2 dose (RP2D). Pts in part A (dose finding) will be enrolled using a Bayesian optimal interval (BOIN) design in up to 6 dose levels. Part B (dose expansion) will evaluate preliminary efficacy in 10 additional pts with osteosarcoma treated at the RP2D. Treatment:Pts will undergo leukapheresis to collect peripheral blood mononuclear cells (PBMCs) for generation of attIl12-T cells. Bridging therapy is permitted but not required. Pts will receive cyclophosphamide (Cy) IV prior to planned T cell administration. attIL12 T cells will be administered at the specified dose level IV in a single infusion (dose level 1 and 2) or 2 serial doses (dose level 3-6) on day 0 and day 14. Pts will be monitored for toxicity and response evaluation. Pts will also undergo pre-treatment/on-treatment tumor biopsies for translational and correlative analysis. Eligibility:Pts must be ≥ 12 years of age, have a confirmed diagnosis of locally advanced or metastatic sarcoma, evaluable disease, received at least 1 prior line of standard systemic therapy, ECOG PS 0-1, and adequate organ function to tolerate immune-effector cell therapy. Pts with known sensitivity to Cy, active/prior autoimmune disease, uncontrolled CNS disease, or other uncontrolled comorbidities that pose potential safety risk will be excluded. Enrollment to cohort 1 began in Dec 2023. Clinical trial information: NCT05621668 .

Mathematical analysis of intrahost spread and control of Dengue Virus: Unraveling the crucial role of antigenic immunity

Studying viral infections within the host is crucial for understanding healthy cell responses and immunity. This research employed a reaction-diffusion Caputo fractional order model and a modified homotopy perturbation method to explore how immune cell memory and mobility affect the dynamic interactions of cytotoxic T-lymphocyte cells (CTLs), B-cell antibodies, uninfected monocytes, infected monocytes, and Dengue Virus (DENV) particle concentration within the host. The model guaranteed a positive solution, with the existence and uniqueness of the solution assured by the Banach fixed point theorem and a general stability supported by the Hyers-Ulam theorem. Sensitivity analysis highlighted that the DENV invasion rate speeds the spread of infected cells, while simulation results and fractional order analysis revealed that cell-mediated memory from past exposure will enhance the activation of CTLs and B-cell antibodies to strengthen immunity against dengue virus.

Effect of AVM0703 treatment on the limitations of R-CHOP and survival in a model applicable to ABC subtype DLBCL.

e19060 Background: The current treatment regimen for DLBCL consisting of rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone (RCHOP), is challenged by molecular and prognostic characterization of DLBCL. Activated B-cell (ABC) lymphoma has a significantly worse prognosis (5 yr OS rate: 45% - 56%) than germinal center B-cell (GCB) lymphoma (78% - 80%) after RCHOP treatment. Around 40% of patients ultimately relapse and/or develop primary refractory disease, cardiotoxicity and long-term secondary malignancies. Efforts are being made to improve the RCHOP backbone by including dose intensification and by the addition of new agents to increase the efficacy and reduced toxicity of RCHOP (McKelvey EM Cancer 1976; Wilson WH Blood 2002; Molina TJ JCO 2014; Coiffier B Hematology 2016). AVM0703, an immunomodulatory drug, mobilizes bispecific γδ and inv-TCR double-positive novel T and NKT cells. In a previous study employing an aggressive, immune resistant A20 mouse lymphoma model (Bascuas T J Transl Med. 2016), neoadjuvant AVM0703 was additive/synergistic, when cyclophosphamide/fludarabine (CyFlu) was dosed 3 and 24 hr later, with no additional toxicities. In the present study we combined AVM0703 with RCHOP to evaluate the efficacy in A20 mice model. Methods: 10 week old Balb/c mice were injected with 2x106 murine A20 B-cells in the flank and were randomized (1:1 male: female) into 1) Placebo 2) 3 cycles RCHOP 3) 3 cycles AVM0703 (18mg/kg HED) 4) 3 cycles AVM0703+RCHOP, when tumor size reached ~100 mm3. Mice who achieved complete remission (CR) were re-challenged at 21-25 wks later. Pre and post re-challenge, presence of memory cells was analyzed using flow cytometer. All mice were monitored continuously as per the IACUC protocol. Results: Mice treated with the combination of AVM0703+RCHOP achieved superior CR compared to RCHOP alone, which was not curative in any mice. In first phase of the study, 3 out of 11 AVM0703 +RCHOP treated mice showed CR after only 1-cycle. In second phase, 2 of 12 mice survived in CR for >150 days after 3 cycles, whereas no RCHOP mice survived beyond 2 cycles. AVM0703+RCHOP treated mice in long-term CR, had memory cells (CD44hi-Cd62low) pre- and post re-challenge, and no A20 engraftment, suggesting strong immunological memory induced by AVM0703+RCHOP. Conclusions: AVM+RCHOP demonstrated anti-tumor activity in A20 lymphoma mice, with reduced toxicity, compared to RCHOP. Larger preclinical studies are underway to confirm the activity of AVM0703+RCHOP against RCHOP resistant ABC DLBCL, and the potential to reduce total RCHOP exposure to only 3 cycles while maintaining or improving efficacy. [Table: see text]

A phase 1, open-label, dose escalation study on the safety and tolerability of ANK-101 in advanced solid tumors.

TPS2689 Background: IL-12 is a cytokine that can stimulate both innate and adaptive tumor immunity. Clinical trials of intravenous IL-12 demonstrated anti-tumor activity limited by significant systemic toxicity, including patient deaths. ANK-101 is an anchored immunotherapy that links IL-12 to aluminum hydroxide through an alum-binding protein (ABP). The ANK-101 complex anchors IL-12 in the tumor microenvironment (TME), resulting in prolonged local retention and low levels of systemic absorption. Preclinical studies in murine tumor models showed that ANK-101 is retained at the injection site for up to 28 days, recruits and activates T and NK cells, promotes M1 myeloid cell differentiation, induces regression of both injected and un-injected tumors, and induces immunologic memory. Methods: This is a first-in-human, open-label dose escalation study of ANK-101 in advanced solid tumors with a planned sample size of 12-36 participants. The first three dose escalation cohorts include a single participant, and then study enrollment follows a standard 3+3 dose escalation design. If no dose limiting toxicity (DLT) is observed, the dose level will be escalated until ≥1/3 or ≥2/6 patients experience a DLT. An additional ten patients will be enrolled at the recommended dose for expansion (RDE). Participants will be treated with intratumoral ANK-101 every 3 weeks for 4 cycles. Imaging or clinical assessments will be performed at week 12. If there is no significant clinical deterioration or unacceptable toxicity at this visit, participants may receive four more cycles. Eligible patients must have an advanced solid malignancy refractory to standard treatment and be accessible for injection and biopsy, measurable disease by RECIST v1.1, and ECOG PS of 0-1. Key exclusion criteria include tumors close to vital structures, uncontrolled bleeding disorders, and active autoimmune disease. Primary objectives of the study are to determine the safety and tolerability of ANK-101 and identify the RDE. Secondary objectives include pharmacokinetics (PK) and immunogenicity (ADA) of ANK-101 and clinical activity as measured by ORR, DCR, DOR and PFS by RECIST v1.1. Exploratory objectives include assessment of QOL using FACT-G and profiling immune-based pharmacodynamic (PD) changes. PD assessments will include serum cytokines and circulating immune cells, and local levels of PD-L1, CD8+ T cells, and CD68+ macrophages, and changes in gene expression within the TME. This clinical trial is in progress. Clinical trial information: NCT06171750 .

A phase 1 trial in progress for in situ immunomodulation with CDX-301, radiation therapy, poly-ICLC, and CDX-1140 in patients with unresectable and metastatic solid tumors.

TPS2697 Background: The prognosis for patients with unresectable and metastatic solid tumors that progress on standard of care therapy remains poor due to limited treatment options. Compelling evidence suggests that the induction and activation of tumor-residing conventional type-1 dendritic cells (cDC1) is critical to elicit anti-tumor immunity. Recently, we have demonstrated that a combinatorial regimen comprised of in situ delivery of Fms-like tyrosine kinase 3 ligand (Flt3L), radiation therapy (9Gy), and dual TLR3/CD40 stimulation 1) mobilizes cDC1 to the tumor microenvironment; 2) induces maturation of cDC1; 3) facilitates trafficking of cDC1 carrying tumor antigens to tumor-draining lymph nodes; 4) elicits de novo adaptive T cell immunity; 5) triggers regression of primary tumors, as well as non-irradiated distant tumors; and 6) develops tumor-specific systemic immunological memory using multiple syngeneic orthotopic murine models (1-4). Based on results from preclinical studies, we have initiated a phase 1 study as below. Methods: This is a phase 1 study of in situ immunomodulation with CDX-301 (Flt3L), radiation therapy, CDX-1140 and Poly-ICLC (dual CD40/TLR3 stimulation) in patients with unresectable and metastatic solid tumors. Eligibility for this study includes patients ≥ 18 yrs who have clinically or pathologically confirmed diagnosis of unresectable and metastatic melanoma, cutaneous squamous cell carcinoma, Merkel cell carcinoma, high-grade bone and soft tissue sarcoma or HER2/neu (-) breast cancer with no curative treatment options, and progressed on at least one line of standard systemic therapy. The unresectable disease to be irradiated and injected with medications must be located in breast, dermal, subcutaneous, or soft tissue, or lymph nodes with the longest axis of the tumor 2-7 cm, and should be considered safe for injection by the investigator. The metastatic disease must be measurable per irRECIST criteria. Patients will be treated with daily intratumoral injection of CDX-301 for 5 days (Day 1-5), radiation therapy (9Gy, Day 8) followed by administration of CDX-1140 and Poly-ICLC (Day 9). Up to 4 cycles of this combination therapy can be given every 3 weeks. The primary endpoints are safety/tolerability and to evaluate the MTD of for injection (intratumoral in the cohort A and intratumoral and intravenous in the cohort B) of CDX-1140. A standard 3+3 design, allowing for dose de-escalation, will be used within each cohort. Secondary endpoints are to evaluate immune signatures in blood and the tumor. This phase 1 trial opened to enrollment at the University of Southern California Norris Comprehensive Cancer Center in January 2023 (recruitment is currently 4 on February 6, 2024). 1. Nature Communications 2020. 2. J. Immunology 2021. 3. Cancer Research 2021. 4. Scientific Reports 2022. Clinical trial information: NCT04616248 .

Effect of NIR-II on cancer nanocomposite vaccines for lymph node targeted delivery and enhanced immunotherapy.

e20506 Background: Cancervaccines have become one of the hot areas of research in recent years. However, different types of tumors and the tumor tissue itself are heterogeneous. Some cancervaccines contain a single epitope and have weak immunogenicity. The antigen-presenting cells cannot adequately absorb and present the antigen peptide contained in the vaccine. As a result, the body fails to elicit an effective immune response, which greatly limits the therapeutic effect of the cancervaccine. In situ cancervaccines composed of antigens and adjuvants are a promising cancer treatment modality; however, convenient manufacturing of vaccines in vivo and their efficient delivery to lymph nodes (LNs) remain a significant challenge. In this study, we outline a facile approach to simultaneously achieve in situ programming of vaccines via two synergistic nanomedicines to generate robust immune responses. Methods: We first prepared two synergistic nanocomposite systems: Gold nanorods, amphiphilic polymer polyphosphate mPEG- b-PHEP encapsulating the immune adjuvant R848, and nanoparticles doped with cationic liposomes DOTAP. Two nanomedicines were characterized and the efficacy of the nanovaccine was verified at the Cellular Experiments. At the animal level, the lymph node targeting of the nanoparticles was demonstrated through IVIS. We also constructed distant model and lung metastasis model to verify the nanovaccine's effect on enhancing systemic immunotherapy. Results: We used amphiphilic polymer polyphosphate mPEG- b-PHEP to encapsulate TLR7/8 agonist R848 to obtain VNPR848 nanoparticles. Gold nanorods (~ 100nm) can produce a strong photothermal effect mediated by NIR-II, killing tumor cells and releasing abundant antigens at the same time. The small size of VNPR848 (~ 30nm) is beneficial to the enrichment of lymph nodes. After capturing the antigens produced by photothermal, nanoparticles will be targeted and delivered to the tumor draining lymph nodes together with R848, and will be effectively absorbed by DC cells. This in situ tumor vaccine with the ability of targeted delivery of lymph nodes can trigger a strong anti-tumor immune response. This therapy can completely inhibit distant tumors in some mice and produce a long-term immune memory effect on NSCLC metastasis. Conclusions: We propose a simple personalized in situ cancervaccine strategy, which uses nanotechnology to remove tumors in situ and release antigens. Antigens and immune adjuvants are simultaneously delivered to the draining lymph nodes to initiate the antigen presentation function of DC cells, resulting in an anti-tumor immune response to inhibit tumor recurrence and metastasis. The nano-vaccine based on powerful therapeutic effect provides an attractive technology for in situ programming of personalized cancervaccine and an effective strategy for the development of cancervaccine.

Expand and pull: A new treatment paradigm for glioblastoma using a long-acting recombinant interleukin-7 and oncolytic viral therapy.

2043 Background: Patients with glioblastoma (GBM) face three major challenges. First, the tumor itself as well as chemoradiation treatment result in lymphopenia, which is associated with shorter survival. Second, the tumor microenvironment (TME) has a paucity of T cells and consequently, immunotherapies have failed in multiple phase 3 clinical trials for GBM. Third, a treatment resistant population of cancer stem cells (CSCs) contribute to inevitable tumor recurrence. In preclinical models, we have shown that a long-acting IL-7, NT-I7, significantly increases peripheral CD8 T cells and separately, oncolytic Zika virus (ZIKV) directly targets CSC and induces an anti-tumor CD8 T cell response. The aim of this study was to determine whether we can leverage the NT-I7 driven T cell expansion peripherally and combine it with ZIKV therapy to pull immune cells into the TME to successfully treat a highly immunosuppressive mouse model of GBM. Methods: SB28 syngeneic tumor cells were intracranially implanted in C57BL/6J mice. Mice were treated with NT-I7 subcutaneously on days 7 and 10 post tumor implantation, followed by intratumoral ZIKV on day 14. Mice were monitored for survival and bled weekly to assess the systemic T-cell response to NT-I7. Immunoprofiling of brain, draining lymph node, and peripheral blood via flow cytometry was done on days 17 and 21. Results: NT-I7 significantly expanded peripheral T cells compared to control (5,623 cells/µL vs 136 cells/µL, p<0.05). Cytotoxic CD8 T cells were particularly increased (4,776 cells/µL vs 47 cells/µL, p<0.05), with the expansion peak at day 7 after the first dose of NT-I7 and persisting for 21 days. When ZIKV was administered at the peak of the NT-I7-driven CD8 T cell expansion, the combination resulted in significant improvement in survival compared to NT-I7 or ZIKV monotherapy (median 47 days vs 35 days and 33 days, respectively, p<0.05). Combined NT-I7 and ZIKV treatment significantly increased TME CD8 T cell infiltration (369,814 cells/g vs 23,947 cells/g and 63,961 cells/g, respectively) as well as increased expression of interferon-γ, TNF-α, perforin, and granzyme B (p<0.05). Long-term survivors were protected against tumor rechallenge, suggesting that this treatment strategy confers immune memory against tumor antigens. The addition of immune checkpoint blockade with anti-PD1 antibody resulted in nearly 80% complete tumor clearance. Conclusions: Timing the oncolytic ZIKV injection with the NT-I7-induced peak expansion of peripheral CD8 T cells greatly increased tumor infiltration of cytotoxic T cells and improved survival in the immunotherapy resistant SB28 glioma model. This work suggests a new “expand and pull” approach for the treatment of highly immunosuppressive tumors such as GBM: priming the systemic immune system with NT-I7, followed by an oncolytic stimulus to draw them into the TME to engage and clear tumor cells.

Covid lockdown and repaying the immunity debt in children

Non-pharmaceutical interventions (NPIs) implemented during the SARS-CoV-2 pandemic have been proven effective. While reducing SARS-CoV-2 transmission, NPIs also reduced children's exposure to other pathogens, leading to a decline in the incidence of many viral and bacterial infections. The reduction in contact with viruses and bacteria could result in insufficient immune stimulation of pathogens in the population, leading to an increase in susceptible populations and a decline in herd immunity, which form the immunity debt during the SARS-CoV-2 pandemic. Immunity debt can impact the pattern of seasonal pathogens, increase the incidence and severity of invasive infections, and potentially raise the risk of allergic diseases in children. Immunization, continuing to implement NPIs, pathogen monitoring, and health education are important measures to repay immunity debt. Besides, trained immunity, referring to the memory immunity produced by the innate immune system upon re-stimulation, can be employed as a non-specific measure to prevent the spread of pathogens. The protective effect of trained immunity can be used as a temporary preventive measure for emerging infectious diseases and create conditions for vaccine development.

HVEM in acute lymphocytic leukemia facilitates tumour immune escape by inhibiting CD8+ T cell function.

Leukaemia remains a major contributor to global mortality, representing a significant health risk for a substantial number of cancer patients. Despite notable advancements in the field, existing treatments frequently exhibit limited efficacy or recurrence. Here, we explored the potential of abolishing HVEM (herpes virus entry mediator, TNFRSF14) expression in tumours as an effective approach to treat acute lymphoblastic leukaemia (ALL) and prevent its recurrence. The clinical correlations between HVEM and leukaemia were revealed by public data analysis. HVEM knockout (KO) murine T cell lymphoblastic leukaemia cell line EL4 were generated using CRISPR-Cas9 technology, and syngeneic subcutaneous tumour models were established to investigate the in vivo function of HVEM. Immunohistochemistry (IHC), RNA-seq and flow cytometry were used to analyse the tumour immune microenvironment (TIME) and tumour draining lymph nodes (dLNs). Immune functions were investigated by depletion of immune subsets in vivo and T cell functional assays in vitro. The HVEM mutant EL4 cell lines were constructed to investigate the functional domain responsible for immune escape. According to public databases, HVEM is highly expressed in patients with ALL and acute myeloid leukemia (AML) and is negatively correlated with patient prognosis. Genetic deletion of HVEM in EL4 cells markedly inhibited tumour progression and prolonged the survival of tumour-bearing mice. Our experiments proved that HVEM exerted its immunosuppressive effect by inhibiting antitumour function of CD8+ T cell through CRD1 domain both in vivo and in vitro. Additionally, we identified a combination therapy capable of completely eradicating ALL tumours, which induces immune memory toward tumour protection. Our study reveals the potential mechanisms by which HVEM facilitates ALL progression, and highlights HVEM as a promising target for clinical applications in relapsed ALL therapy.

Multiparametric analysis of the specific immune response against SARS-CoV-2

Background SARS-CoV-2, which causes COVID-19, has killed more than 7 million people worldwide. Understanding the development of postinfectious and postvaccination immune responses is necessary for effective treatment and the introduction of appropriate antipandemic measures. Objectives We analysed humoral and cell-mediated anti-SARS-CoV-2 immune responses to spike (S), nucleocapsid (N), membrane (M), and open reading frame (O) proteins in individuals collected up to 1.5 years after COVID-19 onset and evaluated immune memory. Methods Peripheral blood mononuclear cells and serum were collected from patients after COVID-19. Sampling was performed in two rounds: 3-6 months after infection and after another year. Most of the patients were vaccinated between samplings. SARS-CoV-2-seronegative donors served as controls. ELISpot assays were used to detect SARS-CoV-2-specific T and B cells using peptide pools (S, NMO) or recombinant proteins (rS, rN), respectively. A CEF peptide pool consisting of selected viral epitopes was applied to assess the antiviral T-cell response. SARS-CoV-2-specific antibodies were detected via ELISA and a surrogate virus neutralisation assay. Results We confirmed that SARS-CoV-2 infection induces the establishment of long-term memory IgG+ B cells and memory T cells. We also found that vaccination enhanced the levels of anti-S memory B and T cells. Multivariate comparison also revealed the benefit of repeated vaccination. Interestingly, the T-cell response to CEF was lower in patients than in controls. Conclusion This study supports the importance of repeated vaccination for enhancing immunity and suggests a possible long-term perturbation of the overall antiviral immune response caused by SARS-CoV-2 infection.

BCG Vaccination Suppresses Glucose Intolerance Progression in High-Fat-Diet-Fed C57BL/6 Mice.

Background and Objectives: Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccine administration has been suggested to prevent glucose metabolism abnormalities and fatty liver in genetically obese ob/ob mice; however, it is not clear whether the beneficial effects of BCG are also observed in the progression of glucose intolerance induced by a high-fat diet (HFD). Therefore, the effects of BCG vaccination on changes in glucose tolerance and insulin response were investigated in HFD-fed C57BL/6 mice. Materials and Methods: We used the BCG Tokyo 172 strain to determine effects on abnormalities in glucose metabolism. For vaccination, five-week-old male mice were injected intraperitoneally with BCG and maintained on a HFD for three weeks. The mice were regularly subjected to intraperitoneal glucose tolerance and insulin tolerance tests (IGTTs and ITTs). These tests were also performed in mice transplanted with bone marrow cells from BCG-vaccinated donor mice. Results: Significant effects of BCG vaccination on blood glucose levels in the IGTTs and ITTs were observed from week 12 of the experiment. BCG vaccination significantly improved changes in fasting glucose and insulin levels, insulin resistance indexes, and glucagon-to-insulin ratios in conjunction with the HFD at the end of the experiment. Significant inhibitory effects in the IGTTs and ITTs on glucose intolerance were also observed with transplantation with bone marrow cells derived from BCG-vaccinated donor mice. Conclusions: BCG vaccination significantly delayed glucose intolerance progression, suggesting a beneficial effect of BCG on the pathogenesis of type 2 diabetes. It has also been suggested that the effects of BCG vaccination may be at least partially due to an immune memory (trained immunity) for hematopoietic stem and progenitor cells of the bone marrow.

Construction of janus mesenchymal stem cell-hitchhiked melanin nanoparticles to modulate the Th17/Treg balance for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a common chronic inflammatory disease capable of causing the disability. Although various antioxidant strategies have been attempted for prevention and treatment of RA through scavenging the free radicals, the therapeutic effect is limited. Recently, it is reported that the unremitting course of RA intensely correlates with the persistence of immunologic memory, in which the imbalance of T helper 17 (Th17) cells/regulatory T (Treg) cells plays an important role. Herein, we constructed Janus mesenchymal stem cell (MSC)-hitchhiked melanin nanoparticles (MSCFM) for RA therapy, where one half of MSC kept intact for chemotactically migrating towards the RA inflammatory sites and efficiently restoring the Th17/Treg balance based on the property of MSCs, while the other half hitchhiked the iron-doped melanin (FM) nanoparticles (NPs) and release them to scavenge free radicals for maintaining the durability of Th17/Treg balance. In vitro studies indicated MSCFM could migrate towards CXCL12 inflammatory cytokine, scavenge reactive oxygen and nitrogen species, inhibit Th17 cell proliferation and induce Treg cell production. Further in vivo studies corroborated that intravenously injected MSCFM could target the RA site of collagen-induced arthritis mouse model and alleviate the pathological progression of RA. MSCFM holds great potential as an anti-inflammatory agent for RA management.

Heart failure promotes multimorbidity through innate immune memory.

Patients with heart failure (HF) often experience repeated acute decompensation and develop comorbidities such as chronic kidney disease and frailty syndrome. Although this suggests pathological interaction among comorbidities, the mechanisms linking them are poorly understood. Here, we identified alterations in hematopoietic stem cells (HSCs) as a critical driver of recurrent HF and associated comorbidities. Bone marrow transplantation from HF-experienced mice resulted in spontaneous cardiac dysfunction and fibrosis in recipient mice, as well as increased vulnerability to kidney and skeletal muscle insults. HF enhanced the capacity of HSCs to generate proinflammatory macrophages. In HF mice, global chromatin accessibility analysis and single-cell RNA-seq showed that transforming growth factor-β (TGF-β) signaling was suppressed in HSCs, which corresponded with repressed sympathetic nervous activity in bone marrow. Transplantation of bone marrow from mice in which TGF-β signaling was inhibited similarly exacerbated cardiac dysfunction. Collectively, these results suggest that cardiac stress modulates the epigenome of HSCs, which in turn alters their capacity to generate cardiac macrophage subpopulations. This change in HSCs may be a common driver of repeated HF events and comorbidity by serving as a key carrier of "stress memory."

Proteomimetic Polymers Trigger Potent Antigen-Specific T Cell Responses to Limit Tumor Growth.

Elicitation of effective antitumor immunity following cancer vaccination requires the selective activation of distinct effector cell populations and pathways. Here we report a therapeutic approach for generating potent T cell responses using a modular vaccination platform technology capable of inducing directed immune activation, termed the Protein-like Polymer (PLP). PLPs demonstrate increased proteolytic resistance, high uptake by antigen-presenting cells (APCs), and enhanced payload-specific T cell responses. Key design parameters, namely payload linkage chemistry, degree of polymerization, and side chain composition, were varied to optimize vaccine formulations. Linking antigens to the polymer backbone using an intracellularly cleaved disulfide bond copolymerized with a diluent amount of oligo(ethylene glycol) (OEG) resulted in the highest payload-specific potentiation of antigen immunogenicity, enhancing dendritic cell (DC) activation and antigen-specific T cell responses. Vaccination with PLPs carrying either gp100, E7, or adpgk peptides significantly increased the survival of mice inoculated with B16F10, TC-1, or MC38 tumors, respectively, without the need for adjuvants. B16F10-bearing mice immunized with gp100-carrying PLPs showed increased antitumor CD8+ T cell immunity, suppressed tumor growth, and treatment synergy when paired with two distinct stimulator of interferon gene (STING) agonists. In a human papillomavirus-associated TC-1 model, combination therapy with PLP and 2'3'-cGAMP resulted in 40% of mice completely eliminating implanted tumors while also displaying curative protection from rechallenge, consistent with conferment of lasting immunological memory. Finally, PLPs can be stored long-term in a lyophilized state and are highly tunable, underscoring the unique properties of the platform for use as generalizable cancer vaccines.

Intake of imidacloprid in lethal and sublethal doses alters gene expression in Apis mellifera bees

Bees are important pollinators for ecosystems and agriculture; however, populations have suffered a decline that may be associated with several factors, including habitat loss, climate change, increased vulnerability to diseases and parasites and use of pesticides. The extensive use of neonicotinoids, including imidacloprid, as agricultural pesticides, leads to their persistence in the environment and accumulation in bees, pollen, nectar, and honey, thereby inducing deleterious effects. Forager honey bees face significant exposure to pesticide residues while searching for resources outside the hive, particularly systemic pesticides like imidacloprid. In this study, 360 Apis mellifera bees, twenty-one days old (supposed to be in the forager phase) previously marked were fed syrup (honey and water, 1:1 m/v) containing a lethal dose (0.081 μg/bee) or sublethal dose (0.00081 μg/bee) of imidacloprid. The syrup was provided in plastic troughs, with 250 μL added per trough onto each plastic Petri dish containing 5 bees (50 μL per bee). The bees were kept in the plastic Petri dishes inside an incubator, and after 1 and 4 h of ingestion, the bees were euthanised and stored in an ultra-freezer (−80 °C) for transcriptome analysis. Following the 1-h ingestion of imidacloprid, 1516 genes (73 from lethal dose; 1509 from sublethal dose) showed differential expression compared to the control, while after 4 h, 758 genes (733 from lethal dose; 25 from sublethal) exhibited differential expression compared to the control. All differentially expressed genes found in the brain tissue transcripts of forager bees were categorised based on gene ontology into functional groups encompassing biological processes, molecular functions, and cellular components. These analyses revealed that sublethal doses might be capable of altering more genes than lethal doses, potentially associated with a phenomenon known as insecticide-induced hormesis. Alterations in genes related to areas such as the immune system, nutritional metabolism, detoxification system, circadian rhythm, odour detection, foraging activity, and memory in bees were present after exposure to the pesticide. These findings underscore the detrimental effects of both lethal and sublethal doses of imidacloprid, thereby providing valuable insights for establishing public policies regarding the use of neonicotinoids, which are directly implicated in the compromised health of Apis mellifera bees.