Cell-mediated immune (CMI) responses to adeno-associated virus (AAV) can lead to tissue damage and loss of therapeutic transgene expression. Identifying robust biomarkers and mechanisms of CMI can aid clinical practice and advancement of AAV gene therapies. The present work evaluated peripheral blood mononuclear cells (PBMC) from non-human primates (NHP) before and after immunization with adenovirus 5 encoding AAV9 capsid antigen. PBMC were stimulated with AAV9 capsid peptides to evaluate CMI responses by interferon (IFN)-γ ELISpot, intracellular cytokines/activation markers, secreted cytokines, and RNAseq. AAV peptide stimulation produced a robust IFNγ ELISpot 11 days after immunization and ≈ 4 years after cryopreservation. Flow cytometry revealed increased IFNγ, interleukin (IL)-2, or tumor necrosis factor (TNF)-positive T-cells. Increases in secreted CXCR3 ligands (IP-10, I-TAC) were detected. Robust changes and correlations to ELISpot responses were revealed by RNAseq, including IFNγ, IP-10, and I-TAC, many downstream transcripts, and several IFN-independent pathways. These data from AAV-immunized NHP identify biomarkers that could serve as robust and sensitive supplements/alternatives to ELISpot for early detection of CMI responses. Assessment of these biomarkers in non-clinical and clinical studies is a critical next step to determine the translation of this work to administration of a therapeutic AAV vector.

Immunotherapeutics targeting immune checkpoint receptors or their ligands (i.e., immune checkpoint inhibitors), have been groundbreaking in the field of oncology, radically changing the approach to treatment and improving the clinical outcomes of an ever-expanding list of solid tumors and hematological malignancies. However, immune checkpoint inhibitors (ICI) are not devoid of side effects, collectively regarded as immune-related adverse events (irAE); they are not easily uncovered in preclinical immunotoxicological investigations and are often due to the very low expression of their targets in immunologically-unchallenged non-clinical species. We have characterized expression of a broad range of immune checkpoint receptors in peripheral blood mononuclear cell (PBMC) subpopulations from cynomolgus monkeys and healthy human volunteers, under resting and T-cell stimulatory conditions by multicolor flow cytometry to inform appropriate species selection for modeling potential irAE in immunotherapeutic preclinical research. Focusing on the response of the main lymphocyte populations to interleukin (IL)-2 alone, or in combination with anti-CD3 and anti-CD28 antibodies, checkpoints with shared similarities and key differences between the two species were identified. The results of this first study provide a database for the expression and response to stimulation for immune checkpoint receptors and can help guide future model selection in the design of preclinical studies involving immunotherapeutics directed against these targets.

Efgartigimod is a human IgG antibody F fragment that reduces IgG levels through neonatal F receptor blockade. This study evaluated whether efgartigimod affects the generation of T-cell-dependent antibodies and cellular immune responses to keyhole limpet hemocyanin (KLH) immunization in non-human primates. Cynomolgus monkeys received efgartigimod or vehicle control intravenously for 11 wk, followed by a recovery phase. KLH challenges occurred during both the dosing phase and the recovery phase. No statistically significant differences emerged in anti-KLH IgM levels between the efgartigimod and control groups. Likewise, comparable KLH-specific T cell responses were observed between groups. Anti-KLH IgG titers were lower in efgartigimod-treated animals compared with controls only after the first boost of KLH, coinciding with decreases in total IgG titers in efgartigimod-treated animals, and returned to baseline levels by the end of the recovery phase. Taken together, these results indicate that efgartigimod does not suppress T-cell-dependent antibody responses or antibody class-switching. The findings of this study are consistent with efgartigimod's pharmacological mechanism of action and suggest that efgartigimod does not impair the generation of effective immune responses.

The aim of the current study was to evaluate the incidence of soy allergy in patients with atopic dermatitis (AD) and to evaluate the results of specific IgE against molecular components of soy. Altogether, 100 AD patients were examined. Soy allergy was confirmed in an open exposure test (history), and the presence of specific IgE against molecular components of soy (Gly m 4, Gly m 5, Gly m 6, Gly m 8) was evaluated using an ALEX2 Allergy Explorer test. The results for the measures of specific IgE against molecular components of soy (Gly m 4, Gly m 5, Gly m 6, Gly m 8) and clinical reactions in the open exposure test were then compared. Soy allergy was confirmed in 12% of patients. The sensitivity of specific IgE against Gly m 4 was 50.0% (21.1-78.9%). In another 29% of patients we recorded the positive results for specific IgE against Gly m 4 without any clinical reaction to soy. Compared to results from a previous study in 2013, there was an increase in the incidence of soy allergy in AD patients. An elimination diet and an exposure test are recommended to detect a reaction to soy. ALEX2 Allergy Xplorer test gives us a comprehensive picture of sensitization and the possibility of evaluation of cross-reacting allergens.

It was previously reported that half of the anaphylaxis cases occurring after intra-articular administration of diclofenac etalhyaluronate (DEH) - developed as SI-613/ONO-5704 and marketed as JOYCLU - were induced by IgE-mediated mechanisms; mechanisms for the remaining cases remain unclear. In this study, we investigated the relationship of DEH-induced anaphylaxis to non-IgE-mediated mechanisms . Assays were carried out based on the production of downstream products of the complement cascade, calcium influx due to Mas-related G protein-coupled receptor-X2 (MRGPRX2) activation, mast cell degranulation, and expression of basophil activation markers. Human plasma, CHO-K1 cells stably expressing MRGPRX2, the human mast cell line LAD2, and the human basophil leukemia cell line KU812 were used for these evaluations. No effect of DEH treatment was found on complement activation, MRGPRX2 agonist activity, direct mast cell activation, or direct basophil activation. From this it could be concluded that DEH-induced anaphylaxis is unlikely to involve complement activation or direct activation of mast cells and basophils. However, the possibility remains that the anaphylaxis might be a non-immunological hypersensitivity reaction due to inhibition of cyclooxygenase-1 by non-steroidal anti-inflammatory drugs (NSAID). Further investigation into the relationship between the non-immunological hypersensitivity and anaphylaxis following DEH administration is warranted.

Inflammation plays a critical role in prostate cancer (PCa) pathophysiology, yet the diagnostic value of specific inflammatory markers remains unclear. This study evaluates the association between circulating and tissue inflammatory markers with PCa presence and their potential as biomarkers for risk stratification. This prospective study analyzed serum and prostate biopsy samples from 60 patients with PCa and 22 cancer-free controls. Concentrations of inflammatory markers, including IL-2, IL-4, IL-10, IL-13, IL-33, Oncostatin M, TNFα, PDGF-BB, and TREM-1, were measured using Luminex technology. Statistical analyses included the Mann-Whitney test, logistic regression, and ROC curve analysis to assess differences and diagnostic performance. PCa patients exhibited significantly higher serum levels of IL-2 ( = 0.001), IL-10 ( < 0.001), IL-33 ( < 0.001), Oncostatin M ( = 0.018), and TNFα ( = 0.017) compared to controls. In contrast, biopsy tissue levels of IL-4 ( < 0.001), IL-10 ( < 0.001), IL-13 ( = 0.004), Oncostatin M ( = 0.012), PDGF-BB ( = 0.039), and TREM-1 ( = 0.013) were significantly lower in PCa patients, suggesting an inverse association. IL-10 (inverse) and IL-4 (inverse) in biopsy tissue showed high specificity in ROC analysis (AUC = 0.788 and 0.804, respectively), while IL-2 and IL-33 in serum were positively associated with PCa risk. This study suggests that IL-4, IL-10, and IL-13 in biopsy tissue may serve as biomarkers of a protective effect, while elevated IL-2 and IL-33 in serum are associated with an increased risk of PCa. These findings highlight the potential of inflammatory markers in PCa risk stratification, warranting further investigation in larger cohorts.

evaluate the association between expression of CD23 molecule on B-lymphocytes and the level of specific IgE to molecular components of birch, Bermuda grass, hazel pollen, timothy, and rye grass in atopic dermatitis (AD) patients (with and without dupilumab therapy). A total of 46 patients suffering from AD were included: 26 without dupilumab treatment and 20 with dupilumab treatment. Serum levels of specific IgE were measured by the components resolved diagnostic assay ALEX2 Allergy Xplorer, the expression of CD23 molecule on B-lymphocytes was evaluated with flow cytometry. For the statistical analysis, the Spearman's rank correlation coefficient was used. In patients treated with dupilumab, the higher association was observed between the expression of CD23 on B-lymphocytes and specific IgE to molecular components Bet v 1, Cor a 1.0103, Cor a 1.0401, and Phl p 1. This study demonstrated that the relationship between CD23 expression on B-lymphocytes and specific IgE to pollen molecular components varies depending on whether the patient was treated with dupilumab and the type of molecular component involved.

In December 2019, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China, leading to the global Coronavirus Disease pandemic. The rapid spread of SARS-CoV-2 highlighted the urgent need for effective vaccines. However, the high cost, cold storage requirements, and scalability challenges associated with mRNA vaccines have necessitated alternative vaccine technologies. In the study, the safety of a plant-based vaccine was evaluated. The vaccine, an emulsion of the SARS-CoV-2 S1 antigen and a synthetic TLR4 agonist produced and purified from , was administered to Sprague-Dawley rats three times over 4 wk. Mortality, clinical signs, body weight, food consumption, vision, urinalysis, gross findings, organ weight, hematology, serum biochemistry, histopathology, and immunogenicity were evaluated. The results showed that antibodies were efficiently produced and maintained for one month following vaccination with the plant-derived receptor-binding domain (RBD) antigen of COVID-19. Furthermore, the rats showed no toxicological symptoms, with reversible changes at the injection site and minor histological alterations in the spinal cord and bone marrow, typical of vaccine responses. The plant-derived SARS-CoV-2 vaccine appears safe following repeated administration over 4 wk and represents a promising alternative for potential use in human clinical trials and clinical applications.

Trichloroethylene (TCE) is a volatile synthetic chemical used in various industrial processes like metal degreasing. Large amounts of TCE have been released into the environment. Exposure to TCE can occur through routes, such as inhalation for workers using TCE or ingestion of drinking water in contaminated areas. Macrophages are key immune cells in virtually all tissues in the human body, including the fetal membranes, making them a plausible target for DCVC-induced immunotoxicity. Macrophages are critical for maintaining anti-microbial defenses during pregnancy, but little data exists on TCE immunotoxicity during pregnancy. We previously showed that the TCE metabolite, -(1,2-dichlorovinyl)-L-cysteine (DCVC), down-regulates immune functions in fetal membranes. To gain insight into immune functions impacted by DCVC, we treated a macrophage cell model (THP-1 cells) with DCVC followed by stimulation with bacterial or fungal toxins relevant for intrauterine infections: lipopolysaccharide (LPS), lipoteichoic acid (LTA), or zymosan. DCVC inhibited toxin-stimulated release of cytokines (e.g. TNFα and IL-1β) for all three microbial toxins. We then conducted benchmark dose modeling and compared benchmark doses for DCVC cytotoxicity cytokine suppression and determined that inhibition of cytokine release was the more potent endpoint compared to cytotoxicity. Finally, we analyzed a previously generated transcriptomic dataset from THP-1 cells stimulated with LPS, with or without DCVC treatment. We identified transcription factors that were enriched with DCVC and/or LPS treatment, including NF-kB and Vitamin D receptor (VDR). Our findings show that DCVC potently alters cellular and molecular macrophage immune responses involved in defense against intrauterine pathogens.

Unwanted immunogenicity of therapeutic proteins arises through the combination of many factors, with the route of administration considered a significant contributor. Contrary to historic data on vaccine delivery, analysis of various therapeutic protein products indicates that the subcutaneous route is not a systematic risk. However, individual product assessments may identify factors specific to the circumstance of their use. Preclinical studies may add additional information to the comparative immunogenicity risk assessment of intravenous versus subcutaneous administrations. Moreover, immunogenicity risk assessment of new biotherapeutic modalities, such as bispecific antibodies and antibody-linked cytokines, may benefit from a full analysis of risk factors, including preclinical data. The study here provides immunogenicity analysis of an IgG, two CD3 bispecific antibodies, and two Fc-linked immunocytokines administered intravenously and subcutaneously, aiming to highlight similarities and differences between these administration routes. The current results suggest that the development of anti-drug antibodies does not solely depend on the route of administration but is influenced by multiple risk factors, which should be addressed on a case-by-case basis. This paper reflects on the challenges of interpreting the data and propose standards for improving sample and data collection to aid future analysis.

The aim of this study was to assess the relationship between the expression of the CD23 molecule on B-cells and the levels of specific IgE against allergens and molecular components of storage mites (Gly d 2, Lep d 2), dog (Can f 1, Can f 2), cat (Fel d 1), shrimp (Pen m 2), molds (Asp f 6, Mala s 11, Alt a 6, Alt a 1, Mala s 6, Cla h), and German cockroach (Bla g 9) in atopic dermatitis (AD) patients (with and without dupilumab therapy). Here, 46 patients with AD were included (26 without dupilumab treatment, 20 with dupilumab treatment). Serum levels of specific IgE were measured using the component-resolved diagnostic microarray ALEX2 Allergy Xplorer, and the expression of the CD23 molecule on B-cells was evaluated using flow cytometry. For statistical analysis, a Spearman's rank correlation was used. The data indicated there was a higher correlation between CD23 expression on B-cells and specific IgE against molecular components of storage mites Bla g 9 (up to 27%), cat Fel d 1 (22.7%), and allergen extract Cla h () up to 38.9% in AD patients treated with dupilumab. These results regarding the higher association suggested a significant role in the non-inflammatory clearance and uptake of these specific IgE antibodies.

L., a perennial herb in the family , has been shown to impart several pharmacologic activities, including anti-oxidative, anti-inflammatory, and diuretic effects. In the study here, the anti-gout(y) arthritis (GA) effects of a crude extract from (PAE) were investigated in a rat GA model. For this, PAE was prepared by ethanol extraction and analyzed for phytochemicals by RP-HPLC and Q-TOF-MS. Thereafter, potential therapeutic effects of the PAE were investigated in rats; Wistar rats (male, 8 wk-of-age) were randomly allocated into four groups ( = 9/group) and intra-articularly injected with 3 mg monosodium urate (MSU) in saline solution to establish a GA model. For the study, rats received oral dosings of 0.3 mg colchicine/kg or 1 g PAE/kg (w/w) before and after gout was established. At fixed times after the treatments, assessment of joint swelling ratios and pathological changes in the joints, as well as of select cytokine expression in the blood, was done. RP-HPLC results showed the PAE contained at least 8 'active' ingredients, with plantamajoside, verbascoside, and cymaroside being the most abundant. In comparison to in control rats, MSU induced joint space narrowing, ankle joint swelling, and increased levels of pro-inflammatory interleukin (IL)-1β, IL-17a, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, and reductions in anti-inflammatory IL-10 in the blood. PAE treatment significantly reversed patho- genic joint space narrowing and swelling, reversed the MSU-induced changes in inflammatory factors, and in general imparted effects very similar to those seen with colchicine (COL; known non-steroidal anti-inflammatory drug for clinical treatment of GA). Collectively, these findings provide experimental evidence supporting the potential applicability of PAE to treat gouty arthritis.

Immune mechanisms associated with normal pregnancy have only been being substantively investigated since the early 1990s. In parallel with the progress in that area of research, in the past few years it has become increasingly clear that several xenobiotics - including a variety of environmental chemicals, pharmaceuticals, and metals are considered to be both generally immunotoxic and specifically able to affect pregnancy. Among these, there is intense interest regarding potential effects from synthetic cannabinoids, immune checkpoint inhibitors, nanometals, and microplastics, with immunotoxic events that impact on pregnancy being shown for these agents. For instance, phytocannabinoids have been shown to interfere with reproduction in mice through effects on the endocannabinoid system. Because of effects of immune enhancement, as a requirement for regulatory submission, co-inhibitory immune checkpoint molecule inhibitors were also evaluated for effects on pregnancy. Similarly, because of increasing use and concerns about incidental environmental exposures, nanometals, and micro-plastics have also been examined for effects. Several studies in humans or mice showed that exposures to each during gestation increased the risk/rate of fetal loss, in part, by disruption of the placenta-associated immune system. Furthermore, signaling by endogenous danger molecules and/or impairment of physiological intercellular mediators may have contributed to the pregnancy loss. As there are clearly a variety of immunotoxic effects that can impact on a pregnancy, this review attempts to briefly introduce immune mechanisms associated with pregnancy as well as reasons for its loss, and proposes that 'immunotoxicological disruption of pregnancy' be accepted as a new research area in immunotoxicology.

This study investigated the relationship between CD200 molecule expression on B- lymphocytes and the levels of specific IgE to molecular components of storage mites (Gly d 2, Lep d 2), dog (Can f 1, Can f 2), cat (Fel d 1), shrimp (Pen m 2), molds (Asp f 6, Mala s 11, Alt a 6, Alt a 1, Mala s 6, Cla h), and German cockroach (Bla g 9) in patients with atopic dermatitis (AD), both with and without dupilumab therapy. The study included 46 patients with AD- 26 without dupilumab treatment and 20 with dupilumab treatment. Serum levels of specific IgE were measured using the ALEX2 Allergy Xplorer diagnostic microarray and CD200 molecule was evaluated with the use of flow cytometry. Spearman's rank correlation coefficient was used to assess the relationship between B-lymphocyte CD200 expression and specific IgE levels to molecular components. According to the results, the association between CD200 expression and specific IgE levels to molecular components was low (up to 10%) in AD  patients without dupilumab therapy. In patients with dupilumab therapy, the association was non-linear, indicating that the two monitored parameters had opposite effects. In conclusion, the present study did not confirm any association between the CD200 molecule on B-lymphocytes and specific IgE levels to molecular components.

Cetylpyridinium chloride (CPC) is a quaternary ammonium antimicrobial used in numerous personal care products, human food, cosmetic products, and cleaning solutions. Yet, there is minimal published data on CPC effects on eukaryotes, immune signaling, and human health. Previously, it was shown that low-micromolar CPC inhibits rat mast cell function by inhibiting antigen (Ag)-stimulated Ca mobilization, microtubule polymerization, and degranulation. In the current study, these findings are extended to human mast cells (LAD2); this paper presents data indicating that a mechanism of action for CPC might center on its positively-charged quaternary nitrogen in its pyridinium headgroup. The inhibitory effect of CPC was independent of signaling platform receptor architecture. Tyrosine phosphorylation events are a trigger of Ca mobilization necessary for degranulation. CPC inhibits global tyrosine phosphorylation in Ag-stimulated mast cells. Specifically, CPC inhibits tyrosine phosphorylation of specific key players Syk kinase and LAT, a substrate of Syk. In contrast, CPC did not affect Lyn kinase phosphorylation. Thus, a root mechanism for CPC effect might be electrostatic disruption of particular tyrosine phosphorylation events essential for signaling. This work presented here outlines biochemical mechanisms underlying the effects of CPC on immune signaling.

Diclofenac etalhyaluronate, an active pharmaceutical ingredient in JOYCLU (JCL), serves as a joint function improvement agent in knee and hip osteoarthritis patients. However, frequent cases of anaphylaxis induced by JCL administration have been reported. Recent clinical research suggests the potential utility of the basophil activation test (BAT) in predicting JCL-induced anaphylaxis. Nonetheless, the BAT is deemed impractical for routine diagnostic testing due to complex procedures involving whole blood stimulation and flow cytometry-based analyses. In the study reported here, an IgE crosslinking-induced luciferase expression (EXiLE) test which uses patient sera without complicated procedures, was performed with patients who had received JCL, with or without subsequent anaphylactic symptoms. The results of this test were then compared with those of the BAT reported in a clinical research study. Of the six BAT-positive JCL-induced anaphylaxis-experienced patients, four were positive in the EXiLE test and all non-experienced patients were negative in both the BAT and EXiLE tests, thus illustrating a high concordance rate of 92.3%. Further validation of testing conditions is expected to improve these rates. Notably, complement inactivation treatment led to a positive EXiLE result in a BAT-negative patient. In conclusion, it appears that the EXiLE test exhibits promise as an alternative to BAT for predicting JCL-induced anaphylaxis, and in so doing offers a simpler diagnostic approach.

The skin is the organ most often affected by adverse drug reactions. Although these cutaneous adverse drug reactions (CADRs) often are mild, they represent a major burden for patients. One of the drugs inducing CADRs is aldesleukin, a recombinant interleukin-2 (recIL-2) originally approved to treat malignant melanoma and metastatic renal cell carcinoma which frequently led to skin rashes when applied in high doses for anti-cancer therapy. Skin rashes and other side effects, together with poor efficacy led to a drawback of the therapeutic, but modified recIL-2 molecules are on the rise to treat both cancer and inflammatory diseases such as autoimmunity. Still, pathophysiological mechanisms of recIL-2-induced skin rashes are not understood. In the study reported here, a hypothetical literature-based immune-related adverse outcome pathway (irAOP) was developed to identify possible key cells and molecules in recIL-2-induced skin rash. Using this approach, a hypothesis was formed that the induced immune response predominantly is Type 2-driven by T-helper and innate lymphoid cells, leading to the occurrence of cutaneous side effects during recIL-2 therapy. This paper further discusses mechanisms beyond the proposed irAOP which might add to the pathology but currently are less-studied. Together, this hypothetic irAOP forms a basis to clarify possible cellular and molecular interactions leading to recIL-2-induced skin rash. This might be used to adapt existing or develop new test systems to help predict and prevent cutaneous side effects in future IL-2-based or similar therapies.

Interleukin-2 (IL-2) was one of the first cytokines discovered and its central role in T cell function soon led to the notion that the cytokine could specifically activate immune cells to combat cancer cells. Recombinant human IL-2 (recIL-2) belonged to the first anti-cancer immunotherapeutics that received marketing authorization and while it mediated anti-tumor effects in some cancer entities, treatment was associated with severe and systemic side effects. RecIL-2 holds an exceptional therapeutic potential, which can either lead to stimulation of the immune system - favorable during cancer treatment - or immunosuppression - used for treatment of inflammatory diseases such as autoimmunity. Due to these pleiotropic immune effects, recIL-2 therapy is still a hot topic in research and modified recIL-2 drug candidates show ameliorated efficacy and safety in pre-clinical and clinical studies. The Immune Safety Avatar (imSAVAR) consortium aims to systemically assess mechanisms leading to adverse events provoked by recIL-2 immunotherapy as a use case in order to aid safety evaluation of future recIL-2-based therapies. Here, we summarize the historical use of recIL-2 therapy, associated side effects, and describe the molecular basis of the dual role of IL-2. Finally, an overview of new recIL-2 compounds and delivery systems, which are currently being developed, will be given, highlighting a possible comeback of recIL-2 therapy.

The chances and opportunities in modern biology inspired devising new therapeutics are mind blowing. The promises reach from successfully treating so-far incurable diseases like cancer and certain infections, to modulating and fine tuning the immune response to prolong the lifespan by inhibiting aging. However, as underlying therapies become more and more complex and sophisticated, it becomes increasingly difficult to find ways to ensure and predict the safety of these new therapeutics. The ICH guideline S6 (R1) from June 2011 EMA/CHMP/ICH/731268/ 1998 Committee for Medicinal Products for Human Use (CHMP) already stated "Conventional approaches to toxicity testing of pharmaceuticals may not be appropriate for biopharmaceuticals due to the unique and diverse structural and biological properties of the latter that may include species specificity, immunogenicity, and unpredicted pleiotropic activities" and is committed to a "flexible, case-by-case, science-based approach to preclinical safety evaluation". Initial approaches to this are described in the OECD Test Guidelines for new approach methods (NAM) with the newest update released in 2023 and alternative non-animal test guidelines (https://www.icapo.org/test-guidelines) provided from the International Council on Animal Protection in OECD Programmes (ICAPO; https://www.icapo.org). Beyond that, the European Union-funded innovative medicine initiative project Immune Safety Avatar (imSAVAR) decided to develop a systematic and holistic framework for non-clinical safety assessment of biopharmaceuticals and Advanced Therapy Medicinal Products (ATMP); thereby, the consortium focuses on immuno-regulatory therapeutics. Science-based approaches, such as the mechanistic description of adverse outcomes would be essential to demonstrate the safety of a particular new immuno-therapeutic agent. Here, we re-use the concept of adverse outcome pathways (AOP) to capture immune-related adverse outcomes (irAO), which are aimed to guide us to the use of relevant test systems and experiments. Thus, the focus within imSAVAR is on the use and (further) develop-ment of human and alternative models.

The success of cellular immunotherapies such as chimeric antigen receptor (CAR) T cell therapy has led to their implementation as a revolutionary treatment option for cancer patients. However, the safe translation of such novel immunotherapies, from non-clinical assessment to first-in-human studies is still hampered by the lack of suitable and models recapitulating the complexity of the human immune system. Additionally, using cells derived from human healthy volunteers in such test systems may not adequately reflect the altered state of the patient's immune system thus potentially underestimating the risk of life-threatening conditions, such as cytokine release syndrome (CRS) following CAR T cell therapy. The IMI2/EU project imSAVAR (immune safety avatar: non-clinical mimicking of the immune system effects of immunomodulatory therapies) aims at creating a platform for novel tools and models for enhanced non-clinical prediction of possible adverse events associated with immunomodulatory therapies. This platform shall in the future guide early non-clinical safety assessment of novel immune therapeutics thereby also reducing the costs of their development. Therefore, we review current opportunities and challenges associated with non-clinical and models for the safety assessment of CAR T cell therapy ranging from organ-on-chip models up to advanced biomarker screening.