Kristina Lundberg

Background: The development of effective cancer immunotherapies is hindered by the lack of preclinical models that faithfully preserve tumor-immune interactions. Current approaches provide limited representation of immune components, creating a critical translational gap between laboratory findings and clinical outcomes. Precision Cut Tumor Slices (PCTS) offer a promising solution by maintaining complete tumor architecture including native immune cell populations and spatial organization. Methods: We established a PCTS platform using fresh bladder cancer specimens and optimized culture conditions to preserve tissue integrity and cell viability. Comprehensive phenotyping was performed using flow cytometry to characterize tumor and immune cell populations. Immune functionality was validated through CD3/CD28 stimulation experiments measuring activation markers (CD69, CD137, HLA-DR) and cytokine secretion. Nine patient samples were treated with the PD-1 checkpoint inhibitor nivolumab to assess ex vivo effects. Additionally, multiplex immunofluorescence microscopy was employed on fixed PCTS as a readout for spatial distribution and cytotoxic effects of chemotherapy agents. Results: PCTS maintained viability of both cancer cells and diverse immune populations for up to six days. Functional validation demonstrated immune responsiveness upon T cell stimulation, with elevated activation markers and significantly increased secretion of inflammatory mediators including IFNγ and CXCL10, in treated as compared to control samples. The platform successfully addressed intra-tumor heterogeneity while maintaining experimental reproducibility across patient samples. Treatment with nivolumab revealed heterogeneous responses, with two out of nine samples (22%) demonstrating dose-dependent immune activation in the PCTS model, consistent with published response rates. Multiplex immunofluorescence analysis confirmed the ability to capture both immune-mediated responses and direct cytotoxic effects on cancer cells, enabling comprehensive evaluation of combination therapies. Conclusions: This validated PCTS platform represents a versatile human-derived tool for evaluating cancer immunotherapies while maintaining physiological tumor microenvironment complexity. The technical foundation established here enables future prospective studies correlating ex vivo responses with patient clinical outcomes, potentially advancing personalized treatment selection and reducing reliance on animal models in immunotherapy development.

Bladder cancer is a heterogenous disease, and molecular subtyping is a promising method to capture this variability. Currently, the immune compartment in relation to subtypes is poorly characterized. Here, we analyzed the immune compartment in bladder tumors and normal bladder urothelium with a focus on T cell subpopulations using flow cytometry and RNA sequencing. The results were investigated in relation to tumor invasiveness (NMIBC/MIBC) and molecular subtypes according to the Lund Taxonomy system. Whereas the NMIBC/MIBC differed in the overall immune infiltration only, the molecular subtypes differed both in terms of immune infiltration and immune compartment compositions. The Basal/Squamous (Ba/Sq) and genomically unstable (GU) tumors displayed increased immune infiltration compared to urothelial-like (Uro) tumors. Additionally, the GU tumors had a higher proportion of regulatory T cells within the immune compartment compared to Uro tumors. Furthermore, sequencing showed higher levels of exhaustion in CD8⁺ T cells from GU tumors compared to both Uro tumors and the control. Although no such difference was detected at the transcriptomic level in Uro tumors compared to the controls, CD8⁺ T cells in Uro tumors showed higher expression of several exhaustion markers at the protein level. Taken together, our findings indicate that depending on the molecular subtype, different immunotherapeutic interventions might be warranted.

Background: Acute myeloid leukemia (AML) patients have limited effect from T‐cell‐based therapies, such as PD‐1 and CTLA‐4 blockade. However, recent data indicate that AML patients with TP53 mutation have higher immune infiltration and other immunomodulatory therapies could thus potentially be effective. Here, we performed the transcriptional analysis of distinct T‐cell subpopulations from TP53‐mutated AML to identify gene expression signatures suggestive of altered functional properties.Methods: CD8⁺ cytotoxic T lymphocytes (CTLs), conventional helper T cells (Th), and regulatory T cells (Tregs) were sorted from peripheral blood of AML patients with TP53 mutation (n = 5) and healthy donors (n = 3), using FACS, and the different subpopulations were subsequently subjected to RNA‐sequencing. Differentially expressed genes were identified and gene set enrichment analysis (GSEA) was performed to outline altered pathways and exhaustion status. Also, expression levels for a set of genes encoding established and emerging immuno‐oncological targets were defined.Results: The results showed altered transcriptional profiles for each of the T‐cell subpopulations from TP53‐mutated AML as compared to control subjects. IFN‐α and IFN‐γ signaling were stronger in TP53‐mutated AML for both CTLs and Tregs. Furthermore, in TP53‐mutated AML as compared to healthy controls, Tregs showed gene expression signatures suggestive of metabolic adaptation to their environment, whereas CTLs exhibited features of exhaustion/dysfunction with a stronger expression of TIM3 as well as enrichment of a gene set related to exhaustion.Conclusions: The results provide insights on mechanisms underlying the inadequate immune response to leukemic cells in TP53‐mutated AML and open up for further exploration toward novel treatment regimens for these patients.

Allergen-specific immunotherapy (AIT) induces tolerance and shifts the Th2 response towards a regulatory T-cell profile. The underlying mechanisms are not fully understood, but dendritic cells (DC) play a vital role as key regulators of T-cell responses. DCs interact with allergens via Fc receptors (FcRs) and via certain C-type lectin receptors (CLRs), including CD209/DC-SIGN, CD206/MR and Dectin-2/CLEC6A. In this study, the effect of AIT on the frequencies as well as the FcR and CLR expression profiles of human DC subsets was assessed. PBMC was isolated from peripheral blood from seven allergic donors before and after 8 weeks and 1 year of subcutaneous AIT, as well as from six non-allergic individuals. Cells were stained with antibodies against DC subset-specific markers and a panel of FcRs and CLRs and analyzed by flow cytometry. After 1 year of AIT, the frequency of CD123⁺ DCs was increased and a larger proportion expressed FcεRI. Furthermore, the expression of CD206 and Dectin-2 was reduced on CD141⁺ DCs after 1 year of treatment and CD206 as well as Dectin-1 was additionally down regulated in CD1c⁺ DCs. Interestingly, levels of DNGR1/CLEC9A on CD141⁺ DCs were increased by AIT, reaching levels similar to cells isolated from non-allergic controls. The modifications in phenotype and occurrence of specific DC subsets observed during AIT suggest an altered capacity of DC subsets to interact with allergens, which can be part of the mechanisms by which AIT induces allergen tolerance.

Summary: Dendritic cells (DCs) operate as the link between innate and adaptive immunity. Their expression of pattern recognition receptors (PRRs), such as Toll‐like receptors (TLRs) and C‐type lectin receptors (CLRs), enables antigen recognition and mediates appropriate immune responses. Distinct subsets of human DCs have been identified; however their expression of PRRs is not fully clarified. Expressions of CLRs by DC subpopulations, in particular, remain elusive. This study aimed to identify and compare PRR expressions on human blood DC subsets, including CD1c⁺, CD141⁺ and CD16⁺ myeloid DCs and CD123⁺ plasmacytoid DCs, in order to understand their capacity to recognize different antigens as well as their responsiveness to PRR‐directed targeting. Whole blood was obtained from 13 allergic and six non‐allergic individuals. Mononuclear cells were purified and multi‐colour flow cytometry was used to assess the expression of 10 CLRs and two TLRs on distinct DC subsets. PRR expression levels were shown to differ between DC subsets for each PRR assessed. Furthermore, principal component analysis and random forest test demonstrated that the PRR profiles were discriminative between DC subsets. Interestingly, CLEC9A was expressed at lower levels by CD141⁺ DCs from allergic compared with non‐allergic donors. The subset‐specific PRR expression profiles suggests individual responsiveness to PRR‐targeting and supports functional specialization.

The aim of the study was to investigate self-experienced nasal symptoms among adults treated for UCLP and the association to clinical findings, and to evaluate whether palate closure in one-stage or two-stages affected the symptoms or clinical findings. All people with UCLP born between 1960–1987, treated at Uppsala University Hospital, were considered for participation in this cross-sectional population study with long-term follow-up. Eighty-three patients (76% participation rate) participated, a mean of 37 years after the first operation. Fifty-two patients were treated with one-stage palate closure and 31 with two-stage palate closure. An age-matched group of 67 non-cleft controls completed the same study protocol, which included a questionnaire regarding nasal symptoms, nasal inspection, anterior rhinoscopy, and nasal endoscopy. Patients reported a higher frequency of nasal symptoms compared with the control group, e.g., nasal obstruction (81% compared with 60%) and mouth breathing (20% compared with 5%). Patients also rated their nasal symptoms as having a more negative impact on their daily life and physical activities than controls. Nasal examination revealed higher frequencies of nasal deformities among patients. No positive correlation was found between nasal symptoms and severity of findings at nasal examination. No differences were identified between patients treated with one-stage and two-stage palate closure regarding symptoms or nasal findings. Adult patients treated for UCLP suffer from more nasal symptoms than controls. However, symptoms are not associated with findings at clinical nasal examination or method of palate closure.

Dendritic cells (DCs) comprise heterogeneous populations of cells, which act as central orchestrators of the immune response. Applicability of primary DCs is restricted due to their scarcity and therefore DC models are commonly employed in DC-based immunotherapy strategies and in vitro tests assessing DC function. However, the interrelationship between the individual in vitro DC models and their relative resemblance to specific primary DC populations remain elusive. To describe and assess functionality and applicability of the available in vitro DC models by using a genome-wide transcriptional approach. Transcriptional profiling was performed with four commonly used in vitro DC models (MUTZ-3-DCs, monocyte-derived DCs, CD34-derived DCs and Langerhans cells (LCs)) and nine primary DC populations (dermal DCs, LCs, blood and tonsillar CD123⁺, CD1c⁺ and CD141⁺ DCs, and blood CD16⁺ DCs). Principal Component Analysis showed that transcriptional profiles of each in vitro DC model most closely resembled CD1c⁺ and CD141⁺ tonsillar myeloid DCs (mDCs) among primary DC populations. Thus, additional differentiation factors may be required to generate model DCs that more closely resemble other primary DC populations. Also, no model DC stood out in terms of primary DC resemblance. Nevertheless, hierarchical clustering showed clusters of differentially expressed genes among individual DC models as well as primary DC populations. Furthermore, model DCs were shown to differentially express immunologically relevant transcripts and transcriptional signatures identified for each model DC included several immune-associated transcripts. The unique transcriptional profiles of in vitro DC models suggest distinct functionality in immune applications. The presented results will aid in the selection of an appropriate DC model for in vitro assays and assist development of DC-based immunotherapy.