Immunological Characterization Research Articles

Immunological characterization of IgG subclass deficiency reveals decreased Tregs and increased circulating costimulatory and regulatory immune checkpoints.

Immunoglobulin G subclass deficiencies (IgGsd) comprise a wide clinical spectrum from no symptoms to repeated respiratory infections and risk for the development of lung damage. Our aims were to investigate whether the immunological phenotype of IgGsd patients on and off immunoglobulin replacement therapy (IgRT) was reflected in the clinical features of IgGsd. Thirty patients with IgGsd were included in this prospective study of 18 months of IgRT, followed by 7-18 months of IgRT discontinuation. Blood samples were collected when patients were on and off IgRT and compared with samples from 34 cross-sectional healthy controls. An in-depth lymphocyte phenotyping was performed by flow cytometry and plasma levels of immune checkpoints were assessed. IgG3 subclass deficiency was most common. Patients with IgGsd had decreased levels of activated T cells and B cells and plasma levels of negative immune checkpoint molecules correlated negatively with T cell and B cell activation. The decreased T cell activation level was unaffected by IgRT, while the B cell activation was partly restored. Of note, decreased levels of activated regulatory T cells (Tregs) were found in IgGsd patients and was partly restored during IgRT. The profile of comorbidities did not associate with Treg levels. IgGsd is associated with decreased B cell and T cell activation including Tregs, and increased plasma levels of negative immune checkpoint molecules. The consequence of reduced activated Tregs in IgGsd remains unclear. Decreased immune cell activation was partly restored during IgRT, demonstrating that IgRT may contribute to improved immune function in patients with IgGsd.

A novel immunofluorescence study of Lingual Salivary Glands in the Egyptian Tortoise (Testudo kleinmanni) and its ecological significance

The Egyptian tortoise (Testudo kleinmanni) is remarkably adapted to its harsh desert environment, a characteristic that is crucial for its survival under extreme conditions. This study was aimed at providing a deeper understanding of the lingual salivary gland structures in the Egyptian tortoise and examining how these structures help the tortoise manage hydration and nutrition in arid conditions. Utilizing a combination of light microscopy and immunofluorescence, this research introduced pioneering methods involving seven different antibodies, marking a first in the study of reptilian salivary glands. Our investigations categorized the tortoise’s salivary glands into papillary and non-papillary types. The papillary glands were further classified into superficial, deep, interpapillary, and intraepithelial salivary glands, while non-papillary glands included superficial and deep lingual types. Structurally, these glands are organized into lobules, delineated by interlobular septa, and are equipped with a duct system comprising interlobular, intercalated, and main excretory ducts with gland openings on the tongue's surface and the papillae surfaces. Notably, the superficial glands displayed both tubuloalveolar and acinar configurations, whereas the deep lingual glands were exclusively acinar. Immunofluorescence results indicated that α-smooth muscle actin (α-SMA) was prevalent in myoepithelial cells, myofibroblasts, and blood vessels, suggesting their integral role in glandular function and support. E-cadherin was predominantly found in epithelial cells, enhancing cell adhesion and integrity, which are critical for efficient saliva secretion. Importantly, Mucin 1 (MUC1) and Mucin 5B (MUC5B) staining revealed that most glands were mucous in nature, with MUC5B specifically marking mucin within secretory cells, confirming their primary function in mucous secretion. PDGFRα and CD34 highlighted the presence of telocytes and stromal cells within the glandular and interlobular septa, indicating a role in structural organization and possibly in regenerative processes. Cytokeratin 14 expression was noted in the basal cells of the glands, underscoring its role in upholding the structural foundation of the epithelial barrier. In conclusion, this detailed morphological and immunological characterization of the Egyptian tortoise’s salivary glands provides new insights into their complex structure and essential functions. These findings not only enhance our understanding of reptilian physiology but also underline the critical nature of salivary glands in supporting life in arid environments. This study's innovative use of a broad range of immunofluorescence markers opens new avenues for further research into the adaptive mechanisms of reptiles.

Exploring cuproptosis-related molecular clusters and immunological characterization in ischemic stroke through machine learning

Exploring cuproptosis-related molecular clusters and immunological characterization in ischemic stroke through machine learning

Pan-cancer evaluation of tumor-infiltrating lymphocytes and programmed cell death protein ligand-1 in metastatic biopsies and matched primary tumors.

Tumor immunological characterization includes evaluation of tumor-infiltrating lymphocytes (TILs) and programmed cell death protein ligand-1 (PD-L1) expression. This study investigated TIL distribution, its prognostic value, and PD-L1 expression in metastatic and matched primary tumors (PTs). Specimens from 550 pan-cancer patients of the SHIVA01 trial (NCT01771458) with available metastatic biopsy and 111 matched PTs were evaluated for TILs and PD-L1. Combined positive score (CPS), tumor proportion score (TPS), and immune cell (IC) score were determined. TILs and PD-L1 were assessed according to PT organ of origin, histological subtype, and metastatic biopsy site. We found that TIL distribution in metastases did not vary according to PT organ of origin, histological subtype, or metastatic biopsy site, with a median of 10% (range: 0-70). TILs were decreased in metastases compared to PT (20% [5-60] versus 10% [0-40], p < 0.0001). CPS varied according to histological subtype (p = 0.02) and biopsy site (p < 0.02). TPS varied according to PT organ of origin (p = 0.003), histological subtype (p = 0.0004), and metastatic biopsy site (p = 0.00004). TPS was higher in metastases than in PT (p < 0.0001). TILs in metastases did not correlate with overall survival. In conclusion, metastases harbored fewer TILs than matched PT, regardless of PT organ of origin, histological subtype, and metastatic biopsy site. PD-L1 expression increased with disease progression. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Suppression of viral rebound by a Rev-dependent lentiviral particle in SIV-infected rhesus macaques.

Persistence of human immunodeficiency virus (HIV) reservoirs prevents viral eradication, and consequently HIV-infected patients require lifetime treatment with antiretroviral therapy (ART) [1-5]. Currently, there are no effective therapeutics to prevent HIV rebound upon ART cessation. Here we describe an HIV/SIV Rev-dependent lentiviral particle that can be administered to inhibit viral rebound [6-9]. Using simian immunodeficiency virus (SIV)-infected rhesus macaques as a model, we demonstrate that the administration of pre-assembled SIV Rev-dependent lentiviral particles into SIVmac239-infected Indian rhesus macaques can lead to reduction of viral rebound upon ART termination. One of the injected animals, KC50, controlled plasma and CNS viremia to an undetectable level most of the time for over two years after ART termination. Surprisingly, detailed molecular and immunological characterization revealed that viremia control was concomitant with the induction of neutralizing antibodies (nAbs) following the administration of the Rev-dependent vectors. This study emphasizes the importance of neutralizing antibodies (nAbs) for viremia control [10-15], and also provides proof of concept that the Rev-dependent vector can be used to target viral reservoirs, including the CNS reservoirs, in vivo. However, future large-scale in vivo studies are needed to understand the potential mechanisms of viremia control induced by the Rev-dependent vector.

Identification and immunological characterization of genes associated with ferroptosis in Alzheimer's disease and experimental demonstration.

The incidence of Alzheimer's disease (AD) is rising globally, yet its treatment and prediction of this condition remain challenging due to the complex pathophysiological mechanisms associated with it. Consequently, the objective of the present study was to analyze and characterize the molecular mechanisms underlying ferroptosis‑related genes (FEGs) in the pathogenesis of AD, as well as to construct a prognostic model. The findings will provide new insights for the future diagnosis and treatment of AD. First, the AD dataset GSE33000 from the Gene Expression Omnibus database and the FEGs from FerrDB were obtained. Next, unsupervised cluster analysis was used to obtain the FEGs that were most relevant to AD. Subsequently, enrichment analyses were performed on the FEGs to explore biological functions. Subsequently, the role of these genes in the immune microenvironment was elucidated through CIBERSORT. Then, the optimal machine learning was selected by comparing the performance of different machine learning models. To validate the prediction efficiency, the models were validated using nomograms, calibration curves, decision curve analysis and external datasets. Furthermore, the expression of FEGs between different groups was verified using reverse transcription quantitative PCR and western blot analysis. In AD, alterations in the expression of FEGs affect the aggregation and infiltration of certain immune cells. This indicated that the occurrence of AD is strongly associated with immune infiltration. Finally, the most appropriate machine learning models were selected, and AD diagnostic models and nomograms were built. The present study provided novel insights that enhance understanding with regard to the molecular mechanism of action of FEGs in AD. Moreover, the present study provided biomarkers that may facilitate the diagnosis of AD.

Morphological and immunological characterization of primary cultured chicken caecal epithelial cells.

Cell cultures are models in biological and medical research to understand physiological and pathological processes. Cell lines are not always available depending on cell type and required species. In addition, the immortalization process often affects cell biology. Primary cells generally maintain a greater degree of similarity in short-term culture to the cells in tissue. Goal of this study was to verify the suitability of chicken primary epithelial caecal cells (PECCs) for in vitro investigations of host‒pathogen interactions. Epithelial nature of PECCs was confirmed by detection of tight and adherens junctions and cobblestone-like cell morphology. Sialic acids distribution was similar to that in caecal cyrosections. To understand the capacity of PECCs to respond to microbial challenges, the Toll-like receptors (TLRs) repertoire was determined. Exposure of PECCs to polyinosinic-polycytidylic acid (poly(I:C)) or lipopolysaccharide (LPS) led to upregulation of type I and III interferon (IFN) as well as interleukin (IL-) 1β, IL-6 and IL-8 mRNA expression. Overall, the PECCs showed properties of polarized epithelial cells. The presence of TLRs, their differential expression, as well as pattern recognition receptor dependent immune responses enable PECCs to act as suitable in vitro model for host‒pathogen interaction studies, which are difficult to conduct under in vivo conditions.

Multiomics integration-based immunological characterizations of adamantinomatous craniopharyngioma in relation to keratinization

Although adamantinomatous craniopharyngioma (ACP) is a tumour with low histological malignancy, there are very few therapeutic options other than surgery. ACP has high histological complexity, and the unique features of the immunological microenvironment within ACP remain elusive. Further elucidation of the tumour microenvironment is particularly important to expand our knowledge of potential therapeutic targets. Here, we performed integrative analysis of 58,081 nuclei through single-nucleus RNA sequencing and spatial transcriptomics on ACP specimens to characterize the features and intercellular network within the microenvironment. The ACP environment is highly immunosuppressive with low levels of T-cell infiltration/cytotoxicity. Moreover, tumour-associated macrophages (TAMs), which originate from distinct sources, highly infiltrate the microenvironment. Using spatial transcriptomic data, we observed one kind of non-microglial derived TAM that highly expressed GPNMB close to the terminally differentiated epithelial cell characterized by RHCG, and this colocalization was verified by asmFISH. We also found the positive correlation of infiltration between these two cell types in datasets with larger cohort. According to intercellular communication analysis, we report a regulatory network that could facilitate the keratinization of RHCG+ epithelial cells, eventually causing tumour progression. Our findings provide a comprehensive analysis of the ACP immune microenvironment and reveal a potential therapeutic strategy base on interfering with these two types of cells.

Immunologic characterization of the Bm05br protein using the Rhipicephalus linnaei (Audouin, 1826) species as a tick model

The identification and characterization of tick proteins allow us to discover new physiological targets useful for the development of tick control methods. Bm05br (Brazil Rhipicephalus microplus protein 05) is a protein with unknown function identified in the saliva of R. microplus. Rs05br (Brazil Rhipicephalus sanguineus protein 05), a protein with 99 % similarity to Bm05br, was identified in Rhipicephalus linnaei egg, larval, and nymphal stages, as well as in adult saliva. To improve the knowledge about both proteins, immunological characterization was performed, including antigenicity analysis, vaccination trials, and artificial feeding. The sequence and antigenicity analysis of Bm05br and Rs05br proteins showed that R. linnaei could serve as a tick model for cross-protection studies. The recombinant Bm05br protein was immunogenic. Anti-Bm05br antibodies recognized the homologous protein Rs05br in different stages, organs, and in the saliva of R. linnaei. Although rBm05br did not induce a protective response against infestation in R. linnaei in this study, further experiments could be developed taking into account new formulations and animal models for vaccination. These results also serve as a reference for future research on the function of these proteins in R. microplus and R. linnaei physiology, as well as other species of the genus Rhipicephalus.

Genetic and immune identification and functional analysis of TRPM8 as a potential biomarker for pancreatic adenocarcinoma proliferation.

Pancreatic adenocarcinoma (PAAD), a member of highly lethal malignant tumors, has a poor outcome and extremely poor prognosis. The transient receptor potential (TRP) superfamily, a group of nonselective cation channels, is capable of influencing cellular functions by regulating calcium homeostasis. In addition, it has been shown that TRP channels can also affect various cellular phenotypes by regulating gene transcription levels and are involved in the development of a variety of malignant tumors. In order to find new therapeutic targets and biomarkers to improve the clinical prognosis of pancreatic cancer, we performed genetic and immunological characterization of TRP channels in PAAD, as well as related functional and prognostic analyses. We investigated the expression, genetic alterations, methylation levels, and immune infiltration levels of TRP channels in PAAD, and further also analyzed the function of TRP channels in PAAD and their prognostic value for PAAD patients. Our results suggest that TRPM8 may contribute to tumor proliferation by controlling the PI3K-AKT-mTOR signaling pathway in PAAD. After careful evaluation of the accumulated data, we concluded that TRPM8 has potential as a prognostic indicator and prospective therapeutic target in PAAD.

Molecular and immunological characterization of androgen receptor expression in different breast cancer subtypes.

1114 Background: While estrogen receptor (ER) is well-studied in breast cancer (BC), the role of androgen receptor (AR) in prognosis and therapy response is less understood. Here, we aimed to characterize the clinicopathologic and molecular features of AR gene expression in BC subtypes. Methods: 10,728 BC samples were tested by NGS (592, NextSeq; WES, NovaSeq) and WTS (NovaSeq; Caris Life Sciences, Phoenix, AZ). MSI was tested by IHC and NGS. TMB-high was designated as &gt;10 somatic mutations/MB. Tumors with AR-high(H) and AR-low(L) RNA expression were classified by top and bottom quartile, respectively. Real world overall survival (OS) and treatment-associated survival was obtained from insurance claims and calculated from treatment start to last contact using Kaplan-Meier estimates. Statistical significance was determined by chi-square and Mann-Whitney U test with p-values adjusted for multiple comparisons ( q&lt;.05). Results: Lobular carcinoma had higher AR expression (2.37-fold) and AR positivity by IHC (93.6% vs 63.6%) compared to ductal carcinoma ( q&lt;.05). Luminal A (LumA) had higher AR expression and IHC positivity compared to HER2-enriched, basal-like, and normal-like tumors ( q&lt;.05). AR-H tumors were significantly ( p&lt;.05) enriched for PIK3CA mutations in LumA (60.3% vs 29.8%), LumB (48.1% vs 23.2%), HER2-enriched (51.2% vs 39.3%), and basal-like (23.8% vs 8.3%); CDH1 mutations in LumA (26% vs 10.3%) and normal-like (55.5% vs 4.8%); MAP3K1 in LumA (17.1% vs 5.3%); ESR1 in LumB (17.9% vs 10.7%); and NF1 in HER2-enriched (19.3% vs 7.1%). AR-H had higher immune infiltration for LumA (B cells, M2 Mφ, neutrophils, NK cells, DC), LumB (B cells, M2 Mφ, neutrophils, NK cells, CD4+ T cells, DC), basal-like (NK cells, CD4+ T cells), and normal-like (NK cells, DC; q&lt;.05) than AR-L. Conversely, AR-H HER2-enriched tumors had lower immune infiltration (B cells, M1 and M2 Mφ, NK cells, CD8+ T cells, DC) and fewer TMB-high (15.1% vs 23.2%), dMMR/MSI-high (0.3% vs 2%), and PD-L1+ tumors (15% vs 40.8%; p&lt;.05) compared to AR-L (all q&lt;.05). Post-doxorubicin survival was longer for patients with AR-H tumors; however, opposing trends were observed for patients with LumB (75.5 vs 56.3 m; p=.081) and HER2-enriched tumors (47.9 vs 65.2 m; p.071). AR-H was associated with longer post-dox survival in patients with LumB PIK3CA-mt tumors (81.7 vs 39.3 m; p=.036), but shorter post-dox survival in HER2-enriched PIK3CA-wt (50.4 vs 70.4 m) and PIK3CA-mt cohorts (40.8 vs 58.0 m; p=.18). Conclusions: Findings from our updated analysis based on PAM50 designation suggest a strong association between AR and PIK3CA mutations across subtypes and suggest that distinct AR-associated alterations in the immune microenvironment require further study. Exploration of specific mutations and immune-oncology markers associated with AR-H may aid in molecularly selected clinical trial design for advanced BC patients.

Loxosceles amazonica Brown Spider venom: Insights into enzymatic activities, immunorecognition, and novel phospholipase D isoforms

The Loxosceles genus represents one of the main arachnid genera of medical importance in Brazil. Despite the gravity of Loxosceles-related accidents, just a handful of species are deemed medically important and only a few have undergone comprehensive venom characterization. Loxosceles amazonica is a notable example of a potentially dangerous yet understudied Loxosceles species. While there have been limited reports of accidents involving L. amazonica to date, accidents related to Loxosceles are increasing in the North and Northeast regions of Brazil, where L. amazonica has been reported. In this work, we provide a complementary biochemical and immunological characterization of L. amazonica venom, considering its most relevant enzymatic activities and its immunorecognition and neutralization by current therapeutic antivenoms. Additionally, a cDNA library enriched with phospholipase D (PLD) sequences from L. amazonica venom glands was built and subsequently sequenced. The results showed that L. amazonica venom is well immunorecognised by all the tested antibodies. Its venom also displayed proteolytic, hyaluronidase, and sphingomyelinase activities. These activities were at least partially inhibited by available antivenoms. With cDNA sequencing of PLDs, seven new putative isoforms were identified in the venom of L. amazonica. These results contribute to a better knowledge of the venom content and activities of a synanthropic, yet understudied, Loxosceles species. In vivo assays are essential to confirm the medical relevance of L. amazonica, as well as to assess its true toxic potential and elucidate its related pathophysiology.

Comparison of T cell maturation profiles in the 1st and 5th wave of COVID-19 in the Polish population.

The coronavirus pandemic has become the most critical global health threat of this century and the greatest challenge to the human population. The search for simple and quick diagnostic methods enabling the identification of patients infected with the SARS-CoV-2 virus may be a valuable method to track infection. The aim of the study was the clinical and immunological characterization of patients by assessing the degrees of maturity of T lymphocytes from the 1st and 5th waves of coronavirus disease 2019 (COVID-19) in comparison to a healthy control group (HC). We determined leukocyte and T lymphocyte subpopulations (recent thymic emigrant (RTE), naïve, effector, central memory and effector memory) in patients from the 1st COVID-19 wave (n = 23), the 5th COVID-19 wave (n = 38) and HC (n=20) using a panel of monoclonal antibodies using multiparameter flow cytometry. We observed a lower median proportion of lymphocytes and NK cells, and elevated percentage and number of neutrophils in patients from the 5th wave compared to the 1st. We found a reduced percentage of CD4+ effector memory cells in the 1st wave group compared to the 5th wave (14.1 vs 23.2, p < 0.05), and a higher percentage of RTE and naïve CD8+ cells in the 1st wave compared to the 5th wave (p < 0.05). The effector memory CD8+ cells were highest in the 5th wave compared to both 1st wave and HC patients (respectively, 35.1 vs 18.1 vs 19.3%, p < 0.05). The 5th wave group showed significantly more differences compared to HC. Our results showed a clear increase of effector cells with a simultaneous decrease in virgin T cells in the 5th COVID-19 infection. Monitoring lymphocyte subsets during infection allows assessment of the patient's immune status and of readiness of lymphocytes to respond to the immune response, and may be necessary to improve clinical outcomes.

Cuproptosis-related Gene Signatures and Immunological Characterization in Sepsis-associated Acute Lung Injury.

Sepsis is a frequent cause of acute lung injury (ALI), characterized by immune dysregulation and a high mortality rate. The role of cuproptosis, a recently discovered cell death mechanism, in sepsis-associated ALI is still unclear. The study aimed to investigate the regulatory mechanisms and immune characteristics associated with cuproptosis in sepsisassociated ALI, with implications for novel diagnostic and therapeutic approaches. Data from the GEO database was utilized to conduct a comprehensive analysis of the cuproptosis-related genes (CRGs) in sepsis-associated ALI. Gene enrichment analysis, WGCNA, CIBERSORT algorithm, and consensus clustering were employed to investigate the associations between CRGs and immune cells. A predictive model for sepsis-associated ALI was developed based on key CRGs, and its diagnostic accuracy was assessed. Finally, qPCR was employed to validate alterations in the expression of CRGs in the sepsis-associated ALI cellular model. A total of 14 CRGs were identified in sepsis-associated ALI. Strong correlations between the CRGs and immune cells were observed, and two different CRG subtypes were identified. The expression of immune-related factors in both the CRG and gene clusters exhibited similarities, suggesting a connection between the subgroups and immune cells. The prediction model effectively forecasted the incidence of sepsis-associated ALI based on the expression of CRGs. Finally, qPCR analysis confirmed that the expressions of CRGs in the sepsis-associated ALI cell model closely matched those identified through bioinformatic analyses. The study comprehensively evaluated the complex relationship between cuproptosis and sepsis-associated ALI. CRGs were found to be significantly associated with the occurrence, immune characteristics, and biological processes of sepsis-associated ALI. These findings provide valuable new insights into the mechanisms underlying sepsis-associated ALI.

Establishment of a new equine embryo brain primary cell culture with long-term expansion

Primary cell cultures derived from human embryo lung play a crucial role in virology by aiding virus propagation and vaccine development. These cultures exhibit a notable ability to undergo multiple subcultures, often reaching up to 70 passages. However, finding alternative primary cell cultures with similar longevity and usefulness is challenging. In this study, we introduce a novel primary culture cells derived from equine embryo brain (FEB), which cells exhibited remarkable long-term cultivation potential. The FEB was established and maintained using Sumitomo Nerve-Cell Culture System Comparison studies were conducted with fetal equine kidney cell line (FEK-Tc13) to assess growth rates and subculture longevity. Immunological characterization was performed using neuronal markers to confirm the neural nature of FEB cells. Viral growth assessments were conducted using equine herpesviruses (EHV-1 and EHV-4) to evaluate infectivity and cytopathic effects in FEB cells. PCR analysis and real-time PCR assays were employed to detect viral genomic DNA and transcription activity of EHVs in infected FEB cells. FEB cells demonstrated faster growth rates compared to fetal equine kidney cell line (FEK-Tc13 cells) and exhibited sustained subculture capability exceeding 50 passages. Immunostaining confirmed the glial identity of FEB cells. Both equine herpesviruses 1 and 4 EHV-1 and EHV-4 viruses efficiently replicated in FEB cells, resulting in clear cytopathic effects. PCR analysis detected genomic DNA of EHVs in infected FEB cells, indicating successful viral infection. The establishment of FEB cells with extended subculture capability highlights their potential utility as a model system for studying neural cell biology and viral infections.

Immunological isolation and characterization of neuronal progenitors from human dental pulp: A laboratory-based investigation.

Dental pulp stem cells (DPSCs) contain a population of stem cells with a broad range of differentiation potentials, as well as more lineage-committed progenitors. Such heterogeneity is a significant obstacle to experimental and clinical applications. The aim of this study is to isolate and characterize a homogenous neuronal progenitor cell population from human DPSCs. Polysialylated-neural cell adhesion molecule (PSA-NCAM+) neural progenitors were isolated from the dental pulp of three independent donors using magnetic-activated cell sorting (MACS) technology. Immunofluorescent staining with a panel of neural and non-neural markers was used to characterize the magnetically isolated PSA-NCAM+ fraction. PSA-NCAM+ cells were then cultured in Neurobasal A supplemented with neurotrophic factors: dibutyryl cyclic-AMP, neurotrophin-3, B27 and N2 supplements to induce neuronal differentiation. Both PSA-NCAM+ and differentiated PSA-NCAM+ cells were used in Ca2+ imaging studies to assess the functionality of P2X3 receptors as well as membrane depolarization. PSA-NCAM+ neural progenitors were isolated from a heterogeneous population of hDPSCs using magnetic-activated cell sorting and anti-PSA-NCAM MicroBeads. Flow cytometry analysis demonstrated that immunomagnetic sorting significantly increased the purity of PSA-NCAM+ cells. Immunofluorescent staining revealed expression of pan-neuronal and mature neuronal markers, PGP9.5 and MAP2, respectively, as well as weak expression of the mature sensory markers, peripherin and islet1. ATP-induced response was mediated predominately by P2X3 receptors in both undifferentiated and differentiated cells, with a greater magnitude observed in the latter. In addition, membrane depolarizations were also detected in cells before and after differentiation when loaded with fast-voltage-responding fluorescent molecule, FluoVolt™ in response to potassium chloride. Interestingly, only differentiated PSA-NCAM+ cells were capable of spontaneous membrane oscillations. In summary, DPSCs contain a population of neuronal progenitors with enhanced neural differentiation and functional neural-like properties that can be effectively isolated with magnetic-activated cell sorting (MACS).

A glucan-particle based tularemia subunit vaccine induces T-cell immunity and affords partial protection in an inhalation rat infection model.

Tularemia is a zoonotic disease caused by the facultative intracellular gram-negative bacterium Francisella tularensis. F. tularensis has a very low infection dose by the aerosol route which can result in an acute, and potentially lethal, infection in humans. Consequently, it is classified as a Category A bioterrorism agent by the US Centers for Disease Control (CDC) and is a pathogen of concern for the International Biodefence community. There are currently no licenced tularemia vaccines. In this study we report on the continued assessment of a tularemia subunit vaccine utilising β-glucan particles (GPs) as a vaccine delivery platform for immunogenic F. tularensis antigens. Using a Fischer 344 rat infection model, we demonstrate that a GP based vaccine comprising the F. tularensis lipopolysaccharide antigen together with the protein antigen FTT0814 provided partial protection of F344 rats against an aerosol challenge with a high virulence strain of F. tularensis, SCHU S4. Inclusion of imiquimod as an adjuvant failed to enhance protective efficacy. Moreover, the level of protection afforded was dependant on the challenge dose. Immunological characterisation of this vaccine demonstrated that it induced strong antibody immunoglobulin responses to both polysaccharide and protein antigens. Furthermore, we demonstrate that the FTT0814 component of the GP vaccine primed CD4+ and CD8+ T-cells from immunised F344 rats to express interferon-γ, and CD4+ cells to express interleukin-17, in an antigen specific manner. These data demonstrate the development potential of this tularemia subunit vaccine and builds on a body of work highlighting GPs as a promising vaccine platform for difficult to treat pathogens including those of concern to the bio-defence community.

Abstract PO4-24-01: Comprehensive Molecular and Immunological Characterization of Invasive Ductal Triple-Negative Breast Cancer

Abstract Background: Triple-negative breast cancer (TNBC) is a heterogeneous disease and characterized by poor outcomes with a lack of targeted therapies. A comprehensive analysis of the molecular and immune landscape of invasive ductal TNBC can help improve our understanding of TNBC biology and identify novel targets and/or pathways for better management of this disease. Here, we characterized the molecular and immune signature of invasive ductal (ID) TNBC. Methods: 13,036 BC samples (ID TNBC, n=392; ID non-TNBC, n=927) were analyzed by NGS (592, NextSeq; WES, NovaSeq), WTS (NovaSeq) (Caris Life Sciences, Phoenix, AZ). A total of 10 pro-apoptotic (BAX, BAK1, BID, BAD, BIK, BCL2L11, BMF, HRK, PMAIP1, BBC3) and 6 anti-apoptotic (BCL2, BCL2L1, BCL2L2, MCL1, BCL2A1, BCL2L10) BCL2 family genes were analyzed. Immune cell fractions were calculated by deconvolution of WTS: Quantiseq. Real world overall survival (OS) and treatment-associated survival was extracted from insurance claims and calculated from tissue collection or treatment start to last contact using Kaplan-Meier estimates. Statistical significance was determined using chi-square and Mann-Whitney U test with p-values adjusted for multiple comparisons (q &amp;lt; 0.05). Results: ID TNBC had a higher frequency of TP53, RB1, NF1, PIK3R1, NOTCH1, CREBBP, BRCA1, FANCI, and HRAS mutations (Table 1), NOTCH2 (4.3% vs 0.47%), EGFR (3.4% vs 0%), NFIB (4% vs 0.6%), MYB (3.5% vs 0.5%), CCNE1 (4.4% vs 1.1%) and AKT2 (2.4% vs 0.3%) copy number alterations, and NOTCH2 (1.6% VS 0.2%) fusion (all p &amp;lt; 0.05) compared to invasive ductal non-TNBC. Analysis of inferred immune cell infiltrates showed that ID TNBC had increased infiltration of Tregs (2% vs 1.7%), DC (3.2% vs 2.4%), CD8 T cells (0.5% vs 0.1%), and M1 macrophages (M) (3.4% vs 2.9%), but decreased infiltration of B cells (4.5% vs 6%) and M2M (2.9% vs 4.5%) (all p &amp;lt; 0.05). ID TNBC had increased T cell inflamed score (23 vs -9, p &amp;lt; 0.05), IFNy score (-0.24 vs -0.34, p &amp;lt; 0.05), MHC class I genes (HLA-A, HLA-B, TAP1, TAP2, FC: 1.1-1.5, all p &amp;lt; 0.05), immune checkpoint genes (CD274, PDCD1, CTLA4, PD-L2, FOXP3, IDO, FC: 1.1-2, all p &amp;lt; 0.05) and PD-L1 protein expression (SP142: 49.8% vs. 28.4%; 22c3: 41.7% vs. 16.8%, all p &amp;lt; 0.05). ID TNBC had differential expression of BCL2 family genes (upregulation: BAK1, BID, MCL1, BCL2A1, BCL2L10, FC: 1.1-2.0; downregulation: BAD, BIK, BBC3, BCL2, BCL2L1, BCL2L2, FC: 1.2-2.8, all p &amp;lt; 0.05) compared to invasive ductal non-TNBC. ID TNBC was associated with worse OS compared to ID non-TNBC (mOS: 24.5 vs 54.6 months; HR: 0.5, 95% CI 0.47-0.57; p &amp;lt; 0.00001) but trend towards better survival with pembrolizumab (mOS: 29.4 vs 8.8 month; HR: 0.67, 95% CI 0.28-1.5; p=0.3) treatment. No significant OS difference was noted for by high vs. low pro and anti-apoptotic BCL2 genes except for anti-apoptotic BCL2A1 (higher expression associated with better OS (mOS: 5.7 months, HR: 0.78, 95% CI 0.6-0.99; p=0.047). Conclusion: These data indicate that ID TNBC is associated with distinct mutational profile compared to non-TNBC, has increased T cell inflamed score, IFNy score, MHC class I and immune checkpoint gene expression, and differential immune cell infiltration. Interestingly, TNBC was associated with increased M1 and decreased M2M. There is evidence to suggest that transcriptomically defined M1 high tumors are clinically aggressive and have worse OS in TNBC. BCL2 family genes are not prognostic for TNBC outcomes except BCL2A1, which needs further prospective validation. Table 1: Mutation frequency in invasive ductal TNBC and invasive ductal non-TNBC Citation Format: Pooja Advani, Sachin Deshmukh, Sharon Wu, Jacob Andring, Joanne Xiu, Alex Farrell, Jose Leone, Priya Jayachandran, Stephanie Graff, Matthew Oberley, George Sledge Jr, Asher Chanan-Khan. Comprehensive Molecular and Immunological Characterization of Invasive Ductal Triple-Negative Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-24-01.

Immune-monitoring of myelodysplastic neoplasms: Recommendations from the i4MDS consortium.

Advancements in comprehending myelodysplastic neoplasms (MDS) have unfolded significantly in recent years, elucidating a myriad of cellular and molecular underpinnings integral to disease progression. While molecular inclusions into prognostic models have substantively advanced risk stratification, recent revelations have emphasized the pivotal role of immune dysregulation within the bone marrow milieu during MDS evolution. Nonetheless, immunotherapy for MDS has not experienced breakthroughs seen in other malignancies, partly attributable to the absence of an immune classification that could stratify patients toward optimally targeted immunotherapeutic approaches. A pivotal obstacle to establishing "immune classes" among MDS patients is the absence of validated accepted immune panels suitable for routine application in clinical laboratories. In response, we formed International Integrative Innovative Immunology for MDS (i4MDS), a consortium of multidisciplinary experts, and created the following recommendations for standardized methodologies to monitor immune responses in MDS. A central goal of i4MDS is the development of an immune score that could be incorporated into current clinical risk stratification models. This position paper first consolidates current knowledge on MDS immunology. Subsequently, in collaboration with clinical and laboratory specialists, we introduce flow cytometry panels and cytokine assays, meticulously devised for clinical laboratories, aiming to monitor the immune status of MDS patients, evaluating both immune fitness and identifying potential immune "risk factors." By amalgamating this immunological characterization data and molecular data, we aim to enhance patient stratification, identify predictive markers for treatment responsiveness, and accelerate the development of systems immunology tools and innovative immunotherapies.

Genetic and Immunological Characterization of Brain Metastases from Solid Cancers.

Brain metastasis, a leading cause of cancer death, is a clinical challenge. Recently, genetic characterization of brain metastatic lesions based on next generation sequencing-based advanced technologies, such as single-cell RNA sequencing, has been performed to develop novel efficient therapies. The present study aimed to investigate brain-metastasis-specific biomarkers as well as relevant prognostic factors. The genetic profiles and expression levels of immune response-associated genes and 820 cancer-associated genes were compared between primary cancer lesions and metastatic cancer lesions obtained from nine cancer patients at the Shizuoka Cancer Center. Cytokine and chemokine marker genes were analyzed via quantitative PCR. T-cell receptor (TCR) repertoire profiling was performed for the same patients. For survival analysis, survival data of 52 cancer patients with brain metastases were utilized. Comparison of driver mutation profiling between primary and metastatic lesions revealed shared core mutations in both lesions and a few new mutations in metastatic lesions. A high tumor mutation burden (TMB) was detected in metastatic lesions. Volcano plot analysis revealed specific features of the metastatic tumor microenvironment, such as cancer signaling promotion and immune suppression due to decreased immune cell infiltration. Survival analysis revealed that three genes, the TREML2 gene, the BTLA gene on activated microglia and the CERS2 gene on metastatic tumor, were potent prognostic factors. High TMB in metastatic lesions indicates potential benefit from immune checkpoint inhibitor usage for brain metastasis and TREML2 and BTLA are factors associated with poor prognosis. Activated microglia may be novel targets for the treatment of brain metastasis.