[Neuroendocrine expression markers in triple-negative, luminal-A, luminal-B and HER2neu breast cancer]. / Expresión de marcadores neuroendócrinos en cáncer de mama triple-negativo, luminal-A, luminal-B y HER2neu.

Background: Primary breast tumors with neuroendocrine (NE) differentiation are a heterogeneous tumor group with diversity of biological behavior, with poorly defined prevalence and prognosis. Objective: To evaluate the chromogranin, synaptophysin, CD56, INSM1 markers expression prevalence and the association between NE differentiation and tumor molecular type. Material and methods: Observational, cross-sectional study which included 110 breast tissue samples with primary invasive carcinoma. Immunohistochemistry was performed for chromogranin, synaptophysin, CD56 and INMS1 markers. NE differentiation was considered with 10-90% positive cells, and NE tumor with > 90% positive cells. Results: 26.3% showed neuroendocrine differentiation. Out of these, 48.2% were luminal-A type, 24.1% luminal-B, 11.5% HER2neu, 17.2% triple-negative; 1.8% were NE tumors. Tumors were marker positive, and out of these to chromogranin in 24.5%, synaptophysin in 28.2%, CD56 in 2.7%, INSM1 in 16.4%. Synaptophysin was expressed in 17.3% luminal-A type, 6.4% luminal-B, 0.9% HER2neu, 3.6% triple-negative. NE differentiation showed association with synaptophysin expression (r = 0.586, p = 0.0001). Conclusion: The NE differentiation prevalence was 26.3% in primary invasive breast cancers, with luminal-A molecular type predominance.

Introducción: los tumores primarios de mama con diferenciación neuroendócrina (NEBC por sus siglas en inglés) son un grupo heterogéneo de tumores con diversidad de comportamiento biológico, con prevalencia y pronóstico poco definido. Objetivo: evaluar la prevalencia de la expresión los marcadores cromogranina, sinaptofisina, CD56, INSM1 y la asociación entre la diferenciación neuroendócrina y el tipo molecular del tumor. Material y métodos: estudio observacional, transversal que incluyó 110 muestras de tejido mamario con carcinoma invasor primario. Se realizó inmunohistoquímica para los marcadores cromogranina, sinaptofisina, CD56 y INMS1. La presencia 10-90% de células positivas se consideró diferenciación neuroendócrina y tumor neuroendócrino con > 90% de células positivas. Resultados: el 26.3% mostró diferenciación neuroendócrina. De estos, 48.2% fueron tipo luminal-A, 24.1% luminal-B, 11.5% HER2neu y 17.2% triple-negativo; 1.8% resultaron tumores neuroendócrinos. Los tumores presentaron marcadores positivos y de estos, 24.5% fueron a cromogranina, 28.2% a sinaptofisina, 2.7% a CD56 y 16.4% a INSM1. La sinaptofisina se expresó en 17.3% del tipo luminal-A, 6.4% luminal-B, 0.9% HER2neu, 3.6% triple-negativo. La diferenciación neuroendócrina mostró asociación con la expresión de sinaptofisina (r = 0.586, p = 0.0001). Conclusión: la prevalencia de la diferenciación neuroendócrina fue del 26.3% en los cánceres invasores primarios de mama, con predominio en el tipo molecular luminal-A.

Impaired Epithelial CD200L Tolerance Signaling in Irritable Bowel Syndrome Cases With Diarrhea May Be Associated With Recurrent Miscarriages.

PROBLEM: There is a higher incidence of irritable bowel syndrome with miscarriages, and recurrent miscarriages of otherwise normal embryos have been linked to subnormal expression of the immune checkpoint inhibitor CD200L. We sought to determine if alterations in the expression of the CD200 immune checkpoint inhibitor occur in colonic tissue in IBS-D patients. METHOD OF STUDY: Quantitative immunohistochemical staining of biopsies from proximal and distal colon or rectum for the inhibitory CD200L and CD200S molecules was done. CD56 cells were also enumerated as they play a role in recurrent miscarriages and may express CD200S. RESULTS: CD200L was decreased and CD200S was unchanged in epithelium but not stroma of 3 IBS-D cases. One case had an increase in both CD200L and CD200S. CD56 cells were also stained for CD200S. Degranulation was assessed by the percentage of extracellular CD200S that was increased as epithelial CD200L decreased. CONCLUSIONS: This pilot study was promising and warrants a larger sample to determine if a correlation between uterine implantation site CD200L and CD200S expression in normal and failing implantation sites is needed. Colonic epithelial CD200L may then provide useful information about the pathogenesis of the spontaneous miscarriage in individual cases.

Uterine tumors mimicking ovarian sex cord tumors with rhabdoid differentiation: a clinicopathologic study of 4 cases: A case series analysis.

RATIONALE: Uterine tumors resembling ovarian sex cord tumors (UTROSCT) with rhabdoid features are uncommon mesenchymal neoplasms exhibiting diverse histological patterns, including significant rhabdoid morphology. A thorough comprehension of their clinicopathologic features is crucial for precise diagnosis and effective management. PATIENT CONCERNS: This study presents 4 cases of UTROSCT with rhabdoid features, diagnosed in patients aged 31 to 58. Varied recurrence patterns were observed, including similar recurrent lesions to the primary tumors with subsequent mortality, initial invasion and lymph node metastasis, and presence of only primary tumor. DIAGNOSES: Histopathological examination revealed diverse morphological patterns, prominently featuring rhabdoid differentiation. Immunohistochemical analysis showed expression of hormone receptors, sex cord, smooth muscle, and epithelial markers, notably WT1, CD56, and CD99. Molecular analysis identified ESR1-NCOA2 fusions and ESR1 and NCOA2/3 rearrangements, indicating a potential association between these genetic alterations and extensive rhabdoid differentiation. INTERVENTIONS: Various treatments were administered post-recurrence, including chemotherapy and targeted therapies. However, poor clinical outcomes were observed in all cases. OUTCOMES: Despite aggressive treatments, including chemotherapy and targeted therapies, poor clinical outcomes were observed, highlighting the aggressive nature of UTROSCT with significant rhabdoid differentiation. LESSONS: This case series emphasizes the importance of detailed pathological reporting, comprehensive molecular testing, and thorough tumor staging in UTROSCT cases with rhabdoid features. Enhanced understanding of the clinicopathologic characteristics of UTROSCT with rhabdoid differentiation is crucial for accurate diagnosis, prognostication, and management strategies.

Clinical Characteristics of Peripheral Lymphocyte Subtypes in Chronic Active Epstein-Barr Virus Infection.

BACKGROUND: We aimed to analyze the clinical characteristics of peripheral Epstein-Barr virus (EBV)-infected lymphocyte subtypes in children with chronic active EBV infection (CAEBV). METHODS: The levels of peripheral EBV infection of CD4+ T cells, CD8+ T cells, and CD56+ natural killer (NK) cells were determined by flow cytometry and quantitative polymerase chain reaction (qPCR) in patients with CAEBV from July 2017 to July 2022. RESULTS: In total, 112 children with CAEBV were evaluated. Of these, CD4+ type, CD8+ type, and CD56+ type were defined in 44, 21, and 47 patients, respectively. Patients with CD8+ T-cell type had a significantly higher frequency of rash, while hepatomegaly was more common in patients with CD4+ T-cell type. Generally, patients with CD8+ T-cell type had the lowest overall survival rate (P = .017). Patients treated with chemotherapy and hematopoietic stem cell transplantation (HSCT) had a better prognosis (P = .001). In multivariate analysis, rash, hemophagocytic lymphohistiocytosis, CD8+ T-cell type, and no decrease of plasma EBV-DNA after treatment were independent indicators of poor prognosis (P = .002, .024, .022, and .012, respectively). CONCLUSIONS: In children with CAEBV, rash was more frequent in patients with CD8+ T-cell type, whereas patients with CD4+ T-cell type were more likely to develop hepatomegaly. Patients with CD8+ T-cell type had a poor prognosis despite receiving chemotherapy or further HSCT.

Decreased Peripheral Blood Natural Killer Cell Count in Untreated Juvenile Dermatomyositis Is Associated with Muscle Weakness.

Juvenile Dermatomyositis (JDM) is the most common inflammatory myopathy in pediatrics. This study evaluates the role of Natural Killer (NK) cells in Juvenile Dermatomyositis (JDM) pathophysiology. The study included 133 untreated JDM children with an NK cell count evaluation before treatment. NK cell subsets (CD56low/dim vs. CD 56bright) were examined in 9 untreated children. CD56 and perforin were evaluated in situ in six untreated JDM and three orthopedic, pediatric controls. 56% of treatment-naive JDM had reduced circulating NK cell counts, designated "low NK cell". This low NK group had more active muscle disease compared to the normal NK cell group. The percentage of circulating CD56low/dim NK cells was significantly lower in the NK low group than in controls (0.55% vs. 4.6% p < 0.001). Examination of the untreated JDM diagnostic muscle biopsy documented an increased infiltration of CD56 and perforin-positive cells (p = 0.023, p = 0.038, respectively). Treatment-naive JDM with reduced circulating NK cell counts exhibited more muscle weakness and higher levels of serum muscle enzymes. Muscle biopsies from treatment-naive JDM displayed increased NK cell infiltration, with increased CD56 and perforin-positive cells.

Pan-cancer profiling of tumor-infiltrating natural killer cells through transcriptional reference mapping.

The functional diversity of natural killer (NK) cell repertoires stems from differentiation, homeostatic, receptor-ligand interactions and adaptive-like responses to viral infections. In the present study, we generated a single-cell transcriptional reference map of healthy human blood- and tissue-derived NK cells, with temporal resolution and fate-specific expression of gene-regulatory networks defining NK cell differentiation. Transfer learning facilitated incorporation of tumor-infiltrating NK cell transcriptomes (39 datasets, 7 solid tumors, 427 patients) into the reference map to analyze tumor microenvironment (TME)-induced perturbations. Of the six functionally distinct NK cell states identified, a dysfunctional stressed CD56bright state susceptible to TME-induced immunosuppression and a cytotoxic TME-resistant effector CD56dim state were commonly enriched across tumor types, the ratio of which was predictive of patient outcome in malignant melanoma and osteosarcoma. This resource may inform the design of new NK cell therapies and can be extended through transfer learning to interrogate new datasets from experimental perturbations or disease conditions.

Analysis of granulysin expression in vitiligo and halo-nevus.

Vitiligo and halo nevus are immune-mediated skin diseases that have a similar pathogenesis and involve cellular cytotoxicity mechanisms that are not yet fully understood. In this study, we investigated the expression patterns of the cytolytic molecule granulysin (GNLY) in different cytotoxic cells in skin samples of vitiligo and halo nevus. Skin biopsies were taken from perilesional and lesional skin of ten vitiligo patients, eight patients with halo nevus and ten healthy controls. We analysed the expression of GNLY by immunohistochemistry in CD8+ and CD56+ NK cells. A significantly higher accumulation of GNLY+, CD8+ GNLY+ and fewer CD56+ GNLY+ cells was found in the lesional skin of vitiligo and halo nevus than in the healthy skin. These cells were localised in the basal epidermis and papillary dermis, suggesting that GNLY may be involved in the immune response against melanocytes. Similarly, but to a lesser extent, upregulation of GNLY+ and CD8+ GNLY+ cells was observed in the perilesional skin of vitiligo and halo nevus compared to healthy controls. In this study, we demonstrated for the first time an increased expression of CD8+ GNLY+ T lymphocytes and CD56+ GNLY+ NK cells in lesions of vitiligo and halo nevus, indicating the role of GNLY in the pathogenesis of both diseases.

Distinct developmental pathways generate functionally distinct populations of natural killer cells.

Natural killer (NK) cells function by eliminating virus-infected or tumor cells. Here we identified an NK-lineage-biased progenitor population, referred to as early NK progenitors (ENKPs), which developed into NK cells independently of common precursors for innate lymphoid cells (ILCPs). ENKP-derived NK cells (ENKP_NK cells) and ILCP-derived NK cells (ILCP_NK cells) were transcriptionally different. We devised combinations of surface markers that identified highly enriched ENKP_NK and ILCP_NK cell populations in wild-type mice. Furthermore, Ly49H+ NK cells that responded to mouse cytomegalovirus infection primarily developed from ENKPs, whereas ILCP_NK cells were better IFNγ producers after infection with Salmonella and herpes simplex virus. Human CD56dim and CD56bright NK cells were transcriptionally similar to ENKP_NK cells and ILCP_NK cells, respectively. Our findings establish the existence of two pathways of NK cell development that generate functionally distinct NK cell subsets in mice and further suggest these pathways may be conserved in humans.

CD56-mediated activation of human natural killer cells is triggered by Aspergillus fumigatus galactosaminogalactan.

Invasive aspergillosis causes significant morbidity and mortality in immunocompromised patients. Natural killer (NK) cells are pivotal for antifungal defense. Thus far, CD56 is the only known pathogen recognition receptor on NK cells triggering potent antifungal activity against Aspergillus fumigatus. However, the underlying cellular mechanisms and the fungal ligand of CD56 have remained unknown. Using purified cell wall components, biochemical treatments, and ger mutants with altered cell wall composition, we herein found that CD56 interacts with the A. fumigatus cell wall carbohydrate galactosaminogalactan (GAG). This interaction induced NK-cell activation, degranulation, and secretion of immune-enhancing chemokines and cytotoxic effectors. Supernatants from GAG-stimulated NK cells elicited antifungal activity and enhanced antifungal effector responses of polymorphonuclear cells. In conclusion, we identified A. fumigatus GAG as a ligand of CD56 on human primary NK cells, stimulating potent antifungal effector responses and activating other immune cells.

BCG priming followed by a novel interleukin combination activates Natural Killer cells to selectively proliferate and become anti-tumour long-lived effectors.

The short-lived nature and heterogeneity of Natural Killer (NK) cells limit the development of NK cell-based therapies, despite their proven safety and efficacy against cancer. Here, we describe the biological basis, detailed phenotype and function of long-lived anti-tumour human NK cells (CD56highCD16+), obtained without cell sorting or feeder cells, after priming of peripheral blood cells with Bacillus Calmette-Guérin (BCG). Further, we demonstrate that survival doses of a cytokine combination, excluding IL18, administered just weekly to BCG-primed NK cells avoids innate lymphocyte exhaustion and leads to specific long-term proliferation of innate cells that exert potent cytotoxic function against a broad range of solid tumours, mainly through NKG2D. Strikingly, a NKG2C+CD57-FcεRIγ+ NK cell population expands after BCG and cytokine stimulation, independently of HCMV serology. This strategy was exploited to rescue anti-tumour NK cells even from the suppressor environment of cancer patients' bone marrow, demonstrating that BCG confers durable anti-tumour features to NK cells.

NK-92 cells labeled with Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobes for the targeted treatment and noninvasive therapeutic evaluation of breast cancer.

Adoptive cellular immunotherapy as a promising and alternative cancer therapy platform is critical for future clinical applications. Natural killer (NK) cells have attracted attention as an important type of innate immune regulatory cells that can rapidly kill multiple adjacent cancer cells. However, these cells are significantly less effective in treating solid tumors than in treating hematological tumors. Herein, we report the synthesis of a Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobe labeled with NK-92 cells that can be used for adoptive cellular immunotherapy, photodynamic therapy and dual-modality imaging-based in vivo fate tracking. The labeled NK-92 cells specifically target the tumor cells, which increases the amount of cancer cell apoptosis in vitro. Furthermore, the in vivo results indicate that the labeled NK-92 cells can be used for tumor magnetic resonance imaging and fluorescence imaging, adoptive cellular immunotherapy, and photodynamic therapy after tail vein injection. These data show that the developed multifunctional nanostructure is a promising platform for efficient innate immunotherapy, photodynamic treatment and noninvasive therapeutic evaluation of breast cancer.

Immunoexpression Patterns of Adhesion Molecules (E-cadherin, ß-catenin, CD56) and Cytokeratins (CK19, CK20, HMWCK, CAM5.2) During Hair Development in Human Fetuses Compared With Adults.

ABSTRACT: Abnormalities in the expression of cytokeratins or adhesion molecules have been associated with hair disorders. The expression patterns of these molecules in the hair follicles of developing human fetuses are not obvious. We aimed to investigate the expression patterns of some cytokeratins and adhesion molecules in the hair follicle of human fetuses and compared them with adults. Forty-eight fetuses of >16 gestational weeks and 22 adult cases with total excisions of benign nevi or cysts were enrolled. The skin samples were taken from both the scalp and back of the fetuses. The histopathologically normal skin areas were evaluated in adults. CK19, CK20, CAM5.2, high-molecular-weight cytokeratin, E-cadherin, ß-catenin, and CD56 immunohistochemical stainings were performed. In the fetus group, the staining scores declined in the third trimester but elevated and reached the highest level in adults, except for CD56, which did not stain any adult samples. All stainings were mostly observed in the outer root sheath, except CD56 that stained the perifollicular dermal sheath only in fetuses. E-cadherin, ß-catenin, and high-molecular-weight cytokeratin strongly and diffusely stained all adult samples. CAM5.2 and CK19 scores were correlated in fetuses (scalp scores: r s = 0.405, P = 0.004; back scores: r s = 0.422, P = 0.003) and adults (back scores: r s = 0.562, P = 0.046). CD56 negativity indicated the immune-privilege feature of adult hair follicles. As CK19, CAM5.2 may be used to find the regions of stem cells or transient amplifying cells.

Unraveling the non-fitness status of NK cells: Examining the NKp30 receptor and its isoforms distribution in HIV/HCV coinfected patients.

BACKGROUND: HIV/HCV coinfection is associated with a rapid progression to liver damage. Specifically, NK cell population dysregulation is of particular interest, as these cells have been shown to block HCV replication effectively and have an anti-fibrogenic activity. The NKp30 receptor is linked to tumor cell lysis and has a crucial role during viral infections. In the present study, we determined the subpopulations of NK cells based on CD56 and CD16 expression, NKp30 receptor expression, its isoforms A, B, and C, along with the cytotoxicity molecules in patients with HIV/HCV. RESULTS: evidenced by the APRI and FIB-4 indices, the HCV-infected patients presented greater liver damage than the HIV and HIV/HCV groups. The HCV group presented a decreased expression of NKp30 isoform A, and NK cell frequency was not different between groups; however, CD56brigth subpopulation, NKp30 receptor, and CD247 adaptor chain were decreased in HIV/HCV patients; further, we described increased levels of soluble IL-8, IL-10, IL-12, and IL-23 in the serum of HIV/HCV patients. CONCLUSIONS: HCV and HIV/HCV patients have multiple parameters of non-fitness status in NK cells; awareness of these dysfunctional immunological parameters in HIV/HCV and HCV patients can elucidate possible novel therapeutics directed towards the improvement of NK cell fitness status, in order to improve their function against liver damage.

A specific natural killer cells phenotypic signature associated to long term elite control of HIV infection.

Elite controllers (ECs) are an exceptional group of people living with HIV (PLWH) that control HIV replication without therapy. Among the mechanisms involved in this ability, natural killer (NK)-cells have recently gained much attention. We performed an in-deep phenotypic analysis of NK-cells to search for surrogate markers associated with the long term spontaneous control of HIV. Forty-seven PLWH (22 long-term EC [PLWH-long-term elite controllers (LTECs)], 15 noncontrollers receiving antiretroviral treatment [ART] [PLWH-onART], and 10 noncontrollers cART-naïve [PLWH-offART]), and 20 uninfected controls were included. NK-cells homeostasis was analyzed by spectral flow cytometry using a panel of 15 different markers. Data were analyzed using FCSExpress and R software for unsupervised multidimensional analysis. Six different subsets of NK-cells were defined on the basis of CD16 and CD56 expression, and the multidimensional analysis revealed the existence of 68 different NK-cells clusters based on the expression levels of the 15 different markers. PLWH-offART presented the highest disturbance of NK-cells homeostasis and this was not completely restored by long-term ART. Interestingly, long term spontaneous control of HIV (PLWH-LTEC group) was associated with a specific profile of NK-cells homeostasis disturbance, characterized by an increase of CD16dimCD56dim subset when compared to uninfected controls (UC) group and also to offART and onART groups (p < 0.0001 for the global comparison), an increase of clusters C16 and C26 when compared to UC and onART groups (adjusted p-value < 0.05 for both comparisons), and a decrease of clusters C10 and C20 when compared to all the other groups (adjusted p-value < 0.05 for all comparisons). These findings may provide clues to elucidate markers of innate immunity with a relevant role in the long-term control of HIV.

HLA-DR Expression in Natural Killer Cells Marks Distinct Functional States, Depending on Cell Differentiation Stage.

HLA-DR-positive NK cells, found in both healthy individuals and patients with different inflammatory diseases, are characterized as activated cells. However, data on their capacity for IFNγ production or cytotoxic response vary between studies. Thus, more precise investigation is needed of the mechanisms related to the induction of HLA-DR expression in NK cells, their associations with NK cell differentiation stage, and functional or metabolic state. In this work, HLA-DR-expressing NK cell subsets were investigated using transcriptomic analysis, metabolic activity assays, and analysis of intercellular signaling cascades. We demonstrated that HLA-DR+CD56bright NK cells were characterized by a proliferative phenotype, while HLA-DR+CD56dim NK cells exhibited features of adaptive cells and loss of inhibitory receptors with increased expression of MHC class II trans-activator CIITA. The activated state of HLA-DR-expressing NK cells was confirmed by higher levels of ATP and mitochondrial mass observed in this subset compared to HLA-DR- cells, both ex vivo and after stimulation in culture. We showed that HLA-DR expression in NK cells in vitro can be induced both through stimulation by exogenous IL-2 and IL-21, as well as through auto-stimulation by NK-cell-produced IFNγ. At the intracellular level, HLA-DR expression depended on the activation of STAT3- and ERK1/2-mediated pathways, with subsequent activation of isoform 3 of the transcription factor CIITA. The obtained results broaden the knowledge about HLA-DR-positive NK cell appearance, diversity, and functions, which might be useful in terms of understanding the role of this subset in innate immunity and assessing their possible implications in NK cell-based therapy.

The alteration of NK cells phenotypes related to the functions and dengue disease outcomes.

Natural killer cells (NK cells) are the front line of immune cells to combat pathogens and able to influence the subsequent adaptive immune responses. One of the factors contributing to pathogenesis in dengue hemorrhagic fever (DHF) disease is aberrant immune activation during early phase of infection. This study explored the profile of NK cells in dengue infected pediatric patients with different degrees of disease severity. DHF patients contained higher frequency of activated NK cells but lower ratio of CD56dim:CD56bright NK subsets. Activated NK cells exhibited alterations in several NK receptors. Interestingly, the frequencies of NKp30 expressing activated NK cells were more pronounced in dengue fever (DF) than in DHF pediatric patients. In vitro functional analysis indicated that degranulation of NK cells in responding to dengue infected dendritic cells (DCs) required cell-cell contact and type I IFNs. Meanwhile, Interferon gamma (IFN-γ) production initially required cell-cell contact and type I IFNs followed by Interleukin-12 (IL-12), Interleukin-15 (IL-15) and Interleukin-18 (IL-18) resulting in the amplification of IFN-γ producing NK cells over time. This study highlighted the complexity and the factors influencing NK cells responses to dengue virus. Degree of activation, phenotypes of activated cells and the crosstalk between NK cells and other immune cells, could modulate the outcome of NK cells function in the dengue disease.

Null T-cell phenotype mycosis fungoides with aberrant CD20 and CD56 expression: A diagnostic dilemma.

Mycosis fungoides (MF) represents the most common type of primary cutaneous T-cell lymphoma. Recognition of MF variants with divergent immunophenotypes is important for accurate diagnosis and appropriate management, as they can be confused with other lymphoma subtypes. We present a case of a 49-year-old male previously diagnosed with a cutaneous lymphoproliferative disorder with an unusual NK/T-cell phenotype. He presented with a 10-year history of pelvic girdle rash involving the right hip and upper thigh. The lesions were characterized as atrophic patches concentrated in sun-protected areas and involving 10% of the body surface area. Shave biopsies revealed an atypical epidermotropic infiltrate composed of hyperchromatic small to medium-sized lymphocytes with perinuclear halos and "tagging" along the dermal-epidermal junction. The immunophenotype was unusual in that the neoplastic lymphocytes showed complete loss of pan T-cell antigens along with expression of CD56, cytotoxic markers, and weak CD20. All other B-cell markers were negative. The combination of clinical findings, in addition to the histopathologic and immunophenotypic profile, were diagnostic of null T-cell phenotype MF with aberrant expression of CD56 and CD20. Null T-cell phenotype MF is very uncommon, can be diagnostically challenging, and can mislead the diagnosis of aggressive lymphoma subtypes.

Replication Stress in Activated Human NK Cells Induces Sensitivity to Apoptosis.

NK cells are innate immune effectors that kill virally infected or malignant cells. NK cell deficiency (NKD) occurs when NK cell development or function is impaired and variants in MCM4, GINS1, MCM10, and GINS4 result in NKD. Although NK cells are strongly impacted by mutational deficiencies in helicase proteins, the mechanisms underlying this specific susceptibility are poorly understood. In this study, we induced replication stress in activated NK cells or T cells by chemical and genetic methods. We found that the CD56bright subset of NK cells accumulates more DNA damage and replication stress during activation than do CD56dim NK cells or T cells. Aphidicolin treatment increases apoptosis of CD56bright NK cells through increased pan-caspase expression and decreases perforin expression in surviving cells. These findings show that sensitivity to replication stress affects NK cell survival and function and contributes to NKD.

The dynamic TRPV2 ion channel proximity proteome reveals functional links of calcium flux with cellular adhesion factors NCAM and L1CAM in neurite outgrowth.

TRPV2 voltage-insensitive, calcium-permeable ion channels play important roles in cancer progression, immune response, and neuronal development. Despite TRPV2's physiological impact, underlying endogenous proteins mediating TRPV2 responses and affected signaling pathways remain elusive. Using quantitative peroxidase-catalyzed (APEX2) proximity proteomics we uncover dynamic changes in the TRPV2-proximal proteome and identify calcium signaling and cell adhesion factors recruited to the molecular channel neighborhood in response to activation. Quantitative TRPV2 proximity proteomics further revealed activation-induced enrichment of protein clusters with biological functions in neural and cellular projection. We demonstrate a functional connection between TRPV2 and the neural immunoglobulin cell adhesion molecules NCAM and L1CAM. NCAM and L1CAM stimulation robustly induces TRPV2 [Ca2+]I flux in neuronal PC12 cells and this TRPV2-specific [Ca2+]I flux requires activation of the protein kinase PKCα. TRPV2 expression directly impacts neurite lengths that are modulated by NCAM or L1CAM stimulation. Hence, TRPV2's calcium signaling plays a previously undescribed, yet vital role in cell adhesion, and TRPV2 calcium flux and neurite development are intricately linked via NCAM and L1CAM cell adhesion proteins.

Changes in subset distribution and impaired function of circulating natural killer cells in patients with colorectal cancer.

Natural killer (NK) cells are closely associated with malignant tumor progression and metastasis. However, studies on their relevance in colorectal cancer (CRC) are limited. We aimed to comprehensively analyze the absolute counts, phenotypes, and function of circulating NK cells in patients with CRC using multiparametric flow cytometry. The distribution of NK cell subsets in the peripheral circulation of patients with CRC was significantly altered relative to the control group. This is shown by the decreased frequency and absolute count of CD56dimCD16+ NK cells with antitumor effects, contrary to the increased frequency of CD56bright NK and CD56dimCD16- NK cells with poor or ineffective antitumor effects. NK cells in patients with CRC were functionally impaired, with decreased intracellular interferon (IFN)-γ secretion and a significantly lower percentage of cell surface granzyme B and perforin expression. In addition, IFN-γ expression decreased significantly with the tumor stage progression. Based on a comprehensive analysis of the absolute counts, phenotypes, and functional markers of NK cells, we found an altered subset distribution and impaired function of circulating NK cells in patients with CRC.