Color Panel Research Articles

Optical immunosensor panel using quantum dot-antibody conjugates for highly sensitive detection of carbohydrate antigen 19–9 (CA19-9)

This study introduces a fluorescent immunosensor colour panel with antibody-conjugated quantum dots for detecting CA19-9 in human serum. The immunosensors presented decreasing fluorescence with increasing CA19-9 concentrations, with a linear detection range from 0.01 to 501.87 U mL−1 and detection limits of 1.66 × 10⁻⁴, 2.71 × 10⁻⁴, and 5.45 × 10⁻⁴ U mL−1 for the green-, orange-, and red-emitting conjugates in human serum. These limits are well below the 37 U mL−1 cutoff for early pancreatic cancer risk. The immunosensor panel is simple, sensitive, and specific, offering a visual colour readout for rapid CA19-9 detection, making it ideal for point-of-care applications. The results highlight the potential of the developed conjugates as a sensitive fluorescence colour panel for detecting CA19-9 across a wide range in human serum, both below and above the pancreatic cancer cutoff. With just 200 μL of sample and a single pre-filtration step, the assay delivers results in under 15 min, offering a cost-effective and efficient platform for point-of-care use.

Development of a Spectral Flow Cytometry Analysis Pipeline for High-dimensional Immune Cell Characterization.

Flow cytometry is used for immune cell analysis for cell composition and function. Spectral flow cytometry allows for high-dimensional analysis of immune cells, overcoming limitations of conventional flow cytometry. However, analyzing data from large Ab panels is challenging using traditional biaxial gating strategies. We present, to our knowledge, a novel analysis pipeline to improve analysis of spectral flow cytometry. We employ this method to identify rare T cell populations in aging. We isolated splenocytes from young (2-3 mo old) and aged (18-19 mo old) female C57BL/6N mice and then stained these with a panel of 20 fluorescently labeled Abs. We performed spectral flow cytometry and then data processing and analysis using Python within a Jupyter Notebook environment to perform dimensionality reduction, batch correction, unsupervised clustering, and differential expression analysis. Our analysis of 3,776,804 T cells from 11 spleens revealed 35 distinct T cell clusters identified by surface marker expression. We observed significant differences between young and aged mice, with clusters enriched in one age group over the other. Naive, effector memory, and central memory CD8+ and CD4+ T cell subsets exhibited age-associated changes in abundance and marker expression. We also demonstrate the utility of our pipeline in a human PBMC dataset that used a 50-fluorescent color panel. By leveraging high-dimensional analysis methods, we provide insights into the immune aging process. This approach offers a robust and easily implemented analysis pipeline for spectral flow cytometry data that may facilitate the discovery of novel therapeutic targets for age-related immune dysfunction.

Colour Vision Defects: Awareness, Prevalence And Effects Among Secondary School Students In Imo State, Nigeria

Abstract Background: Colour vision defect (CVD) is a public health issue with approximately one in ten males exhibiting some form of colour deficiency. Colour is used extensively in education so CVD has a dramatic impact on the learning, educational and social potentials of children. Racial differences have been reported with higher values noted amongst people of European ancestry. Objective: This study aims to assess CVDs, their magnitude and impact on the daily activities of secondary school students in Imo State, Nigeria. Materials and Methods: This was a multistage, cross-sectional, descriptive study which assessed the prevalence and effect of congenital CVD on secondary school students in Imo state using a questionnaire modified and adapted for this purpose. Colour vision was tested uniocularly for each student under bright illumination using the 38-plate Ishihara colour vision chart and Lanthony D-15 colour panel. The test was administered on a black background between the hours of 10 a.m. and 2 p.m. Results: Eight hundred and twenty-eight secondary school students were studied with a mean age of 15 ± 1.89 years. There were 468 males (57.0%) and 360 females (43%) with a male-to-female ratio of 1.3:1. There was a 3% prevalence of CVD. More males were significantly affected than females. Deutan defect was more common and none of the students had tritan defect. Conclusion: There is a low level of awareness of congenital CVD. This disorder resulted in various degrees of difficulty with colour-related school and daily living tasks. Advocacy to government and schools is needed to create awareness of CVDs and offer early counselling to those affected.

Expression of Concern: Development of a 43 color panel for the characterization of conventional and unconventional T-cell subsets, B cells, NK cells, monocytes, dendritic cells, and innate lymphoid cells using spectral flow cytometry.

Expression of Concern: Development of a 43 color panel for the characterization of conventional and unconventional T-cell subsets, B cells, NK cells, monocytes, dendritic cells, and innate lymphoid cells using spectral flow cytometry.

Combinatorial antibody titrations for high-parameter flow cytometry.

The objective of titrating fluorochrome-labeled antibodies is to identify the optimal concentration for a given marker-fluorochrome pair that results in the best possible separation between the positive and negative cell populations, while minimizing the background within the negative population. Best practices in flow cytometry dictate that each new lot of antibody should be titrated on the sample of interest. However, many researchers routinely use large (30+) color panels due to recent technical advancements in fluorescence-based cytometry instrumentation which quickly leads to an unmanageable number of individual titrations. In this technical note, we provide evidence that antibodies can be effectively titrated in groups rather than individually, resulting in considerable time and cost savings. This approach streamlines the process, without compromising data quality, thereby enhancing the efficiency of setting up high-parameter cytometry experiments.

Topical Application of Acerola Cherry Powder in Combination With Rosemary Extract Extends the Shelf Life of Beef Chuck Roll and Bone-In Short Rib Steaks

Improving the shelf life of steaks from beef chuck rolls and bone-in short ribs, items commonly exported, will increase the demand of beef in international markets. Our objectives were to determine the effect of topically applying combinations of acerola cherry powder and rosemary extract on steak color and lipid oxidation of beef chuck roll and bone-in short rib. USDA Choice beef chuck rolls (Institutional Meat Purchase Specifications [IMPS] 116A; N=9) andbone-in short ribs (IMPS 123A; N=18) were aged (0°C) 28 d and cut into 1.0 cm-thick steaks. Steak treatments included the following: untreated control (C) or topically sprayed (2 mL) with an acerola cherry powder solution (0.05% A), rosemary extract solution (0.10% R), or mixture of acerola cherry powder and rosemary extract (M1=0.05% A+0.1% R; M2=0.1% A+0.1% R; M3=0.05% A+0.2% R; M4=0.1% A+0.2% R). On day 0 of retail display, oxygen consumption, metmyoglobin-reducing activity, and lipid oxidation were measured. Lipid oxidation was evaluated again following 4 d of retail display. Chuck roll steak color was scored twice daily, whereas short rib lean and bone marrow color were scored once daily throughout 4 d of retail display. Treating chuck roll steaks with M2, M3, and M4 decreased lipid oxidation compared to C and A (P=0.004). In short rib steaks, lipid oxidation remained constant from day 0 to 4 treated with M4 but increased for all other treatments (P<0.001). Chuck roll steaks treated with A, M2, and M3 were redder than C steaks (P=0.001). On days 0 and 4, untreated bone marrow was less red than all the antioxidant treated bone marrow (P=0.011). Antioxidant treatment did not improve subjective lean color for the chuck roll (P=0.324) or bone-in short rib (P=0.081). Topical application of M4 (0.1% acerola cherry powder and 0.2% rosemary extract) reduced lipid oxidation in both chuck roll and bone-in short rib steaks. Additionally, antioxidants alone or in combination with one another improve objective redness scores by up to 2 points; however, the subjective color panel did not observe lean color improvement.

Use of High-Pressure Processing to Improve the Redness of Dark-Cutting Beef

The objective was to evaluate the effects of high-pressure processing (HPP) levels on retail color of dark-cutting beef. Eight USDA Choice (mean pH=5.5; normal-pH beef) and 12 dark-cutting (mean pH=6.3) strip loins were obtained from a commercial packing plant within 2 d of harvest. Dark-cutting loins were cut into equal sections, vacuum packaged,and randomly assigned to 0 (no HPP), 300, 450, and 600 MPa of pressure for 90 s using chilled water. Following 48 h of dark storage at 2°C, dark-cutting loin sections were cut into 1.9-cm-thick steaks, placed in Styrofoam trays overwrapped in polyvinyl chloride (PVC) film, and placed in a simulated retail display for 8 d. The surface color readings were measured every 24 h using a HunterLab MiniScan XE Plus spectrophotometer, whereas a trained color panel (n=6) evaluated dis-coloration, paleness, and lean color on steaks. Lipid oxidation was evaluated on day 0, 4, and 8 of retail display, and structural changes were determined using light microscopy on day 0 of display. There was a significant HPP level×day of retail display interaction for all instrumental color measurements. Throughout the retail display, L* values of 450 and 600 MPa applied steaks were greater (P<0.05) than 300 MPa and controls. There was a significant pressure level×day of retail display interaction when panelists evaluated lean color and discoloration. Steaks treated at 300 MPa exhibited brighter red color and lower (P=0.0023) thiobarbituric acid reactive substance values than other pressure levels and normal-pH control steaks. Light microscopy analysis indicated that HPP increased space between muscle structures. In conclusion, low (300 MPa) and moderate (450 MPa) pressure levels can improve redness of dark-cutting steaks.

Abstract 4229: Differential impact of rice bran based dietary interventions during inflammation-associated colorectal cancer on distinct immune infiltrates and their spatial distribution signature

Abstract Modulating the immune cell infiltrates in the colonic tissue via dietary intervention or modulation of the gut microbiota and its crosstalk with the components of the diet is now recognized as an effective strategy to protect against inflammation-associated colorectal cancer (CRC). In this regard, we recently reported, both gut microbiota-dependent and independent mechanisms for dietary rice bran (RB) meditated protective efficacy against inflammation-associated azoxymethane/dextran sodium sulfate (AOM/DSS)-induced CRC. We also reported that ex vivo fermentation of RB with beneficial microbe ‘Bifidobacterium longum’ did not exhibit similar protective benefits as RB in damaged colonic tissues in the absence of gut microbiota [germ-free (gf) mice]. The role of rice bran (RB) constituents as prebiotics and in preserving gut barrier and a healthy gut microbiota led to in-depth investigation into the protective efficacy of RB against CRC. Accordingly, in the present study, we performed multiplex imaging (9 color panel) to assess immune sub-typing and spatial phenotypic signature of the colonic tissue/tumor microenvironment in the AOM/DSSgf mice [following RB and fermented RB (FRB) dietary intervention]. Briefly, we determined the presence of T cells [CD3+], cytotoxic T cells [CD3+ CD8+], helper T cells [CD3+ CD8−], regulatory T (Treg) cells [CD3+CD8−FoxP3+), natural killer (NK) cells [CD49b+], NKT cells [CD3+CD49b+], macrophage (MΦ) [F4/80 +], M1 [F4/80+iNOS+CD206−] and M2 [F4/80+CD206+] subtypes and B cells [B220+]. Results indicated an overall high infiltration of immune cells in female AOM/DSSgf mice on control diet compared to males, which was positively correlated with severe pathological changes observed in the female colon tissues. Notably, RB and FRB diets showed a differential impact on the sub-type of immune cells and their spatial localization. Protective efficacy of RB was associated with decrease in infiltration of T cells (including their subtypes). Interestingly, while cytotoxic T cells were lower in FRB (AOM/DSSgf) female mice, there was a significant increase in pro-inflammatory M1 MΦ sub-types in colon tissue of mice marred by epithelial erosion which compromised FRB potential. Spatial distance analysis also indicated that immune cells were distantly spaced in RB intervention groups compared to FRB and AOM/DSSgf controls. Though, M2 MΦ were relatively higher in number in AOM/DSSgf controls, their presence did not have influence on protective efficacy or lack thereof. In general, it was inferenced that the protective efficacy of the RB diets in the absence of gut microbiota was positively correlated with modulation of T cell infiltration while inflammation-associated CRC and epithelial erosion in FRB diet groups were associated with skewed MΦ sub-types-with increased presence of M1MΦ. Citation Format: Robin Kumar, Akhilendra K. Maurya, Lakshmi S. Bugata, Md. I. Kabir, Munendra Tomar, Rajesh Agarwal, Elizabeth P. Ryan, Komal Raina. Differential impact of rice bran based dietary interventions during inflammation-associated colorectal cancer on distinct immune infiltrates and their spatial distribution signature. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4229.

Cross-platform immunophenotyping of human peripheral blood mononuclear cells with four high-dimensional flow cytometry panels.

Immunophenotyping using high dimensional flow cytometry is a central component of human immune system multi-omic studies. We present four high parameter flow cytometry panels for deep immunophenotyping of human peripheral blood mononuclear cells (PBMC). This set of four 25+ color panels include 64 cell surface markers to resolve broad immune compartment populations, as well as activation and memory of specific T, B, natural killer (NK), and myeloid lineages. Common lineage bridging markers are integrated into each panel to allow for inter-panel quality control through major lineage frequency verification. These panels were developed using a five laser BD Symphony A5 conventional cytometer and successfully transferred to a five laser Cytek Aurora spectral cytometer capable of acquiring the panels. Nine representative PBMC samples were stained with the four phenotyping panels and acquired on both instruments to evaluate population frequency and visual staining patterns for gating between the systems. Both instruments produced comparable high quality flow cytometry data and supported our decision to acquire samples on the spectral cytometer moving forward. This modular set of panels and instrument performance metrics provide guidelines for designing flow cytometry experiments suitable for longitudinal or cross-sectional immune profiling.

Paper] Autostereoscopic Display Based on Time-Division Multiplexing Parallax Barrier Using a Monochrome LCD Panel

This paper presents a full-HD autostereoscopic display with a pair of monochrome and color panels based on time-division multiplexing parallax barrier. In the conventional system, usage of two color LCD panels with limited transmittance decreased the display luminance. In the proposed method, a monochrome panel is used in place of a color panel to generate an active barrier pattern, which is expected to increase transmittance. A prototype system is made, where moire is removed without using a diffuser. The maximum luminance given by the proposed method is measured and compared with that given by the conventional method. It is confirmed that the prototype system based on the proposed method has approximately 2.5 times higher luminance than the conventional system. It is also confirmed that the proposed method slightly decreases stereoscopic crosstalk, which is further reduced by widening the slit from 3 subpixels to 5 subpixels to alleviate diffraction.

Solar panel surface dirt detection and removal based on arduino color recognition

Color sensing is a technique for identifying physical changes in materials based on appearance assessment. Dirt deposition on solar panels can change their physical appearance and performance. Considering that dirt accumulation on solar panels needs monitoring to make efficient cleaning schedules, reduce unnecessary costs, and optimize solar panel output generation. Color sensing can achieve fast, accurate, and economical dirt detection, unlike the use of robotic cameras, mathematical formulae, and considering varying output current and voltage methods. Here, we introduce a method that detects and removes dirt on solar panels based on TCS3200 and Arduino Uno components. The approach targets (i.) Panel color measurement, calibration, threshold selection process, (ii.) comparison of color measurement values, and (iii.) align further calibration in response to discoloration of solar panels. This method aims to correct the dirt detection methods previously in use. Hence, a high-speed rolling brush arrangement is designed to improve the cleaning of the solar panel without using water. Further investigations of the panel's color may require some improvement in terms of increasing the sensitivity of the color sensor even with increased distance from the solar panel. Combining multiple color sensors may also be necessary.

A wearable shear force transducer based on color spectrum analysis

The need for miniaturized shear force sensors is expanding, particularly for biomedical applications. Examples include measuring interfacial shear stresses between a human and an external device (e.g. footwear or a prosthesis). However, there are considerable challenges in designing a shear sensor for these applications due to the need for a small package, low power requirements, and resistance to interference from motion artifact and electromagnetic fields. This paper presents the design, fabrication, and characterization sensor that measures two-axis shear force by detecting displacement between a color panel and a red, green, and blue light-sensing photodiode. The sensor response to applied displacements and forces was characterized under benchtop testing conditions. We also present the design of a prototype wireless version of the sensor for integration into footwear. The sensor exhibited strong agreement with gold standard measurements for two-axis shear displacements (R 2 > 0.99, RMSE ⩽ 5.0 µm) and forces (R 2 > 0.99, RMSE ⩽ 0.94 N). This performance, along with the sensor’s scalability, miniaturized form, and low power requirements make it well-suited a variety of biomedical applications.

Effect of Extended Postmortem Aging on Beef Muscles of Differing Quality Grade during Retail Display

Aging of beef subprimals is a common industry practice to improve tenderness. However, the effect of extended aging (up to 63 d) on retail shelf life, tenderness, and eating quality of beef strip loin and sirloin of differing quality grades is not clearly understood. Therefore, in the current study, longissimus dorsi (strip loin) and gluteus medius muscles (sirloin) were collected from USDA Choice or Select carcasses and fabricated into 6 portions. Each of these portions was designated to an assigned time of wet aging (14, 21, 28, 35, 45, or 63 d) in vacuum bags. After aging, samples were fabricated into steaks and placed into a multideck retail display case for 72 h. Steaks were evaluated for color (instrumental and color panelists) every 8 h during retail display, and Warner-Bratzler shear force and sensory analysis were conducted after retail display. The results were analyzed using the PROC MIXED procedure of SAS with repeated measures for the color data. Among the effects evaluated (aging, quality grade, and aging×quality grade), quality grade was not significant (P>0.05) for either strip loin or sirloin steaks. An aging×display hour interaction was identified (P<0.05) for the color measurements. In general, as aging time increased over the display period, color was negatively impacted. Although tenderness improved (P<0.05) with aging, the incidence of off-flavors also increased, especially in sirloin steaks, suggesting that beef processors need to consider flavor changes during extended aging.

Effects of glucono delta-lactone enhancement and nitrite-embedded packaging on fresh color, cooked color, and sensory attributes of dark-cutting beef

The objective was to determine the effects of nitrite-embedded packaging (NEP) and enhancement on quality of dark-cutting beef. Dark-cutting strip loins (n = 10; pH > 6.0) and USDA Low Choice strip loins (USDA Choice, n = 10; normal-pH) were selected from a local purveyor. Dark-cutting loins were divided into two sections and randomly designated as non-enhanced and enhanced dark-cutting treatments. Sections assigned to enhancement treatment were injected with 0.5% glucono delta-lactone and 0.1% rosemary. One steak from USDA Choice and non-enhanced dark-cutting loins was packaged in Styrofoam™ trays overwrapped with polyvinyl chloride film, and one steak from enhanced dark-cutting loins was packaged in NEP. Steaks were kept in simulated retail display for 6 d, and the surface color was evaluated using a HunterLab MiniScan spectrophotometer and trained color panel every 24 h. The remaining steaks were randomly assigned to cooked color, sensory, and Warner-Bratzler shear force analyses. By d 6 of retail display, enhanced dark-cutting steaks in NEP had greater (P < 0.05) redness (a* values) than non-enhanced dark-cutting and USDA Choice steaks in PVC. There was more surface discoloration (P < 0.05) on USDA Choice steaks than enhanced dark-cutting in NEP and non-enhanced dark-cutting steaks by d 6 of retail display. Enhanced dark-cutting and USDA Choice steaks had similar (P > 0.05) cooked internal redness (a* values and visual color). However, external cooked color of enhanced dark-cutting steaks in NEP was significantly pinker than USDA Choice and non-enhanced dark-cutting steaks. In conclusion, nitrite packaging improved surface redness dark cutting steaks, and the enhancement decreased cooked internal redness commonly associated with high-pH beef.

52‐5: A Color Gamut Mapping Method Using an OLED Display Model

In this paper, we introduce how to map the native Organic Light Emitting Diode (OLED) panel's color gamut to the standard gamut (i.e., sRGB or P3). In order to achieve better accuracy and speedy mapping for the overall gamut region, we modeled OLED panel considering IR‐drop and Lateral leakage which are unique properties of OLED. In the experiment results, it is confirmed that the native mobile OLED panel was tuned to the standard gamut properly and proposed Color Gamut Mapping (CGM) result had an average distortion less than 0.4 in CIEDE2000. (It almost equals to 0.5 JNCD) In addition, whole calibration procedure can be performed within 1 minute by using proposed method, so that could be applied to individual panel calibration in a factory line.

Quantitative definition of strength of chromophores in gemstones and the impact on color change in pyralspite garnets

AbstractThe color of most garnets is derived from multiple color‐producing elements (chromophores). In this study we selectively isolate the ultraviolet–visible–near infrared (UV–Vis–NIR) spectra of four major chromophores (Fe2+, Mn2+, Cr3+ and V3+) by collecting and extrapolating the spectra of four representative pyrope‐almandine‐spessartine (pyralspite) garnets. In order to study the color strength of these isolated chromophores and their impact on color change in garnet, we have proposed a new quantitative definition of strength of a chromophore. With the isolated garnet chromophore spectra, hypothetical garnet spectra with various chemical compositions can be simulated. By using these hypothetical garnet spectra, the impact of each chromophore on the color change behavior in pyralspite garnet was also quantitatively studied. Most pyralspite garnets can be successfully modeled using these four chromophores, however, this model cannot adequately describe those garnets containing the Fe3+/Fe2+ intervalence charge‐transfer transitions. Finally, a comprehensive excel data processing template (Appendix 3) written with VBA macro code was generated to help other researchers calculate colorimetric parameters and color panels from UV–Vis–NIR spectrum. In the template, we provided multiple types of conversion matrices and power distribution curves of different illuminants, so that different colorimetric parameter conversion and color panel calculation from UV–Vis–NIR spectrum can be selected with different combinations based on people's preference. The user guide of the excel template can be found in Appendix 4. The detailed calculation procedures and formulae used for the excel template can be found in Appendix 5.

Residual Monoclonal Free Light Chain Positivity By Mass Spectrometry Identifies Patients at Increased Risk of Early Relapse Following First-Line Anti-Myeloma Treatment

Residual Monoclonal Free Light Chain Positivity By Mass Spectrometry Identifies Patients at Increased Risk of Early Relapse Following First-Line Anti-Myeloma Treatment

Multiparametric Flow Cytometry Evaluation of CD200L/CD200R- LSC/NK Synapse Including Leukemia Stem Cell (LSC) Fraction As a Potential Therapeutic Target and Marker of NK Cell Exhaustion in Pediatric AML-Conect-AML French Collaborative Network

BACKGROUNDNK cells play a crucial role in the immune surveillance of malignant hemopathies. They undergo fine regulation by the microenvironment and by integrating activating and inhibiting signals trough several receptor/ligand couple interactions, hereafter referred to as “NK synapse”. The ligands are expressed by a variety of cell types in the hematopoietic niche, including most immature leukemic stem cells CD34+CD38-. High expression of inhibiting ligands on AML (acute myeloid leukemia) blasts was associated with adverse clinical outcome . This observation highlights the relevance of identifying new ligand/receptor (L/R) pairs that could be targeted to prevent inhibiting interactions at the NK synapse. Relevant interactions to be blocked would display both ligand and receptor expressions on the leukemic cells and NK cells respectively. PATIENTS AND METHODS23 pediatric AML patients from the pediatric MyeChild01 protocol including in CONECT-AML French national collaborative network project diagnosed between 2018 and 2019 were included in this study. Reference bone marrows used were regenerative (4) or healthy bone marrows (5) . Multicolour flowcytometry protocole used fresh EDTA bone marrow at AML diagnosis and immunostaining with fluorochrome-coupled antibodies using 14 colour panel of L/R couples (Figure 1). Data was acquired on the FORTESSA Becton Dickinson with the Diva software and analysis using script R-PCA and FlowJo . RESULTSWe studied 5 inhibiting NK synapses (iinhibitory ligand/receptor pairs) . Four out of five inhibiting synapses (TIGIT/CD155; PD1-1/PD-L1; CD94/HLA-E and KIR2DL/HLA-A-B-C), showed not significant expression of ligand associated with the corresponding receptor expression. The CD200/CD200R synapse was the only one in which high ligand expression in blasts was significantly associated with high receptor expression on NK cells (Figure 2). This synapse could thus be of interest to develop targeting therapies for CD200-positive pediatric AML, with the strong advantage that patient eligibility could be easily identified at diagnosis. We then realized a principal component analysis, using the R software (PCA), integrating the MFIs of the 5 inhibiting NK synapses and 6 activating NK synapses (Figure 1) for the pediatric AML cohort (ID #1 to #23 ) together with reference bone marrows (healthy donors (n=5; ID #24 to #28) and regenerative bone marrows (n=4; ID #29 to #32)) . The CD200/CD200R synapse was identified as the main variable, explaining the distribution of patients and healthy donors as both CD200 and CD200R expressions happened to be among the most contributive to PCA axes. Interestingly, healthy donors clustered together, close to regenerative bone marrows. Pediatric AML patients distributed heterogeneously (Figure 3). In parallel, we evaluated whether CD200 expression on bulk leukemia blasts including most immature CD34+CD38- LSC was associated with exhaustion markers on NK cells. We found that patients with high and intermediate expression of CD200 on blasts (MFI > 3 rd quartile and comprised between 2 nd and 3 rd quartile, respectively) displayed strong PD-1 and TIGIT expressions on NK cells. Reciprocally, patients with low CD200 expression (MFI< 2 nd quartile) displayed a moderate PD-1 expression on NK cells, and TIGIT expression was more heterogeneous among individuals (Figure 4). CONCLUSIONSHere, we identified CD200 expression in AML blasts including LSC as a marker that could be associated with NK cell exhaustion. at diagnosis. A PCA strategy allowed to observe that this marker differentiated pediatric AML patients NK synapse profiles from healthy donors and regenerative bone marrows sugesting a potential deregulation of bone marrow niche including NK-LSC escape. This suggests that CD200 expression assessment on blasts at diagnosis could be a tool to evaluate NK cell antitumor potential. Indeed, direct NK cell assessment by flow cytometry can be challenging because of blast invasion in the bone marrow. Nevertheless, it remains to be elucidated whether this clustering and exhaustion markers on NK cells correlated with patient clinical outcomes and MRD kinetics including CD34+CD38- LSC flow frequency evaluation that should be useful in most clinical trials to overcome chemoresistance of LSC. These results should be confirmed in a prospectively larger cohort of patients in future clinical trials. [Display omitted] DisclosuresRenard: Jazz Pharmaceuticals: Research Funding.

391 Biomarker correlates of response in patients with advanced myxoid/round cell liposarcoma (MRCLS) treated with NY-ESO-1 TCR T cells (Letetresgene autoleucel)

BackgroundThis is an open label pilot study (NCT02992743) on letetresgene autoleucel (lete-cel; GSK3377794), an NY-ESO-1-specific autologous CD4+ and CD8+ T cells expressing a high affinity T-cell receptor which recognizes the NY-ESO-1 antigen epitope in complex with specific HLA- alleles A*02, which exhibited anti-tumor activity and manageable safety profiles in patients with advanced MRCLS based on interim analysis (IA) data.1 Lymphodepletion has been shown to enhance the expansion, persistence, and homing of therapeutically infused T-cells, thereby potentiating therapeutic efficacy against malignant diseases.2 Initial T-cell kinetics data from this study demonstrated that lymphodepletion regimen (LDR)-B robustly depleted lymphocytes at infusion and was trended with higher peak cell expansion (Cmax) vs. LDR-A. The peak expansion was significantly associated with weight-normalized transduced cell dose and trended with response.1 Here, we will be discussing additional cell kinetics data and other exploratory biomarker correlates of response.MethodsPatients with advanced MRCLS were enrolled to 2 cohorts and received either planned A (N=10) or B (N=10) LDRs prior to lete-cel infusion (table 1). Response was assessed per RECIST v1.1. Transduced cell kinetics were measured by quantitative PCR of transgene vector copies in DNA from peripheral blood mononuclear cells (PBMCs). Serum cytokines (Meso Scale Discovery immunoassay) as pharmacodynamic (PD) markers of response and their association with T cell kinetics will be discussed. Phenotypic characterization of the cell product (pre- and post- infusion) via Flow cytometry using Cytek Aurora (23 color panel), to help understand correlation of response with engineered cell product attributes, will be presented. Potential biomarker correlates of clinical response were tested using generalized linear models.ResultsFive out of 6 responders with available lab data exhibited robust lymphocyte depletion at infusion (0–25 cell/µL) and high Cmax (&gt;50,000 vector copies/µg gDNA) with LDR. Only 6/14 non-responders exhibited low lymphocytes counts at infusion and high Cmax. LDR-B also induced strong depletion of monocytes at infusion (p=0.03) vs. LDR-A, but depletion of monocytes did not show association with response. Higher Cmax was correlated with exposure (AUC0–28d) (Adj. R2=0.606). AUC0–28d was a better predictor of response in patients receiving LDR-B (p=0.0182), with AUC0–28d trending towards predicting response in the LDR-A cohort. AUC0–28d was associated with tumor volume reduction (p=0.0569).Abstract 391 Table 1ConclusionsExposure–response analysis of this study reveals that efficacy appears to be driven by weight-normalized transduced cell dose and LDR via AUC0–28d. Higher AUC0–28d was correlated with Cmax and maximum tumor volume reduction.AcknowledgementsThis study (208469; NCT02992743) was funded by GlaxoSmithKline.Trial RegistrationNCT02992743ReferencesD’Angelo SP, et al. J Clin Oncol 2021;39:15_suppl:11521.Bechman, Maher. Expert Opin Biol Ther 2021;21(5):627–637.Ethics ApprovalThis study was approved by institutional review boards (IRB) at the six participating sites.

Effects of Rosemary and Green Tea Antioxidants on Ground Beef Patties in Traditional and Modified Atmosphere Packaging

The objective of this study was to analyze the effects of rosemary (RSM) and green tea (GT) added to groundbeef to extend shelf life. Four antioxidant treatments were used: control, 2,500 ppm RSM, 300 ppm GT, and 2,500 ppm RSM + 300 ppm GT (RSM + GT). Patties from each treatment (n = 42) were randomly packaged into one of 3 types: polyvinyl chloride (PVC) overwrap, modified atmospheric packaging (MAP), or master packages (MP). Packages of MAP and MP were flushed with 0.4% CO, 69.6% nitrogen (N2), and 30% carbon dioxide (CO2). Patties in PVC and MAP were placed directly into display cases for 7 d, and MP patties were placed in dark storage for 7 d and then in display cases for another 7 d. Instrumental and subjective color, lipid oxidation, and sensory panel scores were measured. In MAP, patties with GT had increased (P &amp;lt; 0.05) a* and chroma values by day 6 of retail display. In MP at 3 d of retail display, GT patties exhibited increased (P &amp;lt; 0.05) L* values (lighter), display color (deeper red), and surface discoloration (greater discoloration) scores compared with RSM + GT patties. However, GT and RSM patties were not different (P &amp;gt; 0.05) for these parameters. Trained sensory panelists did not detect a difference between control and GT patties for the green-hay attribute; however, RSM patties had highly detectable (P &amp;lt; 0.05) green-hay flavor. Panelists were unable to detect any differences (P &amp;gt; 0.05) for rancid or fatty flavors regardless of treatment. Patties in MAP were more color stable than those in PVC after 6 d of retail display. In conclusion, patties in MP with GT showed positive instrumental and objective color measurements, as well as lipid oxidation values after 3 d of display, combined with undetectable flavor, warranting further research.