[Effects of cerium oxide nanoenzyme-gelatin methacrylate anhydride hydrogel in the repair of infected full-thickness skin defect wounds in mice]

Objective: To investigate the effects of cerium oxide nanoenzyme-gelatin methacrylate anhydride (GelMA) hydrogel (hereinafter referred to as composite hydrogel) in the repair of infected full-thickness skin defect wounds in mice. Methods: This study was an experimental study. Cerium oxide nanoenzyme with a particle size of (116±9) nm was prepared by hydrothermal method, and GelMA hydrogel with porous network structure and good gelling performance was also prepared. The 25 μg/mL cerium oxide nanoenzyme which could significantly promote the proliferation of human skin fibroblasts and had high superoxide dismutase activity was screened out. It was added to GelMA hydrogel to prepare composite hydrogel. The percentage of cerium oxide nanoenzyme released from the composite hydrogel was calculated after immersing it in phosphate buffer solution (PBS) for 3 and 7 d. The red blood cell suspension of mice was divided into PBS group, Triton X-100 group, cerium oxide nanoenzyme group, GelMA hydrogel group, and composite hydrogel group, which were treated with corresponding solution. The hemolysis of red blood cells was detected by microplate reader after 1 h of treatment. The bacterial concentrations of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli were determined after being cultured with PBS, cerium oxide nanoenzyme, GelMA hydrogel, and composite hydrogel for 2 h. The sample size in all above experiments was 3. Twenty-four 8-week-old male BALB/c mice were taken, and a full-thickness skin defect wound was prepared in the symmetrical position on the back and infected with MRSA. The mice were divided into control group without any drug intervention, and cerium oxide nanoenzyme group, GelMA hydrogel group, and composite hydrogel group applied with corresponding solution, with 6 mice in each group. The wound healing was observed on 3, 7, and 14 d after injury, and the remaining wound areas on 3 and 7 d after injury were measured (the sample size was 5). The concentration of MRSA in the wound exudation of mice on 3 d after injury was measured (the sample size was 3), and the blood flow perfusion in the wound of mice on 5 d after injury was observed using a laser speckle flow imaging system (the sample size was 6). On 14 d after injury, the wound tissue of mice was collected for hematoxylin-eosin staining to observe the newly formed epithelium and for Masson staining to observe the collagen situation (the sample size was both 3). Results: After immersion for 3 and 7 d, the release percentages of cerium oxide nanoenzyme in the composite hydrogel were about 39% and 75%, respectively. After 1 h of treatment, compared with that in Triton X-100 group, the hemolysis of red blood cells in PBS group, GelMA hydrogel group, cerium oxide nanoenzyme group, and composite hydrogel group was significantly decreased (P<0.05). Compared with that cultured with PBS, the concentrations of MRSA and Escherichia coli cultured with cerium oxide nanoenzyme, GelMA hydrogel, and composite hydrogel for 2 h were significantly decreased (P<0.05). The wounds of mice in the four groups were gradually healed from 3 to 14 d after injury, and the wounds of mice in composite hydrogel group were all healed on 14 d after injury. On 3 and 7 d after injury, the remaining wound areas of mice in composite hydrogel group were (29±3) and (13±5) mm2, respectively, which were significantly smaller than (56±12) and (46±10) mm2 in control group and (51±7) and (38±8) mm2 in cerium oxide nanoenzyme group (with P values all <0.05), but was similar to (41±5) and (24±9) mm2 in GelMA hydrogel group (with P values both >0.05). On 3 d after injury, the concentration of MRSA on the wound of mice in composite hydrogel group was significantly lower than that in control group, cerium oxide nanoenzyme group, and GelMA hydrogel group, respectively (with P values all <0.05). On 5 d after injury, the volume of blood perfusion in the wound of mice in composite hydrogel group was significantly higher than that in control group, cerium oxide nanoenzyme group, and GelMA hydrogel group, respectively (P<0.05). On 14 d after injury, the wound of mice in composite hydrogel group basically completed epithelization, and the epithelization was significantly better than that in the other three groups. Compared with that in the other three groups, the content of collagen in the wound of mice in composite hydrogel group was significantly increased, and the arrangement was also more orderly. Conclusions: The composite hydrogel has good biocompatibility and antibacterial effect in vivo and in vitro. It can continuously sustained release cerium oxide nanoenzyme, improve wound blood perfusion in the early stage, and promote wound re-epithelialization and collagen synthesis, therefore promoting the healing of infected full-thickness skin defect wounds in mice.

[Research progress of long-chain non-coding RNA in lipid metabolism reprogramming in primary hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) is the most common liver malignant tumor with complex pathogenesis and a poor prognosis. Metabolic reprogramming has been recognized as one of the important cancer markers, and the liver, as an important organ for lipid metabolism in the human body, plays an important role in the process of the occurrence and development of HCC. More and more evidence shows that long-chain non-coding RNA (lncRNA) can influence the lipid metabolism process by regulating key enzymes and transcription factors, as well as being involved in the occurrence and development of HCC. Therefore, explicating the mechanism of lncRNA in lipid metabolism reprogramming is conducive to providing new targets and strategies for the diagnosis and treatment and improving the prognosis of HCC patients. This article summarizes the latest research progress on the involvement of lncRNA in the reprogramming process of HCC lipid metabolism.

Heat stress-associated changes in the intestinal barrier, inflammatory signals, and microbiome communities in dairy calves

Recent studies indicate that heat stress pathophysiology is associated with intestinal barrier dysfunction, local and systemic inflammation, and gut dysbiosis. However, inconclusive results and a poor description of tissue-specific changes must be addressed to identify potential intervention targets against heat stress illness in growing calves. Therefore, the objective of this study was to evaluate components of the intestinal barrier, pro- and anti-inflammatory signals, and microbiota community composition in Holstein bull calves exposed to heat stress. Animals (mean age = 12 wk old; mean body weight = 122 kg) penned individually in temperature-controlled rooms were assigned to (1) thermoneutral conditions (constant room temperature at 19.5°C) and restricted offer of feed (TNR, n = 8), or (2) heat stress conditions (cycles of room temperatures ranging from 20 to 37.8°C) along with ad libitum offer of feed (HS, n = 8) for 7 d. Upon treatment completion, sections of the jejunum, ileum, and colon were collected and snap-frozen immediately to evaluate gene and protein expression, cytokine concentrations, and myeloperoxidase activity. Digesta aliquots of the ileum, colon, and rectum were collected to assess bacterial communities. Plasma was harvested on d 2, 5, and 7 to determine cytokine concentrations. Overall, results showed a section-specific effect of HS on intestinal integrity. Jejunal mRNA expression of TJP1 was decreased by 70.9% in HS relative to TNR calves. In agreement, jejunal expression of heat shock transcription factor-1 protein, a known tight junction protein expression regulator, decreased by 48% in HS calves. Jejunal analyses showed that HS decreased concentrations of IL-1α by 36.6% and tended to decrease the concentration of IL-17A. Conversely, HS elicited a 3.5-fold increase in jejunal concentration of anti-inflammatory IL-36 receptor antagonist. Plasma analysis of pro-inflammatory cytokines showed that IL-6 decreased by 51% in HS relative to TNR calves. Heat stress alteration of the large intestine bacterial communities was characterized by increased genus Butyrivibrio_3, a known butyrate-producing organism, and changes in bacteria metabolism of energy and AA. A strong positive correlation between the rectal temperature and pro-inflammatory Eggerthii spp. was detected in HS calves. In conclusion, this work indicates that HS impairs the intestinal barrier function of jejunum. The pro- and anti-inflammatory signal changes may be part of a broader response to restore intestinal homeostasis in jejunum. The changes in large intestine bacterial communities favoring butyrate-producing organisms (e.g., Butyrivibrio spp.) may be part of a successful response to maintain the integrity of the colonic mucosa of HS calves. The alteration of intestinal homeostasis should be the target for heat stress therapies to restore biological functions, and, thus highlights the relevance of this work.

[Research progress of non-coding RNA-encoding polypeptides in primary hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, with rapid progression and a poor prognosis. More and more studies have shown that there are small open reading frames (sORFs) on the molecular sequences of a large number of non-coding RNAs (ncRNAs), which can encode conserved peptides that play an important role in controlling the occurrence and development of HCC. This article introduces the discovery, prediction, and validation methods of ncRNA-encoding polypeptides and reviews its research progress, with the aim of providing new targets and ideas for early-stage diagnosis, targeted therapy, and prognosis assessment of HCC.

A Cholecystokinin Analogue Ameliorates Cognitive Deficits and Regulates Mitochondrial Dynamics via the AMPK/Drp1 Pathway in APP/PS1 Mice

BACKGROUND

There are no drugs on the market that can reverse or slow Alzheimer's disease (AD) progression. A protease-resistant Cholecystokinin (CCK) analogue used in this study is based on the basic structure of CCK, which further increases the stability of the peptide fragment and prolongs its half-life in vivo. We observed a neuroprotective effect of CCK-8L in APPswe/PS1dE9 (APP/PS1) AD mice. However, its corresponding mechanisms still need to be elucidated.

OBJECTIVE

This study examined CCK-8L's neuroprotective effects in enhancing cognitive impairment by regulating mitochondrial dynamics through AMPK/Drp1 pathway in the APP/PS1 AD mice.

METHODS

Behavioural tests are applied to assess competence in cognitive functions. Transmission electron microscopy (TEM) was performed to observe the ultrastructure of mitochondria of hippocampal neurons, Immunofluorescent staining was employed to assay for Aβ1-42, APP, Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and dynamin-related protein1 (Drp1). CRISPR/Cas9 was utilized for targeted knockout of the CCKB receptor (CCKBR) in the mouse APP/PS1 hippocampal CA1 region. A model of lentiviral vector-mediated overexpression of APP in N2a cells was constructed.

RESULTS

In vivo, experiments revealed that CCK analogue and liraglutide significantly alleviated cognitive deficits in APP/PS1 mice, reduced Aβ1-42 expression, and ameliorated l damage, which is associated with CCKBR activation in the hippocampal CA1 region of mice. In vitro tests showed that CCK inhibited mitochondrial fission and promoted fusion through AMPK/Drp1 pathway.

CONCLUSIONS

CCK analogue ameliorates cognitive deficits and regulates mitochondrial dynamics by activating the CCKB receptor and the AMPK/Drp1 pathway in AD mice.

Tissue-resident alveolar macrophages reduce O3-induced inflammation via MerTK mediated efferocytosis

Lung inflammation, caused by acute exposure to ozone (O3) - one of the six criteria air pollutants - is a significant source of morbidity in susceptible individuals. Alveolar macrophages (AMØs) are the most abundant immune cells in the normal lung and their number increases following O3 exposure. However, the role of AMØs in promoting or limiting O3-induced lung inflammation has not been clearly defined. Here, we used a mouse model of acute O3 exposure, lineage tracing, genetic knockouts, and data from O3-exposed human volunteers to define the role and ontogeny of AMØs during acute O3 exposure. Lineage tracing experiments showed that 12, 24, and 72 h after exposure to O3 (2 ppm) for 3h all AMØs were tissue-resident origin. Similarly, in humans exposed to FA and O3 (200 ppb) for 135 minutes, we did not observe ~21h post-exposure an increase in monocyte-derived AMØs by flow cytometry. Highlighting a role for tissue-resident AMØs, we demonstrate that depletion of tissue-resident AMØs with clodronate-loaded liposomes led to persistence of neutrophils in the alveolar space after O3 exposure, suggesting that impaired neutrophil clearance (i.e., efferocytosis) leads to prolonged lung inflammation. Moreover, depletion of tissue-resident AMØ demonstrated reduced clearance of intratracheally instilled apoptotic Jurkat cells, consistent with reduced efferocytosis. Genetic ablation of MerTK - a key receptor involved in efferocytosis - also resulted in impaired clearance of apoptotic neutrophils followed O3 exposure. Overall, these findings underscore the pivotal role of tissue-resident AMØs in resolving O3-induced inflammation via MerTK-mediated efferocytosis.

CREB3L2 Regulates Hemidesmosome Formation during Epithelial Sealing

The long-term success rate of dental implants can be improved by establishing a favorable biological sealing with a high-quality epithelial attachment. The application of mesenchymal stem cells (MSCs) holds promise for facilitating the soft tissue integration around implants, but the molecular mechanism is still unclear and the general application of MSC sheet for soft tissue integration is also relatively unexplored. We found that gingival tissue-derived MSC (GMSC) sheet treatment significantly promoted the expression of hemidesmosome (HD)-related genes and proteins in gingival epithelial cells (GECs). The formation of HDs played a key role in strengthening peri-implant epithelium (PIE) sealing. Further, high-throughput transcriptome sequencing showed that GMSC sheet significantly upregulated the PI3K/AKT pathway, confirming that cell adhesion and HD expression in GECs were regulated by GMSC sheet. We observed that the expression of transcription factor CREB3L2 in GECs was downregulated. After treatment with PI3K pathway inhibitor LY294002, CREB3L2 messenger RNA and protein expression levels were upregulated. Further experiments showed that overexpression or knockdown of CREB3L2 could significantly inhibit or promote HD-related genes and proteins, respectively. We confirmed that CREB3L2 was a transcription factor downstream of the PI3K/AKT pathway and participated in the formation of HDs regulated by GMSC sheet. Finally, through the establishment of early implant placement model in rats, we clarified the molecular function of CREB3L2 in PIE sealing as a mechanical transmission molecule in GECs. The application of GMSC sheet-implant complex could enhance the formation of HDs at the implant-PIE interface and decrease the penetration distance of horseradish peroxidase between the implant and PIE. Meanwhile, GMSC sheet reduced the length of CREB3L2 protein expression on PIE. These findings elucidate the potential function and molecular mechanism of MSC sheet regulating the epithelial sealing around implants, providing new insights and ideas for the application of stem cell therapy in regenerative medicine.

Principal Component Analysis to Design Planning Target Volume in Oropharyngeal Cancers

PURPOSE/OBJECTIVE(S)

Standard translational shifts of the Clinical Target volume (CTV) to generate the Planning Target Volume (PTV) do not account for rotations. Head and neck positional misalignments derive in large part from rotations due to cervical spine arching and twisting in Cone Beam Computed Tomography (CBCT). Translational expansions do not track rotations, yielding coverage envelopes that unnecessarily overlap with adjacent structures. This work examines whether principal component analysis of the motion along all 6 degrees of freedom may be used to produce a more favorable PTV.

MATERIALS/METHODS

Seventy-five CBCTs of ten oropharyngeal cases were included. The records of couch shifts needed to align individual bony structures (C1-5, mandible and mastoid) between the planning image and CBCTs were recorded. A Principal Component Analysis of the shifts was used to generate an ellipsoid inflation of each CTV vertex along 6 degrees of freedom. The result was compared to a 3D ellipsoid based translational expansion, and to a described ellipsoid based vertex expansion along 6 degrees of freedom, with axes oriented in parallel to the treatment reference frame.

RESULTS

Themean (x, y) shifts in mm needed to align individually bodies C1 - C5 were respectively (-0.4, 0.5), (+.5, -0.2), (+-0.2, -0.2), (-0.2, +0.4), and (-0.5, +0.7), the monophasic pattern showing acquired curvature along both axes during treatment and demanding a PTV for coverage. A PTV was constructed using a described 6D ellipsoidal based boundary point expansion aligned along the reference frame axis or using a new theory to align against the principal components of the motion. A cyclical one-out method was used to validate the PTV models. Selected confidence intervals yielded complete coverage in >80% weeks in 80% cases. Validation testing disclosed similar complete coverage in 83-86% weekly CBCTs in the test cases with either method. The PCA 6D PTV could yield less normal structure overlap. A one out method was used to test overlap avoidance from PTVs constructed from a population of weekly CBCTs drawn from seven cases with one excluded. PTVs were drawn around target and constrictors on an extraneous case and imaged on a CT slice. Both a rolling 'ball' expansion of the vertices that applies a 3D translational ellipsoid and a PTV constructed using a 6D ellipsoid aligned against the standard reference frame overlapped with all or nearly all the constrictors in all but one trial (1/7). The 6D ellipsoid aligned against the principal motion components spared >70% of a constrictor in all trials (7/7).

CONCLUSION

PTVs remain needed to ensure target coverage in head and neck radiotherapy even with daily CT accuracy because of acquired spinal curvatures resulting in rotational displacements. A described 6D ellipsoid oriented to the reference frame can yield good coverage, but with unneeded constrictor coverage. A PCA analysis yields a PTV with equally good coverage but able to spare 70% of a constrictor.

Identification of neoepitope reactive T-cell receptors guided by HLA-A*03:01 and HLA-A*11:01 immunopeptidomics

BACKGROUND

Tumor-specific mutated proteins can create immunogenic non-self, mutation-containing 'neoepitopes' that are attractive targets for adoptive T-cell therapies. To avoid the complexity of defining patient-specific, private neoepitopes, there has been major interest in targeting common shared mutations in driver genes using off-the-shelf T-cell receptors (TCRs) engineered into autologous lymphocytes. However, identifying the precise naturally processed neoepitopes to pursue is a complex and challenging process. One method to definitively demonstrate whether an epitope is presented at the cell surface is to elute peptides bound to a specific major histocompatibility complex (MHC) allele and analyze them by mass spectrometry (MS). These MS data can then be prospectively applied to isolate TCRs specific to the neoepitope.

METHODS

We created mono-allelic cell lines expressing one class I HLA allele and one common mutated oncogene in order to eliminate HLA deconvolution requirements and increase the signal of recovered peptides. MHC-bound peptides on the surface of these cell lines were immunoprecipitated, purified, and analyzed using liquid chromatography-tandem mass spectrometry, producing a list of mutation-containing minimal epitopes. To validate the immunogenicity of these neoepitopes, HLA-transgenic mice were vaccinated using the minimal peptides identified by MS in order to generate neoepitope-reactive TCRs. Specificity of these candidate TCRs was confirmed by peptide titration and recognition of transduced targets.

RESULTS

We identified precise neoepitopes derived from mutated isoforms of KRAS, EGFR, BRAF, and PIK3CA presented by HLA-A*03:01 and/or HLA-A*11:01 across multiple biological replicates. From our MS data, we were able to successfully isolate murine TCRs that specifically recognize four HLA-A*11:01 restricted neoepitopes (KRAS G13D, PIK3CA E545K, EGFR L858R and BRAF V600E) and three HLA-A*03:01 restricted neoepitopes (KRAS G12V, EGFR L858R and BRAF V600E).

CONCLUSIONS

Our data show that an MS approach can be used to demonstrate which shared oncogene-derived neoepitopes are processed and presented by common HLA alleles, and those MS data can rapidly be used to develop TCRs against these common tumor-specific antigens. Although further characterization of these neoepitope-specific murine TCRs is required, ultimately, they have the potential to be used clinically for adoptive cell therapy.

Reprogramming of Tumor-reactive Tumor-infiltrating Lymphocytes to Human-induced Pluripotent Stem Cells

Tumor-infiltrating lymphocytes (TIL) that can recognize and kill tumor cells have curative potential in subsets of patients treated with adoptive cell transfer (ACT). However, lack of TIL therapeutic efficacy in many patients may be due in large part to a paucity of tumor-reactive T cells in TIL and the exhausted and terminally differentiated status of those tumor-reactive T cells. We sought to reprogram exhausted TIL that possess T-cell receptors (TCR) specific for tumor antigens into induced pluripotent stem cells (iPSC) to rejuvenate them for more potent ACT. We first attempted to reprogram tumor neoantigen-specific TIL by αCD3 Ab prestimulation which resulted in failure of establishing tumor-reactive TIL-iPSCs, instead, T cell-derived iPSCs from bystander T cells were established. To selectively activate and enrich tumor-reactive T cells from the heterogenous TIL population, CD8⁺ PD-1⁺ 4-1BB⁺ TIL population were isolated after coculture with autologous tumor cells, followed by direct reprogramming into iPSCs. TCR sequencing analysis of the resulting iPSC clones revealed that reprogrammed TIL-iPSCs encoded TCRs that were identical to the pre-identified tumor-reactive TCRs found in minimally cultured TIL. Moreover, reprogrammed TIL-iPSCs contained rare tumor antigen-specific TCRs, which were not detectable by TCR sequencing of the starting cell population. Thus, reprogramming of PD-1⁺ 4-1BB⁺ TIL after coculture with autologous tumor cells selectively generates tumor antigen-specific TIL-iPSCs, and is a distinctive method to enrich and identify tumor antigen-specific TCRs of low frequency from TIL.

SIGNIFICANCE

Reprogramming of TIL into iPSC holds great promise for the future treatment of cancer due to their rejuvenated nature and the retention of tumor-specific TCRs. One limitation is the lack of selective and efficient methods for reprogramming tumor-specific T cells from polyclonal TIL. Here we addressed this limitation and present a method to efficiently reprogram TIL into iPSC colonies carrying diverse tumor antigen reactive TCR recombination.

Prediction of nitrogen excretion from data on dairy cows fed a wide range of diets compiled in an intercontinental database: A meta-analysis

Manure nitrogen (N) from cattle contributes to nitrous oxide and ammonia emissions and nitrate leaching. Measurement of manure N outputs on dairy farms is laborious, expensive, and impractical at large scales; therefore, models are needed to predict N excreted in urine and feces. Building robust prediction models requires extensive data from animals under different management systems worldwide. Thus, the study objectives were (1) to collate an international database of N excretion in feces and urine based on individual lactating dairy cow data from different continents; (2) to determine the suitability of key variables for predicting fecal, urinary, and total manure N excretion; and (3) to develop robust and reliable N excretion prediction models based on individual data from lactating dairy cows consuming various diets. A raw data set was created based on 5,483 individual cow observations, with 5,420 fecal N excretion and 3,621 urine N excretion measurements collected from 162 in vivo experiments conducted by 22 research institutes mostly located in Europe (n = 14) and North America (n = 5). A sequential approach was taken in developing models with increasing complexity by incrementally adding variables that had a significant individual effect on fecal, urinary, or total manure N excretion. Nitrogen excretion was predicted by fitting linear mixed models including experiment as a random effect. Simple models requiring dry matter intake (DMI) or N intake performed better for predicting fecal N excretion than simple models using diet nutrient composition or milk performance parameters. Simple models based on N intake performed better for urinary and total manure N excretion than those based on DMI, but simple models using milk urea N (MUN) and N intake performed even better for urinary N excretion. The full model predicting fecal N excretion had similar performance to simple models based on DMI but included several independent variables (DMI, diet crude protein content, diet neutral detergent fiber content, milk protein), depending on the location, and had root mean square prediction errors as a fraction of the observed mean values of 19.1% for intercontinental, 19.8% for European, and 17.7% for North American data sets. Complex total manure N excretion models based on N intake and MUN led to prediction errors of about 13.0% to 14.0%, which were comparable to models based on N intake alone. Intercepts and slopes of variables in optimal prediction equations developed on intercontinental, European, and North American bases differed from each other, and therefore region-specific models are preferred to predict N excretion. In conclusion, region-specific models that include information on DMI or N intake and MUN are required for good prediction of fecal, urinary, and total manure N excretion. In absence of intake data, region-specific complex equations using easily and routinely measured variables to predict fecal, urinary, or total manure N excretion may be used, but these equations have lower performance than equations based on intake.

Cancer genes disfavoring T cell immunity identified via integrated systems approach

Adoptive T cell therapies (ACT) have been curative for a limited number of cancer patients. The sensitization of cancer cells to T cell killing may expand the benefit of these therapies for more patients. To this end, we use a three-step approach to identify cancer genes that disfavor T cell immunity. First, we profile gene transcripts upregulated by cancer under selection pressure from T cell killing. Second, we identify potential tumor gene targets and pathways that disfavor T cell killing using signaling pathway activation libraries and genome-wide loss-of-function CRISPR-Cas9 screens. Finally, we implement pharmacological perturbation screens to validate these targets and identify BIRC2, ITGAV, DNPEP, BCL2, and ERRα as potential ACT-drug combination candidates. Here, we establish that BIRC2 limits antigen presentation and T cell recognition of tumor cells by suppressing IRF1 activity and provide evidence that BIRC2 inhibition in combination with ACT is an effective strategy to increase efficacy.

Ectopic expression of BrIQD35 promotes drought stress tolerance in Nicotiana benthamiana

The plant IQD gene family is responsive to a variety of stresses. In this study, we studied the structural features and functions of the gene BrIQD35 in Chinese cabbage, a member of the IQD gene family. BrIQD35 was cloned and shown to contain an IQ motif. Transient expression of BrIQD35 indicated that it was localized on the plasma membrane and was significantly upregulated under drought and salt stress in Chinese cabbage. To further identify the function of BrIQD35, it was heterologously overexpressed in Nicotiana benthamiana. Although there was no significant difference between BrIQD35-overexpressed and wild-type (WT) plants under salt stress, WT N. benthamiana showed more wilting than the BrIQD35-overexpressed plants under drought stress. Since the IQ motif has been annotated as a CaM binding site, yeast two-hybrid assays were used to explore the interaction between BrIQD35 and CaM. The results indicated that BrIQD35 interacts weakly with CaMb, but not with CaMa, suggesting that BrIQD35 may function through the Ca2+ -CaMb pathway. The findings reveal a novel gene involved in drought tolerance, which is important for plant breeding and quality improvement for Chinese cabbage.

Adoptive Cellular Therapy with Autologous Tumor-Infiltrating Lymphocytes and T-cell Receptor-Engineered T Cells Targeting Common p53 Neoantigens in Human Solid Tumors

Adoptive cellular therapy (ACT) targeting neoantigens can achieve durable clinical responses in patients with cancer. Most neoantigens arise from patient-specific mutations, requiring highly individualized treatments. To broaden the applicability of ACT targeting neoantigens, we focused on TP53 mutations commonly shared across different cancer types. We performed whole-exome sequencing on 163 patients with metastatic solid cancers, identified 78 who had TP53 missense mutations, and through immunologic screening, identified 21 unique T-cell reactivities. Here, we report a library of 39 T-cell receptors (TCR) targeting TP53 mutations shared among 7.3% of patients with solid tumors. These TCRs recognized tumor cells in a TP53 mutation- and human leucocyte antigen (HLA)-specific manner in vitro and in vivo. Twelve patients with chemorefractory epithelial cancers were treated with ex vivo-expanded autologous tumor-infiltrating lymphocytes (TIL) that were naturally reactive against TP53 mutations. However, limited clinical responses (2 partial responses among 12 patients) were seen. These infusions contained low frequencies of mutant p53-reactive TILs that had exhausted phenotypes and showed poor persistence. We also treated one patient who had chemorefractory breast cancer with ACT comprising autologous peripheral blood lymphocytes transduced with an allogeneic HLA-A*02-restricted TCR specific for p53R175H. The infused cells exhibited an improved immunophenotype and prolonged persistence compared with TIL ACT and the patient experienced an objective tumor regression (-55%) that lasted 6 months. Collectively, these proof-of-concept data suggest that the library of TCRs targeting shared p53 neoantigens should be further evaluated for the treatment of patients with advanced human cancers. See related Spotlight by Klebanoff .

Abstract 3576: Identification of T-cell receptors targeting RAS hotspot mutations using TIL IVS in human cancers for use in cell-based immunotherapy

Immunotherapies mediate the regression of human tumors through the recognition of tumor antigens by immune cells, which triggers an immune response. Mutations in the RAS oncogene occur across various cancer histologies and are found in about 30% of all cancer patients. These mutations play an essential role in tumor establishment and survival and are most commonly found in hotspots - specifically at amino acid positions 12, 13, and 61. We have recently treated a patient who underwent a durable objective response after receiving tumor-infiltrating lymphocytes (TILs) that recognized a KRAS G12D mutation. T cell receptors (TCR) that recognize shared mutated RAS antigens presented on major histocompatibility complex (MHC) class I and class II molecules are thus promising reagents for “off-the-shelf” adoptive cell therapies (ACT) following insertion of the TCR into lymphocytes. We recently published a paper describing the discovery of anti-mutated RAS reactivities by using screening TIL and by performing in-vitro stimulation (IVS) of peripheral blood lymphocytes (PBLs). Interestingly by those two methods, we sometimes found reactivity or TCR in a patient in one method but not with the other method. In this work, we described the discovery of anti-mutated RAS TCRs by TIL IVS, which combines the best of the two described methods: using TILs coming from the tumor and therefore assumed to have a higher proportion of anti-tumor-reactive cells and stimulate them, which could enrich smaller populations. The specific anti-mutated RAS CD4 and CD8 TCRs were isolated by coculture of the reactive T cells with dendritic cells (DC) loaded with peptides or transfected with mRNA encoding RAS mutated antigens. The reactive T cells were subjected to single-cell sequencing to identify TCRs. The TCRs were reconstructed as a viral plasmid and retrovirally transduced into PBLs. The transduced TCRs were tested for avidity, MHC restriction, and specific recognition of the mutation. In the same patients tested by both methods, by TIL IVS, identified 12 anti-mutated RAS TCRs in addition the 9 TCRs that we could find by TIL screening. Overall, we present here the discovery of multiple mutation-specific anti-RAS TCRs and its MHC class I and class II restriction elements involved in tumor recognition. Each of the newly discovered TCRs recognized mutated RAS with high avidity and specificity and low to no reactivity against wild-type RAS. Testing of the TCR transduced cells to recognize tumor cell lines in-vitro and in-vivo demonstrated tumor cell line recognition.

The anti-RAS mutated TCRs we discovered by all of our methods can potentially be used as an “off the shelf” treatment for the evaluation of TCR-based ACT in 45-60% of patients were tumor bears RAS mutations.

Citation Format: Noam Levin, Frank J. Lowery, Maria R. Parkhurst, Zhiya Yu, Nolan R. Vale, Sanghyun P. Kim, Steven A. Rosenberg. Identification of T-cell receptors targeting RAS hotspot mutations using TIL IVS in human cancers for use in cell-based immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3576.

Susceptibility-weighted imaging cannot distinguish radionecrosis from recurrence in brain metastases after radiotherapy: a comparison with high-grade gliomas

AIM

To explore the efficiency of susceptibility-weighted imaging (SWI) in the differential diagnosis of recurrence from radionecrosis in brain metastases (BM) and in high-grade gliomas (HGG).

MATERIALS AND METHODS

From September 2016 to November 2018, 56 patients with BM and 42 patients with HGG were included in this retrospective study. BM and HGG were assigned to the recurrence and radionecrosis groups according to their histopathology or follow-up results. The proportion of dark signal intensity (proDSI), which was defined as the area of dark signal on SWI or the enhancing area on contrast-enhanced T1-weighted imaging (T1WI), was calculated for each patient. Analysis of variance (ANOVA) with Tukey's honestly significant difference test was used for the repeat multiple comparisons. Receiver operating characteristic curve analysis was performed to validate the diagnostic performance.

RESULTS

For HGG, the proDSI in the recurrence group was significantly lower than that in the radionecrosis group (0.13 ± 0.05 versus 0.43 ± 0.11, p<0.001); however, for BM, no statistical difference was found between groups (0.49 ± 0.09 versus 0.46 ± 0.08, p=0.26). proDSI had the best diagnostic performance (AUC = 0.87, 95% CI: 0.76-0.98; sensitivity = 0.87; specificity = 0.88) for HGG, when a cut-off value of 0.21 was selected.

CONCLUSIONS

Semi-quantitative analysis using SWI is feasible for the differential diagnosis between recurrence and radionecrosis in HGG, but is not feasible in BM. Semi-quantitative assessment based on SWI should interpreted with caution in BM after radiotherapy in clinical practice.

[Analysis of 2 diagnostic criteria of echocardiography for coronary artery aneurysm in Kawasaki disease]

Objective: To analyze the difference between Z score and previous criteria in the diagnosis characteristics of coronary artery aneurysm (CAA) in Kawasaki disease, and to investigate the clinical distribution of Kawasaki disease CAA in the Z score group. Methods: This study retrospectively analyzed the clinical and echocardiographic data of 2 419 children with Kawasaki disease in Shenzhen Children's Hospital from January 2009 to December 2019. The traditional criteria and Z score criteria were used to diagnose CAA, and the differences of diagnostic efficiency between the 2 diagnostic methods were analyzed. The clinical distribution characteristics of CAA in children with Kawasaki disease were analyzed by grouping their sex, clinical classification (complete Kawasaki disease, incomplete Kawasaki disease) the sensitivity to intravenous immunoglobulin (IVIG) (IVIG-sensitive Kawasaki disease,IVIG-unresponsive Kawasaki disease). And the course of the disease (≤6 weeks, >6-8 weeks, >8 weeks to 6 months) etc. The χ² test or Kruskal-Wallis test was used for comparison between the groups, and the Kappa test was used for consistency evaluation. Results: Among the 2 419 children with Kawasaki disease, 1 558 were males and 861 were females. The age of onset was 1.8 (1.0, 3.2) years. The rate of CAA by Z score criteria was higher than that by traditional method (21.9% (529/2 419) vs. 13.9% (336/2 419), χ²=1 074.94, P<0.001). Compared to the traditional method, the Z score criteria found higher rate of CAA in male patients, patients with incomplete Kawasaki disease, and IVIG-unresponsive patients (25.2% (392/1 558) vs. 16.0% (249/1 558), (32.7% (166/507) vs. 19.5% (99/507), 30.5% (95/312) vs. 24.0% (75/312), χ²=694.05, 216.19, 184.37, all P<0.001). The Z score criteria was consistent with the traditional method in diagnosing CAA (κ=0.642,P<0.001). Moreover, in the Z score criteria, the rate of CAA in males (25.2%, 392/1 558) was higher than that in females (15.9%, 137/861), higher in incomplete Kawasaki cases (32.7%, 166/507) than that in complete Kawasaki case (19.0%, 363/1 912), and higher in IVIG-unresponsive cases (30.4%, 95/312) than that in IVIG-sensitive cases (20.6%, 434/2 107), with statistically significant differences (χ²=27.76, 44.38, 15.43, all P<0.001). Coronary Z score of course ≤ 6 weeks was greater than that of course between>6-8 weeks and >8 weeks to 6 months (1.3 (0.7, 2.3) vs. 0.7 (0.3, 1.4), 0.7 (0.3, 1.3), Z=20.65, 13.70, both P<0.001). Conclusions: The rate of CAA in Kawasaki disease by Z score criteria is higher than that by traditional method. In the Z score group, most CAA occur within 6 weeks of the course of the disease, and the rate of CAA in male, incomplete Kawasaki disease, and IVIG-unresponsive is higher.

[Research advances on application of botulinum toxin type A in scar prevention and treatment]

The wound healing time, tension of wound edge, proliferation of fibroblast, and extracellular matrix deposition are the important factors of scar formation, and botulinum toxin type A can regulate the above. Prevention and treatment of scar with botulinum toxin type A is one of the hot topics of clinical research in recent years. This paper briefly reviews researches by scholars at home and abroad on the mechanism, clinical application, complications, and adverse effects of botulinum toxin type A in scar prevention and treatment.

Molecular signatures of antitumor neoantigen-reactive T cells from metastatic human cancers

The accurate identification of antitumor T cell receptors (TCRs) represents a major challenge for the engineering of cell-based cancer immunotherapies. By mapping 55 neoantigen-specific TCR clonotypes (NeoTCRs) from 10 metastatic human tumors to their single-cell transcriptomes, we identified signatures of CD8⁺ and CD4⁺ neoantigen-reactive tumor-infiltrating lymphocytes (TILs). Neoantigen-specific TILs exhibited tumor-specific expansion with dysfunctional phenotypes, distinct from blood-emigrant bystanders and regulatory TILs. Prospective prediction and testing of 73 NeoTCR signature-derived clonotypes demonstrated that half of the tested TCRs recognized tumor antigens or autologous tumors. NeoTCR signatures identified TCRs that target driver neoantigens and nonmutated viral or tumor-associated antigens, suggesting a common metastatic TIL exhaustion program. NeoTCR signatures delineate the landscape of TILs across metastatic tumors, enabling successful TCR prediction based purely on TIL transcriptomic states for use in cancer immunotherapy.

[Evaluation of the perioperative period and long-term outcomes of minimally invasive LTE and minimally invasive CTLE esophagectomy for stage Ⅰ-Ⅲ cervical esophageal carcinoma based on propensity score matching analysis]

Objective: To evaluate the perioperative period and long-term effects of minimally invasive gasless laparoscopic transhiatal esophagectomy (LTE) and minimally invasive combined thoracoscopic and laparoscopic esophagectomy (CTLE) for stageⅠ-Ⅲ cervical esophageal cancer. Methods: The clinical data of 158 consecutive patients with cervical esophageal cancer stageⅠto Ⅲ who underwent minimally invasive CTLE or LTE esophagectomy in the Department of Thoracic Surgery, Beijing Tongren Hospital from January 2008 to December 2019 were retrospectively analyzed. A total of 40 pairs of cases were matched (40 cases of CTLE and 40 cases of LTE surgery) after using the propensity score matching analysis which aimed to balance the influence of confounding factors between groups, including 43 males and 37 females, aged 51 to 81 (62.5±7.0) years old. The perioperative variables and long-term outcomes of the two groups were compared. Results: The operation time ((148.0±31.3) min vs (201.3±48.3) min), intraoperative blood loss ((192.6±77.9) ml vs (387.8±112.4) ml), ICU monitoring time (0 day vs 1 day), and the complication rates of postoperative pneumonia (0 vs 15%) and arrhythmia (2.5% vs 20%) were lower in the LTE group than that of in the CTLE group(all P<0.05). The number of lymph node dissections in the CTLE group was higher than that of in the LTE group (21.2±6.1 vs 12.9±4.3, P<0.001). The 3-and 5-year overall survival (OS) rate and disease-free survival (DFS) rate in the LTE group (OS: 53.53% and 34.27%, DFS: 43.62% and 24.89%, respectively) and the CTLE group (OS: 59.48% and 37.29%, DFS: 49.12% and 28.82%, respectively) had no statistical differences (all P>0.05). Conclusion: The LTE group has advantages in reducing operation time, intraoperative bleeding, ICU monitoring time, postoperative incidence of pneumonia and arrhythmia, and its long-term prognosis is comparable to that of the CTLE group.

TREATMENT OF SECONDARY LOWER LIMB LYMPHEDEMA AFTER GYNECOLOGIC CANCER WITH COMPLEX DECONGESTIVE THERAPY

Secondary lower extremity lymphedema is a common complication of treatment for gynecological cancers. Conservative therapy plays an important role in the treatment of patients with secondary lower extremity lymphedema; in particular, complex decongestive therapy (CDT) has been recognized as an effective nonoperative technique for these patients. But CDT therapy for secondary lower extremity lymphedema remains a problem in China because this technique and its effectiveness have not achieved widespread use and popularity. Our goal was to assess effects of CDT in patients with secondary lower limb lymphedema after treatment for gynecological cancers. The retrospective study consisted of 60 patients who were treated with 20 sessions of CDT. Assessments included objective changes in limb circumference, degree of LE, imaging features, and incidence of erysipelas before and after CDT treatment. We found that CDT can effectively improve lymph stasis and promote backflow, and decrease circumference, interstitial fluid content, and incidence of erysipelas of lymphedematous lower limb. Our results demonstrate that CDT is an effective treatment method for patients with secondary lower limb lymphedema following treatment for gynecologic cancers. This technique should be more widely utilized and popularized in China to improve the quality of life of millions of patients with secondary lower limb lymphedema.

A high precision phase measurement system implemented in FPGA with phase interpolator

High precision timing distribution is crucial to many large scale cosmology and particle physics experiments. Besides the space and energy information, the accurate timing provides an extra dimension for physics event reconstruction. In the timing distribution system, accurate clock phase measurement is an indispensable tool to monitor the phase drift and to achieve accurate phase adjustment. This paper introduces a novel phase measurement method implemented in the Xilinx Field Programmable Gate Array (FPGA). It uses the dedicated phase interpolator in the multi-gigabit transceiver. A design based on this method is implemented within the Kintex Ultrascale series FPGA. The preliminary test result shows that a sub-picosecond level precision is achieved. With this system, the nonlinearity of the phase adjustment in the Xilinx transceiver is measured.

[Association between serum uric acid to creatinine ratio and metabolic syndrome based on community residents in Chashan town, Dongguan city]

Objective: To analyze the association between serum uric acid to creatinine ratio (SUA/Cr) and metabolic syndrome among community residents in Chashan town, Dongguan city. Methods: Participants were from the prospective cohort study of chronic diseases in natural populations in South China conducted in Chashan town, Dongguan city from 2018 to 2019. A total of 11 334 participants with complete data were included by using convenient sampling method. Demographic characteristics, lifestyle and health status were collected through questionnaire and physical examination. The venous blood of the subjects was collected to detect the levels of serum uric acid, creatinine and blood lipid. All participants were divided into four groups (Q1-Q4) according to the quartile of SUA/Cr level. The relationship between SUA/Cr and metabolic syndrome and its components (abdominal obesity, high triglyceride, low level of high density lipoprotein cholesterol, hypertension and abnormal glucose metabolism) were analyzed by using logistic regression model. Results: The mean age of 11 334 participants was (49.52±10.02) years. Male participants accounted for 44.2% (5 015/11 334). The prevalence of metabolic syndrome was 31.2% (3 532/11 334), and the level of SUA/Cr was 5.17±1.53. The prevalence of metabolic syndrome in group Q1-Q4 was 22.3% (631/2 834), 26.5% (752/2 833), 34.9% (988/2 833) and 41.0% (1 161/2 834), respectively. After adjusting for relevant confounding factors, the result of logistic regression model showed that compared with group Q1, the risk of metabolic syndrome in group Q2-Q4 was significantly higher, with OR (95%CI) values about 1.41 (1.23-1.60), 2.19 (1.93-2.49) and 3.01 (2.65-3.42) respectively. The risk of each component of metabolic syndrome in group Q2-Q4 was higher (P_trend<0.001). The SUA/Cr level of participants with normal uric acid level was significantly positively correlated with metabolic syndrome. The risk of metabolic syndrome increased with the increase of SUA/Cr level, but there was the same trend without significant differences in patients with hyperuricemia (P_interaction=0.008). Conclusion: There is a positive correlation between SUA/Cr level and the risk of metabolic syndrome among community residents in Chashan town, Dongguan city.

167 High-efficiency capture of anti-tumor neoantigen-reactive T cell receptors from tumor digest

Background

As cellular immunotherapies utilizing genetically engineered T cells become a more significant focus of clinical investigation, identification of patient-specific neoantigen-reactive T cell receptors (TCRs) in a practical and efficient manner is a top priority. Using high-dimensional single-cell analysis, we recently identified a common gene expression signature in anti-tumor, neoantigen-reactive tumor-infiltrating lymphocytes (TIL) from patients with metastatic cancer, which included high gene expression of cell-surface markers of exhaustion.1 Furthermore, analyses of intra-tumoral T cell populations have shown that neoantigen-specific TIL are enriched in subsets defined by cell-surface markers of exhaustion, likely secondary to oligoclonal expansion that occurs upon tumor antigen recognition in vivo.2–5 In this study we describe an efficient method to prospectively capture and reconstruct neoantigen-reactive T cell receptors from tumor digest based on co-expression of CD39, PD-1, and TIGIT.

Methods

We evaluated the ability of PD-1+, CD39+, and TIGIT+ TIL (TIL-TP) to enrich for neoantigen-reactivity by sorting, sequencing, and reconstructing high-frequency TCR alpha/beta pairs from tumor digest in 5 patients with metastatic epithelial cancers. We then tested the ability of PD-1/CD39/TIGIT co-expressing TILs to sustain reactivity to patient-specific tumor neoantigens following in vitro expansion under similar conditions to our current clinical trial protocols (figure 1).

Results

We prospectively reconstructed TIL-TP TCRs to identify additional novel TCRs, with 35% of prospectively screened TCRs being neoantigen- or tumor-reactive. Including both previously known and newly predicted TCRs, TIL-TP demonstrated enrichment for neoantigen-reactivity in 4 of 5 patients, with a median of at least 26.8% of sequenced TIL-TP cells being neoantigen-reactive (range: 11.9 – 88.4%). TIL-TP TCR isolation demonstrated a high degree of correlation with single-cell transcriptomic approaches to identification of neoantigen-reactive TCRs, though TIL-TP TCRs represent a more cost-effective and widely available approach compared to those utilizing more advanced technologies. However, despite their substantial enrichment for neoantigen-reactive TCR clonotypes, the majority of TIL-TP populations failed to demonstrate neoantigen-reactivity following in vitro expansion and exhibited loss of neoantigen-reactive clones as well as functional impairment.

Abstract 167 Figure 1

Conclusions

TIL-TP serve as a highly efficient and reliable source of tumor-reactive TCRs. While direct utilization of these TIL-TP as a source for cellular therapy presents significant challenges, sorting for TIL-TP offers a streamlined approach using readily available and affordable technology to identify neoantigen-reactive TCRs that may be used to design TCR engineered cellular immunotherapies.

References

Lowery, FJ, et al. Single cell mapping of tumor infiltrating lymphocytes enables neoantigen-reactive T cell identification in metastatic human cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10–15 and May 17–21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 127.

Duhen, T. et al. Co-expression of CD39 and CD103 identifies tumor-reactive CD8 T cells in human solid tumors. Nat Commun 2018;9:2724, doi:10.1038/s41467-018-05072-0.

Gros A, et al. PD-1 identifies the patient-specific CD8(+) tumor-reactive repertoire infiltrating human tumors. J Clin Invest 2014;124:2246–2259, doi:10.1172/JCI73639.

Pasetto, A. et al. Tumor- and Neoantigen-Reactive T-cell Receptors Can Be Identified Based on Their Frequency in Fresh Tumor. Cancer Immunol Res 2016;4:734–743, doi:10.1158/2326-6066.CIR-16-0001.

Yossef, R. et al. Enhanced detection of neoantigen-reactive T cells targeting unique and shared oncogenes for personalized cancer immunotherapy. JCI Insight 2018;3: doi:10.1172/jci.insight.122467.

[Application effects of free transplantation of autologous omentum in treating maxillofacial infection complicated with complex sinus tract]

Objective: To investigate the application effects of free transplantation of autologous omentum in treating maxillofacial infection complicated with complex sinus tract. Methods: The retrospective observational study method was used. Four patients with maxillofacial infection complicated with complex sinus tract were admitted to Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Air Force Medical University from July 2017 to the December 2019, including 3 males and 1 female aged 36-60 years. Preoperative facial computed tomography (CT) was performed on patients for calculating the volume of sinus tract. During the operation, the sinus tract was thoroughly debrided, and the volume of the tissue defect was about 5 cm×3 cm×2 cm-10 cm×5 cm×3 cm after debridement. The tissue defect area was filled with omentum of 100-300 mL which was cut under laparoscopy. The artery and vein on the right side of the omentum were reserved as the vascular pedicle of the donor area, which were anastomosed with the facial artery and external jugular vein of the recipient area. The survival of omentum, and the occurrences of reinfection and complication were observed after operation, respectively. On the 10th day and in 1 month after the operation, the blood supply of omentum was examined by colored Doppler ultrasound and CT angiography, and the filling of tissue defect area was examined by head and face CT. During follow-up after the operation, the recoveries of face appearance and function and scar hyperplasia in the donor area. Results: The transplanted omentums in 4 patients survived after the operation with no reinfection and complication. On the 10th day and in 1 month after the operation, the transplanted omentums had good blood supply, and the filled area with omentum was in good shape, without formation of dead cavity. During follow-up of 6-10 months after surgery, the appearance and function of face recovered well, and there was no obvious scar hyperplasia in the donor area. Conclusions: After free transplantation of omentum in treating maxillofacial infection with complex sinus tract, the patients have good facial appearance and function, and the application of laparoscopy results in little damage to the patients and quick postoperative recovery.

[Explorative study of the immobilizing effect of full-thickness skin subcutaneous grafting on allogeneic full-thickness skin graft in rats]

Objective: To investigate the immobilizing effect of full-thickness skin subcutaneous grafting on allogeneic full-thickness skin graft in rats. Methods: The experimental research method was used. The inbred male Brown-Norway rats (n=10) and Lewis rats (n=10) were used as donors and recipients respectively. After subcutaneously full-thickness separation of a 2.2 cm×2.2 cm area on the nape of the recipient rat, a full-thickness skin of 2.0 cm×2.0 cm taken from the abdomen of the donor rat was subcutaneously grafted, and the donor site was pulled together and sutured. The autologous skin over the allograft in the recipient rat was excised 5-6 d after grafting, and the stitches were removed 7 d after excision. Within 2 months after grafting, the feeding, activity, and survival of the donor and recipient rats, behavior of tearing and scratching the wounds of the recipient rats, the wound condition after autologous skin excision in recipient rats, and the survival and hair growth of the grafted allogeneic skin were observed. Results: Within 2 months after grafting, the donor and recipient rats all ate normally and could move freely with no abnormal death. No tearing or scratching of the wounds occurred in recipient rats. There was a small amount of exudation and partial epidermal desquamation after autologous skin excision in recipient rats. All transplanted allografts survived, which were free of infection and necrosis, with new hairs growing out smoothly. Conclusions: The immobilizing method of full-thickness skin subcutaneous grafting of allogeneic full-thickness skin graft in rats is simple and time-saving without postoperative dressing change, with reliable pressure fixation and high survival rate of skin grafts, which can be promoted for animal skin grafting models.

[Establishment and validation of a clinical prediction model for infection risk at the placement sites of skin and soft tissue expanders]

Objective: To establish a clinical prediction model for infection risk at the placement sites of skin and soft tissue expanders (hereinafter termed as expanders) and to validate the predictive value of the model. Methods: A retrospective observational study was conducted. Totally 2 934 patients who underwent skin and soft tissue dilatation surgery in the Department of Plastic Surgery of the First Affiliated Hospital of Air Force Medical University from January 2009 to December 2018 and met the selection criteria were included. There were 1 867 males and 1 067 females, with a median age of 18 years. Totally 3 053 skin and soft tissue expansion procedures were performed with 4 266 expanders implanted. The following indexes were selected as predictor variables, including patients' age, gender, marital status, ethnicity, hospital admission, surgical indication, disease duration, with/without history of smoking, history of drinking, history of blood transfusion, history of underlying diseases, and inability to use cephalosporin antibiotics due to allergy, number of expander in a single placement, rated volume of expander, water injection rate of expander in the first time, placement site of expander, anesthesia method, duration of operation, and with/without postoperative hematoma evacuation, and infection at the placement site of expander as the outcome variable. Univariate analysis of the data was performed using least absolute shrinkage and selection operator (LASSO) regression to screen the potential risk factors affecting infection at the placement sites of expanders, the factors selected by the univariate analysis were subjected to binary multivariate logistic regression analysis to screen the independent risk factors affecting infection at the placement sites of expanders, and a nomogram prediction model for the occurrence of infection at the placement sites of expanders was established. The C index and Hosmer-Lemeshow goodness of fit test were used to evaluate the discrimination and accuracy of the model, respectively, and the bootstrap resampling was used for internal verification. Results: The results of LASSO regression showed that age, gender, hospital admission, surgical indication, disease duration, history of drinking, history of heart disease, history of viral hepatitis, history of hypertension, inability to use cephalosporin antibiotics due to allergy, number of expander in a single placement, rated volume of expander, placement site of expander, postoperative hematoma evacuation were the potential risk factors for infection at the placement sites of expanders (regression coefficient=-0.005, 0.170, 0.999, 0.054, 0.510, -0.003, 0.395, -0.218, 0.029, 0.848, -0.116, 0.175, 0.085, 0.202). Binary multivariate logistic regression analysis showed that male, emergency admission, disease duration ≤1 year, inability to use cephalosporin antibiotics due to allergy, rated volumes of expanders ≥200 mL and <400 mL or ≥400 mL, and expanders placed in the trunk or the limbs were the independent risks factors for infection at the placement sites of expanders (odds ratio=1.37, 3.21, 2.00, 2.47, 1.70, 1.73, 1.67, 2.16, 95% confidence interval=1.04-1.82, 1.09-8.34, 1.38-2.86, 1.29-4.41, 1.07-2.73, 1.02-2.94, 1.09-2.58, 1.07-4.10, P<0.05 or P<0.01). The C index for evaluating the discriminative degree of the model was 0.63, the Hosmer-Lemeshow goodness of fit test for evaluating the accuracy of the model showed P=0.685, and the C index for internal validation by the bootstrap resampling was 0.60. Conclusions: Male, emergency admission, disease duration ≤1 year, inability to use cephalosporin antibiotics due to allergy, rated volume of expander ≥200 mL, and expanders placed in the trunk or the limbs are the independent risk factors for infection at the placement sites of expanders. The clinical prediction model for infection risk at the placement sites of expanders was successfully established based on these factors and showed a certain predictive effect.

Abstract 1527: Integrated computational and experimental analysis identifies the mitochondrial uncoupling protein 2 (Ucp2) as a key regulator of T cell anti-tumor function

T cells play a central role in cancer immunosurveillance and current cancer immunotherapies, including adoptive cell transfer (ACT), T cell receptor or chimeric antigen receptor (CAR) T cell therapies and immune checkpoint blockade. Understanding the factors regulating T cell function is hence critical for improving the success of these immunotherapies. It has been recognized that metabolism can greatly affect different aspects of T cell function, including differentiation, cytokine production, longevity and exhaustion. Here we integrate genome-scale metabolic modeling (GEM) with biological experiments to discover novel metabolic determinants of T cell function. Previously we developed the metabolic transformation algorithm (MTA), a GEM method that was successfully applied to identify driving factors and targets for different diseases. Here applying MTA to data on CAR-T cell gene expression and patient response to anti-CD19 CAR-T therapy, we predicted mitochondrial metabolite transport and specifically proton transport in mitochondrial uncoupling, as key determinants of CAR-T therapy response. Mitochondrial uncoupling is also important for the in vivo persistence of adoptively transferred tumor-infiltrating lymphocytes, as further confirmed by analyzing their gene expressions from a KRAS-targeting ACT dataset. Focusing on the mitochondrial uncoupling protein 2 (Ucp2), which is abundantly expressed in T cells, we experimentally validated that it is required for T cell longevity and anti-tumor function. Specifically, the loss of Ucp2 either via knock-out (KO) or treatment by genipin (a Ucp2 inhibitor) in mice T cells results in accelerated differentiation into “terminal effector cells”, as shown by increased levels of T cell cytotoxicity and exhaustion markers, and decreased levels of central memory and stemness markers. Adoptive transfer of Ucp2-KO Pmel-1 T cells to mice bearing B16 melanomas displayed poorer anti-tumor efficacy and worse survival than the transfer of Ucp2-wildtype T cells. We find that Ucp2 modulates oxidative stress and DNA damage by regulating the levels of mitochondrial superoxide. Reducing mitochondrial reactive oxygen species was sufficient to rescue the loss of Ucp2-mediated effector T cell differentiation, senescence, cytokine production and anti-tumor activity Ucp2-KO Pmel-1 T cells. Tumor-specific CD8+ T cells could be metabolically reprogrammed by Ucp2 overexpression, which improved T cell longevity and anti-tumor function in the Pmel-1/B16 ACT mice model. In sum, our study establishes a novel role of Ucp2 in regulating T cell longevity and anti-tumor activity by repressing increased ROS levels accompanying mitochondrial dysfunction in differentiated and exhausted cells, suggesting that manipulating Ucp2 levels in T cells can be exploited to enhance T cell-based cancer immunotherapies.

Citation Format: Madhusudhanan Sukumar, Kuoyuan Cheng, Arunakumar Gangaplara, Yogin Patel, Suman K. Vodnala, Rafiqul Islam, Arash Eidizadeh, Carolyn Subramaniam, Ping Lee, Rigel Kishton, Amanda N. Henning, Michael J. Kruhlak, Zhiya Yu, Ethan M. Shevach, Toren Finkel, Eytan Ruppin, Nicholas P. Restifo. Integrated computational and experimental analysis identifies the mitochondrial uncoupling protein 2 (Ucp2) as a key regulator of T cell anti-tumor function [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1527.

Identification and Validation of T-cell Receptors Targeting RAS Hotspot Mutations in Human Cancers for Use in Cell-based Immunotherapy

PURPOSE

Immunotherapies mediate the regression of human tumors through recognition of tumor antigens by immune cells that trigger an immune response. Mutations in the RAS oncogenes occur in about 30% of all patients with cancer. These mutations play an important role in both tumor establishment and survival and are commonly found in hotspots. Discovering T-cell receptors (TCR) that recognize shared mutated RAS antigens presented on MHC class I and class II molecules are thus promising reagents for "off-the-shelf" adoptive cell therapies (ACT) following insertion of the TCRs into lymphocytes.

EXPERIMENTAL DESIGN

In this ongoing work, we screened for RAS antigen recognition in tumor-infiltrating lymphocytes (TIL) or by in vitro stimulation of peripheral blood lymphocytes (PBL). TCRs recognizing mutated RAS were identified from the reactive T cells. The TCRs were then reconstructed and virally transduced into PBLs and tested.

RESULTS

Here, we detect and report multiple novel TCR sequences that recognize nonsynonymous mutant RAS hotspot mutations with high avidity and specificity and identify the specific class-I and -II MHC restriction elements involved in the recognition of mutant RAS.

CONCLUSIONS

The TCR library directed against RAS hotspot mutations described here recognize RAS mutations found in about 45% of the Caucasian population and about 60% of the Asian population and represent promising reagents for "off-the-shelf" ACTs.

Mutations of the c-Kit and PDGFRA gene in gastrointestinal stromal tumors among hakka population of Southern China

Aims

The aim of the present study was to investigate mutation status of the cKit and PDGFRA genes in patients with a gastrointestinal stromal tumor (GIST).

Methods

In total, 96 patients with a GIST were included in the study, in which polymerase chain reaction amplification and gene sequencing were used to detect the sequences of exons 9, 11, 12, 13, 14, 17, and 18 in KIT and exons 12, 14, and 18 in PDGFRA.

Results

KIT mutations were detected in 65 cases (67.71%), of which 81.54% (53/65) were located on exon 11, 12.31% (8/65) were located on exon 9, 4.61% (3/65) were located on exon 17, which included a concomitant mutation of exon 9 and 11, and 4.08% (2/65) were located on exon 13, which included a concomitant mutation on exon 11. The most common mutation in exon 11 was deletion, which accounted for 77.36% (41/53) of the cases, followed by a point mutation observed in 22.64% (12/53) of the cases. Among the 31 GIST cases without a KIT mutation, a mutation in PDGFRA was detected in 5 cases (5.21%, 5/96; 16.13%, 5/31). With respect to gender, age, tumor max diameter, tumor position, and mitotic index, there were no significant differences between KIT/PDGFRA mutations and non-mutations.

Conclusions

GIST mainly occurs in the stomach, and the cytological morphology is mainly spindle cells, and the mutations mainly occur in KIT genes. We need a large sample size to analyze the regularity of GIST gene mutations in Hakka population and understand the independent prognostic correlation of all KIT/PDGFRA genotypes.