Hydraulic retention time optimization achieved unexpectedly high nitrogen removal rate in pilot-scale anaerobic/aerobic/anoxic system for low-strength municipal wastewater treatment.

Applications of post-denitrification processes are subjected to low reaction rates caused by a lack of carbon resources. To offer a solution for reaction rate promotion, this research found a pilot-scale anaerobic/aerobic/anoxic bioreactor treating 55-120 m3/d low-strength municipal wastewater for 273 days. A short hydraulic retention time (HRT, 5-6 h) and a high nitrogen removal rate (63.2 ± 9.3 g-N/m3·d) were achieved using HRT optimization. The effluent total nitrogen concentration was maintained at 5.8 ± 1.4 mg/L while operating at a high nitrogen loading rate of 86.2 ± 12.8 g-N/m3·d. The short aeration (1.25-1.5 h) minimized the Glycogen loss. The endogenous denitrification rate increased to above 1.0 mg/(g-VSS·h). The functional genus Ca. Competibacter enriched to 2.3 %, guaranteeing the efficient post-denitrification process. Dechloromonas rose to 1.1 %, aiding in the synchronous phosphorus removal. These findings offered fresh insights into AOA processes to achieve energy/cost-saving wastewater treatment.

Nasal delivery of an IgM offers broad protection from SARS-CoV-2 variants.

Resistance represents a major challenge for antibody-based therapy for COVID-191-4. Here we engineered an immunoglobulin M (IgM) neutralizing antibody (IgM-14) to overcome the resistance encountered by immunoglobulin G (IgG)-based therapeutics. IgM-14 is over 230-fold more potent than its parental IgG-14 in neutralizing SARS-CoV-2. IgM-14 potently neutralizes the resistant virus raised by its corresponding IgG-14, three variants of concern-B.1.1.7 (Alpha, which first emerged in the UK), P.1 (Gamma, which first emerged in Brazil) and B.1.351 (Beta, which first emerged in South Africa)-and 21 other receptor-binding domain mutants, many of which are resistant to the IgG antibodies that have been authorized for emergency use. Although engineering IgG into IgM enhances antibody potency in general, selection of an optimal epitope is critical for identifying the most effective IgM that can overcome resistance. In mice, a single intranasal dose of IgM-14 at 0.044 mg per kg body weight confers prophylactic efficacy and a single dose at 0.4 mg per kg confers therapeutic efficacy against SARS-CoV-2. IgM-14, but not IgG-14, also confers potent therapeutic protection against the P.1 and B.1.351 variants. IgM-14 exhibits desirable pharmacokinetics and safety profiles when administered intranasally in rodents. Our results show that intranasal administration of an engineered IgM can improve efficacy, reduce resistance and simplify the prophylactic and therapeutic treatment of COVID-19.

The rare entity of cystadenocarcinoma (CAC) in parotid gland: A single-center experience.

PURPOSE: Cystadenocarcinoma (CAC) is an extremely rare disease in parotid gland. This study aimed to identify the clinical characteristics of CAC, and the therapeutic options for its treatment. An attempt was also made to identify postoperative recurrence-related risk factors. MATERIAL AND METHODS: A retrospective study was conducted of CAC patients treated between 2008 and 2018. Predictive factors for postoperative recurrence (5-year RFS rate) were preliminarily filtered by Kaplan-Meier analysis and then further confirmed by a Cox regression model. Postoperative recurrence was defined as the primary outcome variable and was measured using both univariate and multivariate analysis. RESULTS: A total of 27 patients were analyzed, and the total incidence of postoperative recurrence was 33.3% (9/27). In the Cox regression analysis, patients who received a superficial parotidectomy were 0.046 times more likely to develop tumor relapse than those who only underwent enucleation (p = 0.032; 95% CI: 0.003-0.070). The chances of tumor recurrence in patients with the cribriform subtype were 9.701 times that for cases with a papillary pattern (p = 0.016; 95% CI: 1.517-62.030). The risk of postoperative recurrence increased abruptly, with an OR of 6.373 (p = 0.042; 95% CI: 1.070-37.965), when LN metastasis was found in patients. CONCLUSION: Preoperative diagnosis of CAC in parotid gland is extremely important for allowing surgeons to apply appropriate therapeutic strategies (enucleation or superficial parotidectomy). Patients with LN metastasis, cribriform pattern, and Ki-67 positivity should be treated further to avoid tumor relapse.

Nomogram model to predict postoperative relapse after mandibular osteoradionecrosis surgery.

PURPOSE: Osteoradionecrosis of the mandible (ORNM) is one of the most devastating complications following radiotherapy. Postoperative relapse (POR) occurs with high incidence even if a radical resection is performed. The current investigation was designed to identify prognostic factors for POR and to establish a nomogram model to estimate the risk for the onset of POR of ORNM. MATERIALS AND METHODS: A retrospective study was conducted in ORNM patients during the period from 2003 to 2016. Predictive factors for POR were preliminarily filtered by Kaplan-Meier analysis and were further confirmed by Cox regression model. A nomogram model was established to predict the risk for the onset of POR, and the performance was estimated by receiver operating characteristic (ROC) and calibration curve. POR was defined as the primary outcome variable and was measured using univariate and multivariate analyses. RESULTS: A total of 213 patients were analyzed, and the total incidence of POR was 24.4% (52/213). In the Cox regression analysis, radiation doses ≥80 Gy (versus＜80 Gy, OR = 3.528, P＜0.001, 95% CI: 1.759-7.076), location of ORNM (lesion only in mandibular body versus that involving mandibular body, angulus and ramus versus, OR = 2.900, P = 0.007, 95% CI: 1.345-6.253), S classification (S2 versus S0, OR = 8.926, P = 0.001, 95% CI: 2.487-32.036), and surgical treatment (sequestretomy versus ER + reconstruction, OR = 3.299, P = 0.012, 95% CI: 1.294-8.411) were significantly associated with POR. The current nomogram model can effectively evaluate the hazard risk and survival rate of POR. The discrimination capability was tested by the ROC curve with an area under the curve of 0.813, revealing highly predictive abilities. The calibration curve showed sufficient fitness. CONCLUSION: The current nomogram model was effective in predicting the risk of POR in ORNM patients.

Gene expression profiling in pachyonychia congenita skin.

BACKGROUND: Pachyonychia congenita (PC) is a skin disorder resulting from mutations in keratin (K) proteins including K6a, K6b, K16, and K17. One of the major symptoms is painful plantar keratoderma. The pathogenic sequelae resulting from the keratin mutations remain unclear. OBJECTIVE: To better understand PC pathogenesis. METHODS: RNA profiling was performed on biopsies taken from PC-involved and uninvolved plantar skin of seven genotyped PC patients (two K6a, one K6b, three K16, and one K17) as well as from control volunteers. Protein profiling was generated from tape-stripping samples. RESULTS: A comparison of PC-involved skin biopsies to adjacent uninvolved plantar skin identified 112 differentially-expressed mRNAs common to patient groups harboring K6 (i.e., both K6a and K6b) and K16 mutations. Among these mRNAs, 25 encode structural proteins including keratins, small proline-rich and late cornified envelope proteins, 20 are related to metabolism and 16 encode proteases, peptidases, and their inhibitors including kallikrein-related peptidases (KLKs), and serine protease inhibitors (SERPINs). mRNAs were also identified to be differentially expressed only in K6 (81) or K16 (141) patient samples. Furthermore, 13 mRNAs were identified that may be involved in pain including nociception and neuropathy. Protein profiling, comparing three K6a plantar tape-stripping samples to non-PC controls, showed changes in the PC corneocytes similar, but not identical, to the mRNA analysis. CONCLUSION: Many differentially-expressed genes identified in PC-involved skin encode components critical for skin barrier homeostasis including keratinocyte proliferation, differentiation, cornification, and desquamation. The profiling data provide a foundation for unraveling the pathogenesis of PC and identifying targets for developing effective PC therapeutics.

In vivo and in situ imaging of head and neck squamous cell carcinoma using near-infrared fluorescent quantum dot probes conjugated with epidermal growth factor receptor monoclonal antibodies in mice.

In this study, we applied near-infrared fluorescent quantum dots (NIRF-QDs) for non-invasive in vivo and in situ imaging of head and neck squamous cell carcinoma (HNSCC). The U14 squamous cancer cell line with high expression of epidermal growth factor receptor (EGFR) was implanted subcutaneously into the head and neck regions of nude mice to establish HNSCC models. NIRF-QDs with an emission wavelength of 800 nm (NIRF-QD800) were conjugated with EGFR monoclonal antibodies to develop the QD800-EGFR Ab probe. In vivo and in vitro studies demonstrated that the QD800-EGFR Ab probe can specifically bind EGFR expressed on U14 cells. U14 squamous cell carcinoma in the head and neck can be clearly visualized by in vivo imaging after intravenous injection of QD800-EGFR Ab probes. The results suggested that in situ imaging using NIRF-QD-EGFR Ab probes has unique advantages and prospects for the investigation of tumor development, early diagnosis and personalized therapy of HNSCC.

In-vivo imaging of oral squamous cell carcinoma by EGFR monoclonal antibody conjugated near-infrared quantum dots in mice.

OBJECTIVES: The purpose of this study was to investigate in-vivo visible imaging of oral squamous cell carcinoma (OSCC) by targeting epidermal growth factor receptor (EGFR) with near-infrared quantum dots. MATERIALS AND METHODS: Quantum dots with an emission wavelength of 800 nm (QD800) were conjugated to monoclonal antibodies against EGFR, resulting in the probe designated as QD800-EGFR Ab. OSCC cell line (BcaCD885) expressing high levels of EGFR was transplanted subcutaneously into nude mice cheeks to develop an OSCC animal model. QD800-EGFR Ab containing 100 pmol equivalent of QD800 was intravenously injected into the animal model, and in-situ and in-vivo imaging of cheek squamous cell carcinoma was analyzed at 10 different time points. RESULTS AND CONCLUSION: In-vivo imaging and immunohistochemical examination of the tumors showed that intravenously injected QD800-EGFR Ab probe could bind EGFR expressed on BcaCD885 cells. Fluorescence signals of BcaCD885 cells labeled with QD800-EGFR Ab probe could be clearly detected, and these fluorescence signals lasted for 24 hours. The most complete tumor images with maximal signal-to-noise ratio were observed from 15 minutes to 6 hours after injection of the probe. To the best of the authors' knowledge, this is the first study that has obtained clear in-situ and in-vivo imaging of head and neck cancer by using QD800-EGFR Ab probe. The authors conclude that the combination of near-infrared quantum dots that are highly penetrating for tissues with EGFR monoclonal antibody has promising prospects in in-vivo imaging of OSCC and development of personalized surgical therapies.

Heme oxygenase-1 deletion affects stress erythropoiesis.

BACKGROUND: Homeostatic erythropoiesis leads to the formation of mature red blood cells under non-stress conditions, and the production of new erythrocytes occurs as the need arises. In response to environmental stimuli, such as bone marrow transplantation, myelosuppression, or anemia, erythroid progenitors proliferate rapidly in a process referred to as stress erythropoiesis. We have previously demonstrated that heme oxygenase-1 (HO-1) deficiency leads to disrupted stress hematopoiesis. Here, we describe the specific effects of HO-1 deficiency on stress erythropoiesis. METHODOLOGY/PRINCIPAL FINDINGS: We used a transplant model to induce stress conditions. In irradiated recipients that received hmox(+/-) or hmox(+/+) bone marrow cells, we evaluated (i) the erythrocyte parameters in the peripheral blood; (ii) the staining intensity of CD71-, Ter119-, and CD49d-specific surface markers during erythroblast differentiation; (iii) the patterns of histological iron staining; and (iv) the number of Mac-1(+)-cells expressing TNF-α. In the spleens of mice that received hmox(+/-) cells, we show (i) decreases in the proerythroblast, basophilic, and polychromatophilic erythroblast populations; (ii) increases in the insoluble iron levels and decreases in the soluble iron levels; (iii) increased numbers of Mac-1(+)-cells expressing TNF-α; and (iv) decreased levels of CD49d expression in the basophilic and polychromatophilic erythroblast populations. CONCLUSIONS/SIGNIFICANCE: As reflected by effects on secreted and cell surface proteins, HO-1 deletion likely affects stress erythropoiesis through the retention of erythroblasts in the erythroblastic islands of the spleen. Thus, HO-1 may serve as a therapeutic target for controlling erythropoiesis, and the dysregulation of HO-1 may be a predisposing condition for hematologic diseases.

[Visual imaging for buccal carcinoma with near-infrared fluorescent quantum dots in vivo].

OBJECTIVE: To examine the in vivo visual imaging of buccal carcinoma with the near-infrared fluorescent quantum dots. METHODS: The U14 cells were labeled by endocytosis with QD800 (U14/QD800) which was linked with cell-penetrating peptide. Different number of U14/QD800 was injected under the buccal mucosa of nude mice and Kunming mice separately and imaged at different time to detect the in vivo sensitivity and dynamic imaging of U14/QD800. RESULTS: The minimum number of U14/QD800 cells which could be detected by in vivo imaging system was 1 × 10(4) in nude mice's cheek and 1 × 10(5) in Kunming mice's. The time for visual imaging of 1 × 10(4), 1 × 10(5) and 1 × 10(6) U14/QD800 cells in nude mice was 3, 7 and 16 d separately, and 3 and 10 d separately in Kunming mice. CONCLUSIONS: Due to its strong tissue penetration, near-infrared fluorescent quantum dots have great prospects in cancer early diagnosis, visual observation and individual treatment.

[Study on effect of peptide-conjugated near-infrared fluorescent quantum dots on invasion and metastasis of human buccal squamous cell carcinoma cell line BcaCD885].

OBJECTIVE: To study the effect of peptide-conjugated near-infrared quantum dots (QDs) on growth, invasion and metastasis of human buccal squamous cell carcinoma cell line (BcaCD885 cell). METHODS: (1) BcaCD885 cells were labeled by cell-penetrating peptide-conjugated QDs with a maximum emission wavelength of 800 nm (QD800), then labeling efficiency was detected by flow cytometry, and laser-scanning confocal microscope was used to observe the distribution of QD800 within the cells. (2) Different concentrations of QD800 was applied to BcaCD885 cells, and the cell growth of control and three test groups were compared respectively. (3) BcaCD885 cells were labeled by QD800 (BcaCD885/QD800), then transwell chambers and wash way were used to detect the difference of invasion and metastasis ability between BcaCD885/QD800 and BcaCD885 cells. RESULTS: (1) The labeling rate of BcaCD885 cells after 6h was 94.07%, and QD800 distributes in the BcaCD885 cytoplasm. (2) Different concentrations of QD800 showed no negative effects on growth of BcaCD885 cells. (3) The ability of invasion, attachment and motion of BcaCD885 cells were not significantly different between test and control group (P > 0.05). CONCLUSION: QDs showed no effects on growth, invasion and metastasis ability of BcaCD885 cells. Our results provide science foundation for QDs as a new fluorescence probes to real-time monitor cells and cells imaging in a living.

Quantum dot-based visual in vivo imaging for oral squamous cell carcinoma in mice.

To explore the competence of near-infrared luminescent quantum dots for visual in vivo imaging on oral squamous carcinoma BcaCD885 cells. Peptide-conjugated near-infrared quantum dots, with an emission wavelength of 800 nm (QD800), were used to label BcaCD885 cells by endocytosis. The QD800-labeled BcaCD885 cells were inoculated in the dorsum subcutaneous, back muscle and under the cheek oral mucosa of nude mice at cell counts of 1×10³, 1×104, 1×105, and 1×106 respectively. At different time points, these mice were examined by an in vivo imaging system to investigate the sensitivity of QD800 to visual detection in BcaCD885 cells and the conditions of dynamic imaging. The minimum detectable counts of BcaCD885 cells for QD800-based in vivo imaging were 1×104 in the dorsum subcutaneous, back muscle and under the cheek oral mucosa. As tissue depth increased, the detectable fluorescence intensity dropped; as cell counts increased, the fluorescence intensity and the visual image duration also increased, especially for the QD800-labeled BcaCD885 cells in which counts of 1×106 were visual imaged in the dorsum subcutaneous, back muscle and under the cheek oral mucosa for 16 d. Our study successfully used cell-penetrating peptides to conjugate near-infrared quantum dots for the first time and labeled oral squamous carcinoma cells with quantum dot conjugates by endocytosis for visual in vivo imaging. Because of the strong penetration power to tissues, near-infrared quantum dot technology exhibits great promise for the early diagnosis, visual observation and individualized treatment of oral cancer.

Near-infrared quantum-dot-based non-invasive in vivo imaging of squamous cell carcinoma U14.

Near-infrared (near-ir) quantum dots (QDs) are well known for their excellent optical characteristics. They hold great potential for applications in non-invasive long term observation and tracing of cells in vivo. Here, near-ir QDs with an emission wavelength of 800 nm (QD800) were used to label squamous cell carcinoma cell line U14 (U14/QD800). The effect of tissue depth and animal fur on the imaging sensitivity and stability was evaluated following subcutaneous and intramuscular injection into Kunming mice, employing an in vivo imaging system. We have demonstrated that QD800-based visual in vivo imaging increased the sensitivity of cancer early detection by a factor of 100 compared with traditional detection methods. More importantly, this study proved for the first time that animal fur has a serious impact on the detection sensitivity and duration of QD-based in vivo imaging. In general, the duration and sensitivity of QD800 for in vivo imaging were not greatly affected by a depth less than 1.8 ± 0.21 mm (subcutaneous or intramuscular). This study provides critical reference data for further research on near-ir QD-based early detection and in vivo visual observation of cancer.

[Effect of peptide-conjugated quantum dots on the tumorigenicity and lymph node metastasis of human tongue squamous cell carcinoma cell line Tca8113 and mouse uterine cervix carcinoma U14 in vivo].

OBJECTIVE: To observe the effect of peptide-conjugated quantum dots with a maximal emission of 655 nm (QD655) on growth, proliferation, apoptosis and lymphatic metastasis of human tongue squamous cell carcinoma cell line Tca8113 and mouse uterine cervix carcinoma U14 in vivo. METHODS: Tca8113 and U14 cells were labeled by QD655 (Tca8113-QD655, U14-QD655). Tca8113-QD655 and U14-QD655 were inoculated subcutaneously into nude mice and Kunming mice. The tumor formation of Tca8113-QD655 and Tca8113, U14-QD655 and U14 was observed and compared in vivo. The proliferation and apoptosis of Tca8113-QD655 and Tca8113, U14-QD655 and U14 cells from tumors formed in vivo were analyzed by flow cytometry. U14-QD655 and U14 were inoculated into the buccal mucosa of Kunming mice to establish the cervical lymph node metastasis model of buccal cancer. The cervical lymph node metastatic ability of U14-QD655 and U14 was compared. RESULTS: The tumor weight and volume of Tca8113-QD655 and Tca8113, U14-QD655 and U14 in vivo were not significantly different (P>0.05), the cell proliferation index and apoptosis index of Tca8113-QD655 and Tca8113, U14-QD655 and U14 in vivo were not significantly different (P>0.05). The cervical lymph node metastasis rate of U14-QD655 and U14 buccal cancer were not significantly different (P>0.05). CONCLUSIONS: QD showed no effects on tumorigenicity and lymph node metastasis of Tca8113 and U14 cells. These results provide the scientific basis for noninvasive imaging and long-term tracing study.

Induction of chimerism permits low-dose islet grafts in the liver or pancreas to reverse refractory autoimmune diabetes.

OBJECTIVE: To test whether induction of chimerism lowers the amount of donor islets required for reversal of diabetes and renders the pancreas a suitable site for islet grafts in autoimmune diabetic mice. RESEARCH DESIGN AND METHODS: The required donor islet dose for reversal of diabetes in late-stage diabetic NOD mice after transplantation into the liver or pancreas was compared under immunosuppression or after induction of chimerism. Recipient mice were monitored for blood glucose levels and measured for insulin-secretion capacity. Islet grafts were evaluated for beta-cell proliferation, beta-cell functional gene expression, and revascularization. RESULTS: With immunosuppression, transplantation of 1,000, but not 600, donor islets was able to reverse diabetes when transplanted into the liver, but transplantation of 1,000 islets was not able to reverse diabetes when transplanted into the pancreas. In contrast, after induction of chimerism, transplantation of as few as 100 donor islets was able to reverse diabetes when transplanted into either the liver or pancreas. Interestingly, when lower doses (50 or 25) of islets were transplanted, donor islets in the pancreas were much more effective in reversal of diabetes than in the liver, which was associated with higher beta-cell replication rate, better beta-cell functional gene expression, and higher vascular density of graft islets in the pancreas. CONCLUSIONS: Induction of chimerism not only provides immune tolerance to donor islets, but also markedly reduces the required amount of donor islets for reversal of diabetes. In addition, this process renders the pancreas a more superior site than the liver for donor islets in autoimmune mice.

IL-12 enhances efficacy and shortens enrichment time in cytokine-induced killer cell immunotherapy.

Cytokine-induced killer (CIK) cells are T cell derived ex vivo expanded cells with both NK and T cell properties. They exhibit potent anti-tumor efficacy against various malignancies in preclinical models and have proven safe and effective in clinical studies. We combined CIK cell adoptive immunotherapy with IL-12 cytokine immunotherapy in an immunocompetent preclinical breast cancer model. Combining CIK cells with IL-12 increased anti-tumor efficacy in vivo compared to either therapy alone. Combination led to full tumor remission and long-term protection in 75% of animals. IL-12 treatment sharply increased the anti-tumor efficacy of short-term cultured CIK cells that exhibited no therapeutic effect alone. Bioluminescence imaging based in vitro cytotoxicity and in vivo homing assays revealed that short-term cultured CIK cells exhibit full cytotoxicity in vitro, but display different tumor homing properties than fully expanded CIK cells in vivo. Our data suggest that short-term cultured CIK cells can be "educated" in vivo, producing fully expanded CIK cells upon IL-12 administration with anti-tumor efficacy in a mouse model. Our findings demonstrate the potential to improve current CIK cell-based immunotherapy by increasing efficacy and shortening ex vivo expansion time. This holds promise for a highly efficacious cancer therapy utilizing synergistic effects of cytokine and cellular immunotherapy.

In vivo study of the effects of peptide-conjugated near-infrared fluorescent quantum dots on the tumorigenic and lymphatic metastatic capacities of squamous cell carcinoma cell line Tca8113 and U14.

Quantum dots (QDs) have great potential in non-invasive monitoring and imaging of tumor cells in vivo, but it is unknown if QDs affect their tumorigenesis and metastasis. Here, we applied peptide-conjugated near-infrared fluorescent QDs (NIRF-QDs) to label the squamous cell carcinoma cells Tca8113 and U14. We tested the proliferation and apoptotic capacities of both cells, and the capacity of cervical lymph node metastasis after tumorigenesis in U14 cells'. We find that QDs do not affect the tumor cells' capacities to grow, proliferate, and metastasize. Our study provides critical data to support the application of NIRF-QDs in non-invasive monitoring and imaging of tumor cells in vivo.

In vivo analysis of heat-shock-protein-70 induction following pulsed laser irradiation in a transgenic reporter mouse.

Induction of heat shock protein (Hsp) expression appears to correlate with a cytoprotective effect in cultured cells and with improved healing of damaged tissues in animal models and in humans. This family of proteins can also serve as indicators of thermal stress in cases of burn injury or surgical procedures that produce heat. Thus, a rapid in vivo readout for induction of Hsp transcription would facilitate studies of Hsp genes and their encoded proteins as mediators of therapeutic effects and as reporters of thermal damage to tissues. We created a transgenic reporter mouse where expression of luciferase is controlled by the regulatory region of the inducible 70 kDa Hsp, and assessed activation of Hsp70 transcription in live animals in response to rapid, high temperature stresses using in vivo bioluminescence imaging (BLI). This model can be used to noninvasively reveal levels of Hsp70 transcription in living tissues, and has utility in studies of the predictive and protective effects of Hsp70 expression, and of various stress responses in tissues.

Heme oxygenase-1 deficiency leads to disrupted response to acute stress in stem cells and progenitors.

An effective response to extreme hematopoietic stress requires an extreme elevation in hematopoiesis and preservation of hematopoietic stem cells (HSCs). These diametrically opposed processes are likely to be regulated by genes that mediate cellular adaptation to physiologic stress. Herein, we show that heme oxygenase-1 (HO-1), the inducible isozyme of heme degradation, is a key regulator of these processes. Mice lacking one allele of HO-1 (HO-1(+/-)) showed accelerated hematopoietic recovery from myelotoxic injury, and HO-1(+/-) HSCs repopulated lethally irradiated recipients with more rapid kinetics. However, HO-1(+/-) HSCs were ineffective in radioprotection and serial repopulation of myeloablated recipients. Perturbations in key stem cell regulators were observed in HO-1(+/-) HSCs and hematopoietic progenitors (HPCs), which may explain the disrupted response of HO-1(+/-) HPCs and HPCs to acute stress. Control of stem cell stress response by HO-1 presents opportunities for metabolic manipulation of stem cell-based therapies.

Donor CD8+ T cells mediate graft-versus-leukemia activity without clinical signs of graft-versus-host disease in recipients conditioned with anti-CD3 monoclonal antibody.

Donor CD8(+) T cells play a critical role in mediating graft-vs-leukemia (GVL) activity, but also induce graft-vs-host disease (GVHD) in recipients conditioned with total body irradiation (TBI). In this study, we report that injections of donor C57BL/6 (H-2(b)) or FVB/N (H-2(q)) CD8(+) T with bone marrow cells induced chimerism and eliminated BCL1 leukemia/lymphoma cells without clinical signs of GVHD in anti-CD3-conditioned BALB/c (H-2(d)) recipients, but induced lethal GVHD in TBI-conditioned recipients. Using in vivo and ex vivo bioluminescent imaging, we observed that donor CD8(+) T cells expanded rapidly and infiltrated GVHD target tissues in TBI-conditioned recipients, but donor CD8(+) T cell expansion in anti-CD3-conditioned recipients was confined to lymphohematological tissues. This confinement was associated with lack of up-regulated expression of alpha(4)beta(7) integrin and chemokine receptors (i.e., CXCR3) on donor CD8(+) T cells. In addition, donor CD8(+) T cells in anti-CD3-conditioned recipients were rendered unresponsive, anergic, Foxp3(+), or type II cytotoxic T phenotype. Those donor CD8(+) T cells showed strong suppressive activity in vitro and mediated GVL activity without clinical signs of GVHD in TBI-conditioned secondary recipients. These results indicate that anti-CD3 conditioning separates GVL activity from GVHD via confining donor CD8(+) T cell expansion to host lymphohemological tissues as well as tolerizing them in the host.

In vivo visualization of cardiac allograft rejection and trafficking passenger leukocytes using bioluminescence imaging.

BACKGROUND: We investigated the feasibility of bioluminescence imaging (BLI) for the in vivo assessment of cardiac allograft viability and visualization of passenger leukocytes during the course of acute rejection. METHODS AND RESULTS: Hearts of FVB (H-2q) luciferase-green fluorescent protein transgenic mice (beta-actin promoter) or FVB luciferase transgenic mice (CD5 promoter) were heterotopically transplanted into either BALB/c (H-2d) or FVB recipients. Light intensity emitting from the recipient animals was measured daily by in vivo BLI until 12 days after transplantation. Graft beating score (0 to 4) was assessed by daily abdominal palpation until 12 days after transplantation. Inflammatory cell infiltration (CD45 stain) and structural changes of green fluorescent protein-positive cardiomyocytes were followed by immunohistochemistry. All cardiac allografts were acutely rejected by 12 days after transplantation. The intensity of light emitting from cardiac allografts declined 4 days after transplantation and correlated with graft beating scores (R2=0.91, P=0.02). Immunohistochemistry confirmed these results by showing an increase of CD45+ inflammatory cell infiltration and destruction of green fluorescent protein-positive cardiomyocytes in the cardiac allografts during acute rejection. In vivo BLI visualized migration and proliferation of CD5+ passenger leukocytes in both syngeneic and allogeneic recipients. In the allograft recipients, light signal from CD5+ passenger leukocytes peaked at 6 hours and diminished by 12 hours, whereas in the syngeneic recipients, the signal remained high until 10 days after transplantation. CONCLUSIONS: BLI is a useful modality for the quantitative assessment of in vivo cardiac graft viability and tracking of passenger leukocytes in vivo during the course of acute rejection.