[Clinical characteristics and prognostic factors of breast cancer patients with tumor deposits in the ipsilateral axillary region]

Objective: To investigate the clinicopathologic features and prognostic factors of breast cancer patients with tumor deposits in the ipsilateral axillary region. Methods: We retrospectively analyzed the clinicopathologic data and follow-up results of 155 patients with breast cancer diagnosed for the first time and complicated with tumor deposits in the ipsilateral axillary region in the Department of Thyroid-Breast-Vascular Surgery of Xijing Hospital from January 2008 to September 2018. Kaplan-Meier method was used for survival analysis. Log rank test was used for the univariate analysis of prognostic factors, and Cox regression was used for multivariate analysis. Results: The median disease free survival (DFS), median distant metastasis free survival (DMFS), and median overall survival (OS) of the 155 patients were 52.0 months, 66.6 months, and 102.2 months, respectively. The 5-year and 10-year DFS rates were 45.7% and 23.1%, the 5-year and 10-year DMFS rates were 56.9% and 28.9%, and the 5-year and 10-year OS rates were 79.3% and 46.0%, respectively. Multivariate Cox regression analysis showed that family tumor history (HR=0.362, 95% CI: 0.140-0.937), clinical T stage (T3: HR=3.508, 95% CI: 1.380-8.918; T4: HR=2.220, 95% CI: 1.076-4.580), estrogen/progesterone receptor status (HR=0.476, 95% CI: 0.261-0.866), number of tumor deposits (HR=1.965, 95% CI:1.104-3.500) and neoadjuvant chemotherapy (HR=1.961, 95% CI: 1.032-3.725) were independent influencing factors for DFS. Molecular subtype [human epidermal growth factor receptor-2(HER-2) positive and hormone receptor negative: HR=7.862, 95% CI: 3.189-19.379], number of tumor deposits (HR=2.155, 95% CI: 1.103-4.212), neoadjuvant chemotherapy (HR=5.002, 95% CI: 2.300-10.880) and radiotherapy (HR=2.316, 95% CI: 1.005-5.341) were independent influencing factors of DMFS. Histological grade (HR=4.362, 95% CI: 1.932-9.849), estrogen/progesterone receptor expression (HR=0.399, 95% CI: 0.168-0.945), HER-2 expression (HR=2.535, 95% CI: 1.114-5.768) and neoadjuvant chemotherapy (HR=4.080, 95% CI: 1.679-9.913) were independent influencing factors of OS. Conclusions: The presence of tumor deposits weakens the influence of axillary lymph node status and distant metastases on the prognosis of breast cancer patients. Therefore, a clinicopathological staging system taking into account tumor deposits should be developed. Since the number of tumor deposits affects the risk of recurrence and metastasis of breast cancer patients, we recommend that the number of tumor deposits should be reported in detail in the pathological report after breast cancer surgery.

[Clinical features and antimicrobial resistance of invasive non-typhoid Salmonella infection in children at Xiamen]

Objective: To investigate the clinical characteristics, serogroups and antimicrobial resistance of invasive non-typhoid Salmonella infection in children at Xiamen. Methods: Retrospective cohort study. The clinical manifestations, treatment, prognosis, serogroups and antimicrobial resistance of 29 hospitalized children with invasive non-typhoid Salmonella infection confirmed by blood, cerebrospinal fluid, bone marrow and other sterile body fluids or deep pus culture at the Department of Infectious Diseases, the Department of Orthopedics and the Department of General Surgery in Xiamen Children's Hospital from January 2016 to December 2021 were analyzed. According to the clinical diagnosis criteria, the patients were divided into sepsis group and non-sepsis group (bacteremia and local suppurative infection). The inflammatory markers, serogroups distribution and drug resistance were compared between the two groups. Comparison between groups using Mann-Whitney U test and χ² test. Results: Among the 29 cases, there were 17 males and 12 females, with an onset age of 14 (9, 25) months, and 10 cases (34%) of patients were younger than 1 year old, 15 cases (52%) under 1 to 3 years old, and 4 cases (14%) greater than or equal 3 years old. The onset time of 25 cases (86%) was from April to September. The diseases included 19 cases (66%) septicemia (2 of which were combined with suppurative meningitis), 10 cases (34%) non-sepsis group, including 7 cases bacteremia and 3 cases local suppurative infection (2 cases of osteomyelitis, 1 case of appendicitis with peritonitis). The clinical manifestations were fever in 29 cases (100%), diarrhea and abdominal pain in 18 cases (62%), cough and runny nose in 10 cases (34%). Eighteen cases (62%) were cured and 11 cases (38%) were improved by effective antibiotics treatment. C-reactive protein in sepsis group was significantly higher than that in non-sepsis group (25.2 (16.1, 56.4) vs. 3.4 (0.5, 7.5) mg/L, Z=-3.81, P<0.001).The serogroups of C, B and E were the most prevalent among non-typhoid Salmonella isolates, accounting for 10 cases (34%), 9 cases (31%) and 7 cases (24%) respectively. Antibacterial drug sensitivity test showed that the sensitivity rates of imipenem, ertapenem and piperaciratazobactam were all 100% (31/31), those of ceftazidime, ceftriaxone, and cefepime were 94% (29/31), 94% (29/31) and 97% (30/31) respectively. The drug resistance rates of ampicillin, ampicillin-sulbactam and trimethoprim-sulfamethoxazole were 51% (16/31), 48% (15/31) and 48% (15/31) respectively, those of cefazolin, cefotetan, tobramycin, gentamicin and amikacinwere all 100% (31/31). There were no significant differences in the drug resistance rates of ceftazidime, ceftriaxone, aztreonam, ampicillin-sulbactam, ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin between the sepsis group and the non-sepsis group (χ²=0.31,0.31,0.00,0.02,0.02,0.02,0.26, all P>0.05). Conclusions: Invasive non-typhoid Salmonella infection in children at Xiamen mainly occurred in infants younger than 3 years old.The main clinical manifestations are fever, abdominal pain and diarrhea. C-reactive protein can be served as the laboratory indicators for indicating sepsis. The third generation of cephalosporins is recommended as the first choice for treatment.

Surfaceome Profiling Identifies Basigin-Chaperoned Protein Clients

The surface proteome or "surfaceome" is a critical mediator of cellular biology, facilitating cell-to-cell interactions and communication with extracellular biomolecules. Constituents of the surfaceome can serve as biomarkers for changing cell states and as targets for pharmacological intervention. While some pathways of cell surface trafficking are well characterized to allow prediction of surface localization, some non-canonical trafficking mechanisms do not. Basigin (Bsg), a cell surface glycoprotein, has been shown to chaperone protein clients to the cell surface. However, understanding which proteins are served by Bsg is not always straightforward. To accelerate such identification, we applied a surfaceome proximity labeling method that is integrated with quantitative mass spectrometry-based proteomics to discern changes in the surfaceome of hepatic stellate cells that occur in response to the genetic loss of Bsg. Using this strategy, we observed that the loss of Bsg leads to corresponding reductions in the cell surface expression of monocarboxylate transporters MCT1 and MCT4. We also found that these relationships were unique to Bsg and not found in neuroplastin (Nptn), a related family member. These results establish the utility of the surfaceome proximity labeling method to determine clients of cell surface chaperone proteins.

Stereoselective synthesis of photoactivatable Man(β1,4)GlcNAc-based bioorthogonal probes

We report an operationally facile protocol to prepare photoactivatable probes of the bioactive mammalian disaccharide, Man(β1,4)GlcNAc. Using conformationally restricted mannosyl hemi-acetal donors in a one-pot chlorination, iodination and glycosylation sequence, β-mannosides were generated in excellent diastereoselectivities and yields. Upon accessing the disaccharide, we generated the corresponding photoactivatable probes by appending a diazirine-alkyne equipped linker via a condensation reaction between a diazirine-containing linker and C-1 and C-2 derivatized mannosylamines to furnish the desired C-1 and C-2 modified Man(β1,4)GlcNAc-based probes. This new synthetic protocol greatly simplifies the preparation of this important bioactive disaccharide to enable future work to identify its protein binding partners in cells.

Proximity labeling technologies to illuminate glycan-protein interactions

Glycosylation is a ubiquitous post-translational modification read by glycan-binding proteins (GBP) to encode important functions, but a robust understanding of these interactions and their consequences can be challenging to uncover. Glycan-GBP interactions are transient and weak, making them difficult to capture, and glycosylation is dynamic and heterogenous, necessitating study in native cellular environments to identify endogenous ligands. Proximity labeling, an experimental innovation that labels biomolecules close to a protein of interest, has recently emerged as a powerful strategy to overcome these limitations, allowing interactors to be tagged in cells for subsequent enrichment and identification by mass spectrometry-based proteomics. We will describe this nascent technique and discuss its applications in the last five years with different GBP classes, including Siglecs, galectins, and non-human lectins.

(Glycan Binding) Activity‐Based Protein Profiling in Cells Enabled by Mass Spectrometry‐Based Proteomics

The presence of glycan modifications at the cell surface and other locales positions them as key regulators of cell recognition and function. However, due to the complexity of glycosylation, the annotation of which proteins bear glycan modifications, which glycan patterns are present, and which proteins are capable of binding glycans is incomplete. Inspired by activity-based protein profiling to enrich for proteins in cells based on select characteristics, these endeavors have been greatly advanced by the development of appropriate glycan-binding and glycan-based probes. Here, we provide context for these three problems and describe how the capability of molecules to interact with glycans has enabled the assignment of proteins with specific glycan modifications or of proteins that bind glycans. Furthermore, we discuss how the integration of these probes with high resolution mass spectrometry-based technologies has greatly advanced glycoscience.

Chemoproteomic mapping of human milk oligosaccharide (HMO) interactions in cells

Human milk oligosaccharides (HMOs) are a family of unconjugated soluble glycans found in human breast milk that exhibit a myriad of biological activity. While recent studies have uncovered numerous biological functions for HMOs (antimicrobial, anti-inflammatory & probiotic properties), the receptors and protein binding partners involved in these processes are not well characterized. This can be attributed largely in part to the low affinity and transient nature of soluble glycan-protein interactions, precluding the use of traditional characterization techniques to survey binding partners in live cells. Here, we present the use of synthetic photoactivatable HMO probes to capture, enrich and identify HMO protein targets in live cells using mass spectrometry-based chemoproteomics. Following initial validation studies using purified lectins, we profiled the targets of HMO probes in live mouse macrophages. Using this strategy, we mapped hundreds of HMO binding partners across multiple cellular compartments, including many known glycan-binding proteins as well as numerous proteins previously not known to bind glycans. We expect our findings to inform future investigations of the diverse roles of how HMOs may regulate protein function.

Mucopedia 101: capturing and assigning mucin-domain glycoproteins

Glycoproteins bearing mucin domains serve important biological functions, yet they are understudied due to their dense glycosylation. Malaker et al. describe a new tool that will advance the capture, identification, and prediction of new members of the 'mucinome'.

Excavating proteoglycan structure-function relationships: Modern approaches to capture the interactions of ancient biomolecules

Proteoglycans are now well regarded as key facilitators of cell biology. While a majority of their interactions and functions are attributed to the decorating glycosaminoglycan chains, there is a growing appreciation for the roles of the proteoglycan core protein and for considering proteoglycans as replete protein-glycan conjugates. This appreciation, seeded by early work in proteoglycan biology, is now being advanced and exalted by modern approaches in chemical glycobiology. In this review, we discuss up-and-coming methods to unearth the fine-scale architecture of proteoglycans that modulate their functions and interactions. Crucial to these efforts is the production of chemically defined materials, including semi-synthetic proteoglycans and the in situ capture of interacting proteins. Together, the integration of chemical biology approaches promises to expedite the dissection of the structural heterogeneity of proteoglycans and deliver refined insight into their functions.

Chemical editing of proteoglycan architecture

Proteoglycans are heterogeneous macromolecular glycoconjugates that orchestrate many important cellular processes. While much attention has focused on the poly-sulfated glycosaminoglycan chains that decorate proteoglycans, other important elements of their architecture, such as core proteins and membrane localization, have garnered less emphasis. Hence, comprehensive structure-function relationships that consider the replete proteoglycan architecture as glycoconjugates are limited. Here we present an extensive approach to study proteoglycan structure and biology by fabricating defined semisynthetic modular proteoglycans that can be tailored for cell surface display. The expression of proteoglycan core proteins with unnatural amino acids permits bioorthogonal click chemistry with functionalized glycosaminoglycans for methodical dissection of the parameters required for optimal binding and function of various proteoglycan-binding proteins. We demonstrate that these sophisticated materials can recapitulate the functions of native proteoglycan ectodomains in mouse embryonic stem cell differentiation and cancer cell spreading while permitting the analysis of the contributing architectural elements toward function.

Cell Surface Engineering Enables Surfaceome Profiling

Cell surface proteins (CSPs) are vital molecular mediators for cells and their extracellular environment. Thus, understanding which CSPs are displayed on cells, especially in different cell states, remains an important endeavor in cell biology. Here, we describe the integration of cell surface engineering with radical-mediated protein biotinylation to profile CSPs. This method relies on the prefunctionalization of cells with cholesterol lipid groups, followed by sortase-catalyzed conjugation with an APEX2 ascorbate peroxidase enzyme. In the presence of biotin-phenol and H₂O₂, APEX2 catalyzes the formation of highly reactive biotinyl radicals that covalently tag electron-rich residues within CSPs for subsequent streptavidin-based enrichment and analysis by quantitative mass spectrometry. While APEX2 is traditionally used to capture proximity-based interactomes, we envisioned using it in a "baitless" manner on cell surfaces to capture CSPs. We evaluate this strategy in light of another CSP labeling method that relies on the presence of cell surface sialic acid. Using the APEX2 strategy, we describe the CSPs found in three mammalian cell lines and compare CSPs in adherent versus three-dimensional pancreatic adenocarcinoma cells.

Proximity Tagging Identifies the Glycan-Mediated Glycoprotein Interactors of Galectin-1 in Muscle Stem Cells

Myogenic differentiation, the irreversible developmental process where precursor myoblast muscle stem cells become contractile myotubes, is heavily regulated by glycosylation and glycan-protein interactions at the cell surface and the extracellular matrix. The glycan-binding protein galectin-1 has been found to be a potent activator of myogenic differentiation. While it is being explored as a potential therapeutic for muscle repair, a precise understanding of its glycoprotein interactors is lacking. These gaps are due in part to the difficulties of capturing glycan-protein interactions in live cells. Here, we demonstrate the use of a proximity tagging strategy coupled with quantitative mass-spectrometry-based proteomics to capture, enrich, and identify the glycan-mediated glycoprotein interactors of galectin-1 in cultured live mouse myoblasts. Our interactome dataset can serve as a resource to aid the determination of mechanisms through which galectin-1 promotes myogenic differentiation. Moreover, it can also facilitate the determination of the physiological glycoprotein counter-receptors of galectin-1. Indeed, we identify several known and novel glycan-mediated ligands of galectin-1 as well as validate that galectin-1 binds the native CD44 glycoprotein in a glycan-mediated manner.

[Preoperative treatment of uterine fibroids with low-dose mifepristone: a multicenter, randomized, double-blind, placebo-controlled, parallel-group study]

Objective: To evaluate the clinical efficacy and safety of oral mifepristone (10 mg/day) versus placebo in the preoperative treatment of uterine fibroids. Methods: This study was a multi-center, randomized, double-blind, placebo, parallel controlled trial. A total of 132 patients with uterine fibroids were randomly divided into study group and control group, with 66 cases in each group. The patients in the study group orally took 1 tablet/day of mifepristone (dose of 10 mg/tablet), the patients in the control group orally took 1 tablet/day of placebo, and both groups were treated for 3 months. The primary efficacy evaluation indicators were the change rate of maximum fibroid volume; the secondary efficacy evaluation indicators included amenorrhea rate, improvement of subjective symptoms and anemia; the safety evaluation indicators included the analysis of adverse events and changes in laboratory biochemical indicators. Results: At the end of treatment, the maximum leiomyoma volume was reduced by 25.97% (95%CI: -34.79%--15.95%) in the study group and reduced by 1.51% (95%CI: -13.03%-11.54%) in the control group. The change rate of the maximum leiomyoma volume before and after treatment in the study group was significantly greater than that in the control group, and the difference in the change rate of the maximum leiomyoma volume between the two groups was -24.84% (95%CI: -36.56%--10.94%), which was much higher than the 10% superiority threshold goal set by this study within the 95%CI interval. At the end of treatment, the complete amenorrhea rate [84% (52/62)], dysmenorrhea elimination rate [98% (61/62)], and menstrual blood loss disappearance rate [87% (54/62)] in the study group were significantly higher than those in the control group (all P<0.05). At the end of treatment, the mean hemoglobin [(131±13) g/L], red blood cell count [(4.5±0.4)×10¹²/L] and hematocrit (0.39±0.03) in the study group were significantly increased compared with the baseline, and the differences had statistical significance (all P<0.05); after treatment, the differences in the above three indicators between the two groups had statistical significance (all P<0.01). The serum estradiol level in the study group was significantly lower than that in the control group at the end of treatment, and the difference was statistically significant (P<0.01). There were no significant differences in follicle-stimulating hormone and cortisol levels before and after treatment between the two groups (P>0.05). The overall incidences of any adverse event were not significantly different between the two groups (all P>0.05). Abdominal pain was the most common adverse event in the study group [9% (6/65)], but the incidence was not significantly increased compared with the control group [3% (2/64); P>0.05]. Conclusion: Compared with placebo, oral mifepristone 10 mg/day is significantly superior to placebo in reducing the size of uterine fibroids and improving anemia, without significant adverse reactions, and could be used as a drug treatment for patients with of uterine fibroids before surgery.

[Diagnostic performance of a novel Mycobacterium Tuberculosis specific T-Cell based assay for tuberculosis]

Objective: To evaluate the diagnosic performance of a novel Mycobacterium tuberculosis (MTB) specific T-cell based assay for tuberculosis, which targets the mRNA detection of interferon gamma-induced protein 10 (IP-10). Methods: Suspected tuberculosis patients were prospectively and consecutively recruited in Beijing Chest Hospital between March 2018 and November 2019, and individuals with lower risk of MTB infection were also recruited. IP-10.TB and T-SPOT.TB assays were simulataneously performed on peripheral blood samples. The diagnostic performance of IP-10.TB and T-SPOT.TB were analyzed using the receiver operating characteristic curve. Accordance of IP-10.TB and T-SPOT.TB was analyzed by Cohen's kappa test, while the correlation between the expression level of IP-10 mRNA in IP-10.TB test and the number of SFCs in T-SPOT.TB test were analyzed by Pearson correlation test. Results: A total of 235 patients with tuberculosis, 110 patients with other diseases and 153 individuals with lower risk of MTB infection were included in the final analysis. No significant difference was detected in the rate of indeterminate results between IP-10.TB assay (3/498, 0.60%) and T-SPOT.TB assay (6/498, 1.21%). The total sensitivity and specificity of IP-10.TB assay were 91.3% (95%CI 86.8%-94.6%) and 81.1% (95%CI 75.8%-85.7%). The specificity of IP-10.TB in individuals with lower risk of MTB infection was 98.0% (95%CI 94.4%-99.6%). The total sensitivity and specificity of T-SPOT.TB assay were 93.0% (95%CI 88.9%-96.0%) and 83.8% (95%CI 78.7%-88.1%). The specificity of T-SPOT.TB in individuals with lower risk of MTB infection was 100% (95%CI 97.6%-100.0%). No significant differences were detected in sensitivity and specificity between IP-10.TB and T-SPOT.TB assays (P>0.05). The positive coincidence rate of these 2 methods was 91.0% (95%CI 87.5%-94.5%), and the negative coincidence rate was 88.9% (95%CI 84.9%-92.9%) and the total coincidence rate was 90.0% (95%CI 87.3%-92.6%). The Cohen's kappa value was 0.80 (95%CI 0.75-0.85, P<0.001) between IP-10.TB and T-SPOT.TB assays. Conclusion: These results showed that the diagnostic performance of IP-10.TB was consistent with that in T-SPOT.TB, and this test could be a novel adjunctive tool for the diagnosis of tuberculosis.

Mapping Interactions between Glycans and Glycan-Binding Proteins by Live Cell Proximity Tagging

Interactions between glycans and glycan-binding proteins (GBPs) consist of weak, noncovalent, and transient binding events, making them difficult to study in live cells void of a static, isolated system. Furthermore, the glycans are often presented as protein glycoconjugates, but there are limited efforts to identify these proteins. Proximity labeling permits covalent tagging of the glycoprotein interactors to query GBP in live cells. Coupled with high-resolution mass spectrometry, it facilitates determination of the proteins bearing the interacting glycans. In this method, fusion protein constructs of a GBP of interest with a peroxidase enzyme allows for in situ spatiotemporal radical-mediated tagging of interacting glycoproteins in living cells that can be enriched for identification. Using this method, the capture and study of glycan-GBP interactions no longer relies on weak, transient interactions, and results in robust capture and identification of the interactome of a GBP while preserving the native cellular environment. This protocol focuses on (1) expression and characterization of a recombinant fusion protein consisting of a peroxidase and the GBP galectin-3, (2) corresponding in situ labeling and visualization of interactors, (3) and proteomic workflow and analysis of captured proteins for robust identification using mass spectrometry. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Expression, purification, and characterization of recombinant fusion protein Alternate Protocol 1: Manual Ni-NTA purification of recombinant fusion protein Basic Protocol 2: In situ proximity labeling and evaluation by fluorescence microscopy Alternate Protocol 2: Western blot analysis of in situ proximity labeling Basic Protocol 3: Proximity labeling of cells for quantitative MS-based proteomics with tandem mass tags.

[Knockout notch1 gene can enhanced radiosensitivity of nasopharyngeal carcinoma cells]

Objective:To investigate the effect of Notch1 gene on radiosensitivity of nasopharyngeal carcinoma cells and its molecular mechanism. Method:A Notch1-knockout CNE-2 cell line was constructed using CRISPR/Cas9 system, and the expression of Notch1 gene was detected by RT-PCR and Western blot. After treatment with different doses of radiation, the survival fraction （SF） of each group was calculated, and used the GraphPad Prism 6.0 software and the Linear quadratic model were used to calculate the fitted dose survival curve and the sensitivity enhancement ratio（SER）. Taking 6 Gy as radiation dose, the experiment was divided into four groups: Notch1（+） group, Notch1（-） group, IR+Notch1（+） group and IR+Notch1（-） group. CCK-8 assay was used to detect cell proliferation in each group. Annexin V-FITC/PI double staining assay was used to detect the changes of apoptosis in each group. The expression of H2AX, CyclinD1, Bax, Bcl-2 and GAPDH proteins were detected by Western blot. Result:The CNE-2 cell line with Notch1 gene knockout was successfully constructed. The clonogenic assay showed knockout of Notch1 enhanced the radiosensitivity of NPC cells. The CCK-8 assay showed that cell proliferation and cell viability were significantly reduced in the IR+Notch1（-） group compared with the IR+Notch1（+） group（P<0.05）. Annexin V-FITC/PI double staining assay showed that the IR+Notch1（-） group had the highest apoptosis rate compared with the other groups （P<0.05）. Western blotting demonstrated that the expression of γH2AX was significantly increased after irradiation of Notch1 nasopharyngeal carcinoma cells, the expression of Cyclin-D1 was increased, and the ratio of Bax:Bcl-2 was higher. Conclusion:Knockout of Notch1 signaling molecule can effectively improve the radiosensitivity of NPC cells cultured in vitro, which may be a potential target for radiosensitization of NPC.

Highlights from Faraday Discussion 301: Nanolithography of Biointerfaces, London, UK, July 3-5 2019

The 2019 Faraday Discussion on the Nanolithography of Biointerfaces brought together a diverse set of interdisciplinary scientists involved in the seemingly disparate fields of materials science, nanolithography and glycoscience. The setting and format of this meeting renders the experience unique, and anyone in the audience is instantly engaged in the debate. This Faraday Discussion attracted about sixty delegates, ranging from graduate students and early career researchers to full professors. The meeting was a reflection on how far lithography techniques, tissue engineering and glycoscience have come, with the aid of scientists working at the realm of the nanoscale. True to its name, this gathering was also a discussion on what the outstanding questions in glycobiology are and how nanolithography can be appropriately applied to answer them. In this report, we will give an overview of the topics and discussions covered during the meeting and highlight the content of each session.

Abstract OT3-05-04: Phase II study of atezolizumab, cobimetinib, and eribulin in patients with recurrent or metastatic inflammatory breast cancer (IBC)

Background: IBCs that do not completely respond to chemotherapy often have dysregulated immune pathways, and novel therapies are needed to improve outcomes in recurrent/metastatic disease. One-third of IBCs express the atezolizumab target PD-L1, and cobimetinib increases PD-L1 expression; thus, we hypothesize that atezolizumab and cobimetinib may act synergistically in IBC. The FDA-approved agent eribulin is active in IBC and has anti-stem cell activity and can reverse the IBC phenotype of epithelial-to-mesenchymal transition. Hence the use of eribulin as a chemotherapy backbone in combination with other novel agents is well justified.

Trial Design: This single-arm, open-label trial is enrolling patients with recurrent IBC or de novo metastatic IBC that has progressed on at least 1 line of standard chemotherapy. During a 4-week pharmacodynamic window, patients have an upfront biopsy, receive atezolizumab and cobimetinib treatment for 4 weeks, and have a second biopsy. Triple-combination treatment then commences, with standard eribulin dosing. After 4 cycles of eribulin, patients receive maintenance targeted therapy until disease progression or intolerable toxicity.

Eligibility Criteria: Patients with metastatic IBC of any molecular subtype must have measurable disease (per RECIST 1.1) amenable to biopsy. Patients with HER2+ disease must have received both pertuzumab and T-DM1. Patients with treated stable brain metastases are allowed. Patients must have recovered from the acute effects of any prior therapies and have adequate hematologic, organ, and cardiac function. Patients with autoimmune diseases or a history of pneumonitis are ineligible.

Specific Aims: The primary objective is to determine the overall response rate (ORR) of the combination therapy. Secondary objectives include determining the safety and tolerability, clinical benefit rate, response duration, progression-free survival, 2-year overall survival rate and predictive biomarker analyses.

Statistical Methods: The trial will enroll up to 9 patients in its phase I/safety lead-in portion and up to 33 patients total. A Bayesian optimal interval design is used to efficiently determine the maximum tolerated cobimetinib dose in phase I. Patients start cobimetinib at the FDA-approved dose of 60 mg/day with a target toxicity rate is 0.3. Phase II will enroll 24 patients to determine the efficacy of the triple-combination therapy. The historical ORR in metastatic IBC is 10%; our sample size provides 80% power to detect an ORR improvement to 25%.

Accrual: The trial has enrolled 7 patients since its start in August 2017.

Citation Format: Alexander A, Marx AN, Reddy SM, Reuben JM, Le-Petross HC, Lane D, Huang ML, Krishnamurthy S, Gong Y, Gombos DS, Patel N, Tung CI, Allen RC, Kandl TJ, Wu J, Liu S, Patel AB, Futreal A, Wistuba I, Layman RM, Valero V, Tripathy D, Ueno NT, Lim B. Phase II study of atezolizumab, cobimetinib, and eribulin in patients with recurrent or metastatic inflammatory breast cancer (IBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-05-04.

Silencing glycosaminoglycan functions in mouse embryonic stem cells with small molecule antagonists

Glycosylation is a ubiquitous post-translational modification that decorates proteins and lipids with glycans. These glycans can play critical roles in regulating biological events, and therefore, the discovery of strategies that target these molecules represent an important advancement toward understanding and controlling glycan-mediated cellular phenotypes. We describe the use of a small molecule, surfen, to temporarily silence the functions mediated by heparan sulfate glycosaminoglycans in mouse embryonic stem cells. Surfen binds heparan sulfate to antagonize growth factor interactions, thereby inhibiting signal transduction events that lead to differentiation. The strategies outlined in this chapter allow the characterization of resulting antagonistic effects caused by glycan-small molecule binding events toward maintaining embryonic stem cell pluripotency, curbing differentiation, and inhibiting signaling events.

Influencing Early Stages of Neuromuscular Junction Formation through Glycocalyx Engineering

Achieving molecular control over the formation of synaptic contacts in the nervous system can provide important insights into their regulation and can offer means for creating well-defined in vitro systems to evaluate modes of therapeutic intervention. Agrin-induced clustering of acetylcholine receptors (AChRs) at postsynaptic sites is a hallmark of the formation of the neuromuscular junction, a synapse between motoneurons and muscle cells. In addition to the cognate agrin receptor LRP4 (low-density lipoprotein receptor related protein-4), muscle cell heparan sulfate (HS) glycosaminoglycans (GAGs) have also been proposed to contribute to AChR clustering by acting as agrin co-receptors. Here, we provide direct evidence for the role of HS GAGs in agrin recruitment to the surface of myotubes, as well as their functional contributions toward AChR clustering. We also demonstrate that engineering of the myotube glycocalyx using synthetic HS GAG polymers can replace native HS structures to gain control over agrin-mediated AChR clustering.

Embryonic Stem Cell Engineering with a Glycomimetic FGF2/BMP4 Co-Receptor Drives Mesodermal Differentiation in a Three-Dimensional Culture

Cell surface glycans, such as heparan sulfate (HS), are increasingly identified as co-regulators of growth factor signaling in early embryonic development; therefore, chemical tailoring of HS activity within the cellular glycocalyx of stem cells offers an opportunity to control their differentiation. The growth factors FGF2 and BMP4 are involved in mediating the exit of murine embryonic stem cells (mESCs) from their pluripotent state and their differentiation toward mesodermal cell types, respectively. Here, we report a method for remodeling the glycocalyx of mutant Ext1^-/- mESCs with defective biosynthesis of HS to drive their mesodermal differentiation in an embryoid body culture. Lipid-functionalized synthetic HS-mimetic glycopolymers with affinity for both FGF2 and BMP4 were introduced into the plasma membrane of Ext1^-/- mESCs, where they acted as functional co-receptors of these growth factors and facilitated signal transduction through associated MAPK and Smad signaling pathways. We demonstrate that these materials can be employed to remodel Ext1^-/- mESCs within three-dimensional embryoid body structures, providing enhanced association of BMP4 at the cell surface and driving mesodermal differentiation. As a more complete understanding of the function of HS in regulating development continues to emerge, this simple glycocalyx engineering method is poised to enable precise control over growth factor signaling activity and outcomes of differentiation in stem cells.

Glycocalyx Scaffolding to Control Cell Surface Glycan Displays

This article describes a protocol for remodeling cells with synthetic glycoprotein and glycolipid mimetics that are functionalized with lipid anchors, allowing for cell surface display of specific glycan structures in predefined nanoscale arrangements. The complex chemical heterogeneity of glycans found on the cell surface or the glycocalyx renders analysis of the individual contributions of glycans difficult. This technique allows for the precise study of individual glycans at different regions of the glycocalyx, and may be useful for interrogating glycan interactions in infection or immunity or in stem cell differentiation. CHO-Lec2 cells are prepared as adherent monolayers and, after reaching confluence, are incubated with the glycomaterials. Synthetic glycopolymers bearing α-2,3-sialyllactose glycans are used to decorate cellular surfaces in the form of 3D multivalent ligands projecting away from the cell surface, while α-2,6-sialyllactose glycolipid conjugates are used to anchor glycans in dynamic 2D arrays proximal to the cell membrane. Following washing, mimetic incorporation and glycan display can be analyzed using lectins with specificity for α-2,3- or α-2,6-linked sialic acids. Flow cytometry data reveals that cell surface remodeling with either glycoconjugate mimetic occurs efficiently in a dose-dependent manner. Combinations of glycoconjugates can also be employed simultaneously to generate a mixed glycocalyx with tunable composition and organization. © 2018 by John Wiley & Sons, Inc.

Hydrophobic interactions modulate antimicrobial peptoid selectivity towards anionic lipid membranes

Hydrophobic interactions govern specificity for natural antimicrobial peptides. No such relationship has been established for synthetic peptoids that mimic antimicrobial peptides. Peptoid macrocycles synthesized with five different aromatic groups are investigated by minimum inhibitory and hemolytic concentration assays, epifluorescence microscopy, atomic force microscopy, and X-ray reflectivity. Peptoid hydrophobicity is determined using high performance liquid chromatography. Disruption of bacterial but not eukaryotic lipid membranes is demonstrated on the solid supported lipid bilayers and Langmuir monolayers. X-ray reflectivity studies demonstrate that intercalation of peptoids with zwitterionic or negatively charged lipid membranes is found to be regulated by hydrophobicity. Critical levels of peptoid selectivity are demonstrated and found to be modulated by their hydrophobic groups. It is suggested that peptoids may follow different optimization schemes as compared to their natural analogues.

Glycocalyx scaffolding with synthetic nanoscale glycomaterials

We report a method for programming complexity into the glycocalyx of live cells. Via a combination of glycomaterial synthesis and membrane remodeling, we have engineered cells to display native-like, mixed sialoglycan populations, while confining the activity of each glycan into a specific nanoscale presentation.

Abstract P5-01-02: Quantitative assessment of tumor response to neoadjuvant chemotherapy in women with locoregional invasive breast cancer using Tc99m sestamibi molecular breast imaging - preliminary results

Purpose: To report preliminary data in a pilot study evaluating the ability of Tc99m sestamibi Molecular Breast Imaging (MBI) to predict response and assess residual disease at the completion of neoadjuvant chemotherapy (NAC) in breast cancer patients.

Materials and Methods: Patients with localized, invasive breast cancer (T1-T4, N0-N3, M0) planned for NAC were enrolled in this prospective IRB approved clinical trial. All patients had digital mammography (DM), ultrasound (US), and MBI at baseline (T0), after 2 NAC cycles (T1), and at after NAC completion (T2). Tumor size and volume changes were compared with residual disease at surgery. MBI images were corrected for scatter and attenuation using a novel approach and regions of interest (ROI) were drawn over tumors to compute three quantitative MBI uptake metrics for correlation with pathologic response: tumor to background ratio (TBR), fractional activity uptake (FAU), and MBI-specific standardized uptake value (SUV). ROC analysis was performed.

Results: Patients (n=25) who completed NAC, had 75 imaging time points and had surgery, were included in this analysis. Median age was 49 years (range 31 -77). Eleven patients (11/25, 44%) had complete pathologic response (pCR). Absolute TBR values after 2 cycles (T1) and before surgery (T2) had highest correlation with pCR (AUC 0.81; 95% CI 0.63 to 0.99, p=0.01, and AUC 0.78; 95% CI 0.59 to 0.97, p=0.015, respectively). Change in SUV after 2 cycles, Δ SUV1 (T1-T0), (AUC 0.84; 95% CI 0.66 to 1.00, p=0.01) and change in SUV prior to surgery, Δ SUV2 (T2-T0) (AUC 0.80; 95% CI 0.60 to 1.00, p=0.02), were most predictive of pCR. Tumor size and volume showed modest specificity for detecting residual disease, and was highest for MBI (79%), followed by MMG (64%), and lowest for US (55%).

Conclusion: Quantitative MBI metrics show promise for the prediction of pCR in breast cancer patients undergoing NAC. Establishment of quantitative metrics for the early prediction of tumor response during NAC of breast cancer patients may provide an alternate to influencing NAC choice early in the management algorithm. Further investigation with a larger sample size is warranted.

Citation Format: Rauch GM, Adrada BE, Kappadath C, Candelaria RP, Huang ML, Santiago L, Moseley T, Scoggins ME, Knudtson JD, Lopez BP, Hess KR, Krishnamurthy S, Moulder S, Valero V, Yang W. Quantitative assessment of tumor response to neoadjuvant chemotherapy in women with locoregional invasive breast cancer using Tc99m sestamibi molecular breast imaging - preliminary results [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-01-02.

Small Molecule Antagonist of Cell Surface Glycosaminoglycans Restricts Mouse Embryonic Stem Cells in a Pluripotent State

Recently, the field of stem cell-based regeneration has turned its attention toward chemical approaches for controlling the pluripotency and differentiation of embryonic stem cells (ESCs) using drug-like small molecule modulators. Growth factor receptors or their associated downstream kinases that regulate intracellular signaling pathways during differentiation are typically the targets for these molecules. The glycocalyx, which plays an essential role in actuating responses to growth factors at the cellular boundary, offers an underexplored opportunity for intervention using small molecules to influence differentiation. Here, we show that surfen, an antagonist of cell-surface glycosaminoglycans required for growth factor association with cognate receptors, acts as a potent and general inhibitor of differentiation and promoter of pluripotency in mouse ESCs. This finding shows that drugging the stem cell Glycome with small molecules to silence differentiation cues can provide a powerful new alternative to existing techniques for controlling stem cell fate. Stem Cells 2018;36:45-54.

Cyclization Improves Membrane Permeation by Antimicrobial Peptoids

The peptidomimetic approach has emerged as a powerful tool for overcoming the inherent limitations of natural antimicrobial peptides, where the therapeutic potential can be improved by increasing the selectivity and bioavailability. Restraining the conformational flexibility of a molecule may reduce the entropy loss upon its binding to the membrane. Experimental findings demonstrate that the cyclization of linear antimicrobial peptoids increases their bactericidal activity against Staphylococcus aureus while maintaining high hemolytic concentrations. Surface X-ray scattering shows that macrocyclic peptoids intercalate into Langmuir monolayers of anionic lipids with greater efficacy than for their linear analogues. It is suggested that cyclization may increase peptoid activity by allowing the macrocycle to better penetrate the bacterial cell membrane.

Synthetic Mucus Nanobarriers for Identification of Glycan-Dependent Primary Influenza A Infection Inhibitors

Current drugs against the influenza A virus (IAV) act by inhibiting viral neuraminidase (NA) enzymes responsible for the release of budding virions from sialoglycans on infected cells. Here, we describe an approach focused on a search for inhibitors that reinforce the protective functions of mucosal barriers that trap viruses en route to the target cells. We have generated mimetics of sialo-glycoproteins that insert into the viral envelope to provide a well-defined mucus-like environment encapsulating the virus. By introducing this barrier, which the virus must breach using its NA enzymes to infect a host cell, into a screening platform, we have been able to identify compounds that provide significant protection against IAV infection. This approach may facilitate the discovery of potent new IAV prophylactics among compounds with NA activities too weak to emerge from traditional drug screens.

Nanoscale materials for probing the biological functions of the glycocalyx

Glycans are among the most intriguing carriers of biological information in living systems. The structures of glycans not only convey the cells' physiological state, but also regulate cellular communication and responses by engaging receptors on neighboring cells and in the extracellular matrix. The assembly of simple monosaccharide building blocks into linear or branched oligo- and polysaccharides gives rise to a large repertoire of diverse glycan structures. Despite their structural complexity, individual glycans rarely engage their protein partners with high affinity. Yet, glycans modulate biological processes with exquisite selectivity and specificity. To correctly evaluate glycan interactions and their biological consequences, one needs to look beyond individual glycan structures and consider the entirety of the cell-surface landscape. There, glycans are presented on protein scaffolds, or are linked directly to membrane lipids, forming a complex, hierarchically organized network with specialized functions, called the glycocalyx. Nanoscale glycomaterials, which can mimic the various components of the glycocalyx, have been instrumental in revealing how the presentation of glycans can influence their biological functions. In this review, we wish to highlight some recent developments in this area, while placing emphasis on the applications of glycomaterials providing new insights into the mechanisms through which glycans mediate cellular functions.

Capture and characterization of influenza A virus from primary samples using glycan bead arrays

Influenza A viruses (IAVs) utilize sialylated host glycans as ligands for binding and infection. The glycan-binding preference of IAV hemagglutinin (HA) is an important determinant of host specificity. Propagation of IAV in embryonated chicken eggs and cultured mammalian cells yields viruses with amino acid substitutions in the HA that can alter the binding specificity. Therefore, it is important to determine the binding specificity of IAV directly in primary samples since it reflects the actual tropism of virus in nature. We developed a novel platform for analysis of IAV binding specificity in samples that contain very low virus titers. This platform consists of a high-density flexible glycan display on magnetic beads, which promotes multivalent interactions with the viral HA. Glycan-bound virus is detected by quantifying the viral neuraminidase activity via a fluorogenic reporter, 2'-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid. This method eliminates the need for labeling the virus and significantly enhances the sensitivity of detection.

Glycomaterials for probing host-pathogen interactions and the immune response

The initial engagement of host cells by pathogens is often mediated by glycan structures presented on the cell surface. Various components of the glycocalyx can be targeted by pathogens for adhesion to facilitate infection. Glycans also play integral roles in the modulation of the host immune response to infection. Therefore, understanding the parameters that define glycan interactions with both pathogens and the various components of the host immune system can aid in the development of strategies to prevent, interrupt, or manage infection. Glycomaterials provide a unique and powerful tool with which to interrogate the compositional and functional complexity of the glycocalyx. The objective of this review is to highlight some key contributions from this area of research in deciphering the mechanisms of pathogenesis and the associated host response.

Glycocalyx Remodeling with Glycopolymer-Based Proteoglycan Mimetics

The cellular glycocalyx controls many of the crucial signaling pathways involved in cellular development. Synthetic materials that can mimic the multivalency and three-dimensional architecture of native glycans serve as important tools for deciphering and exploiting the roles of these glycans. Here we describe a chemical approach for the engineering of growth-factor interactions at the surfaces of stem cells using synthetic glycomimetic materials, with an eye towards promoting their commitment towards specific cell lineages with therapeutic potential.

Growth kinetics of Cu6Sn5 intermetallic compound at liquid-solid interfaces in Cu/Sn/Cu interconnects under temperature gradient

The growth behavior of intermetallic compounds (IMCs) at the liquid-solid interfaces in Cu/Sn/Cu interconnects during reflow at 250 °C and 280 °C on a hot plate was investigated. Being different from the symmetrical growth during isothermal aging, the interfacial IMCs showed clearly asymmetrical growth during reflow, i.e., the growth of Cu₆Sn₅ IMC at the cold end was significantly enhanced while that of Cu₃Sn IMC was hindered especially at the hot end. It was found that the temperature gradient had caused the mass migration of Cu atoms from the hot end toward the cold end, resulting in sufficient Cu atomic flux for interfacial reaction at the cold end while inadequate Cu atomic flux at the hot end. The growth mechanism was considered as reaction/thermomigration-controlled at the cold end and grain boundary diffusion/thermomigration-controlled at the hot end. A growth model was established to explain the growth kinetics of the Cu₆Sn₅ IMC at both cold and hot ends. The molar heat of transport of Cu atoms in molten Sn was calculated as + 11.12 kJ/mol at 250 °C and + 14.65 kJ/mol at 280 °C. The corresponding driving force of thermomigration in molten Sn was estimated as 4.82 × 10⁻¹⁹ N and 6.80 × 10⁻¹⁹ N.

Determination of receptor specificities for whole influenza viruses using multivalent glycan arrays

Influenza viruses bind to mucosal glycans to gain entry into a host organism and initiate infection. The target glycans are often displayed in multivalent arrangements on proteins; however, how glycan presentation influences viral specificity is poorly understood. Here, we report a microarray platform approximating native glycan display to facilitate such studies.

Priming the cellular glycocalyx for neural development

Glycans are important contributors to the development and function of the nervous system with enormous potential as therapeutic targets. However, a general lack of tools for tailoring the presentation of specific glycan structures on the surfaces of cells has left them largely unexplored in the biomedical context. In this Viewpoint, we briefly summarize the distinct challenges and complexities of the Glycome. We also highlight an emerging concept of cell surface engineering using synthetic nanoscale mimetics of native glycoconjugates to harness some of the unique biology of glycans, with an eye toward advancing stem cell-based neuroregenerative therapies.

Oral Helicobacter pylori, its relationship to successful eradication of gastric H. pylori and saliva culture confirmation

The present study was designed to explore the existence of oral Helicobacter pylori (H. pylori), its relationship in the oral cavity to the success rate of eradication of the gastric H. pylori infection, and to determine if the mouthwash solution contained lysine (0.4%) and glycerol monolaurate (0.2%) (LGM) could eliminate oral H. pylori, as well as using the saliva H. pylori culture to confirm the existence of oral H. pylori. A total of 159 symptomatic individuals with stomach pain and 118 asymptomatic individuals with no stomach complaints, were recruited and tested using the saliva H. pylori antigen test (HPS), the H. pylori flagellin test (HPF), the urea breath test (UBT C(13)) and the polymerase chain reaction (PCR) test, which tests were also confirmed by saliva culture. The test subjects also received various treatments. It was found that the H. pylori antigen exists in the oral cavity in UBT C(13) negative individuals. Traditional treatment for gastric eradication had only a 10.67 percent (10.67%) effectiveness rate on the oral H. pylori infection. In groups of patients with the oral H. pylori infection, but with negative UBT C(13), a mouthwash solution provided a 72.58% effectiveness rate in the 95% of the confidence interval (CI) ranges on the oral H. pylori infection. Traditional drug gastric eradication and teeth cleaning (TC) had less than a 10% effectiveness rate. Treatment of the oral infection increased the success rate of eradication of the stomach infection from 61.33% to 82.26% in the 95% CI ranges. We concluded that the successful rate of eradication of gastric H. pylori bears a significant relationship to the oral infection from H. pylori.

Glycocalyx remodeling with proteoglycan mimetics promotes neural specification in embryonic stem cells

Growth factor (GF) signaling is a key determinant of stem cell fate. Interactions of GFs with their receptors are often mediated by heparan sulfate proteoglycans (HSPGs). Here, we report a cell surface engineering strategy that exploits the function of HSPGs to promote differentiation in embryonic stem cells (ESCs). We have generated synthetic neoproteoglycans (neoPGs) with affinity for the fibroblast growth factor 2 (FGF2) and introduced them into plasma membranes of ESCs deficient in HS biosynthesis. There, the neoPGs assumed the function of native HSPGs, rescued FGF2-mediated kinase activity, and promoted neural specification. This glycocalyx remodeling strategy is versatile and may be applicable to other types of differentiation.

Investigation of a pyoderma outbreak caused by methicillin-susceptible Staphylococcus aureus in a nursery for newborns

An outbreak of pyoderma caused by methicillin-susceptible Staphylococcus aureus occurred in a nursery for newborns over 26 days. During this period, six neonates were involved. The mother of the first case had trunk pyoderma before delivery, which was regarded as the source of the outbreak. Contamination of the environment and equipment were implicated as the reservoirs of further pathogen spread, as supported by pulsed-field gel electrophoresis (PFGE) results, which showed that some screening isolates were indistinguishable from the epidemic strain. Termination of the outbreak was achieved by the reinforcement of infection control practices and disinfection of environmental surfaces.

Long-term entecavir treatment results in sustained antiviral efficacy and prolonged life span in the woodchuck model of chronic hepatitis infection

Entecavir (ETV) is a guanosine nucleoside analogue with potent antiviral efficacy in woodchucks chronically infected with woodchuck hepatitis virus. To explore the consequences of prolonged virus suppression, woodchucks received ETV orally for 8 weeks and then weekly for 12 months. Of the 6 animals withdrawn from therapy and monitored for an additional 28 months, 3 had a sustained antiviral response and had no evidence of hepatocellular carcinoma (HCC). Of the 6 animals that continued on a weekly ETV regimen for an additional 22 months, 4 exhibited serum viral DNA levels near the lower limit of detection for >2 years and had no evidence of HCC. Viral antigens and covalently closed circular DNA levels in liver samples were significantly reduced in all animals. ETV was well tolerated, and there was no evidence of resistant variants. On the basis of historical data, long-term ETV treatment appeared to significantly prolong the life of treated animals and delay the emergence of HCC.

Human herpesvirus 6 reactivation and encephalitis in allogeneic bone marrow transplant recipients

To determine whether receipt of an investigational anti-CD3 monoclonal antibody (BC3) increased the risk of human herpesvirus 6 (HHV-6) reactivation and development of encephalitis in bone marrow transplant (BMT) recipients, persons who had and had not received BC3 were compared. Odds of HHV-6 reactivation were higher among BC3 recipients than among control patients (odds ratio, 2.5; 95% confidence interval [CI], 1.3-4.7). In addition, BC3 recipients were more likely than control patients to develop encephalitis (risk ratio [RR], 3.5; 95% CI, 1.3-9.5), and this association followed a BC3 dose-dependent relationship (P=.03, by Mantel-Haenszel chi(2) test). In a multivariable model, HHV-6 reactivation and receipt of BC3 were associated with increased risk of encephalitis (RR, 5.4; 95% CI, 1.9-15.3, and RR, 3.3; 95% CI, 1.2-9.1, respectively). In conclusion, both HHV-6 reactivation and receipt of BC3 for prophylaxis of acute graft-versus-host disease independently increased the risk of encephalitis in allogeneic BMT recipients. Prospective studies to better define the relationship between HHV-6 reactivation and encephalitis in allogeneic BMT recipients are warranted.

Quantitation of BK virus load in serum for the diagnosis of BK virus-associated nephropathy in renal transplant recipients

BK virus-associated nephropathy is an increasingly recognized cause of graft dysfunction among kidney transplant recipients, and definitive diagnosis requires renal biopsy. By using a newly developed, quantitative, real-time polymerase chain reaction (PCR) assay for BK virus DNA, a retrospective analysis was done of sequential serum samples (n=28) from 4 transplant recipients with histopathologically documented BK virus nephropathy and from samples (n=76) from 16 transplant recipient control patients. BK virus DNA was detected in serum samples from all 4 case patients versus 0 of 16 control patients (P< .0001, Fisher's exact test) at a median of 32 weeks (range, 17-61 weeks) before the diagnosis of BK virus nephropathy. BK virus load decreased in 3 of 3 patients after the reduction of immunosuppression and/or nephrectomy. It is concluded that quantitative PCR for BK virus DNA in serum is useful both for identifying transplant recipients at risk for BK virus nephropathy and for monitoring the response to therapy.

Cytomegalovirus (CMV) DNA load in plasma for the diagnosis of CMV disease before engraftment in hematopoietic stem-cell transplant recipients

Among hematopoietic stem-cell transplant (HSCT) recipients, cytomegalovirus (CMV) disease before engraftment is rare but often fatal, and cell-based diagnostic tests have low sensitivity in this clinical setting. We used the quantitative real-time polymerase chain reaction (PCR) assay to test for CMV DNA in plasma samples from 15 HSCT recipients who developed CMV disease before engraftment and from 33 matched control patients. CMV DNA was detected in plasma in 14 (93.3%) of the 15 patients who had CMV disease before engraftment, compared with 5 (15.2%) of 33 control patients (P<.001). CMV DNA was detected a median of 13 days before the onset of CMV disease (range, 0-35 days). The maximum CMV virus load in plasma was >1 log(10) higher among case patients than among control patients (median, 1700 [range, 50 to 5.5x107] vs. <50 [range, <50-350] CMV DNA copies/mL plasma, respectively; P<.001). Quantitative PCR for CMV DNA in plasma appears to be useful for the identification of HSCT recipients at risk for CMV disease before engraftment.

Nonmyeloablative immunosuppressive regimen prolongs In vivo persistence of gene-modified autologous T cells in a nonhuman primate model

The in vivo persistence of gene-modified cells can be limited by host immune responses to transgene-encoded proteins. In this study we evaluated in a nonhuman primate model whether the administration of a nonmyeloablative regimen consisting of low-dose total-body irradiation with 200 cGy followed by immunosuppression with mycophenolate mofetil and cyclosporin A for 28 and 35 days, respectively, could be used to facilitate persistence of autologous gene-modified T cells when a transgene-specific immune response had already been established or to induce long-lasting tolerance in unprimed recipients. Two macaques (Macaca nemestrina) received infusions of T cells transduced to express either the enhanced green fluorescent protein and neomycin phosphotransferase genes or the hygromycin phosphotransferase and herpes simplex virus thymidine kinase genes. In the absence of immunosuppression, both macaques developed potent class I major histocompatibility complex-restricted CD8(+) cytotoxic T-lymphocyte (CTL) responses that rapidly eliminated the gene-modified T cells and that persisted long term as memory CTL. Treatment with the nonmyeloablative regimen failed to abrogate preexisting memory CTL responses but interfered with the induction of transgene-specific CTL and facilitated in vivo persistence of gene-modified cells in an unprimed host. However, sustained tolerance to gene-modified T cells was not achieved with this regimen, indicating that further modifications will be required to permit sustained persistence of gene-modified T cells.