Novel antibody-antibiotic conjugate eliminates intracellular S. aureus.

Staphylococcus aureus is considered to be an extracellular pathogen. However, survival of S. aureus within host cells may provide a reservoir relatively protected from antibiotics, thus enabling long-term colonization of the host and explaining clinical failures and relapses after antibiotic therapy. Here we confirm that intracellular reservoirs of S. aureus in mice comprise a virulent subset of bacteria that can establish infection even in the presence of vancomycin, and we introduce a novel therapeutic that effectively kills intracellular S. aureus. This antibody-antibiotic conjugate consists of an anti-S. aureus antibody conjugated to a highly efficacious antibiotic that is activated only after it is released in the proteolytic environment of the phagolysosome. The antibody-antibiotic conjugate is superior to vancomycin for treatment of bacteraemia and provides direct evidence that intracellular S. aureus represents an important component of invasive infections.

FRET Reagent Reveals the Intracellular Processing of Peptide-Linked Antibody-Drug Conjugates.

Despite the recent success of antibody-drug conjugates (ADCs) in cancer therapy, a detailed understanding of their entry, trafficking, and metabolism in cancer cells is limited. To gain further insight into the activation mechanism of ADCs, we incorporated fluorescence resonance energy transfer (FRET) reporter groups into the linker connecting the antibody to the drug and studied various aspects of intracellular ADC processing mechanisms. When comparing the trafficking of the antibody-FRET drug conjugates in various different model cells, we found that the cellular background plays an important role in how the antigen-mediated antibody is processed. Certain tumor cells showed limited cytosolic transport of the payload despite efficient linker cleavage. Our FRET assay provides a facile and robust assessment of intracellular ADC activation that may have significant implications for the future development of ADCs.

High-Resolution Accurate-Mass Mass Spectrometry Enabling In-Depth Characterization of in Vivo Biotransformations for Intact Antibody-Drug Conjugates.

Antibody-drug conjugates (ADCs) represent a promising class of therapeutics for the targeted delivery of highly potent cytotoxic drugs to tumor cells to improve bioactivity while minimizing side effects. ADCs are composed of both small and large molecules and therefore have complex molecular structures. In vivo biotransformations may further increase the complexity of ADCs, representing a unique challenge for bioanalytical assays. Quadrupole-time-of-flight mass spectrometry (Q-TOF MS) with electrospray ionization has been widely used for characterization of intact ADCs. However, interpretation of ADC biotransformations with small mass changes, for the intact molecule, remains a limitation due to the insufficient mass resolution and accuracy of Q-TOF MS. Here, we have investigated in vivo biotransformations of multiple site-specific THIOMAB antibody-drug conjugates (TDCs), in the intact form, using a high-resolution, accurate-mass (HR/AM) MS approach. Compared with conventional Q-TOF MS, HR/AM Orbitrap MS enabled more comprehensive identification of ADC biotransformations. It was particularly beneficial for characterizing ADC modifications with small mass changes such as partial drug loss and hydrolysis. This strategy has significantly enhanced our capability to elucidate ADC biotransformations and help understand ADC efficacy and safety in vivo.

Novel staphylococcal glycosyltransferases SdgA and SdgB mediate immunogenicity and protection of virulence-associated cell wall proteins.

Infection of host tissues by Staphylococcus aureus and S. epidermidis requires an unusual family of staphylococcal adhesive proteins that contain long stretches of serine-aspartate dipeptide-repeats (SDR). The prototype member of this family is clumping factor A (ClfA), a key virulence factor that mediates adhesion to host tissues by binding to extracellular matrix proteins such as fibrinogen. However, the biological siginificance of the SDR-domain and its implication for pathogenesis remain poorly understood. Here, we identified two novel bacterial glycosyltransferases, SdgA and SdgB, which modify all SDR-proteins in these two bacterial species. Genetic and biochemical data demonstrated that these two glycosyltransferases directly bind and covalently link N-acetylglucosamine (GlcNAc) moieties to the SDR-domain in a step-wise manner, with SdgB appending the sugar residues proximal to the target Ser-Asp repeats, followed by additional modification by SdgA. GlcNAc-modification of SDR-proteins by SdgB creates an immunodominant epitope for highly opsonic human antibodies, which represent up to 1% of total human IgG. Deletion of these glycosyltransferases renders SDR-proteins vulnerable to proteolysis by human neutrophil-derived cathepsin G. Thus, SdgA and SdgB glycosylate staphylococcal SDR-proteins, which protects them against host proteolytic activity, and yet generates major eptopes for the human anti-staphylococcal antibody response, which may represent an ongoing competition between host and pathogen.

An anti-B7-H4 antibody-drug conjugate for the treatment of breast cancer.

B7-H4 has been implicated in cancers of the female reproductive system and investigated for its possible use as a biomarker for cancer, but there are no preclinical studies to demonstrate that B7-H4 is a molecular target for therapeutic intervention of cancer. We provide evidence that the prevalence and expression levels of B7-H4 are high in different subtypes of breast cancer and that only a few normal tissues express B7-H4 on the cell membrane. These profiles of low normal expression and upregulation in cancer provide an opportunity for the use of antibody-drug conjugates (ADCs), cytotoxic drugs chemically linked to antibodies, for the treatment of B7-H4 positive cancers. We have developed an ADC specific to B7-H4 that uses a linker drug consisting of a potent antimitotic, monomethyl auristatin E (MMAE), linked to engineered cysteines (THIOMAB) via a protease labile linker. We will refer to ADCs that use the THIOMAB format as TDCs to help distinguish the format from standard MC-vc-MMAE ADCs that are conjugated to the interchain disulfide bonds. Anti-B7-H4 (h1D11)-MC-vc-PAB-MMAE (h1D11 TDC) produced durable tumor regression in cell line and patient-derived xenograft models of triple-negative breast cancer. It also binds rat B7-H4 with similar affinity to human and allowed us to test for target dependent toxicity in rats. We found that our anti-B7-H4 TDC has toxicity findings similar to untargeted TDC. Our results validate B7-H4 as an ADC target for breast cancer and support the possible use of this TDC in the treatment of B7-H4(+) breast cancer.

Internalization and endosomal degradation of receptor-bound antigens regulate the efficiency of cross presentation by human dendritic cells.

Dendritic cells (DCs) can capture extracellular antigens and load resultant peptides on to MHC class I molecules, a process termed cross presentation. The mechanisms of cross presentation remain incompletely understood, particularly in primary human DCs. One unknown is the extent to which antigen delivery to distinct endocytic compartments determines cross presentation efficiency, possibly by influencing antigen egress to the cytosol. We addressed the problem directly and quantitatively by comparing the cross presentation of identical antigens conjugated with antibodies against different DC receptors that are targeted to early or late endosomes at distinct efficiencies. In human BDCA1+ and monocyte-derived DCs, CD40 and mannose receptor targeted antibody conjugates to early endosomes, whereas DEC205 targeted antigen primarily to late compartments. Surprisingly, the receptor least efficient at internalization, CD40, was the most efficient at cross presentation. This did not reflect DC activation by CD40, but rather its relatively poor uptake or intra-endosomal degradation compared with mannose receptor or DEC205. Thus, although both early and late endosomes appear to support cross presentation in human DCs, internalization efficiency, especially to late compartments, may be a negative predictor of activity when selecting receptors for vaccine development.

Association between HTR7 genetic polymorphisms and alcohol dependence, using the alcohol use disorders identification test (AUDIT).

BACKGROUND: A recent genome-wide association study has identified 5-hydroxytrytamine (serotonin) receptor 7, adenylate cyclase-coupled (HTR7) as a risk gene for alcohol dependence. In addition, the serotonergic system has been considered as a modulator that plays an important role in alcohol use disorders. Functional, pharmacological, and genetic studies of serotonin neurotransmission have revealed that serotonin receptors are potential targets for the treatment of alcohol use disorders. The aim of this study is to investigate whether associations between HTR7 genetic polymorphisms and alcohol dependence could be replicated. METHODS: This study genotyped a total of 22 common single nucleotide polymorphisms (SNPs) in 459 alcoholic patients and 444 nonalcoholic controls. RESULTS: Logistic regression analysis of the case-control study, controlling for age and sex as covariates, showed nominal associations of 7 SNPs (p = 0.02 to 0.04; odds ratio = 0.60 to 1.35). In further linear regression analysis based on the Alcohol Use Disorders Identification Test score for alcohol dependence, 8 SNPs and 3 haplotypes showed relatively significant associations with alcohol dependence (minimum p = 0.001; p(corr) = 0.02). CONCLUSIONS: Although further replications and functional evaluations are needed, our findings suggest that genetic variations of HTR7 may contribute to the predisposition for alcohol dependence.

Pre-Clinical Studies of a Novel Bispecific Fusion Protein Targeting C3b and VEGF in Neovascular and Nonexudative AMD Models.

INTRODUCTION: KNP-301 is a bi-specific fragment crystallizable region (Fc) fusion protein, which inhibits both C3b and vascular endothelial growth factor (VEGF) simultaneously for patients with late-stage age-related macular degeneration (AMD). The present study evaluated in vitro potency, in vivo efficacy, intravitreal pharmacokinetics (IVT PK), and injectability of KNP-301. METHODS: C3b and VEGF binding of KNP-301 were assessed by surface plasmon resonance (SPR) and enzyme-linked immunosorbent assay (ELISA), and cellular bioassays. A laser-induced choroidal neovascularization (CNV) model and a sodium iodate-induced nonexudative AMD model were used to test the in vivo efficacy of mouse surrogate of KNP-301. Utilizing fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT) scans, the reduction in disease lesions were analyzed in a CNV mouse model. In the nonexudative AMD mouse model, outer nuclear layer (ONL) was assessed by immunofluorescence staining. Lastly, intravitreal pharmacokinetic study was conducted with New Zealand white rabbits via IVT administration of KNP-301 and injectability of KNP-301 was examined by a viscosity test at high concentrations. RESULTS: KNP-301 bound C3b selectively, which resulted in a blockade of the alternative pathway, not the classical pathway. KNP-301 also acted as a VEGF trap, impeding VEGF-mediate signaling. Our dual-blockade strategy was effective in both neovascular and nonexudative AMD models. Moreover, KNP-301 had an advantage of potentially less frequent dosing due to the long half-life in the intravitreal chamber. Our viscosity assessment confirmed that KNP-301 meets the criteria of the IVT injection. CONCLUSIONS: Unlike current therapies, KNP-301 is expected to cover patients with late-stage AMD of both neovascular and nonexudative AMD, and its long-term PK profile at the intravitreal chamber would allow convenience in the dosing interval of patients.

Conservative Treatment in Two Patients With Spontaneous Hepatic Artery Dissection.

BACKGROUND: Spontaneous dissection of the hepatic artery is a rare finding for which there is no specific treatment algorithm. Even though endovascular treatment and surgery have been used to treat other visceral artery dissections, these approaches can be challenging in the case of hepatic artery dissection because it is difficult to access the hepatic artery. CASE SUMMARY: 2 patients with spontaneous dissection of the hepatic artery were admitted due to epigastric pain. Although the liver function test results were normal, and there were no complications such as bleeding, shock, or ischemia in other organs, a subsequent computed tomography scan directly revealed the spontaneous dissection of the hepatic artery in both patients. The patients were treated with anticoagulants without surgery. Because it is difficult to perform surgery or endovascular treatment on the hepatic artery, we focused on preventing the progression of hepatic artery dissection and the formation of a new thrombus in the dissection. CONCLUSION: Considering the risk of surgical treatment for the hepatic artery and the condition of the patients, medical treatment with anticoagulants may be considered as an initial treatment and provide more benefits than surgical treatment.

En-bloc resection including SMV and duodenum in patient of locally advanced colon cancer.

Tumor could directly invade or is adherent to other organs, but superior mesentery vein (SMV) and duodenum invasion are very rare. A 62-year-old woman was diagnosed with abdominal pain for several months. Multiple erythematous brownish skin patches and palpable mass were found at epigastric area. Computed tomography imaging showed focal wall thickening at the transverse colon that invaded to the rectus muscle and anterior abdominal wall. On exploration, we identified tumor invaded or was adherent to the duodenum and superior mesenteric vein and performed en-bloc resection. After surgery, the patient received chemotherapy and was followed up without any recurrence for 16 months. Adhesion and invasion of tumor to surrounding organs can be unexpectedly found during surgery. In our case, we found duodenum and SMV invasion and achieved R0 resection by SMV and duodenum resection, which could improve the patient's prognosis.

Patient-derived Organoid Model for Predicting the Chemoresponse in Patients With Colorectal Cancer.

BACKGROUND/AIM: Cancer mortality has decreased due to the contribution of extensive research on cancer treatment, including chemotherapy, radiation, and immunotherapy. However, histopathologically similar tumors originating from the same organ are treated with identical or similar chemotherapeutic regimens regardless of patient characteristics or cancer subtypes. The aim of this study was to evaluate the utility of organoids in predicting responses to chemotherapeutic agents. PATIENTS AND METHODS: This study retrospectively reviewed patient-derived organoids (PDOs) from 10 colorectal cancer patients to compare chemotherapy responses. Drug sensitivities for 5-fluorouracil (5-FU), cisplatin, oxaliplatin, and irinotecan were compared using GI50 (concentration that inhibits cancer cell growth by 50%). RESULTS: When organoids were treated with 5-FU, GI50 was the lowest compared to the other three chemotherapeutic agents (cisplatin, oxaliplatin, and irinotecan). The responsiveness to chemotherapeutic agents differed depending on specific patient characteristics including age, tumor location, stage, and gross type. The response of the patients' organoids to chemotherapeutic agents was consistent with the response to chemotherapy actually performed in those patients with cancer recurrence after surgery. CONCLUSION: PDOs may be useful as a preclinical model in predicting chemotherapy responses in cancer patients.

Huge adrenal schwannoma: a rare type of adrenal tumor, misconceived as adrenocortical carcinoma.

Schwannoma is a benign and uncommon neoplasm arising from the neural crest cells. The most common tumor sites are the skin and subcutaneous tissue of the head and neck. Retroperitoneal schwannomas account for 1-3% of all schwannomas and are predominantly female. In particular, adrenal schwannoma is very rare, and due to its large size at the time of diagnosis, adrenal schwannoma is frequently misdiagnosed as adrenocortical carcinoma or pheochromocytoma. Adrenal schwannoma is difficult to distinguish it from other adrenal diseases based on imaging findings alone. In this report, we introduce the case of a huge left adrenal schwannoma.

Bowel perforation surgery due to fecal impaction immediately after hernia mesh surgery (TAPP).

Inguinal hernia repair using prosthetic mesh is used as a standard treatment in most countries and considered superior to primary suture repair. Although prosthetic mesh has greatly reduced the risk of recurrence, the risk of mesh infection remains. A 71-year-old man was diagnosed with symptomatic bilateral inguinal hernias. He underwent successful laparoscopic transabdominal preperitoneal (TAPP) repair and was discharged the same day. After 3 days, he was diagnosed with small bowel perforation, and underwent emergency surgery. We found perforation of the distal ileum caused by the fecal impaction and severe intra-abdominal contamination. We performed subtotal colectomy and ileosigmoid anastomosis, but did not remove the prosthetic mesh because the previous TAPP site was intact. The patient recovered well post-operatively. Therefore, contaminated or dirty surgery immediately after the hernia mesh surgery could be a feasible treatment.

Modulating native-like residual structure in the fully denatured state of photoactive yellow protein affects its refolding.

Residual structure in the fully unfolded state is a key element for understanding protein folding. We show that the residual structure in fully denatured photoactive yellow protein (PYP) is affected by isomerization of its p-coumaric acid (pCA) chromophore. The exposure of total surface area and hydrophobic surface area upon unfolding was quantified by denaturant m values and heat capacity changes (DeltaC(p)), respectively. The exposure of the buried surface area upon the unfolding of the acid-denatured state of PYP containing trans-pCA is approximately 20% smaller than that of the native state. In contrast, for the partially unfolded pB photocycle intermediate containing cis-pCA, unfolding-induced exposure of the surface area is not decreased. These results show that pCA photoisomerization reduces residual structure in the fully unfolded state. Thus, residual structure in the fully unfolded state of PYP is under direct experimental control by photoexcitation. The sensitivity of the unfolded state to pCA isomerization provides a novel criterion that residual structure in the unfolded state of PYP is native-like, involving native-like protein-chromophore interactions. A largely untested prediction is that native-like residual structure facilitates the conformational search during folding. In the case of PYP, refolding from the less disordered fully unfolded state containing trans-pCA indeed is substantially accelerated. The burial of hydrophobic surface area in the fully unfolded state suggests that a significant part of the hydrophobic collapse process already has occurred in the denatured state.

Free-floating ultrathin two-dimensional crystals from sequence-specific peptoid polymers.

The design and synthesis of protein-like polymers is a fundamental challenge in materials science. A biomimetic approach is to explore the impact of monomer sequence on non-natural polymer structure and function. We present the aqueous self-assembly of two peptoid polymers into extremely thin two-dimensional (2D) crystalline sheets directed by periodic amphiphilicity, electrostatic recognition and aromatic interactions. Peptoids are sequence-specific, oligo-N-substituted glycine polymers designed to mimic the structure and functionality of proteins. Mixing a 1:1 ratio of two oppositely charged peptoid 36mers of a specific sequence in aqueous solution results in the formation of giant, free-floating sheets with only 2.7 nm thickness. Direct visualization of aligned individual peptoid chains in the sheet structure was achieved using aberration-corrected transmission electron microscopy. Specific binding of a protein to ligand-functionalized sheets was also demonstrated. The synthetic flexibility and biocompatibility of peptoids provide a flexible and robust platform for integrating functionality into defined 2D nanostructures.

Selected deceased donor liver transplantation in controlled Fournier's gangrene: a case report.

Bacterial infection represents a turning point in the natural history of cirrhosis, causing the development of acute-on-chronic liver failure. It significantly affects the outcome of patients listed for liver transplantation. We report the case of a 57-year-old man who had been regularly treated for hepatitis B virus, alcoholic liver cirrhosis, and hepatic failure. The patient was hospitalized again due to variceal bleeding and hepatic coma. He visited the emergency room with painful anal swelling, dysuria, icteric sclera, and serious abdominal distension. The painful anal swelling and necrosis progressed; thus, he was diagnosed with Fournier's gangrene. Enterococcus faecium and Candida albicans were detected in the blood. Gangrene wound debris was studied extensively. Despite appropriate antibiotic treatment, vancomycin-resistant enterococcus and C. albicans were continuously present in the blood. Wide debridement of the wound and T-colostomy were performed. After this, norepinephrine and vasopressin were used to maintain stable vital signs. It was difficult to establish a liver transplant operation. Despite repeated bleeding, bacterial infections improved with additional antibiotics. Finally, selected deceased donor liver transplantation in controlled Fournier's gangrene was successfully performed. Controlled infections may be allowed in transplantation surgery.

Initial experience with laparoscopic posterior retroperitoneal adrenalectomy in single tertiary center.

Purpose: Laparoscopic posterior retroperitoneal adrenalectomy (LPRA) is a surgical method that accesses the adrenal gland through the back. The aim of this study was to report initial experience of LPRA and evaluate possibilities for surgical application. Methods: From March 2018 to December 2019, a total of 30 consecutive patients diagnosed with adrenal tumor underwent surgical treatment at Pusan National University Hospital were enrolled. Clinicopathologic features and various peri- and postoperative parameters were analyzed by retrospective medical record review. The mean age of the patients was 48.20±13.66 years. Results: The mean body mass index (BMI) was 25.50±4.30 kg/m2. Primary hyperaldosteronism was the most frequently preoperative diagnosed disease (n=13, 43.4%), followed by adrenal incidentaloma (n=8, 26.6%), Cushing syndrome (n=5, 16.6%) and pheochromocytoma (n=4, 13.3%). The mean size of postoperative adrenal tumor was 2.72±1.76 cm. The mean operating time was 162±58.14 minutes. Among the 30 patients, 28 patients underwent total adrenalectomy (93.3%) and two patients underwent cortical sparing adrenalectomy (6.7%). When LPRA was performed for patients with BMI >23.16 kg/m2, the operating time was longer than the average (P=0.016). Conclusion: LPRA was suitable and safe for patients with benign adrenal tumors. BMI, retroperitoneal fat density and postoperative adrenal weight may be related to the operating time, so they should be considered when deciding on a surgical method for adrenalectomy.

Robot-assisted resection of GIST in the proximal jejunum.

Gastrointestinal stromal tumors (GISTs) are rare. Although most commonly found in the stomach, GISTs in the jejunum are among the rarest subtypes. A 46-year-old woman presented to the surgical department with proximal jejunal mass found in the examinations after abdominal pain and melena. Computed tomography imaging showed a 2.3 cm sized well-defined heterogenous enhancing mass in the proximal jejunum, and GIST was strongly suspected. The jejunal mass was identified 5 cm below the ligament of Treitz intraoperatively. She underwent robotic-assisted jejunal resection with intracorporeal robot-sewn anastomosis. The patient's postoperative course was uneventful, and she was discharged on the seventh postoperative day. A robotic approach for GIST in the proximal jejunum is a safe and feasible procedure with good surgical outcomes.

Application of minimal invasive technique for thyroidectomy without remote access in locally advanced thyroid carcinoma with gross extra-thyroidal extension.

INTRODUCTION: Minimally invasive thyroidectomy (MIT) is technically less damaging tissue and is better cosmetic results with small neck scar, decreasing postoperative pain and neck discomfort. We present the experience of MIT without remote access with case of grossly extra-thyroidal extension positive papillary thyroid carcinoma. PRESENTATION OF CASE: A 44-year-old, female presented 1.6 cm irregular hypoechoic nodule at upper pole in Right thyroid gland and diagnosed to papillary thyroid carcinoma. The tumor was suspicious to have extra-thyroidal extension. We performed MIT without remote access for this patient with 2 cm cervical incision. Postoperative course was uneventful and patient was discharged on the 3th postoperative day. At present, she is taking 100mcg levothyroxine and is free of disease 3 years post-surgery. CONCLUSION: If experienced surgeons can get sufficient resection margin and control bleeding of superior thyroid artery, MIT without remote access can be feasible method for thyroid carcinoma with gross extra-thyroidal extension, especially, upper pole carcinoma.

Influence of Infrapopliteal Runoff Vessels on Primary Patency after Superficial Femoral Artery Angioplasty with Stenting in Patients with Claudication.

Purpose: The number of infrapopliteal runoff vessels seems to be one of the factors influencing arterial patency in patients who had undergone superficial femoral artery (SFA) angioplasty with stenting. However, the effectiveness of infrapopliteal runoff vessels in predicting patency during SFA angioplasty remains unclear. This study aimed to determine whether the number and quality of infrapopliteal runoff vessels affect the primary patency after SFA angioplasty with stenting in patients with claudication. Materials and Methods: This study reviewed a retrospective database of patients with claudication who underwent SFA angioplasty with stenting between March 2011 and December 2016. The preoperative computed tomography findings of all patients were reviewed to assess infrapopliteal runoff vessels. The Trans-Atlantic Inter-Society (TASC) II classification and modified Society for Vascular Surgery (SVS) runoff score were used for subsequent analysis. Kaplan-Meier survival curves were constructed, and Fisher's exact and chi-square tests were used for data analysis. Results: A total of 153 limbs of 122 patients (88.2% male, mean age: 69.1 years) underwent SFA angioplasty with stenting. The overall primary patency rates of TASC II A/B and C/D cases were 77.1% and 31.2%, respectively, at 36 months (P<0.001). The primary patency rates at 36 months using the modified SVS runoff scoring system were 64.6% and 49.8% for the good-to-compromised (≤9 points) and poor (≥10 points) runoff groups, respectively (P=0.011). Conclusion: The modified SVS runoff scoring system is effective in predicting primary patency after SFA angioplasty with stenting in patients treated for claudication.