Targeting the tumor vasculature with antibody-drug conjugates (ADCs) is a promising anti-cancer strategy that in order to be realized must overcome several obstacles, including identification of ...suitable targets and optimal warheads. Here, we demonstrate that the cell-surface protein CD276/B7-H3 is broadly overexpressed by multiple tumor types on both cancer cells and tumor-infiltrating blood vessels, making it a potentially ideal dual-compartment therapeutic target. In preclinical studies CD276 ADCs armed with a conventional MMAE warhead destroyed CD276-positive cancer cells, but were ineffective against tumor vasculature. In contrast, pyrrolobenzodiazepine-conjugated CD276 ADCs killed both cancer cells and tumor vasculature, eradicating large established tumors and metastases, and improving long-term overall survival. CD276-targeted dual-compartment ablation could aid in the development of highly selective broad-acting anti-cancer therapies.
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•CD276/B7-H3 is broadly overexpressed in both cancer cells and tumor vasculature•Both angiogenic and non-angiogenic tumor vasculature express CD276•Anti-CD276-drug conjugates display potent anti-tumor and anti-metastatic activity•Pyrrolobenzodiazepine dimers are optimal warheads for targeting tumor vasculature
Seaman et al. show that CD276 is broadly overexpressed in cancer cells and tumor vascular cells and demonstrate anti-CD276-drug conjugates as promising anti-cancer reagents. The drug selected for conjugation is important because tumor vascular cells can be resistant to a drug to which tumor cells are sensitive.
The incidence of mortality is considerable after ST-elevation myocardial infarction (STEMI) hospitalization; risk assessment is needed to guide postdischarge management. Age shock index (SI) and age ...modified shock index (MSI) were described as useful prognosis instruments; nevertheless, their predictive effect on short and long-term postdischarge mortality has not yet been sufficiently confirmed.
This analysis included 3389 prospective patients enrolled from 2016 to 2018. Endpoints were postdischarge mortality within 30 days and from 30 days to 1 year. Hazard ratios (HRs) were evaluated by Cox proportional-hazards regression. Predictive performances were assessed by area under the curve (AUC), integrated discrimination improvement (IDI), net reclassification improvement (NRI) and decision curve analysis (DCA) and compared with TIMI risk score and GRACE score.
The AUCs were 0.753, 0.746 for age SI and 0.755, 0.755 for age MSI for short- and long-term postdischarge mortality. No significant AUC differences and NRI were observed compared with the classic scores; decreased IDI was observed especially for long-term postdischarge mortality. Multivariate analysis revealed significantly higher short- and long-term postdischarge mortality for patients with high age SI (HR: 5.44 (2.73-10.85), 5.34(3.18-8.96)), high age MSI (HR: 4.17(1.78-9.79), 5.75(3.20-10.31)) compared to counterparts with low indices. DCA observed comparable clinical usefulness for predicting short-term postdischarge mortality. Furthermore, age SI and age MSI were not significantly associated with postdischarge prognosis for patients who received fibrinolysis.
Age SI and age MSI were valuable instruments to identify high postdischarge mortality with comparable predictive ability compared with the classic scores, especially for events within 30 days after hospitalization.
Limited data are available on the changes in the quality of care for ST elevation myocardial infarction (STEMI) during China's health system reform from 2009 to 2020. We aimed to assess the changes ...in care processes and outcome for STEMI patients in Henan province of central China between 2011 and 2018.
We compared the data from the Henan STEMI survey conducted in 2011-2012 (n = 1548, a cross-sectional study) and the Henan STEMI registry in 2016-2018 (n = 4748, a multicenter, prospective observational study). Changes in care processes and in-hospital mortality were determined. Process of care measures included reperfusion therapies, aspirin, P2Y12 antagonists, β-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and statins. Therapy use was analyzed among patients who were considered ideal candidates for treatment.
STEMI patients in 2016-2018 were younger (median age: 63.1 vs. 63.8 years) with a lower proportion of women (24.4% 1156/4748 vs. 28.2 437/1548) than in 2011-2012. The composite use rate for guideline-recommended treatments increased significantly from 2011 to 2018 (60.9% 5424/8901 vs. 82.7% 22,439/27,129, P <0.001). The proportion of patients treated by reperfusion within 12 h increased from 44.1% (546/1237) to 78.4% (2698/3440) (P <0.001) with a prolonged median onset-to-first medical contact time (from 144 min to 210 min, P <0.001). The use of antiplatelet agents, statins, and β-blockers increased significantly. The risk of in-hospital mortality significantly decreased over time (6.1% 95/1548 vs. 4.2% 198/4748, OR: 0.67, 95% CI: 0.50-0.88, P = 0.005) after adjustment.
Gradual implementation of the guideline-recommended treatments in STEMI patients from 2011 to 2018 has been associated with decreased in-hospital mortality. However, gaps persist between clinical practice and guideline recommendation. Public awareness, reperfusion strategies, and construction of chest pain centers need to be further underscored in central China.
Although nonmalignant stromal cells facilitate tumor growth and can occupy up to 90% of a solid tumor mass, better strategies to exploit these cells for improved cancer therapy are needed. Here, we ...describe a potent MMAE-linked antibody-drug conjugate (ADC) targeting tumor endothelial marker 8 (TEM8, also known as ANTXR1), a highly conserved transmembrane receptor broadly overexpressed on cancer-associated fibroblasts, endothelium, and pericytes. Anti-TEM8 ADC elicited potent anticancer activity through an unexpected killing mechanism we term DAaRTS (drug activation and release through stroma), whereby the tumor microenvironment localizes active drug at the tumor site. Following capture of ADC prodrug from the circulation, tumor-associated stromal cells release active MMAE free drug, killing nearby proliferating tumor cells in a target-independent manner. In preclinical studies, ADC treatment was well tolerated and induced regression and often eradication of multiple solid tumor types, blocked metastatic growth, and prolonged overall survival. By exploiting TEM8+ tumor stroma for targeted drug activation, these studies reveal a drug delivery strategy with potential to augment therapies against multiple cancer types.
Several human monoclonal antibodies (hmAbs) including b12, 2G12, and 2F5 exhibit relatively potent and broad HIV-1-neutralizing activity. However, their elicitation in vivo by vaccine immunogens ...based on the HIV-1 envelope glycoprotein (Env) has not been successful. We have hypothesized that HIV-1 has evolved a strategy to reduce or eliminate the immunogenicity of the highly conserved epitopes of such antibodies by using “holes” (absence or very weak binding to these epitopes of germline antibodies that is not sufficient to initiate and/or maintain an efficient immune response) in the human germline B cell receptor (BCR) repertoire. To begin to test this hypothesis we have designed germline-like antibodies corresponding most closely to b12, 2G12, and 2F5 as well as to X5, m44, and m46 which are cross-reactive but with relatively modest neutralizing activity as natively occurring antibodies due to size and/or other effects. The germline-like X5, m44, and m46 bound with relatively high affinity to all tested Envs. In contrast, germline-like b12, 2G12, and 2F5 lacked measurable binding to Envs in an ELISA assay although the corresponding mature antibodies did. These results provide initial evidence that Env structures containing conserved vulnerable epitopes may not initiate humoral responses by binding to germline antibodies. Even if such responses are initiated by very weak binding undetectable in our assay it is likely that they will be outcompeted by responses to structures containing the epitopes of X5, m44, m46, and other antibodies that bind germline BCRs with much higher affinity/avidity. This hypothesis, if further supported by data, could contribute to our understanding of how HIV-1 evades immune responses and offer new concepts for design of effective vaccine immunogens.
► Identified putative receptor for the Crimean-Congo hemorrhagic fever virus which allows new exploration of virus entry and development of inhibitors. ► Identified a putative receptor binding domain ...which also allows new exploration of virus entry and development of inhibitors. ► Expressed and purified soluble viral envelope glycoproteins which can be used as candidate vaccine immunogens.
Entry of enveloped viruses into cells is initiated by binding of their envelope glycoproteins (Envs) to cell surface-associated receptors. The Crimean-Congo hemorrhagic fever virus (CCHFV) has two Envs, Gn and Gc, with poorly understood role in binding to susceptible cells. We expressed codon optimized Gn and Gc, and identified independently folded soluble Env fragments, one of which (Gc residues 180–300) bound CCHFV susceptible cells supposedly by interacting with a putative receptor. This receptor binding domain (RBD) was used to identify its interacting partner by coimmunoprecipitation and mass spectrometry. Thus we identified the human cell surface nucleolin as a putative CCHFV entry factor. Nucleolin was expressed on all susceptible cells tested but not on the surface of cells resistant to CCHFV infection. Further studies are needed to explore the nucleolin function as a plausible CCHFV receptor and the molecular mechanisms of the Gc-nucleolin interactions. The identification of the CCHFV RBD and its binding partner could provide novel targets for therapy and tools for prevention as well as more complete understanding of the mechanisms of CCHFV entry and pathogenesis.
Collagen I, the most abundant protein in humans, is ubiquitous in solid tumors where it provides a rich source of exploitable metabolic fuel for cancer cells. While tumor cells were unable to exploit ...collagen directly, here we show they can usurp metabolic byproducts of collagen-consuming tumor-associated stroma. Using genetically engineered mouse models, we discovered that solid tumor growth depends upon collagen binding and uptake mediated by the TEM8/ANTXR1 cell surface protein in tumor-associated stroma. Tumor-associated stromal cells processed collagen into glutamine, which was then released and internalized by cancer cells. Under chronic nutrient starvation, a condition driven by the high metabolic demand of tumors, cancer cells exploited glutamine to survive, an effect that could be reversed by blocking collagen uptake with TEM8 neutralizing antibodies. These studies reveal that cancer cells exploit collagen-consuming stromal cells for survival, exposing an important vulnerability across solid tumors with implications for developing improved anticancer therapy.
•Advanced antivirals against Nipah and Hendra are a Hendra-sG subunit vaccine and a human monoclonal antibody, m102.4.•The Hendra-sG vaccine was launched in Australia for equine use and is the first ...BSL-4 agent vaccine for public use.•m102.4 has been used in people on a compassionate use basis in Australia and is presently in pre-clinical development.•A structural model of the Hendra-sG vaccine and its complex with the neutralizing human monoclonal antibody is shown.
Hendra virus and Nipah virus are bat-borne paramyxoviruses that are the prototypic members of the genus Henipavirus. The henipaviruses emerged in the 1990s, spilling over from their natural bat hosts and causing serious disease outbreaks in humans and livestock. Hendra virus emerged in Australia and since 1994 there have been 7 human infections with 4 case fatalities. Nipah virus first appeared in Malaysia and subsequent outbreaks have occurred in Bangladesh and India. In total, there have been an estimated 582 human cases of Nipah virus and of these, 54% were fatal. Their broad species tropism and ability to cause fatal respiratory and/or neurologic disease in humans and animals make them important transboundary biological threats. Recent experimental findings in animals have demonstrated that a human monoclonal antibody targeting the viral G glycoprotein is an effective post-exposure treatment against Hendra and Nipah virus infection. In addition, a subunit vaccine based on the G glycoprotein of Hendra virus affords protection against Hendra and Nipah virus challenge. The vaccine has been developed for use in horses in Australia and is the first vaccine against a Biosafety Level-4 (BSL-4) agent to be licensed and commercially deployed. Together, these advances offer viable approaches to address Hendra and Nipah virus infection of livestock and people.
CAR T-cell therapies targeting the B-cell maturation antigen eliminate tumors in relapsed/refractory multiple myeloma patients, however durable remissions remain difficult to attain. Transforming ...growth factor beta (TGF-β) is a multifunctional cytokine abundantly expressed in the multiple myeloma bone marrow niche, where it promotes an immunosuppressive tumor microenvironment. We hypothesized that BCMA CAR T-cells armored to resist the suppressive effects of TGF-β will provide an advantage in treating multiple myeloma. The armored B2ARM CAR T cells, co-expressing BCMA targeting CAR with TGF-β dominant-negative receptor II, were generated by lentiviral transduction of primary human CD4+ and CD8+ T cells. The B2ARM CAR T cells eliminated MM.1S multiple myeloma targets in long-term cytotoxicity assays, even under TGF-β-high conditions, whereas cytotoxic function of the non-armored B2 CAR -T cells was inhibited by TGF-β. Concordantly, after long-term exposure to targets in the presence of TGF-β, the B2ARM CAR T cells were enriched for Granzyme B, CD107a, Ki67 and polyfunctional cells T-cells (double or triple-positive for IFN-γ, IL-2 and/or TNF-α), as determined by flow cytometry. In addition, the B2ARM CAR T-cells, but not the conventional B2 CAR T-cells, resisted the TGF-β-mediated suppression of activation (CD25), exhaustion (PD-1, LAG3), and differentiation to T effectors (CD45RA+ CD45RO-CD62L-). In NSG mice bearing RPMI-8226 tumors overexpressing TGF-β, the B2ARM CAR mediated 100% tumor rejection and survival, superior infiltration of tumors on day 7 post CAR T treatment (%CD3+CAR+), and greater expression of IFN-γ, TNF-α, Ki67, Granzyme B, and PD-1, as compared to tumor-infiltrating non-armored B2 CAR T-cells. In NSG RPMI-8226 xenograft model in which tumors were additionally supplemented with TGF-β injections on days -1 through 11 of CAR T treatment, the B2ARM CAR T cells rejected tumors faster than the non-armored B2 CARs, and showed greater numbers of CD3+ and CD3+CAR+, central memory (CD45RO+CD62L+) and effector memory (CD45RO+CD62L-) T cells in the peripheral blood 18 days after treatment. In summary, the armored B2ARM CAR T cells mediate superior persistence, proliferation, multi-functionality, effector differentiation and anti-tumor function in pre-clinical models of multiple myeloma, while abrogating TGF-β-mediated suppression.
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