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Anti-CTLA-4 antibodies faced challenges due to frequent adverse events and limited efficacy, which spurred the exploration of next-generation CTLA-4 therapeutics to balance regulatory T cells (Tregs) depletion and CD8 T cells activation. CCR8, identified primarily on tumor-infiltrating Tregs, has become a target of interest due to the anti-tumor effects demonstrated by CCR8 antibody-mediated Tregs depletion. Single-cell RNA sequencing analysis reveals that CCR8-positive Tregs constitute a small subset, with concurrent expression of CCR8 and CTLA-4. Consequently, we proposed a novel bispecific antibody targeting CCR8 and CTLA-4 that had the potential to enhance T cell activation while selectively depleting intratumor Tregs. The candidate molecule 2MW4691 was developed in a tetravalent symmetric format, maintaining a strong binding affinity for CCR8 while exhibiting relatively weaker CTLA-4 binding. This selective binding ability allowed 2MW4691 to target and deplete tumor-infiltrating Tregs with higher specificity. In vitro assays verified the antibody's capacity for antibody-dependent cellular cytotoxicity (ADCC) to Tregs with high level of CTLA-4 expression, but not CD8 T cells with relatively low level of CTLA-4 on cell surface. Also, 2MW4691 inhibited the CTLA-4 pathway and enhanced T cell activation. The in vivo therapeutic efficacy of 2MW4691 was further demonstrated using hCCR8 or hCTLA-4 humanized mouse models and hCCR8/hCTLA-4 double knock-in mouse models. In cynomolgus monkeys, 2MW4691 was well-tolerated, exhibited the anticipated pharmacokinetic profile, and had a minimal impact on the peripheral T cell population. The promising preclinical results supported the further evaluation of 2MW4691 as a next-generation Treg-based therapeutics in clinical trials.
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Anticuerpos Biespecíficos , Linfocitos T CD8-positivos , Antígeno CTLA-4 , Linfocitos T Reguladores , Animales , Ratones , Anticuerpos Biespecíficos/farmacología , Anticuerpos Biespecíficos/inmunología , Anticuerpos Biespecíficos/uso terapéutico , Humanos , Antígeno CTLA-4/antagonistas & inhibidores , Antígeno CTLA-4/inmunología , Linfocitos T Reguladores/inmunología , Linfocitos T CD8-positivos/inmunología , Receptores CCR8/inmunología , Neoplasias/inmunología , Neoplasias/tratamiento farmacológico , Neoplasias/terapia , Transducción de Señal/efectos de los fármacos , Femenino , Ensayos Antitumor por Modelo de Xenoinjerto , Macaca fascicularisRESUMEN
BACKGROUND: Mediastinal emphysema is a condition in which air enters the mediastinum between the connective tissue spaces within the pleura for a variety of reasons. It can be spontaneous or secondary to chest trauma, esophageal perforation, medically induced factors, etc. Its common symptoms are chest pain, tightness in the chest, and respiratory distress. Most mediastinal emphysema patients have mild symptoms, but severe mediastinal emphysema can cause respiratory and circulatory failure, resulting in serious consequences. CASE SUMMARY: A 75-year-old man, living alone, presented with sudden onset of severe epigastric pain with chest tightness after drinking alcohol. Due to the remoteness of his residence and lack of neighbors, the patient was found by his nephew and brought to the hospital the next morning after the disease onset. Computed tomography (CT) showed free gas in the abdominal cavity, mediastinal emphysema, and subcutaneous pneumothorax. Upper gastrointestinal angiography showed that the esophageal mucosa was intact and the gastric antrum was perforated. Therefore, we chose to perform open gastric perforation repair on the patient under thoracic epidural anesthesia combined with intravenous anesthesia. An operative incision of the muscle layer of the patient's abdominal wall was made, and a large amount of subperitoneal gas was revealed. And a continued incision of the peritoneum revealed the presence of a perforation of approximately 0.5 cm in the gastric antrum, which we repaired after pathological examination. Postoperatively, the patient received high-flow oxygen and cough exercises. Chest CT was performed on the first and sixth postoperative days, and the mediastinal and subcutaneous gas was gradually reduced. CONCLUSION: After gastric perforation, a large amount of free gas in the abdominal cavity can reach the mediastinum through the loose connective tissue at the esophageal hiatus of the diaphragm, and upper gastrointestinal angiography can clarify the site of perforation. In patients with mediastinal emphysema, open surgery avoids the elevation of the diaphragm caused by pneumoperitoneum compared to laparoscopic surgery and avoids increasing the mediastinal pressure. In addition, thoracic epidural anesthesia combined with intravenous anesthesia also avoids pressure on the mediastinum from mechanical ventilation.
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The immune checkpoint leukocyte immunoglobulin-like receptor B4 (LILRB4) is found specifically on the cell surface of acute monocytic leukemia (monocytic AML), an aggressive and common subtype of AML. We have developed a humanized monoclonal IgG1 LILRB4-blocking antibody (h128-3), which improved immune regulation but reduced cell surface expression of LILRB4 in monocytic AML models by 40-60%. Interestingly, most of this effect was neutralized by mutation of the Fc region of the antibody (h128-3/N297A), which prevents interaction with Fc gamma receptors (FcγRs). This suggested that there is FcγR-dependent antigenic modulation underlying h128-3's effects, a mechanism known to alter the function of antibodies targeting B-cell malignancies. We disrupted the Fc-FcγR interaction pharmacologically and with stable CRISPR-Cas9-mediated genetic knockout of FcγRs in monocytic AML cell lines to investigate the role of FcγR-dependent antigenic modulation in the regulation of LILRB4 by h128-3. When FcγRI is inhibited or removed from the surface of monocytic AML cells, h128-3 cannot optimally perform its blocking function, resulting in activation of the LILRB4 inhibitory receptor and leading to a 15-25% decrease in T-cell-mediated cytotoxicity in vitro. In the absence of FcγRI, scaffolding by FcγRIIa allows h128-3 to maintain LILRB4-blocking function. Here we define a FcγR-dependent antigenic modulation mechanism underlying the function of an immunoreceptor blocking antibody for the first time in myeloid malignancy. This research will facilitate the development of safe, precision-targeted antibody therapeutics in myeloid malignancies with greater potency and efficacy.
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The existing T cell-centered immune checkpoint blockade therapies have been successful in treating some but not all patients with cancer. Immunosuppressive myeloid cells, including myeloid-derived suppressor cells (MDSC), that inhibit antitumor immunity and support multiple steps of tumor development are recognized as one of the major obstacles in cancer treatment. Leukocyte Ig-like receptor subfamily B3 (LILRB3), an immune inhibitory receptor containing tyrosine-based inhibitory motifs (ITIM), is expressed solely on myeloid cells. However, it is unknown whether LILRB3 is a critical checkpoint receptor in regulating the activity of immunosuppressive myeloid cells, and whether LILRB3 signaling can be blocked to activate the immune system to treat solid tumors. Here, we report that galectin-4 and galectin-7 induce activation of LILRB3 and that LILRB3 is functionally expressed on immunosuppressive myeloid cells. In some samples from patients with solid cancers, blockade of LILRB3 signaling by an antagonistic antibody inhibited the activity of immunosuppressive myeloid cells. Anti-LILRB3 also impeded tumor development in myeloid-specific LILRB3 transgenic mice through a T cell-dependent manner. LILRB3 blockade may prove to be a novel approach for immunotherapy of solid cancers.
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Células Supresoras de Origen Mieloide , Neoplasias , Ratones , Animales , Humanos , Células Mieloides , Neoplasias/terapia , Linfocitos T , Receptores Inmunológicos , Microambiente Tumoral , Antígenos CDRESUMEN
Osteoporosis is a metabolic condition distinguished by the degradation of bone microstructure and mechanical characteristics. Traditional Chinese medicine (TCM) has been employed in China for the treatment of various illnesses. Naringin, an ingredient found in Drynariae TCM, is known to have a significant impact on bone metabolism. For this research, we studied the precise potential effect of Drynaria Naringin on protecting against bone loss caused by stress deficiency. In this study, a tail-suspension (TS) test was performed to establish a mouse model with hind leg bone loss. Some mice received subcutaneous injections of Drynaria Naringin for 30 d. Trabecular bone microarchitecture was evaluated using micro-computed tomography analysis and bone histological analysis. Bone formation and resorption markers were quantified in blood samples from mice or in the supernatant of MC3T3-E1 cells by ELISA analysis, Western blotting, and PCR. Immunofluorescence was utilized to visualize the location of ß-catenin. Additionally, siRNA was employed to knockdown-specific genes in the cells. Our findings highlight the efficacy of Drynaria Naringin in protecting against the deterioration of bone loss and promoting bone formation and Rspo1 expression in a mouse model following the TS test. Specifically, in vitro experiments also indicated that Drynaria Naringin may promote osteogenesis through the Wnt/ß-catenin signalling pathway. Moreover, our results suggest that Drynaria Naringin upregulates the expression of Rspo1/Lgr4, leading to the promotion of osteogenesis via the Wnt/ß-catenin signalling pathway. Therefore, Drynaria Naringin holds potential as a therapeutic medication for osteoporosis. Drynaria Naringin alleviates bone loss deterioration caused by mechanical stress deficiency through the Rspo1/Lgr4-mediated Wnt/ß-catenin signalling pathway.
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Osteoporosis , Polypodiaceae , Animales , Ratones , beta Catenina/metabolismo , Diferenciación Celular , Osteogénesis/genética , Osteoporosis/tratamiento farmacológico , Osteoporosis/etiología , Polypodiaceae/química , Estrés Mecánico , Vía de Señalización Wnt , Microtomografía por Rayos X/efectos adversosRESUMEN
Background: Even though PD-1/PD-L1 is an identified key "don't find me" signal to active adaptive immune system for cancer treatment, the overall response rate (ORR) for all cancer patients is still limited. Other effective therapeutic modalities to bridge the innate and adaptive immunity to improve ORR are urgently needed. Recently, CD47/SIRPα interaction is confirmed as a critical "don't eat me" signal to active innate immunity. However, the red blood cell (RBC) toxicity is the big concern for the development of CD47-based anti-cancer therapeutics. Methods: Here, we report the development of a CD47/PD-L1 bispecific antibody 6MW3211 to block both PD-1/PD-L1 and CD47/SIRPα signals, and studied the effects of 6MW3211 on anti-tumor immune functions in vitro and in vivo. The pharmacokinetic and toxicity profiles of 6MW3211 were evaluated in GLP non-human primate (NHP) studies. Results: The dual immune checkpoint inhibitory signaling blocker 6MW3211 shows high binding affinity to PD-L1 and low binding affinity to CD47. This inequivalent binding affinity design makes 6MW3211 preferentially bound to PD-L1 on tumor cells followed by disrupting the interaction of CD47/SIRPα. Complex structure determination and flow cytometry assay demonstrated that 6MW3211 has no binding to either human or rhesus monkey RBCs. 6MW3211 effectively blocked both PD-1/DP-L1 and CD47/SIRPα signaling and promoted macrophage phagocytosis of tumor cells. Potent therapeutic efficacies of 6MW3211 in three different mouse models were further observed. Moreover, 6MW3211 was demonstrated to have a fairly good safety profile in a GLP NHP study. In addition, multiplex fluorescent immunohistochemistry (mIHC) staining shows that PD-L1 and CD47 co-express on several different types of human tumor tissues. Conclusions: These results support the development of 6MW3211 for the treatment of PD-L1 and CD47 double positive cancers.
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Anticuerpos Biespecíficos , Neoplasias , Animales , Ratones , Humanos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Antígeno CD47/metabolismo , Antígeno B7-H1 , Receptor de Muerte Celular Programada 1/uso terapéutico , Fagocitosis , Neoplasias/patología , Inmunoterapia/métodos , Anticuerpos Biespecíficos/farmacología , Anticuerpos Biespecíficos/uso terapéuticoRESUMEN
The current immune checkpoint blockade therapy has been successful in treating some cancers but not others. New molecular targets and therapeutic approaches of cancer immunology need to be identified. Leukocyte associated immunoglobulin like receptor 1 (LAIR1) is an immune inhibitory receptor expressing on most immune cell types. However, it remains a question whether we can specifically and actively block LAIR1 signaling to activate immune responses for cancer treatment. Here we report the development of specific antagonistic anti-LAIR1 monoclonal antibodies and studied the effects of LAIR1 blockade on the anti-tumor immune functions. The anti-LAIR1 antagonistic antibody stimulated the activities of T cells, natural killer cells, macrophages, and dendritic cells in vitro. The single-cell RNA sequencing analysis of intratumoral immune cells in syngeneic human LAIR1 transgenic mice treated with control or anti-LAIR1 antagonist antibodies indicates that LAIR1 signaling blockade increased the numbers of CD4 memory T cells and inflammatory macrophages, but decreased those of pro-tumor macrophages, regulatory T cells, and plasmacytoid dendritic cells. Importantly, the LAIR1 blockade by the antagonistic antibody inhibited the activity of immunosuppressive myeloid cells and reactivated T cells from cancer patients in vitro and impeded tumor metastasis in a humanized mouse model. Blocking LAIR1 signaling in immune cells represents a promising strategy for development of anti-cancer immunotherapy.
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Inhibidores de Puntos de Control Inmunológico , Neoplasias , Animales , Anticuerpos Monoclonales/uso terapéutico , Humanos , Inmunoterapia , Ratones , Linfocitos T ReguladoresRESUMEN
Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, several variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged and have consistently replaced the previous dominant variant. Therapeutics against variants of SARS-CoV-2 are urgently needed. Ideal SARS-CoV-2 therapeutic antibodies would have high potency in viral neutralization against several emerging variants. Neutralization antibodies targeting SARS-CoV-2 could provide immediate protection after SARS-CoV-2 infection, especially for the most vulnerable populations. In this work, we comprehensively characterize the breadth and efficacy of SARS-CoV-2 RBD-targeting fully human monoclonal antibody (mAb) MW3321. MW3321 retains full neutralization activity to all tested 12 variants that have arisen in the human population, which are assigned as VOC (Variants of Concern) and VOI (Variants of Interest) due to their impacts on public health. Escape mutation experiments using replicating SARS-CoV-2 pseudovirus show that escape mutants were not generated until passage 6 for MW3321, which is much more resistant to escape mutation compared with another clinical staged SARS-CoV-2 neutralizing mAb MW3311. MW3321 could effectively reduce viral burden in hACE2-transgenic mice challenged with either wild-type or Delta SARS-CoV-2 strains through viral neutralization and Fc-mediated effector functions. Moreover, MW3321 exhibits a typical hIgG1 pharmacokinetic and safety profile in cynomolgus monkeys. These data support the development of MW3321 as a monotherapy or cocktail against SARS-CoV-2-related diseases.
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Understanding the underlying molecular mechanisms behind ADE of SARS-CoV-2 is critical for development of safe and effective therapies. Here, we report that two neutralizing mAbs, MW01 and MW05, could enhance the infection of SARS-CoV-2 pseudovirus on FcγRIIB-expressing B cells. X-ray crystal structure determination and S trimer-binding modeling showed that MW01 and MW05 could bind to RBDs in S trimer with both "up" and "down" states. While, the neutralizing mAb MW07, which has no ADE activity only binds to RBD in S trimer with "up" state. Monovalent MW01 and MW05 completely diminished the ADE activity compared with their bivalent counterparts. Moreover, both macropinocytosis and endocytosis are confirmed involving in ADE of SARS-CoV-2 pseudoviral infection. Blocking endosome transportation and lysosome acidification could inhibit the ADE activity mediated by MW05. Together, our results identified a novel ADE mechanism of SARS-CoV-2 pseudovirus in vitro, FcγRIIB-mediated uptake of SARS-CoV-2/mAb complex with bivalent interaction.
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Acrecentamiento Dependiente de Anticuerpo , COVID-19 , Anticuerpos Antivirales , Humanos , SARS-CoV-2 , Glicoproteína de la Espiga del CoronavirusRESUMEN
The process of intervertebral disc degeneration (IVDD) is complex, and its mechanism is considered multifactorial. Apoptosis of oxidative stressed nucleus pulposus cells (NPCs) should be a fundamental element in the pathogenesis of IVDD. In our pilot study, we found that the expression of MAT2A decreased, and METTL16 increased in the degenerative nucleus pulposus tissues. Previous studies have shown that the balance of splicing, maturation, and degradation of MAT2A pre-mRNA is regulated by METTL16 m6A modification. In the current study, we aimed to figure out whether this mechanism was involved in the aberrant apoptosis of NPCs and IVDD. Human NPCs were isolated and cultured under oxidative stress. An IVDD animal model was established. It showed that significantly higher METTL16 expression and lower MAT2A expression were seen in either the NPCs under oxidative stress or the degenerative discs of the animal model. MAT2A was inhibited with siRNA in vitro or cycloleucine in vivo. METTL16 was overexpressed with lentivirus in vitro or in vivo. Downregulation of MAT2A or upregulation of METTL16 aggravated nucleus pulposus cell apoptosis and disc disorganization. The balance of splicing, maturation, and degradation of MAT2A pre-mRNA was significantly inclined to degradation in the NPCs with the overexpression of METTL16. Increased apoptosis of NPCs under oxidative stress could be rescued by reducing the expression of METTL16 using siRNA with more maturation of MAT2A pre-mRNA. Collectively, oxidative stress aggravates apoptosis of NPCs through disrupting the balance of splicing, maturation, and degradation of MAT2A pre-mRNA, which is m6A modified by METTL16.
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Metionina Adenosiltransferasa/metabolismo , Metiltransferasas/metabolismo , Núcleo Pulposo/metabolismo , Estrés Oxidativo/genética , Animales , Apoptosis , Modelos Animales de Enfermedad , Humanos , Ratones , Proyectos Piloto , TransfecciónRESUMEN
The global pandemic of COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in widespread social and economic disruption. Effective interventions are urgently needed for the prevention and treatment of COVID-19. Neutralizing monoclonal antibodies (mAbs) have demonstrated their prophylactic and therapeutic efficacy against SARS-CoV-2, and several have been granted authorization for emergency use. Here, we discover and characterize a fully human cross-reactive mAb, MW06, which binds to both SARS-CoV-2 and SARS-CoV spike receptor-binding domain (RBD) and disrupts their interaction with angiotensin-converting enzyme 2 (ACE2) receptors. Potential neutralization activity of MW06 was observed against both SARS-CoV-2 and SARS-CoV in different assays. The complex structure determination and epitope alignment of SARS-CoV-2 RBD/MW06 revealed that the epitope recognized by MW06 is highly conserved among SARS-related coronavirus strains, indicating the potential broad neutralization activity of MW06. In in vitro assays, no antibody-dependent enhancement (ADE) of SARS-CoV-2 infection was observed for MW06. In addition, MW06 recognizes a different epitope from MW05, which shows high neutralization activity and has been in a Phase 2 clinical trial, supporting the development of the cocktail of MW05 and MW06 to prevent against future escaping variants. MW06 alone and the cocktail show good effects in preventing escape mutations, including a series of variants of concern, B.1.1.7, P.1, B.1.351, and B.1.617.1. These findings suggest that MW06 recognizes a conserved epitope on SARS-CoV-2, which provides insights for the development of a universal antibody-based therapy against SARS-related coronavirus and emerging variant strains, and may be an effective anti-SARS-CoV-2 agent.
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Anticuerpos Monoclonales Humanizados/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , COVID-19/virología , SARS-CoV-2/inmunología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , Secuencia de Aminoácidos , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/uso terapéutico , Anticuerpos Antivirales/química , Anticuerpos Antivirales/uso terapéutico , Acrecentamiento Dependiente de Anticuerpo , COVID-19/terapia , Secuencia Conservada , Reacciones Cruzadas , Epítopos/química , Epítopos/genética , Epítopos/inmunología , Humanos , Modelos Moleculares , Pruebas de Neutralización , Pandemias , Dominios Proteicos , Dominios y Motivos de Interacción de Proteínas , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/química , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/genética , SARS-CoV-2/química , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Tratamiento Farmacológico de COVID-19RESUMEN
Background: Hepatic platelet accumulation contributes to acetaminophen (APAP)-induced liver injury (AILI). However, little is known about the molecular pathways involved in platelet recruitment to the liver and whether targeting such pathways could attenuate AILI. Methods: Mice were fasted overnight before intraperitoneally (i.p.) injected with APAP at a dose of 210 mg/kg for male mice and 325 mg/kg for female mice. Platelets adherent to Kupffer cells were determined in both mice and patients overdosed with APAP. The impact of α-chitinase 3-like-1 (α-Chi3l1) on alleviation of AILI was determined in a therapeutic setting, and liver injury was analyzed. Results: The present study unveiled a critical role of Chi3l1 in hepatic platelet recruitment during AILI. Increased Chi3l1 and platelets in the liver were observed in patients and mice overdosed with APAP. Compared to wild-type (WT) mice, Chil1-/- mice developed attenuated AILI with markedly reduced hepatic platelet accumulation. Mechanistic studies revealed that Chi3l1 signaled through CD44 on macrophages to induce podoplanin expression, which mediated platelet recruitment through C-type lectin-like receptor 2. Moreover, APAP treatment of Cd44-/- mice resulted in much lower numbers of hepatic platelets and liver injury than WT mice, a phenotype similar to that in Chil1-/- mice. Recombinant Chi3l1 could restore hepatic platelet accumulation and AILI in Chil1-/- mice, but not in Cd44-/- mice. Importantly, we generated anti-Chi3l1 monoclonal antibodies and demonstrated that they could effectively inhibit hepatic platelet accumulation and AILI. Conclusions: We uncovered the Chi3l1/CD44 axis as a critical pathway mediating APAP-induced hepatic platelet recruitment and tissue injury. We demonstrated the feasibility and potential of targeting Chi3l1 to treat AILI. Funding: ZS received funding from NSFC (32071129). FWL received funding from NIH (GM123261). ALFSG received funding from NIDDK (DK 058369). ZA received funding from CPRIT (RP150551 and RP190561) and the Welch Foundation (AU-0042-20030616). CJ received funding from NIH (DK122708, DK109574, DK121330, and DK122796) and support from a University of Texas System Translational STARs award. Portions of this work were supported with resources and the use of facilities of the Michael E. DeBakey VA Medical Center and funding from Department of Veterans Affairs I01 BX002551 (Equipment, Personnel, Supplies). The contents do not represent the views of the US Department of Veterans Affairs or the US Government.
Acetaminophen, also called paracetamol outside the United States, is a commonly used painkiller, with over 50 million people in the United States taking the drug weekly. While paracetamol is safe at standard doses, overdose can cause acute liver failure, which leads to 30,000 patients being admitted to emergency care in the United States each year. There is only one approved antidote to overdoses, which becomes significantly less effective if its application is delayed by more than a few hours. This has incentivized research into identify new drug targets that could lead to additional treatment options. Acetaminophen overdose triggers blood clotting and inflammation, contributing to liver injury. It also causes a decrease in cells called platelets circulating in the blood, which has been observed in both mice and humans. In mice, this occurs because platelets accumulate in the liver. Removing these excess cells appears to reduce the severity of the damage caused by acetaminophen, but it remains unclear how the drug triggers their accumulation in the liver. In 2018, researchers showed that a protein called Chi3l1 plays an important role in another form of liver damage. Shan et al. including many of the researchers involved in the 2018 study have examined whether the protein also contributes to acetaminophen damage in the liver. Shan et al. showed that mice lacking the gene that codes for Chi3l1 developed less severe liver injury and had fewer platelets in the liver following acetaminophen overdose. They also found that human patients with acute liver failure due to acetaminophen had high levels of Chi3l1 and significant accumulation of platelets in the liver. To test whether damage could be prevented, Shan et al. used antibodies to neutralize Chi3l1 in mice after giving them an acetaminophen overdose. This reduced platelet accumulation in the liver and the associated damage. These findings suggest that targeting Chi3l1 may be an effective strategy to prevent liver damage caused by acetaminophen overdose. Further research could help develop new treatments for acetaminophen-induced liver injury and perhaps other liver conditions.
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Acetaminofén/efectos adversos , Plaquetas , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Proteína 1 Similar a Quitinasa-3 , Hígado , Animales , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas/patología , Proteína 1 Similar a Quitinasa-3/metabolismo , Proteína 1 Similar a Quitinasa-3/farmacología , Femenino , Hígado/citología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
Leukocyte immunoglobulin-like receptor B (LILRB), a family of immune checkpoint receptors, contributes to acute myeloid leukemia (AML) development, but the specific mechanisms triggered by activation or inhibition of these immune checkpoints in cancer is largely unknown. Here we demonstrate that the intracellular domain of LILRB3 is constitutively associated with the adaptor protein TRAF2. Activated LILRB3 in AML cells leads to recruitment of cFLIP and subsequent NF-κB upregulation, resulting in enhanced leukemic cell survival and inhibition of T-cell-mediated anti-tumor activity. Hyperactivation of NF-κB induces a negative regulatory feedback loop mediated by A20, which disrupts the interaction of LILRB3 and TRAF2; consequently the SHP-1/2-mediated inhibitory activity of LILRB3 becomes dominant. Finally, we show that blockade of LILRB3 signaling with antagonizing antibodies hampers AML progression. LILRB3 thus exerts context-dependent activating and inhibitory functions, and targeting LILRB3 may become a potential therapeutic strategy for AML treatment.
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Leucemia Mieloide Aguda , FN-kappa B , Antígenos CD/metabolismo , Humanos , Inmunidad , Receptores Inmunológicos/metabolismo , Linfocitos T/metabolismo , Factor 2 Asociado a Receptor de TNF/metabolismo , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Efficacious interventions are urgently needed for the treatment of COVID-19. Here, we report a monoclonal antibody (mAb), MW05, with SARS-CoV-2 neutralizing activity by disrupting the interaction of receptor binding domain (RBD) with angiotensin-converting enzyme 2 (ACE2) receptor. Crosslinking of Fc with FcγRIIB mediates antibody-dependent enhancement (ADE) activity by MW05. This activity is eliminated by introducing the LALA mutation to the Fc region (MW05/LALA). Potent prophylactic and therapeutic effects against SARS-CoV-2 are observed in rhesus monkeys. A single dose of MW05/LALA blocks infection of SARS-CoV-2 in prophylactic treatment and clears SARS-CoV-2 in three days in a therapeutic treatment setting. These results pave the way for the development of MW05/LALA as an antiviral strategy for COVID-19.
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Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Antivirales/farmacología , Betacoronavirus/inmunología , Infecciones por Coronavirus/terapia , Neumonía Viral/terapia , Glicoproteína de la Espiga del Coronavirus/inmunología , Enzima Convertidora de Angiotensina 2 , Animales , Anticuerpos Antivirales/inmunología , COVID-19 , Línea Celular , Chlorocebus aethiops , Infecciones por Coronavirus/prevención & control , Femenino , Células HEK293 , Humanos , Macaca mulatta , Masculino , Pandemias/prevención & control , Peptidil-Dipeptidasa A/metabolismo , Neumonía Viral/prevención & control , Receptores de IgG/genética , Receptores de IgG/inmunología , Receptores Virales/metabolismo , SARS-CoV-2 , Células Vero , Acoplamiento ViralRESUMEN
Acute myeloid leukemia (AML) is the most common and aggressive blood cancer in adults. In particular, significant unmet medical needs exist for effective treatment strategies for acute myelomonocytic leukemia (M4) and acute monocytic leukemia (M5) AML subtypes. Antibody-drug conjugates (ADC) are a promising drug class for AML therapy, as demonstrated by the FDA-approved anti-CD33 ADC, gemtuzumab ozogamicin (Mylotarg). However, CD33 is expressed in normal hematopoietic stem cells, highlighting the critical need to identify AML-specific targets to minimize the risk of potential adverse effects. We have demonstrated that the leukocyte immunoglobulin-like receptor subfamily B4 (LILRB4) is expressed at significantly higher levels on monocytic M4 and M5 AML cells than on normal counterparts. Here, we test whether LILRB4 is a promising ADC target to kill monocytic AML cells while sparing healthy counterparts. To this end, we generated ADCs from a humanized anti-LILRB4 mAb and the antimitotic payload, monomethyl auristatin F. The conjugates constructed were characterized and evaluated for LILRB4-specific cell killing potency, toxicity to progenitor cells, pharmacokinetics, and therapeutic efficacy. Our ADC linker technology platform efficiently generated homogeneous anti-LILRB4 ADCs with defined drug-to-antibody ratios. The homogeneous anti-LILRB4 ADCs demonstrated the capacity for LILRB4-mediated internalization, suitable physicochemical properties, and high cell killing potency against LILRB4-positive AML cells. Importantly, our data indicate that these ADCs spare normal progenitor cells. One of our homogeneous conjugates exerted a remarkable therapeutic effect and no significant toxicity in a xenograft mouse model of disseminated human AML. Our findings highlight the clinical potential of anti-LILRB4 ADCs in monocytic AML therapy.
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Antineoplásicos Inmunológicos/farmacología , Inmunoconjugados/farmacología , Glicoproteínas de Membrana/antagonistas & inhibidores , Receptores Inmunológicos/antagonistas & inhibidores , Animales , Antineoplásicos Inmunológicos/química , Línea Celular Tumoral , Modelos Animales de Enfermedad , Estabilidad de Medicamentos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoconjugados/química , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/etiología , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/patología , Ratones , Unión Proteica , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/farmacología , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Current immune checkpoint blockade strategies have been successful in treating certain types of solid cancer. However, checkpoint blockade monotherapies have not been successful against most hematological malignancies including multiple myeloma and leukemia. There is an urgent need to identify new targets for development of cancer immunotherapy. LILRB1, an immunoreceptor tyrosine-based inhibitory motif-containing receptor, is widely expressed on human immune cells, including B cells, monocytes and macrophages, dendritic cells and subsets of natural killer (NK) cells and T cells. The ligands of LILRB1, such as major histocompatibility complex (MHC) class I molecules, activate LILRB1 and transduce a suppressive signal, which inhibits the immune responses. However, it is not clear whether LILRB1 blockade can be effectively used for cancer treatment. METHODS: First, we measured the LILRB1 expression on NK cells from cancer patients to determine whether LILRB1 upregulated on NK cells from patients with cancer, compared with NK cells from healthy donors. Then, we developed specific antagonistic anti-LILRB1 monoclonal antibodies and studied the effects of LILRB1 blockade on the antitumor immune function of NK cells, especially in multiple myeloma models, in vitro and in vivo xenograft model using non-obese diabetic (NOD)-SCID interleukin-2Rγ-null mice. RESULTS: We demonstrate that percentage of LILRB1+ NK cells is significantly higher in patients with persistent multiple myeloma after treatment than that in healthy donors. Further, the percentage of LILRB1+ NK cells is also significantly higher in patients with late-stage prostate cancer than that in healthy donors. Significantly, we showed that LILRB1 blockade by our antagonistic LILRB1 antibody increased the tumoricidal activity of NK cells against several types of cancer cells, including multiple myeloma, leukemia, lymphoma and solid tumors, in vitro and in vivo. CONCLUSIONS: Our results indicate that blocking LILRB1 signaling on immune effector cells such as NK cells may represent a novel strategy for the development of anticancer immunotherapy.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Células Asesinas Naturales/inmunología , Receptor Leucocitario Tipo Inmunoglobulina B1/antagonistas & inhibidores , Animales , Anticuerpos Monoclonales/farmacología , Femenino , Humanos , Ratones , Ratones Endogámicos NODRESUMEN
The tungsten diselenide (WSe2) has attracted considerable interest owing to their versatile applications, such as p-n junctions, transistors, fiber lasers, spintronics, and conversion of solar energy into electricity. We demonstrate all-optical tuning of light in WSe2-coated microfiber (MF) using WSe2's broad absorption bandwidth and thermo-optic effect. The transmitted optical power (TOP) can be tuned using external incidence pump lasers (405, 532, and 660 nm). The sensitivity under 405-nm pump light excitation is 0.30 dB/mW. A rise/fall time of ~ 15.3/16.9 ms is achieved under 532-nm pump light excitation. Theoretical simulations are performed to investigate the tuning mechanism of TOP. The advantages of this device are easy fabrication, all-optical control, high sensitivity, and fast response. The proposed all-optical tunable device has potential applications in all-optical circuitry, all-optical modulator, and multi-dimensionally tunable optical devices, etc.
RESUMEN
Human cytomegalovirus (HCMV) is a ubiquitous pathogen that can cause disability in newborns and serious clinical diseases in immunocompromised patients. HCMV has a large genome with enormous coding potential; its viral particles are equipped with complicated glycoprotein complexes and can infect a wide range of human cells. Although multiple host cellular receptors interacting with viral glycoproteins have been reported, the mechanism of HCMV infection remains a mystery. Here we report identification of adipocyte plasma membrane-associated protein (APMAP) as a novel modulator active in the early stage of HCMV infection. APMAP is necessary for HCMV infection in both epithelial cells and fibroblasts; knockdown of APMAP expression significantly reduced HCMV infection of these cells. Interestingly, ectopic expression of human APMAP in cells refractory to HCMV infection, such as canine MDCK and murine NIH/3T3 cells, promoted HCMV infection. Furthermore, reduction in viral immediate early (IE) gene transcription at 6 h post infection and delayed nucleus translocation of tegument delivered pp65 at 4 h post infection were detected in APMAP-deficient cells but not in the wildtype cells. These results suggest that APMAP plays a role in the early stage of HCMV infection. Results from biochemical studies of APMAP and HCMV proteins suggest that APMAP could participate in HCMV infection through interaction with gH/gL containing glycoprotein complexes at low pH and mediate nucleus translocation of tegument pp65. Taken together, our results suggest that APMAP functions as a modulator promoting HCMV infection in multiple cell types and is an important player in the complex HCMV infection mechanism.
Asunto(s)
Infecciones por Citomegalovirus/metabolismo , Infecciones por Citomegalovirus/virología , Citomegalovirus/patogenicidad , Glicoproteínas de Membrana/metabolismo , Adipocitos/metabolismo , Adipocitos/virología , Animales , Membrana Celular/metabolismo , Membrana Celular/virología , Citomegalovirus/genética , Citomegalovirus/metabolismo , Infecciones por Citomegalovirus/etiología , Perros , Células Epiteliales/metabolismo , Células Epiteliales/virología , Fibroblastos/metabolismo , Fibroblastos/virología , Técnicas de Inactivación de Genes , Interacciones Microbiota-Huesped , Humanos , Células de Riñón Canino Madin Darby , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/genética , Ratones , Células 3T3 NIH , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Estructurales Virales/metabolismo , Virulencia , Internalización del VirusRESUMEN
Therapeutic strategies are urgently needed for patients with acute myeloid leukemia (AML). Leukocyte immunoglobulin-like receptor B4 (LILRB4), which suppresses T-cell activation and supports tissue infiltration of AML cells, represents an attractive drug target for anti-AML therapeutics. Here, we report the identification and development of an LILRB4-specific humanized mAb that blocks LILRB4 activation. This mAb, h128-3, showed potent activity in blocking the development of monocytic AML in various models including patient-derived xenograft mice and syngeneic immunocompetent AML mice. MAb h128-3 enhanced the anti-AML efficacy of chemotherapy treatment by stimulating mobilization of leukemia cells. Mechanistic studies revealed four concordant modes of action for the anti-AML activity of h128-3: (i) reversal of T-cell suppression, (ii) inhibition of monocytic AML cell tissue infiltration, (iii) antibody-dependent cellular cytotoxicity, and (iv) antibody-dependent cellular phagocytosis. Therefore, targeting LILRB4 with antibody represents an effective therapeutic strategy for treating monocytic AML.
Asunto(s)
Antineoplásicos Inmunológicos/farmacología , Apolipoproteínas E/metabolismo , Transformación Celular Neoplásica/inmunología , Transformación Celular Neoplásica/metabolismo , Leucemia Mieloide Aguda/etiología , Leucemia Mieloide Aguda/metabolismo , Glicoproteínas de Membrana/metabolismo , Receptores Inmunológicos/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Animales , Anticuerpos Bloqueadores , Anticuerpos Monoclonales , Citotoxicidad Celular Dependiente de Anticuerpos , Antineoplásicos Inmunológicos/uso terapéutico , Apolipoproteínas E/química , Apoptosis , Línea Celular , Transformación Celular Neoplásica/efectos de los fármacos , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Humanos , Leucemia Mieloide Aguda/patología , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/química , Ratones , Ratones Noqueados , Modelos Biológicos , Modelos Moleculares , Unión Proteica/efectos de los fármacos , Conejos , Receptores Inmunológicos/antagonistas & inhibidores , Receptores Inmunológicos/química , Relación Estructura-Actividad , Linfocitos T/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
All-optical light amplitude tuning functionality is demonstrated in a layered tungsten disulfide (WS2) nanosheets coated microfiber (MF) structure. Due to the strong light-matter interactions between WS2 nanosheets and the evanescent field around the MF, a large variation in the transmitted power can be observed under both external and internal pump light excitations over a broadband spectrum (~100 nm). A power variation rate of ~0.3744 dB/mW is obtained under external violet pump light excitation, whereas the power variation rate of similar devices in the state of the art are usually less than 0.3 dB/mW. In terms of the response time, a moderate rise/fall time of â¼20.5/19.6 ms is achieved, which is mainly limited by the employed structure fabrication methods. These results indicate that the optical transmitted power of the WS2 coated MF can be modulated by different pump light with the power in the order of mW, thus the proposed device might have potential applications in all optical controllable devices and sensors, etc.