RESUMEN
Classic major histocompatibility complex class I (MHC-I) presentation relies on shuttling cytosolic peptides into the endoplasmic reticulum (ER) by the transporter associated with antigen processing (TAP). Viruses disable TAP to block MHC-I presentation and evade cytotoxic CD8+ T cells. Priming CD8+ T cells against these viruses is thought to rely solely on cross-presentation by uninfected TAP-functional dendritic cells. We found that protective CD8+ T cells could be mobilized during viral infection even when TAP was absent in all hematopoietic cells. TAP blockade depleted the endosomal recycling compartment of MHC-I molecules and, as such, impaired Toll-like receptor-regulated cross-presentation. Instead, MHC-I molecules accumulated in the ER-Golgi intermediate compartment (ERGIC), sequestered away from Toll-like receptor control, and coopted ER-SNARE Sec22b-mediated vesicular traffic to intersect with internalized antigen and rescue cross-presentation. Thus, when classic MHC-I presentation and endosomal recycling compartment-dependent cross-presentation are impaired in dendritic cells, cell-autonomous noncanonical cross-presentation relying on ERGIC-derived MHC-I counters TAP dysfunction to nevertheless mediate CD8+ T cell priming.
Asunto(s)
Transportador de Casetes de Unión a ATP, Subfamilia B, Miembro 2/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismo , Linfocitos T CD8-positivos/inmunología , Reactividad Cruzada , Células Dendríticas/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/virología , Transportador de Casetes de Unión a ATP, Subfamilia B, Miembro 2/genética , Transportadoras de Casetes de Unión a ATP/genética , Animales , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/virología , Proliferación Celular , Células Cultivadas , Técnicas de Cocultivo , Células Dendríticas/metabolismo , Células Dendríticas/virología , Modelos Animales de Enfermedad , Retículo Endoplásmico/inmunología , Retículo Endoplásmico/metabolismo , Retículo Endoplásmico/virología , Femenino , Aparato de Golgi/inmunología , Aparato de Golgi/metabolismo , Aparato de Golgi/virología , Antígenos de Histocompatibilidad Clase I/metabolismo , Interacciones Huésped-Patógeno , Humanos , Virus de la Influenza A/patogenicidad , Activación de Linfocitos , Masculino , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Infecciones por Orthomyxoviridae/genéticaRESUMEN
Redirecting T cells to specifically kill malignant cells has been validated as an effective anti-cancer strategy in the clinic with the approval of blinatumomab for acute lymphoblastic leukemia. However, the immunosuppressive nature of the tumor microenvironment potentially poses a significant hurdle to T cell therapies. In hematological malignancies, the bone marrow (BM) niche is protective to leukemic stem cells and has minimized the efficacy of several anti-cancer drugs. In this study, we investigated the impact of the BM microenvironment on T cell redirection. Using bispecific antibodies targeting specific tumor antigens (CD123 and BCMA) and CD3, we observed that co-culture of acute myeloid leukemia or multiple myeloma cells with BM stromal cells protected tumor cells from bispecific antibody-T cell-mediated lysis in vitro and in vivo. Impaired CD3 redirection cytotoxicity was correlated with reduced T cell effector responses and cell-cell contact with stromal cells was implicated in reducing T cell activation and conferring protection of cancer cells. Finally, blocking the VLA4 adhesion pathway in combination with CD3 redirection reduced the stromal-mediated inhibition of cytotoxicity and T cell activation. Our results lend support to inhibiting VLA4 interactions along with administering CD3 redirection therapeutics as a novel combinatorial regimen for robust anti-cancer responses.
Asunto(s)
Antineoplásicos Inmunológicos/farmacología , Médula Ósea/efectos de los fármacos , Complejo CD3/inmunología , Integrina alfa4beta1/antagonistas & inhibidores , Leucemia Mieloide Aguda/tratamiento farmacológico , Mieloma Múltiple/tratamiento farmacológico , Animales , Anticuerpos Biespecíficos/farmacología , Anticuerpos Biespecíficos/uso terapéutico , Antineoplásicos Inmunológicos/uso terapéutico , Antígeno de Maduración de Linfocitos B/antagonistas & inhibidores , Antígeno de Maduración de Linfocitos B/inmunología , Médula Ósea/inmunología , Médula Ósea/patología , Complejo CD3/antagonistas & inhibidores , Línea Celular Tumoral , Femenino , Humanos , Integrina alfa4beta1/inmunología , Subunidad alfa del Receptor de Interleucina-3/antagonistas & inhibidores , Subunidad alfa del Receptor de Interleucina-3/inmunología , Leucemia Mieloide Aguda/inmunología , Leucemia Mieloide Aguda/patología , Ratones , Mieloma Múltiple/inmunología , Mieloma Múltiple/patología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/patología , Microambiente Tumoral/efectos de los fármacosRESUMEN
CD33 is expressed in 90% of patients with acute myeloid leukemia (AML), and its extracellular portion consists of a V domain and a C2 domain. A recent study showed that a single nucleotide polymorphism (SNP), rs12459419 (C > T), results in the reduced expression of V domain-containing CD33 and limited efficacy of V domain-binding anti-CD33 antibodies. We developed JNJ-67571244, a novel human bispecific antibody capable of binding to the C2 domain of CD33 and to CD3, to induce T-cell recruitment and CD33+ tumor cell cytotoxicity independently of their SNP genotype status. JNJ-67571244 specifically binds to CD33-expressing target cells and induces cytotoxicity of CD33+ AML cell lines in vitro along with T-cell activation and cytokine release. JNJ-67571244 also exhibited statistically significant antitumor activity in vivo in established disseminated and subcutaneous mouse models of human AML. Furthermore, this antibody depletes CD33+ blasts in AML patient blood samples with concurrent T-cell activation. JNJ-67571244 also cross-reacts with cynomolgus monkey CD33 and CD3, and dosing of JNJ-67571244 in cynomolgus monkeys resulted in T-cell activation, transient cytokine release, and sustained reduction in CD33+ leukocyte populations. JNJ-67571244 was well tolerated in cynomolgus monkeys up to 30 mg/kg. Lastly, JNJ-67571244 mediated efficient cytotoxicity of cell lines and primary samples regardless of their SNP genotype status, suggesting a potential therapeutic benefit over other V-binding antibodies. JNJ-67571244 is currently in phase 1 clinical trials in patients with relapsed/refractory AML and high-risk myelodysplastic syndrome.
Asunto(s)
Leucemia Mieloide Aguda , Linfocitos T , Animales , Dominios C2 , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Macaca fascicularis , Lectina 3 Similar a Ig de Unión al Ácido Siálico/genética , Linfocitos T/metabolismoRESUMEN
Adaptation of the endoplasmic reticulum (ER) pathway for MHC class I (MHC-I) presentation in dendritic cells enables cross-presentation of peptides derived from phagocytosed microbes, infected cells, or tumor cells to CD8 T cells. How these peptides intersect with MHC-I molecules remains poorly understood. Here, we show that MHC-I selectively accumulate within phagosomes carrying microbial components, which engage Toll-like receptor (TLR) signaling. Although cross-presentation requires Sec22b-mediated phagosomal recruitment of the peptide loading complex from the ER-Golgi intermediate compartment (ERGIC), this step is independent of TLR signaling and does not deliver MHC-I. Instead, MHC-I are recruited from an endosomal recycling compartment (ERC), which is marked by Rab11a, VAMP3/cellubrevin, and VAMP8/endobrevin and holds large reserves of MHC-I. While Rab11a activity stocks ERC stores with MHC-I, MyD88-dependent TLR signals drive IκB-kinase (IKK)2-mediated phosphorylation of phagosome-associated SNAP23. Phospho-SNAP23 stabilizes SNARE complexes orchestrating ERC-phagosome fusion, enrichment of phagosomes with ERC-derived MHC-I, and subsequent cross-presentation during infection.
Asunto(s)
Presentación de Antígeno , Endosomas/metabolismo , Fagosomas/metabolismo , Receptores Toll-Like/metabolismo , Animales , Células Dendríticas/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Tejido Linfoide , Ratones , Ovalbúmina/inmunología , Fagocitosis , Fosforilación , Transporte de Proteínas , Proteínas Qb-SNARE/metabolismo , Proteínas Qc-SNARE/metabolismo , Receptores Toll-Like/inmunología , Proteínas de Unión al GTP rab/metabolismoRESUMEN
Cross-presentation involves the presentation of peptides derived from internalized cargo on major histocompatibility complex class I molecules by dendritic cells, a process critical for tolerance and immunity. Detailed studies of the pathways mediating cross-presentation have revealed that this process takes place in a specialized subcellular compartment with a unique set of proteins. In this review, we focus on the recently appreciated role for intracellular vesicular traffic, which serves to equip compartments such as endosomes and phagosomes with the necessary apparatus for conducting the various steps of cross-presentation. We also consider how these pathways may integrate with inflammatory signals particularly from pattern recognition receptors that detect the presence of microbial components during infection. We discuss the consequences of such signals on initiating cross-presentation to stimulate adaptive CD8 T cell responses.