Infection by <i>Salmonella enterica</i> Promotes or Demotes Tumor Development

Cancer is a disease that claims the lives of millions of people every year around the world. To date, multiple risk factors that may contribute to its development have been described. In recent years, a factor that has been associated to cancer development is the presence of bacterial infections that could contribute to its occurrence not only by favoring the inflammatory process, but also through the release of proteins that trigger tumorigenesis. One of the bacterial species that have recently generated interest due to its possible role in cancer development is Salmonella enterica. Nevertheless, for more than a decade, attenuated strains of Salmonella enterica have been proposed as a treatment for different neoplasms due to its bacterium tropism for the tumor microenvironment, its oncolytic activity and its ability to activate the innate and adaptive immune responses of the host. These two facets of Salmonella enterica are addressed in detail in this chapter, allowing us to understand its possible role in cancer development and its well-documented antitumor activity

Lethal iron deprivation induced by non-neutralizing antibodies targeting transferrin receptor 1 in malignant B cells

A number of antibodies have been developed that induce lethal iron deprivation (LID) by targeting the transferrin receptor 1 (TfR1/CD71) and either neutralizing transferrin (Tf) binding, blocking internalization of the receptor and/or inducing its degradation. We have developed recombinant antibodies targeting human TfR1 (ch128.1 and ch128.1Av), which induce receptor degradation and are cytotoxic to certain malignant B-cells. We now show that internalization of TfR1 bound to these antibodies can lead to its sequestration and degradation, as well as reduced Tf uptake, and the induction of a transcriptional response consistent with iron deprivation, which is mediated in part by downstream targets of p53. Cells resistant to these antibodies do not sequester and degrade TfR1 after internalization of the antibody/receptor complex, and accordingly maintain their ability to internalize Tf. These findings are expected to facilitate the rational design and clinical use of therapeutic agents targeting iron import via TfR1 in hematopoietic malignancies.Fil: Rodríguez, José A.. University of California at Los Angeles; Estados UnidosFil: Luria Pérez, Rosendo. University of California at Los Angeles; Estados Unidos. Hospital infantil de México “Federico Gómez”; MéxicoFil: López Valdés, Héctor E.. University of California at Los Angeles; Estados UnidosFil: Casero, David. University of California at Los Angeles; Estados UnidosFil: Daniels, Tracy R.. University of California at Los Angeles; Estados UnidosFil: Patel, Shabnum. University of California at Los Angeles; Estados UnidosFil: Avila, David. University of California at Los Angeles; Estados UnidosFil: Leuchter, Richard. University of California at Los Angeles; Estados UnidosFil: So, Sokuntheavy. University of California at Los Angeles; Estados UnidosFil: Ortiz Sánchez, Elizabeth. University of California at Los Angeles; Estados UnidosFil: Bonavida, Benjamin. University of California at Los Angeles; Estados UnidosFil: Martínez Maza, Otoniel. University of California at Los Angeles; Estados UnidosFil: Charles, Andrew C.. University of California at Los Angeles; Estados UnidosFil: Pellegrini, Matteo. University of California at Los Angeles; Estados UnidosFil: Helguera, Gustavo Fernando. University of California at Los Angeles; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Penichet, Manuel L.. University of California at Los Angeles; Estados Unido

Cancer Immunotherapy: Priming the Host Immune Response with Live Attenuated Salmonella enterica

In recent years, cancer immunotherapy has undergone great advances because of our understanding of the immune response and the mechanisms through which tumor cells evade it. A century after the first immunotherapy attempt based on bacterial products described by William Coley, the use of live attenuated bacterial vectors has become a promising alternative in the fight against cancer. This review describes the role of live attenuated Salmonella enterica as an oncolytic and immunotherapeutic agent, due to its high affinity for tumor tissue and its ability to activate innate and adaptive antitumor immune response. Furthermore, its potential use as delivery system of tumor antigens and immunomodulatory molecules that induce tumor regression is also reviewed

Anticuerpos que reconocen el receptor de transferrina en células tumorales

Iron is essential for cell growth and is imported into cells in part through the action of transferrin (Tf), a protein that binds its receptor (TfR1 or CD71) on the surface of a cell, and then releases iron into endosomes. TfR1 is a single pass type-II transmembrane protein expressed at basal levels in most tissues. High expression of TfR1 is typically associated with rapidly proliferating cells, including various types of cancer. TfR1 is targeted by experimental therapeutics for several reasons: its cell surface accessibility, constitutive endocytosis into cells, essential role in cell growth and proliferation, and its overexpression by cancer cells. Among the therapeutic agents used to target TfR1, antibodies stand out due to their remarkable specificity and affinity. Clinical trials are being conducted to evaluate the safety and efficacy of agents targeting TfR1 in cancer patients with promising results. These observations suggest that therapies targeting TfR1 as direct therapeutics or delivery conduits remain an attractive alternative for the treatment of cancers that overexpress the receptor.El hierro es esencial para el crecimiento celular. Es transportado dentro de las células con la ayuda de la transferrina (Tf), proteína que se une a su receptor (TfR1 o CD71) en la superficie celular y libera el hierro dentro de los endosomas. El TfR1 es una proteína de membrana tipo II que se sobreexpresa en muchos tejidos debido al requerimiento de las células para importar hierro unido a Tf. La sobreexpresión de TfR1 se ha asociado con células que proliferan rápidamente, incluyendo los diferentes tipos de cáncer. El TfR1 se ha empleado como blanco terapéutico por diversos motivos: su accesibilidad a la superficie celular, su capacidad de internalizarse constitutivamente en las células, su papel esencial en el crecimiento y la proliferación celular, así como por su sobreexpresión en las células tumorales proliferantes. Entre los agentes terapéuticos dirigidos contra el TfR1 destacan los anticuerpos, por su alta especificidad, estabilidad y propiedades estructurales. Se han realizado diversos ensayos clínicos para evaluar la seguridad y la eficacia de los anticuerpos que reconocen el TfR1 en pacientes con cáncer y se han obtenido resultados prometedores. Estas observaciones sugieren que las terapias con fundamento en el reconocimiento de TfR1, ya sea como terapia directa o empleados como acarreadores, representan una alternativa muy atractiva de tratamiento contra los diferentes tipos de cáncer que sobreexpresan este receptor.Fil: Luria Pérez, Rosendo. Hospital Infantil de México Federico Gómez; MacaoFil: Helguera, Gustavo Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Rodríguez, José A.. University of California at Los Angeles; Estados Unido

Amino acid residues involved in the heparin-binding activity of murine IL-12 in the context of an antibody-cytokine fusion protein.

An antibody-cytokine fusion protein, composed of the murine single-chain cytokine interleukin-12 (IL-12) genetically fused to a human IgG3 specific for the human tumor-associated antigen HER2/neu maintains antigen binding, cytokine bioactivity, and IL-12 heparin-binding activity. This latter property is responsible for the binding of the cytokine to glycosaminoglycans (GAGs) on the cell surface and the extracellular matrix and has been implicated in modulating IL-12 bioactivity. Previous studies indicate that the p40 subunit of human and murine IL-12 is responsible for the heparin-binding activity of this heterodimeric cytokine. In the present study we used bioinformatic analysis and site-directed mutagenesis to develop a version of the antibody-(IL-12) fusion protein without heparin-binding activity. This was accomplished by replacing the basic arginine (R) and lysine (K) residues in the cluster of amino acids 254-260 (RKKEKMK) of the murine IL-12 p40 subunit by the neutral non-polar amino acid alanine (A), generating an AAAEAMA mutant fusion protein. ELISA and flow cytometry demonstrated that the antibody fusion protein lacks heparin-binding activity but retains antigen binding. A T-cell proliferation assay showed IL-12 bioactivity in this construct. However, the IL-12 bioactivity is decreased compared to its non-mutated counterpart, which is consistent with an ancillary role of the heparin-binding site of IL-12 in modulating its activity. Thus, we have defined a cluster of amino acid residues with a crucial role in the heparin-binding activity of murine IL-12 in the context of an antibody-cytokine fusion protein

Salmonella enterica: un aliado en la terapia contra el cáncer

Salmonella enterica es una especie de bacterias anaeróbicas facultativas que han sido empleadas con gran éxito como vector bacteriano vivo atenuado con fines vacunales. Recientemente se ha documentado que S. enterica tiene propiedades importantes para ser considerada como agente terapéutico contra el cáncer. Estudios preclínicos y clínicos han demostrado que S. enterica coloniza tumores sólidos, semisólidos y metástasis, además de que contribuye a disminuir la resistencia a los tratamientos. En esta revisión se aborda la capacidad de S. enterica atenuada para eliminar células tumorales y su empleo como vector bacteriano vivo acarreador de moléculas heterólogas contra el cáncer

Single-Chain Fragment Variable: Recent Progress in Cancer Diagnosis and Therapy

Cancer remains a public health problem worldwide. Although conventional therapies have led to some excellent outcomes, some patients fail to respond to treatment, they have few therapeutic alternatives and a poor survival prognosis. Several strategies have been proposed to overcome this issue. The most recent approach is immunotherapy, particularly the use of recombinant antibodies and their derivatives, such as the single-chain fragment variable (scFv) containing the complete antigen-binding domains of a whole antibody that successfully targets tumor cells. This review describes the recent progress made with scFvs as a cancer diagnostic and therapeutic tool, with an emphasis on preclinical approaches and their potential use in clinical trials

An Antibody-based Multifaceted Approach Targeting the Human Transferrin Receptor for the Treatment of B-cell Malignancies

We previously developed an antibody-avidin fusion protein (ch128.1Av) targeting the human transferrin receptor 1 (TfR1, also known as CD71), which demonstrates direct in vitro cytotoxicity against malignant hematopoietic cells. This cytotoxicity is attributed to its ability to decrease the level of TfR1 leading to lethal iron deprivation. We now report that ch128.1Av shows the ability to bind the Fc γ receptors and the complement component C1q, suggesting that it is capable of eliciting Fcmediated effector functions such as antibody-dependent cellmediated cytotoxicity and complement-mediated cytotoxicity. In addition, in 2 disseminated multiple myeloma xenograft mouse models, we show that a single dose of ch128.1Av results in significant antitumor activity, including long-term survival. It is interesting to note that the parental antibody without avidin (ch128.1) also shows remarkable in vivo anticancer activity despite its limited in vitro cytotoxicity. Finally, we demonstrate that ch128.1Av is not toxic to pluripotent hematopoietic progenitor cells using the long-term cell-initiating culture assay suggesting that these important progenitors would be preserved in different therapeutic approaches, including the in vitro purging of cancer cells for autologous transplantation and in vivo passive immunotherapy. Our results suggest that ch128.1Av and ch128.1 may be effective in the therapy of human multiple myeloma and potentially other hematopoietic malignancies.Fil: Daniels, Tracy R.. David Geffen School of Medicine; Estados UnidosFil: Ortiz Sanchez, Elizabeth. David Geffen School of Medicine; Estados Unidos. Instituto Nacional de Cancerología; MéxicoFil: Luria Pérez, Rosendo. David Geffen School of Medicine; Estados Unidos. Hospital Infantil de México "Federico Gómez"; MéxicoFil: Quintero, Rafaela. David Geffen School of Medicine; Estados UnidosFil: Helguera, Gustavo Fernando. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. David Geffen School of Medicine; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Bonavida, Benjamin. University of California; Estados UnidosFil: Martinez Maza, Otoniel. University of California; Estados UnidosFil: Penichet, Manuel L.. David Geffen School of Medicine; Estados Unidos. University of California; Estados Unido

Visualization and quantification of cytotoxicity mediated by antibodies using imaging flow cytometry

Conventional approaches for the detection of antibody dependent cell-mediated cytotoxicity (ADCC) activity rely on quantification of the release of traceable compounds from target cells or flow cytometry analysis of population-wide phenomena. We report a new method for the direct imaging and quantification of ADCC of cancer cells. The proposed method using imaging flow cytometry combines the statistical power of flow cytometry with the analytical advantages of cell imaging, providing a novel and more comprehensive perspective of effector/target cell interactions during ADCC events. With this method we can quantify and show in detail the morphological changes in target and effector cells, their apoptotic index, the physical interaction between effector and target cells, and a directional transfer of cytosolic contents from effector to target cells. As a model system we used the therapeutic anti-CD20 antibody rituximab to target CFSE labeled Ramos human Burkitt's lymphoma cells, to CMTPX-labeled human monocytic U-937 effector cells. We expect that similar studies using different effector and target cell populations may contribute to the pre-clinical evaluation of therapeutic antibodies and help to identify mechanisms that could be beneficial in the immunotherapy of cancer.Fil: Helguera, Gustavo Fernando. University of California; Estados Unidos. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Rodríguez, José A.. University of California; Estados UnidosFil: Luria Pérez, Rosendo. University of California; Estados Unidos. Hospital infantil de México “Federico Gómez”; MéxicoFil: Henery, Shannon. Amnis Corporation; Estados UnidosFil: Catterton, Paul. Amnis Corporation; Estados UnidosFil: Bregni, Carlos . Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: George, Thaddeus C.. Amnis Corporation; Estados UnidosFil: Martínez Maza, Otoniel. University of California; Estados UnidosFil: Penichet, Manuel L.. University of California; Estados Unido