Interleukin-21 enhances rituximab activity in a cynomolgus monkey model of B cell depletion and in mouse B cell lymphoma models.

Rituximab, a monoclonal antibody targeting CD20 on B cells, is currently used to treat many subtypes of B cell lymphomas. However, treatment is not curative and response rates are variable. Recombinant interleukin-21 (rIL-21) is a cytokine that enhances immune effector function and affects both primary and transformed B cell differentiation.

Comparison of vascular leak syndrome in mice treated with IL21 or IL2.

Interleukin 21 (IL21) is a T-cell-derived 4-helix-bundle cytokine that has sequence homology to the IL2 family. Recombinant human interleukin 2 (rIL2) is approved for the treatment of metastatic melanoma and renal cell carcinoma. However, toxicity of rIL2, including induction of vascular leak syndrome (VLS), has limited use of this cytokine to a small proportion of eligible patients.

A dual-targeting PDGFRbeta/VEGF-A molecule assembled from stable antibody fragments demonstrates anti-angiogenic activity in vitro and in vivo.

Targeting angiogenesis is a promising approach to the treatment of solid tumors and age-related macular degeneration (AMD). Inhibition of vascularization has been validated by the successful marketing of monoclonal antibodies (mAbs) that target specific growth factors or their receptors, but there is considerable room for improvement in existing therapies. Combination of mAbs targeting both the VEGF and PDGF pathways has the potential to increase the efficacy of anti-angiogenic therapy without the accompanying toxicities of tyrosine kinase inhibitors and the inability to combine efficiently with traditional chemotherapeutics.

Endogenous IL-21 restricts CD8+ T cell expansion and is not required for tumor immunity.

IL-21 has antitumor activity through actions on NK cells and CD8(+) T cells, and is currently in clinical development for the treatment of cancer. However, no studies have addressed the role of endogenous IL-21 in tumor immunity. In this study, we have studied both primary and secondary immune responses in IL-21(-/-) and IL-21R(-/-) mice against several experimental tumors.

Interleukin 21 enhances antibody-mediated tumor rejection.

Interleukin-21 (IL-21) is a cytokine with structural and sequence homology to IL-2 and IL-15 that has antitumor activity alone in mouse experimental tumor models and a tolerable safety profile in phase I trials in patients with metastatic melanoma and renal cell carcinoma. Several monoclonal antibodies (mAb) targeted at tumor-associated antigens also have improved antitumor activities in mice when used in combination with IL-21. Recently, we described a rational three antibody-based approach (triple mAb, TrimAb) to eradicating established mouse tumors that required the generation of tumor-reactive CD8(+) T cells and IFN-gamma.

Interleukin 21: combination strategies for cancer therapy.

In the past 20 years researchers have attempted to activate the host immune defence system to kill tumour cells and eradicate cancer. In some cases, the response of patients to immunotherapy has been extremely successful; however, other trials have shown disappointing results, and so there is a clear need for more effective therapies that can effectively adjunct conventional approaches. Interleukin 21 (IL21) is a new immune-stimulating cytokine that has demonstrated antitumour activity in several preclinical models, and has recently undergone Phase I trials in metastatic melanoma and renal cell carcinoma.

Interleukin-21 signaling: functions in cancer and autoimmunity.

Interleukin-21 (IL-21) is a cytokine with structural and sequence homology to IL-2 and IL-15, yet possesses several biological properties distinct from these cytokines. IL-21 is produced mainly by activated CD4(+) T cells and natural killer T cells and mediates its activity by binding to the IL-21 receptor (IL-21R), consisting of an IL-21-specific alpha chain (IL-21Ralpha; JAK/STAT) that heterodimerizes with the common gamma chain (CD132). Intracellular signaling occurs through the Janus-activated kinase/signal transducer and activator of transcription pathways.

IL-21 enhances tumor rejection through a NKG2D-dependent mechanism.

IL-21 is a cytokine that can promote the anti-tumor responses of the innate and adaptive immune system. Mice treated with IL-21 reject tumor cells more efficiently, and a higher percentage of mice remain tumor-free compared with untreated controls. In this study, we demonstrate that in certain tumor models IL-21-enhanced tumor rejection is NKG2D dependent.

Interleukin-21 is a T-helper cytokine that regulates humoral immunity and cell-mediated anti-tumour responses.

Cytokines and their receptors represent key targets for therapeutic intervention. Ligands are being used to supplement cell numbers that become depleted as a result of disease (organ failure, infection) or subsequent disease treatments (i.e.

Cytokine requirements for acute and Basal homeostatic proliferation of naive and memory CD8+ T cells.

Both naive and memory T cells undergo antigen-independent proliferation after transfer into a T cell-depleted environment (acute homeostatic proliferation), whereas only memory T cells slowly divide in a full T cell compartment (basal proliferation). We show, first, that naive and memory CD8+ T cells have different cytokine requirements for acute homeostatic proliferation. Interleukin (IL)-7 receptor(R)alpha-mediated signals were obligatory for proliferation of naive T cells in lymphopenic hosts, whereas IL-15 did not influence their division.