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Cancer Control Research

Abstract

DESCRIPTION (provided by applicant): Immuno-stimulatory (IS) therapy in cancer patients is often more effective when combined with other interventions, and when limiting mechanisms are deactivated. Various stressors, neuroendocrine responses, and cytokines are known to modulate immune competence, and can thus modulate responses to IS agents and potentially dampen their therapeutic efficacy. Here we aim at studying potential interactions between psycho-neuro-immunological (PNI) processes and IS treatments, with the intention of unraveling underlying mechanisms, and potentiating immunotherapy. Our studies will revolve around three interrelated interactions: (1) Psychological stress before and during IS therapy is common in cancer patients, but is rarely simulated in animal models of immunotherapy. Stress responses often reduce TH1 and promote proinflammatory responses, potentially dampening beneficial impact of IS agents and worsening their side effects. (2) The host physiological response to IS agents includes perturbations in cytokines and stress hormones that can suppress cell mediated immunity (CMI) (see Preliminary Studies) and self-limit the efficacy of IS approaches. (3) At critical times, including the immediate post-operative period, successful IS approaches could be rendered ineffective by the clinically well-established suppression of CMI following major surgeries. Supplementing IS approaches with our recently developed PNI-based pharmacological interventions (see Preliminary Studies) can prevent such immune suppression, thus preserving the potential benefits of IS approaches. We propose to study and improve the efficacy of three immunostimulatory agents, IL-12, poly I-C, and CpG oligodeoxynucleotides (ODN), under ongoing social stress conditions and following surgery. Outcomes will include NK activation markers and cytotoxicity, cytokine levels and their induced production, and in vivo resistance to experimental and spontaneous metastasis in rodents (MADB106, B16, and 3LL tumors). Neuroendocrine and cytokine mediators of the deleterious effects of stress and of IS agents will be studied. Integrated protocols of immune stimulation and pharmacological blockade of deleterious stress and cytokine responses will be developed and used during stress, IS treatment, and surgery. The knowledge gained could reduce side effects and enhance the efficacy of immunotherapy before and after surgery, potentially increasing survival rates in cancer patients.