Until recently, the intrinsically high level of cross-talk between immune cells, the complexity of immune cell development, and the pleiotropic nature of cytokine signaling have hampered progress in understanding the mechanisms of immunosuppression by which tumor cells circumvent native and adaptive immune responses. One technology that has helped to shed light on this complex signaling network is the cytokine antibody array, which facilitates simultaneous screening of dozens to hundreds of secreted signal proteins in complex biological samples. The combined applications of traditional methods of molecular and cell biology with the high-content, high-throughput screening capabilities of cytokine antibody arrays and other multiplexed immunoassays have revealed a complex mechanism that involves multiple cytokine signals contributed not just by tumor cells but by stromal cells and a wide spectrum of immune cell types. This review will summarize the interactions among cancerous and immune cell types, as well as the key cytokine signals that are required for tumors to survive immunoediting in a dormant state or to grow and spread by escaping it. Additionally, it will present examples of how probing secreted cell-cell signal networks in the tumor microenvironment (TME) with cytokine screens have contributed to our current understanding of these processes and discuss the implications of this understanding to antitumor therapies.

Abstract-Time Reversal Multiple Signal Classification (TR-MUSIC) method is studied and adapted for the detection and localization of multiple targets behind the wall in this paper. TR-MUSIC does not involve the FDTD solver for the implementation of the backpropagation of the time reversed field and is very computational efficient. The Green's function vectors for the computation of the TR-MUSIC pseudo-spectrum is efficiently evaluated with the saddle point method for a homogeneous wall. By employing the null space of the multistatic response matrix, simultaneous localization of multiple targets behind the wall can be achieved by TR-MUSIC method. Numerical results are presented to show the effectiveness of throughthe-wall imaging (TWI) with TR-MUSIC method.

The T cell system plays an essential role in infections, allergic reactions, tumor and transplant rejection, as well as autoimmune diseases. It does so by the selective engagement of different antigen-specific effector cell lineages that differentially secrete cytokines and other effector molecules. These T cell subsets may or may not have cytolytic activity, can preferentially migrate to different tissues, and display variable capabilities to expand clonally. The quest of T cell immune diagnostics is to understand which specific effector function and T cell lineage is associated with a given clinical outcome, be it positive or adverse. No single assay can measure all of the relevant parameters. In this chapter, we review the unique contributions that ELISPOT assays can make toward understanding T cell-mediated immunity. ELISPOT assays have an unsurpassed sensitivity in detecting low frequency antigen-specific T cells that secrete effector molecules, including granzyme and perforin. They provide robust, highly reproducible data - even by first time users. Because ELISPOT assays require roughly tenfold less cell material than flow cytometry, ELISPOT is ideally suited for all measurements requiring parallel testing under multiple conditions. These include defining (a) T cell reactivity to individual peptides of extensive libraries, thereby establishing the fine-specificity of the response, and determinant mapping; (b) reactivity to different concentrations of the antigen in serial dilutions to measure the avidity of the T cell response; or (c) different secretory products released by T cells which define their respective effector lineage/functions. Further, because T cells survive ELISPOT assays unaffected, they can be retested for the acquisition of additional information in follow-up assays. These strengths of ELISPOT assays the weaknesses of flow cytometry-based measurements. Thus, the two assays systems compliment each other in the quest to understand T cell-mediated immunity in vivo.

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For immune diagnostic purposes it would be critical to be able to distinguish between ongoing immune processes, such as active infections, and long-term immune memory, for example imprinted by infections that have been cleared a long time ago or by vaccinations. We tested the hypothesis that the secretion of Granzyme B, as detected in ex vivo ELISPOT assays, permits this distinction. We studied EBV-, flu-and CMV-specific CD8 + cells in healthy individuals, Vaccinia virus-reactive CD8 + cells in the course of vaccination, and HIV-specific CD8 + cells in HIV-infected individuals. Antigen-specific ex vivo GzB production was detected only transiently after Vaccinia immunization, and in HIV-infected individuals. Our data suggest that ex vivo ELISPOT measurements of granzyme B permit the identification of actively ongoing CD8 + cell responses -a notion that is pertinent to the immune diagnostic of infections, transplantation, allergies, autoimmune diseases, tumors, and vaccine development.