Effective immune surveillance is essential for maintaining protection and homeostasis of peripheral tissues. However, mechanisms controlling memory T cell migration to peripheral tissues such as the skin are poorly understood. Here, we show that the majority of human T cells in healthy skin express the chemokine receptor CCR8 and respond to its selective ligand I-309/CCL1. These CCR8+ T cells are absent in small intestine and colon tissue, and are extremely rare in peripheral blood, suggesting healthy skin as their physiological target site. Cutaneous CCR8+ T cells are preactivated and secrete proinflammatory cytokines such as tumor necrosis factor–α and interferon-γ, but lack markers of cytolytic T cells. Secretion of interleukin (IL)-4, IL-10, and transforming growth factor–β was low to undetectable, arguing against a strict association of CCR8 expression with either T helper cell 2 or regulatory T cell subsets. Potential precursors of skin surveillance T cells in peripheral blood may correspond to the minor subset of CCR8+CD25− T cells. Importantly, CCL1 is constitutively expressed at strategic cutaneous locations, including dermal microvessels and epidermal antigen-presenting cells. For the first time, these findings define a chemokine system for homeostatic T cell traffic in normal human skin.

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Normal (noninflamed) human skin contains a network of lymphocytes, but little is known about the homing and function of these cells. The majority of αβ T cells in normal skin express CCR8 and produce proinflammatory cytokines. In this study we examined other subsets of cutaneous lymphocytes, focusing on those with potential function in purging healthy tissue of transformed and stressed cells. Human dermal cell suspensions contained significant populations of Vδ1+ γδ T cells and CD56+CD16− NK cells, but lacked the subsets of Vδ2+ γδ T cells and CD56+CD16+ NK cells, which predominate in peripheral blood. The skin-homing receptors CCR8 and CLA were expressed by a large fraction of both cell types, whereas chemokine receptors associated with lymphocyte migration to inflamed skin were absent. Neither cell type expressed CCR7, although γδ T cells up-regulated this lymph node-homing receptor upon TCR triggering. Stimulation of cutaneous Vδ1+ γδ T cell lines induced secretion of large amounts of TNF-α, IFN-γ, and the CCR8 ligand CCL1. In contrast to cutaneous αβ T cells, both cell types had the capacity to produce intracellular perforin and displayed strong cytotoxic activity against melanoma cells. We therefore propose that γδ T cells and NK cells are regular constituents of normal human skin with potential function in the clearance of tumor and otherwise stressed tissue cells.

FoxP3 is a member of the forkhead family of transcription factors critically involved in the development and function of CD25

Dendritic cells (DCs) are major constituents of peripheral tissues, where they control immunity to foreign and self-antigens. The process of continuous DC renewal under homeostatic conditions is largely undefined. Here, we demonstrate that CD14+ DC precursors, either derived from CD34+ hematopoietic progenitor cells or isolated from blood, were attracted by the chemokine CXCL14, which is constitutively produced in healthy skin and other epithelial tissues. In a tissue model we show that human epidermal equivalents profoundly affected CD14+ DC precursors, including their suprabasal positioning and survival as well as their differentiation into Langerhans cell-like cells with potent antigen-presentation functions. Our model assigns unprecedented roles to CXCL14 and epidermal tissue as attractant and niche of differentiation, respectively, in the renewal of Langerhans cells under steady-state conditions.

Glioblastoma is the deadliest form of brain cancer. Aside from inadequate treatment options, one of the main reasons glioblastoma is so lethal is the rapid growth of tumour cells coupled with continuous cell invasion into surrounding healthy brain tissue. Significant intra- and inter-tumour heterogeneity associated with differences in the corresponding tumour microenvironments contributes greatly to glioblastoma progression. Within this tumour microenvironment, the extracellular matrix profoundly influences the way cancer cells become invasive, and changes to extracellular (pH and oxygen levels) and metabolic (glucose and lactate) components support glioblastoma growth. Furthermore, studies on clinical samples have revealed that the tumour microenvironment is highly immunosuppressive which contributes to failure in immunotherapy treatments. Although technically possible, many components of the tumour microenvironment have not yet been the focus of glioblastoma therapies, despite growing evidence of its importance to glioblastoma malignancy. Here, we review recent progress in the characterisation of the glioblastoma tumour microenvironment and the sources of tumour heterogeneity in human clinical material. We also discuss the latest advances in technologies for personalised and in vitro preclinical studies using brain organoid models to better model glioblastoma and its interactions with the surrounding healthy brain tissue, which may play an essential role in developing new and more personalised treatments for this aggressive type of cancer.

Purpose: NY-ESO-1 is a highly immunogenic antigen expressed in a variety of malignancies, making it an excellent target for cancer vaccination. We recently developed a vaccine consisting of full-length recombinant NY-ESO-1protein formulated with ISCOMATRIX adjuvant, which generated strong humoral and T-cell^mediated immune responses and seemed to reduce the risk of disease relapse in patients with fully resected melanoma. This study examines the clinical and immunologic efficacy of the same vaccine in patients with advanced metastatic melanoma. Experimental Design: Delayed-typehypersensitivity responses, circulating NY-ESO-1^specific CD4 + and CD8 + Tcells, and proportions of regulatory Tcells (Treg) were assessed in patients. Results: In contrast to patients with minimal residual disease, advanced melanoma patients showed no clinical responses to vaccination. Although strong antibody responses were mounted, the generation of delayed-type hypersensitivity responses was significantly impaired.The proportion of patients with circulating NY-ESO-1^specific CD4 + Tcells was also reduced, and although many patients had CD8 + T cells specific to a broad range of NY-ESO-1epitopes, the majority of these responses were preexisting. Tregs were enumerated in the blood by flow cytometric detection of cells with a CD4

Summary Since the early 1990s, numerous cancer Ag have been defined and for a handful of these there is now some clinical experience, which has made it possible to assess their value as targets for cancer immunotherapy. The cancer-testis Ag have been particularly attractive because their expression is limited to cancer and virtually no nonmalignant cells apart from germ cells and trophoblast. Among these, NY-ESO-1 has been the focus of our attention. The exceptional immunogenicity of this Ag coupled with its widespread distribution among many cancer types make it a very good vaccine candidate, with the potential to be used in vaccines against many types of malignancies. This article reviews emerging knowledge about the biology of NY-ESO-1 and experience with the early clinical development of vaccines directed against NY-ESO-1. These early studies have yielded a wealth of information about the immunology of NY-ESO-1 and set the scene for future clinical strategies for immune targeting of cancer.Key words: cancer immunology, cancer-testis Ag, cancer vaccine, dendritic cell, ISCOMATRIX, NY-ESO-1. Biology of NY-ESO-1NY-ESO-1 was first discovered using 'SERological identification of antigens by recombinant EXpression cloning' (SEREX). This is a method used for identifying the antibody repertoire of cancer-bearing patients by screening their serum against an expression library that typically displays protein Ag derived from a cancer source such as an autologous tumour or a cell line. In this case, NY-ESO-1 was found by using serum from a patient with squamous cell carcinoma (SCC) of the oesophagus. 1,2 Expression of NY-ESO-1 protein has been shown in multiple cancer types (Table 1), as well as in spermatogonia, oogonia and placenta. 3,4 Although NY-ESO-1 mRNA expression has been detected at low levels in some other normal tissues, it is unclear whether this is significant in the absence of detectable protein. 4,5 Other genes with similar names (NY-ESO-2, -3, -4, -5, -6, -7, -8) have no homology with NY-ESO-1. 2 The NY-ESO-1 gene is located on chromosome Xq28, 1 which carries a disproportionately high number of cancertestis (CT) Ag genes. 6 Up to 10% of the genes on chromosome X are CT Ag genes. The expression of these genes seems to be related to the demethylation of the promoter regions because experimental demethylation leads to the upregulation of CT Ag expression. [7][8][9][10][11][12][13][14][15][16][17][18] The NY-ESO-1 gene encodes a protein of 180 amino acids with M r 18 kDa, 2 which is expressed primarily in the cytoplasm although nuclear expression can be seen in some spermatogonia. 4 A homologue of NY-ESO-1, termed LAGE-1, was identified using representational difference analysis. 14 LAGE-1 and NY-ESO-1 are 84-89% homologous at the protein level. 14 Alternative splicing of LAGE-1 mRNA leads to the expression of two major transcripts encoding proteins of 210 and 180 amino acids, respectively. LAGE-1 is expressed in a wide variety of cancers (Table 1), usually, but not always, in conjunction with NY-ESO-1 or ...