Sparse distribution of gamma/delta T lymphocytes around human epithelial tumors predominantly infiltrated by primed/memory T cells

Human MCS5A1 candidate breast cancer susceptibility gene FBXO10 is induced by cellular stress and correlated with lens epithelium-derived growth factor (LEDGF)

Genetic variation and candidate genes associated with breast cancer susceptibility have been identified. Identifying molecular interactions between associated genetic variation and cellular proteins may help to better understand environmental risk. Human MCS5A1 breast cancer susceptibility associated SNP rs7042509 is located in F-box protein 10 (FBXO10). An orthologous Rattus norvegicus DNA-sequence that contains SNV ss262858675 is located in rat Mcs5a1, which is part of a mammary carcinoma susceptibility locus controlling tumor development in a non-mammary cell-autonomous manner via an immune cell-mediated mechanism. Higher Fbxo10 expression in T cells is associated with Mcs5a increased susceptibility alleles. A common DNA-protein complex bound human and rat sequences containing MCS5A1/Mcs5a1 rs7042509/ss262858675 in electrophoretic mobility shift assays (EMSAs). Lens epithelium-derived growth factor (LEDGF), a stress-response protein, was identified as a candidate to bind both human and rat sequences using DNA-pulldown and mass spectrometry. LEDGF binding was confirmed by LEDGF-antibody EMSA and chromatin immunoprecipitation (ChIP). Ectopic expression of LEDGF/p75 increased luciferase activities of co-transfected reporters containing both human and rat orthologs. Over-expressed LEDGF/p75 increased endogenous FBXO10 mRNA levels in Jurkat cells, a human T-cell line, implying LEDGF may be involved in increasing FBXO10 transcript levels. Oxidative and thermal stress of Jurkat cells increased FBXO10 and LEDGF expression, further supporting a hypothesis that LEDGF binds to a regulatory region of FBXO10 and increases expression during conditions favoring carcinogenesis. We conclude that FBXO10, a candidate breast cancer susceptibility associated gene, is induced by cellular stress and LEDGF may play a role in expression of this gene.

The tumor microenvironment: a pitch for multiple players

The cancer microenvironment may be conceptually regarded as a pitch where the main players are resident and non-resident cellular components, each covering a defined role and interconnected by a complex network of soluble mediators. The crosstalk between these cells and the tumor cells within this environment crucially determines the fate of tumor progression. Immune cells that infiltrate the tumor bed are transported there by blood circulation and exert a variety of effects, either counteracting or favoring tumor outgrowth. Here, we review and discuss the multiple populations composing the tumor bed, with special focus on immune cells subsets that positively or negatively dictate neoplastic progression. In this scenario, the contribution of cancer stem cells within the tumor microenvironment will also be discussed. Finally, we illustrate recent advances on new integrated approaches to investigate the tumor microenvironment in vitro.

Gamma-delta T-cells in patients with squamous cell carcinoma of the head and neck

In our attempt to characterize a general immune-suppression found in patients with squamous cell carcinoma of the head and neck (SCCHN) we now focused on a subset of CD3 lymphocytes described as gamma/delta-T-cells, a cell type with potential relevance in non-MHC restricted anti-tumor immune responses. Peripheral blood of 33 SCCHN patients and 33 age-matched controls (CON) was evaluated for the frequency of gamma/delta-T-cells among CD3+ T-cells and their onset of apoptosis (Annexin V binding) by multicolor flow cytometry. Results were correlated with clinical parameters. Patients with SCCHN had a significantly higher proportion of gamma/delta-T-cells compared to healthy controls (4.4+/-0.4% for SCCHN vs. 3.0+/-0.3% for CON, p=0.01). However, this increase was not paralleled with a difference in the onset of apoptosis if compared to CON. There was also no correlation between the proportion of gamma/delta-T-cells and tumor stage. However, a significantly higher proportion of gamma/delta-T-cells was found in patients with recurrent or metachronous second primary SCCHN (6.0+/-1.0%) if compared to the other SCCHN (3.8+/-0.4%, p=0.02). In a follow up 3-6 months post-treatment patients showed a decrease of gamma/delta-T-cells among CD3+cells (2.7+/-0.4%, n=4) if they were operated only and an increase if primary radio-chemotherapy (6.7+/-1.7%, n=8) or a combination of operation plus radio-chemotherapy (6.8+/-2.3%, n=3) was applied. Furthermore, patients receiving palliative treatment including radio-chemotherapy had highest values of gamma/delta-T-cells (9.1+/-2.7%, n=4) overall implicating that the treatment modality significantly influences the proportion of gamma/delta-T-cells. Since patients with SCCHN, particularly those with recurrent or second primary disease after treatment, had a higher proportion of gamma/delta-T-cells without signs of a reduced onset of apoptosis this could be due to an increased de novo generation. The current study implies that increased frequencies of gamma/delta-T-cells in patients with SCCHN may not only be the result of tumor-host interactions but the consequence of applied treatment modalities.

Distinct subpopulations of gamma delta T cells are present in normal and tumor-bearing human liver

Gamma delta T cells are thought to mediate immune responses at epithelial surfaces. We have quantified and characterized hepatic and peripheral blood gamma delta T cells from 11 normal and 13 unresolved tumor-bearing human liver specimens. gamma delta T cells are enriched in normal liver (6.6% of T cells) relative to matched blood (0.9%; P = 0.008). The majority express CD4(-)CD8(-) phenotypes and many express CD56 and/or CD161. In vitro, hepatic gamma delta T cells can be induced to kill tumor cell lines and release interferon-gamma, tumor necrosis factor-alpha, interleukin-2 and interleukin-4. Analysis of V gamma and V delta chain usage indicated that V delta 3(+) cells are expanded in normal livers (21.2% of gamma delta T cells) compared to blood (0.5%; P = 0.001). Tumor-bearing livers had significant expansions and depletions of gamma delta T cell subsets but normal cytolytic activity. This study identifies novel populations of liver T cells that may play a role in immunity against tumors.

Immune surveillance of mammary tissue by phagocytic cells

The leukocytes in milk consist of lymphocytes, neutrophil polymorphonuclear leukocytes (PMN) and macrophages. Lymphocytes together with antigen-presenting cells function in the generation of an effective immune response. Lymphocytes can be divided into two distinct subsets, T- and B-lymphocytes, that differ in function and protein products. The professional phagocytic cells of the bovine mammary gland are PMN and macrophages. In the normal mammary gland macrophages are the predominate cells which act as sentinels to invading mastitis causing pathogens. Once the invaders are detected, macrophages release chemical messengers called chemoattractants that cause the directed migration of PMN into the infection. Migration of neutrophils into mammary tissue provides the first immunological line of defense against bacteria that penetrate the physical barrier of the teat canal. However, their presence is like a double-edged sword. While the PMN are phagocytosing and destroying the invading pathogens, they inadvertently release chemicals which induces swelling of secretory epithelium cytoplasm, sloughing of secretory cells, and decreased secretory activity. Permanent scarring will result in a loss of milk production. Resident and newly migrated macrophages help reduce the damage to the epithelium by phagocytosing PMN that undergo programmed cell death through a process called apoptosis. Specific ligands on the neutrophil surface are required for directed migration and phagocytosis. In response to infection, freshly migrated leukocytes express greater numbers of cell surface receptors for immunoglobulins and complement and are more phagocytic than their counterparts in blood. However, phagocytic activity rapidly decreases with continued exposure to inhibitory factors such as milk fat globules and casein in mammary secretions. Compensatory hypertrophy in non-mastitic quarters partially compensates for lost milk production in diseased quarters. Advances in molecular biology are making available the tools, techniques, and products to study and modulate host-parasite interactions. For example the cloning and expression of proteins that bind endotoxin may provide ways of reducing damaging effects of endotoxin during acute coliform mastitis. The successful formation of bifunctional monoclonal antibodies for the targeted lysis of mastitis causing bacteria represents a new line of therapeutics for the control of mastitis in dairy cows.

Immunobiology of the mammary gland

The mammary gland is a complex organ that provides neonatal offspring with milk for nourishment and disease resistance. Specific and innate immune factors associated with mammary gland tissues and secretion also play a vital role in protecting the gland from infectious disease. Through genetic selection and technological advances in milk removal, the bovine mammary gland yields for more milk than is needed to nourish the newborn calf. This excess is the basis of the dairy industry. Factors associated with the intense management of dairy cattle can profoundly affect mammary gland immunity and the ability of the host to resist mastitis. Technological advances in immunology have led to the availability of new research tools that can facilitate the study of mammary gland immunity and disease pathogenesis. In recent years, considerable research effort has focused on enhancing the natural defense mechanisms of the mammary gland during periods of heightened susceptibility to disease. This paper provides a comprehensive overview of mammary gland immunity with special emphasis on the bovine system. The underlying mechanisms of disease susceptibility and development of potential immunoregulatory strategies to control mastitis are discussed.

Activated gamma/delta T lymphocytes infiltrating renal cell carcinoma

Gamma/delta (gamma delta) T lymphocytes have been postulated to play a role in a surveillance mechanism that eliminates transformed or otherwise damaged cells. In this study, we examined by flow cytometry the frequency and phenotype of gamma delta T cells in the tumour infiltrating lymphocytes (TIL) and peripheral blood (PBL) from renal cell carcinoma patients. The TCR gamma delta + cells comprised an average of 3.8% of the CD3+ TIL and 5.2% of circulating T cells. Analysis of surface immunophenotype revealed that activation markers of T lymphocytes: CD25 and HLA DR were highly expressed on the tumour infiltrating gamma delta + T lymphocytes (median 27.6% for CD25 and 52.0% for HLA DR). More importantly, percentage of activated gamma delta T cells was found to be much higher than compared to all activated CD3+ cells. Furthermore, an unusually high proportion of gamma delta positive TILs express CD4 or CD8 molecules (17.2 and 36.8%, respectively), indicating that they might recognise antigen presented within MHC II or I context. These results suggest that gamma delta T lymphocytes may play a certain role in immune response against tumour cells.

Accumulation of gamma/delta T cells in human dysgerminoma and seminoma: roles in autologous tumor killing and granuloma formation

The precise biological function of a subset of T cells bearing gamma/delta T cell receptor (TCR) remains poorly understood. The present study demonstrated the presence of gamma/delta T cells in tumor-infiltrating lymphocytes (TIL) and peripheral blood lymphocytes (PBL) of human patients with dysgerminoma and seminoma when determined by flow cytometry and in situ immunohistochemical staining. TIL contained a high percentage of gamma/delta T cells, ranging from 17.3 to 35.1%. gamma/delta T cells often accumulated within the granulomatous inflammation of tumor tissues. The majority of gamma/delta T cells were V gamma 9/V delta 2+ cells. Freshly isolated PBL, TIL and purified gamma/delta T cells showed autologous tumor killing (ATK) activity, which could be inhibited by monoclonal antibodies (mAb) against V delta 2. Furthermore, two gamma/delta T cell clones established from TIL showed cytotoxicity against autologous and allogeneic dysgerminoma, while they had low or no lytic effects on other cell types including carcinomas of ovary and tumor cell lines such as K562, Daudi and Molt-4. Lysis of autologous tumor cells by the clone was inhibited completely by anti-V delta 2 mAb and partially by mAb against CD3, LFA-1 alpha and ICAM-1 molecules, while it was resistant to anti-CD8, anti-HLA-ABC and anti-HLA-DR mAb. Supernatants produced by gamma/delta T cell clones induced adhesion, aggregation and increased DNA synthesis of monocytes and some characteristics of activated macrophages or epithelioid cells. Tumor necrosis factor (TNF)-alpha, granulocyte-macrophage colony stimulating factor (GM-CSF) and interferon (IFN)-gamma were detected in the supernatants of gamma/delta T cell clone. These results suggest that gamma/delta T cells accumulating in dysgerminoma and seminoma exhibit ATK activity through V gamma 9/delta 2 TCR and these gamma/delta T cells also play a role in the formation of granulomatous inflammation, which is associated with human dysgerminoma and seminoma.

Functional analysis of TCR gamma delta+ T cells in tumour-infiltrating lymphocytes (TIL) of human pancreatic cancer

In six patients with advanced pancreatic carcinoma, TIL and tumour-draining lymphocytes (TDL) were isolated from primary pancreatic tumour and regional lymph nodes. In comparison with TDL and peripheral blood lymphocytes (PBL), TIL contained a comparatively higher percentage of TCR gamma delta+ cells, although they were still a small fraction. By 2 weeks culture with rIL-2 and immobilized OKT-3 antibody, the TCR gamma delta+ cells in TIL were preferentially expanded at the early culture periods, although it was temporary. In four cases, the TCR gamma delta+ and CD8+ TCR alpha beta+ TIL were separated by negative sorting using flowcytometry. All the TCR gamma delta+ TIL were CD4-, CD8- (double negative), and one of the TIL lines was mostly composed of delta TCS1+ cells, while the others were delta TCS1-. In comparison with CD8+ TCR alpha beta+ TIL, all the TCR gamma delta+ TIL exhibited much stronger lytic activity against freshly isolated autologous pancreatic cancer cells. However, all the gamma delta+ TIL also exhibited a strong non-MHC-restricted cytotoxicity, and there was no correlation between the lytic pattern and the percentage of delta TCS1+ cells. These data suggest that the TCR gamma delta+ T cells can proliferate vigorously in a certain condition, and if successfully expanded in vitro they might be helpful material for effective adoptive immunotherapy.

A high proportion of the V delta 1+ synovial fluid gamma delta T cells in juvenile rheumatoid arthritis patients express the very early activation marker CD69, but carry the high molecular weight isoform of the leucocyte common antigen (CD45RA)

We have previously shown that gamma delta T cells in the synovial compartment of patients with juvenile rheumatoid arthritis (JRA) express activation antigens (CD69 and HLA-DR) and that they are predominantly of the V delta 1 subset. In this study we have analysed the expression of activation antigens (CD69 and HLA-DR) and different isoforms of the leucocyte common antigen (CD45RO and CD45RA) on the V delta 1 and the V delta 2 subsets of gamma delta T cells in paired samples of synovial fluid and peripheral blood of nine patients with JRA, and in the peripheral blood of five children with idiopathic scoliosis. In the synovial fluid of children with JRA, there were significantly more V delta 1+CD69+ and V delta 2+CD69+ cells compared with the peripheral blood of the same patients. In contrast, however, in the synovial fluid the V delta 1 and the V delta 2 subsets differed with respect to the expression of the two isoforms of the leucocyte common antigen. The majority of the V delta 1+ cells expressed the high molecular weight isoform (CD45RA+) while most of the V delta 2+ cells carried the low molecular weight variant (CD45RO+) of this molecule.