Different pattern of T cell receptor delta gene rearrangement in tumour-infiltrating lymphocytes and peripheral blood in patients with solid tumours

Fast dendritic cells stimulated with alternative maturation mixtures induce polyfunctional and long-lasting activation of innate and adaptive effector cells with tumor-killing capabilities

The clinical usage of dendritic cells (DC) for tumor immunotherapy still requires improvements. In this study, three alternative maturation mixtures were compared with the cytokine-based gold standard, and the overall interaction of the resulting DC with effector cells from the innate as well as the adaptive immunity was evaluated in healthy donors. Stimulation with the TLR-4 ligand monophosphoryl lipid A together with IFN-γ (alt-2 DC) resulted in DC with the highest levels of costimulatory molecule expression and IL-12p70/IL-10 ratio. Whereas all alternative DC were able to induce NK and γδ T cells to acquire cytotoxic properties and secrete type 1 and proinflammatory cytokines, after both short (20-h)- and long (5-8 d)-time coculture, secretion of IFN-γ by the innate populations was induced in response to alt-2 and alt-1 DC (TNF-α, IFN-α, IFN-γ, IL-1β, poly IC), but not to alt-3 DC (TNF-α, IFN-γ, IL-1β, CL097). Regarding CD8(+) T cell-mediated Ag-specific immune responses, a heterogeneous pattern of responses was obtained among the healthy donors, suggesting rather a competition than a synergy among the different effector cells. Our data promote further evaluation of alt-2 fast DC for translatability into clinical immunotherapy trials, while also fostering the need to identify biomarkers for immune cell responsiveness and tumor susceptibility to be able to select for each patient the best possible DC-based therapy.

Unique TCRDV1-positive lymphocytes that infiltrate colonic neoplasia originate from a selected cell population present in the intestinal mucosa and the peripheral blood

TCRDV1-positive lymphocytes, which infiltrate colon carcinomas, were recently shown to be cytolytic for tumour cells. However, the immune compartment from which these cells originate is unknown. The aim of the present studies was to determine the origin of TCRDV1-positive cells in colonic neoplasia. Biopsies were obtained from normal colon, polyps or carcinomas, concurrently with a sample from the peripheral blood. RNA was extracted and a TCRDV1-specific reverse transcriptase-polymerase chain reaction (RT-PCR) was performed. Amplification products were analysed by a CDR3 display and sequence analysis. In five out of six patients, the TCRDV1 CDR3 display of the whole cell population within the neoplastic tissue was distinct from that in the normal mucosa and the peripheral blood. The nucleotide sequences of CDR3 domains from the three compartments were distinct as well. In one patient, a pattern similar to the CDR3 display was detected in neoplastic and normal intestinal tissues. However, using junction-specific RT-PCR of CDR3 sequences derived from the neoplastic cells, such sequences could be detected in all three compartments. These findings suggest that in contrast to the current paradigm, a unique TCRDV1 cell population circulates in the peripheral blood and normal intestinal tissue and infiltrates colon neoplasia rather than being restricted to a single compartment as previously thought.

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.

Enhanced formation of azoxymethane-induced colorectal adenocarcinoma in gammadelta T lymphocyte-deficient mice

T cell receptor (TCR) gammadelta-positive T lymphocytes, which are localized mostly within the intraepithelial space of intestinal epithelium, have been suggested to play a role in maintaining the normal configuration of intestinal epithelium. However, the role of TCRgammadelta-positive T lymphocytes in the formation and progression of colorectal adenocarcinoma that originates from colorectal epithelial cells remains to be elucidated. In this study, TCRalphabeta and TCRgammadelta-positive T lymphocyte-deficient mice (homozygous TCRa and TCRd-gene knockout mice) and the background wild-type mice were administered azoxymethane, and the formation of macroscopic tumors and microscopic aberrant crypt foci in colorectal mucosa were compared among the three types of mice. Well-differentiated adenocarcinoma appeared 5 months after 5 administrations of azoxymethane (10 mg/kg weight) only in a few TCRd -gene knockout mice and the frequency of the carcinoma-bearing mice was increased at 7 and 9 months after the administration. Aberrant crypt foci were also detected in the colorectal mucosa of TCRd -gene knockout mice to a greater extent than in colorectal mucosa of TCRa-gene knockout mice 1 month after the azoxymethane administration. These results suggest that TCRgammadelta-positive T lymphocytes, which are present mainly in the intraepithelial space, play a role in suppression of the formation and progression of colorectal adenocarcinoma in mice.

Alpha/beta- and gamma/delta TCR(+) lymphocyte infiltration in necrotising choroidal melanomas

AIM

To detect specific tumour infiltrating T cells (TIL) carrying antigen specific MHC-I restricted receptor genes on necrotising and non-necrotising malignant melanomas and to correlate the findings with clinical data.

METHODS

alpha/beta- and gamma/delta- TIL were determined by immunohistochemical staining in melanomas of patients with known follow up of more than 10 years. An antigen retrieval method was used to determine variable genes delta1 and gamma1 on TCR(+) cells by an anti-TCR Vdelta1 and anti-CrgammaM1, and of Valpha and Vbeta TCR(+) by an anti-pan-TCR(+) alpha/beta antibody.

RESULTS

Intratumoral TIL were present in 86 of 113 (76.1%) necrotising melanomas (NMM) v 21 of 100 (21%) in non-necrotising melanomas (MM); of these, Valpha/beta- TCR(+) cells were present in 52 of 74 (70.3%) TIL harbouring NMM v four of 21 (19%) MM; Vgamma1 in 29 of 74 (39.2%) NMM v two of 21 (10%) MM; and Vdelta1 in 39 of 74 (52.7%) NMM v three of 21 (14%) MM. Extratumoral lymphocytic infiltration was seen in 86 (76.1%) NMM including Valpha/beta TCR(+) cells in 10 (11.6%) cases, v five (5%) MM cases with no Valpha/beta TCR(+) cells detected. Vgamma1 and Vdelta1 TCR(+) cells were not found in extratumoral infiltrates.

CONCLUSIONS

In NMM, the median survival was 69.3 (range 6-237) months, 19 of 74 patients (25.7%) survived 5 years, and mortality was associated with advanced stage (p<0.001), patient age (p<0.023), and extent of necrosis (p<0.048). Survival was increased with evidence of Vgamma1 and Vdelta1 TCR(+) cells (p<0.026).

Gammadelta T cells in host defense and epithelial cell biology

Recent studies have demonstrated increased numbers of gammadelta T cells in a variety of human infectious as well as noninfectious diseases. In some cases gammadelta T cells could be shown to destroy infected or transformed cells. Advances in the identification of ligands recognized by gammadelta T cells and the development of animal model systems to study these cells in vivo should overcome some of the major obstacles currently preventing a better understanding of gammadelta T cell function in immune responses. As we gain this knowledge it may become possible to design therapeutic strategies exploiting unique properties of gammadelta T cells to promote more effective immunity.

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.