Isolated tumor cells are frequently detectable in the peritoneal cavity of gastric and colorectal cancer patients and serve as a new prognostic marker.

OBJECTIVE: To evaluate the prognostic significance of isolated tumor cells detected by a panel of various monoclonal antibodies. SUMMARY BACKGROUND DATA: Previously, we showed by using immunocytology that cancer cells are frequently found in bone marrow and peritoneal cavity samples of gastrointestinal cancer patients. METHODS: Findings in bone marrow and peritoneal cavity samples were compared and correlated with the 4-year survival rate of 84 gastric and 109 colorectal patients with cancer. RESULTS: Although positive results in the bone marrow showed little prognostic significance, the peritoneal cavity results correlated with the 4-year survival rate (gastric cancer: p = 0.0038; colorectal cancer: p = 0.0079). Additionally, in subgroups of patients with early (gastric cancer: p = 0.02, colorectal cancer: p = 0.48) and advanced (gastric cancer: p = 0.02, colorectal cancer: p < 0.0001) tumor stages, a correlation of immunocytologic findings and the survival rate was seen. CONCLUSIONS: The detection of minimal residual disease in the peritoneal cavity serves as a new prognostic marker.     

Lysis of a broad range of epithelial tumour cells by human gamma delta T cells: involvement of NKG2D ligands and T-cell receptor- versus NKG2D-dependent recognition

Human gammadelta T cells expressing a V gamma 9V delta 2 T-cell receptor (TCR) kill various tumour cells including autologous tumours. In addition to TCR-dependent recognition, activation of NKG2D-positive gammadelta T cells by tumour cell-expressed NKG2D ligands can also trigger cytotoxic effector function. In this study, we investigated the involvement of TCR versus NKG2D in tumour cell recognition as a prerequisite to identify tumour types suitable for gammadelta T-cell-based immunotherapy. We have characterized epithelial tumour cells of different origin with respect to cell surface expression of the known NKG2D ligands MHC class I-chain-related antigens (MIC) A/B and UL16-binding proteins (ULBP), and susceptibility to gammadelta T-cell killing. Most tumour cells expressed comparable levels of MICA and MICB as well as ULBP with the exception of ULBP-1 which was absent or only weakly expressed. Most epithelial tumours were susceptible to allogeneic gammadelta T-cell lysis and in the case of an established ovarian carcinoma to autologous gammadelta T-cell killing. Lysis of resistant cells was enhanced by pre-treatment of tumour cells with aminobisphosphonates or pre-activation of gammadelta T cells with phosphoantigens. A potential involvement of TCR and/or NKG2D was investigated by antibody blockade. These experiments revealed three patterns of inhibition, i.e. preferential inhibition by anti-TCR antibody, preferential inhibition by anti-NKG2D antibody, or additive blockade by anti-TCR plus anti-NKG2D antibodies. Our results indicate for the first time that the NKG2D pathway is involved in the lysis of different melanomas, pancreatic adenocarcinomas, squamous cell carcinomas of the head and neck, and lung carcinoma.     

The role of protein kinases in pancreatic carcinogenesis

BACKGROUND: Pancreatic cancer is a devastating disease with a very poor prognosis. METHODS: Protein kinases are aberrantly expressed in pancreatic ductal adenocarcinoma as analyzed by microarray-based expression analysis and have an impact for pancreatic cancer. Many regulatory proteins have an impact on cancer progression similar to the kinases. The list contains several regulators of kinases derived from the cell cycle control or the mitogen-activated protein (MAP)-kinase pathway. CONCLUSION: Both signalling pathways are essential for tumor progression and pancreatic ductal adenocarcinoma (PDAC) malignancy.     

Differential inhibition of primary versus preactivated T cells by pimecrolimus but not by tacrolimus in vitro

BACKGROUND: Recent studies in murine models of allergic contact dermatitis have shown that systemic treatment with pimecrolimus in contrast to tacrolimus did not inhibit the sensitization phase, whereas both compounds equivalently suppressed the inflammatory response in sensitized animals. This finding indicated a differential sensitivity of antigen-na?ve and primed T cells towards pimecrolimus and tacrolimus. METHODS: T cells obtained from healthy and allergic donors were subjected to primary and secondary stimulation by allogeneic or staphylococcal superantigen-presenting dendritic cells (DC). Human skin-derived, allergen-specific T cell clones from an atopic dermatitis patient were activated by anti-CD3 antibodies or by specific allergen-presenting DC. The inhibition of T cell proliferation and cytokine release by graded doses of calcineurin inhibitors was evaluated. RESULTS: Primary stimulation of T cells was inhibited by pimecrolimus with an approximately 8-fold lower potency as compared with tacrolimus. In contrast, the secondary response of ex vivo expanded T cells activated by allogeneic or staphylococcal superantigen-presenting DC was inhibited by both compounds with equivalent potency. Likewise, both drugs showed very similar potency to inhibit the proliferation and cytokine synthesis from antigen- stimulated T cell clones and the induction of cytokines in Jurkat T cells. CONCLUSION: These data indicate that pimecrolimus has a selectivity for antigen-primed memory T cells not seen with tacrolimus.     

Functional connectivity in the rat at 11.7T: Impact of physiological noise in resting state fMRI

Resting state functional MRI (rs-fMRI) of the brain has the potential to elicit networks of functional connectivity and to reveal changes thereof in animal models of neurological disorders. In the present study, we investigate the contribution of physiological noise and its impact on assessment of functional connectivity in rs-fMRI of medetomidine sedated, spontaneously breathing rats at ultrahigh field of 11.7 Tesla. We employed gradient echo planar imaging (EPI) with repetition times of 3s and used simultaneous recordings of physiological parameters. A model of linear regression was applied to quantify the amount of BOLD fMRI signal fluctuations attributable to physiological sources. Our results indicate that physiological noise - mainly originating from the respiratory cycle -dominates the rs-fMRI time course in the form of spatially complex correlation patterns. As a consequence, these physiological fluctuations introduce severe artifacts into seed-based correlation maps and lead to misinterpretation of corresponding connectivity measures. We demonstrate that a scheme of motion correction and linear regression can significantly reduce physiological noise in the rs-fMRI time course, remove artifacts, and hence improve the reproducibility of functional connectivity assessment. In conclusion, physiological noise can severely compromise functional connectivity MRI (fcMRI) of the rodent at high fields and must be carefully considered in design and interpretation of future studies. Motion correction should be considered the primary strategy for reduction of apparent motion related to respiratory fluctuations. Combined with subsequent regression of physiological confounders, this strategy has proven successful in reducing physiological noise and related artifacts affecting functional connectivity analysis. The proposed new and rigorous protocol now opens the potential of fcMRI to elicit the role of brain connectivity in pathological processes without concerns of confounding contributions from physiological noise.     

Immunization and challenge experiments with a new modified live bovine herpesvirus type 1 marker vaccine prototype adjuvanted with a co-polymer

Western European control programs against bovine herpesvirus type 1 (BoHV-1) infections utilize attenuated BoHV-1 marker vaccines with a deletion of the glycoprotein E (gE) encoding gene. However, a recent study demonstrated the potential risk of virulence recovery of gE-deleted BoHV-1 marker vaccine strains due to recombination (Muylkens et al. [15]). Based on an infectious bacterial artificial chromosome clone, a gE- and thymidine kinase (TK)-gene-deleted BoHV-1 mutant (BoHV-1ΔgEΔTK) was constructed. The recombinant virus was subsequently tested as a novel modified live marker vaccine candidate in an immunization-challenge trial using BoHV-1 seronegative calves. Additionally, a non-virucidal co-polymer was tested together with the recombinant virus acting as a vaccine-adjuvant. Animals were vaccinated twice through intramuscular injection and challenged intranasally 3 weeks later with a virulent BoHV-1 field strain. Duration and titres of challenge virus shedding were significantly reduced in all vaccinees. Importantly, reduction of challenge virus shedding and serological antibody levels in response to vaccination with vaccine preparations containing the co-polymer-adjuvant were markedly improved when compared to vaccine formulations without an adjuvant. Taken together, our study describes a novel double deletion mutant as a safe and efficacious BoHV-1-prototype marker vaccine strain with enhanced protective capacity especially when administered together with a co-polymer adjuvant.