Biomedical subjects

Lindy G Durrant

Publications and source records attributed to Lindy G Durrant.

16 recordsLinked to original sources

PubMed2006

A neoadjuvant/adjuvant randomized trial of colorectal cancer patients vaccinated with an anti-idiotypic antibody, 105AD7, mimicking CD55.

PURPOSE: To assess the tolerability and effectiveness of 105AD7 vaccination in colorectal cancer patients. 105AD7 is a human anti-idiotypic antibody mimicking CD55, a glycoprotein, which is more than expressed on colorectal cancer cells and protects them from attack by complement. EXPERIMENTAL DESIGN: Colorectal cancer patients (n = 67) eligible for primary surgery were randomized to receive the anti-idiotypic antibody 105AD7+/-Bacillus Calmette-Guerin/alum or to no treatment (control group). The immunizations were given i.d./i.m. before surgery and continued for a period of 2 years. The patients were monitored in enzyme-linked immunospot (ELISPOT; gamma-IFN), proliferation assay, and Luminex cytokine assays. RESULTS: No serious adverse events were recorded. Of the 32 investigated immunized patients, 14 (44%) were considered to be responders in the ELISPOT assay. Induced proliferative responses were noted in 17 of 40 (43%) monitored patients. There was no correlation between the ELISPOT and proliferation assays. Luminex analyses revealed tumor necrosis factor-alpha and granulocyte macrophage colony-stimulating factor responses not only to the vaccine but also toward the native antigen CD55 in 9 of 13 (69%) patients. CONCLUSIONS: Immune responses to vaccination were induced in a majority of monitored patients measured by ELISPOT and proliferation assay. The lack of correlation between the ELISPOT and proliferation assays may reflect the fact that the two methods measure different T-cell responses and highlights the importance of multiple readouts in evaluating a potential cancer vaccine. Responses to both the anti-idiotype and the CD55 antigen were measurable, adding support to the use of CD55 as a target in cancer treatment.

Adjuvants, Immunologic↗

PubMed2006

Cytoplasmic expression of p27(kip1) is associated with a favourable prognosis in colorectal cancer patients.

AIM: To evaluate the prognostic significance of p27(kip1) in colorectal cancer patients. METHODS: Cytoplasmic and nuclear p27(kip1) expression was evaluated in 418 colorectal cancers using tissue microarrays. Data were associated with known patient and tumor variables and long-term patient outcomes, providing further insight into the mechanisms by which p27(kip1) may influence tumor development. RESULTS: Nuclear and cytoplasmic p27(kip1) expressions were detected in 59% and 19% of tumors respectively. Cytoplasmic p27(kip1) was almost invariably associated with positive nuclear p27(kip1) expression. Neither case correlated with known clinical or pathological variables, including tumor stage, grade or extramural vascular invasion. Furthermore, nuclear p27(kip1) expression had no impact on survival. However, we identified a significant correlation between expression of cytoplasmic p27(kip1) and longer disease-specific survival times. On multivariate analysis, TNM stage and extramural vascular invasion were highly significant independent prognostic factors, with positive cytoplasmic p27 expression showing a trend towards improved patient survival (P = 0.059). CONCLUSION: These findings support the recent evidence that cytoplasmic p27(kip1) has a distinct and important biological role that can influence tumor outcome.

Aged↗

PubMed2006

Costimulation via CD55 on human CD4+ T cells mediated by CD97.

Decay-accelerating factor (CD55) is a complement regulatory protein, which is expressed by most cells to protect them from complement-mediated attack. CD55 also binds CD97, an EGF-TM7 receptor constitutively expressed on granulocytes and monocytes and rapidly up-regulated on T and B cells upon activation. Early results suggested that CD55 could further enhance T cell proliferation induced by phorbol ester treatment. The present study demonstrates that coengagement of CD55, using either cross-linking mAbs or its natural ligand CD97, and CD3 results in enhanced proliferation of human peripheral blood CD4(+) T cells, expression of the activation markers CD69 and CD25, and secretion of IL-10 and GM-CSF. Recently, an increase in T cell responsiveness in CD55(-/-) mice was shown to be mediated by a lack of complement regulation. In this study, we show that direct stimulation of CD55 on CD4(+) T cells with CD97 can modulate T cell activation but does not interfere with CD55-mediated complement regulation. Our results support a multifaceted role for CD55 in human T cell activation, constituting a further link between innate and adaptive immunity.

Amino Acid Sequence↗

PubMed2006

A new anticancer glycolipid monoclonal antibody, SC104, which directly induces tumor cell apoptosis.

A novel monoclonal antibody was raised by immunization of mice with colorectal tumor cell lines. The fusion was screened by immunohistochemistry for binding to primary colorectal tumors. Subsequent analysis on primary disaggregated colorectal tumors show that the antibody recognizes a cell surface antigen expressed by the majority of colorectal tumors. Antigen characterization has shown that the antibody recognizes a sialyltetraosylceramide but does not bind to GM1, GD1a, GT1b, or sialyl Lewis(X) antigens. Binding to a frozen panel of tumor and normal tissue sections revealed that the antigen was also strongly expressed on esophageal, gastric, and endometrial tumors. Its normal tissue distribution was largely restricted to moderate staining of large intestine. Surprisingly, SC104 antibody directly induces tumor cell death without the need for immune effector cells or complement. This may be related in part to its homophilic binding properties that allow cross-linking of antibody and receptors on the cell surface. Caspase activation can be detected following SC104 treatment of colorectal cells, and cotreatment with caspase inhibitors has been shown to inhibit cell death. This suggests that SC104 induces death by a classic apoptotic pathway. Furthermore, SC104 antibody shows additive killing with complement and 5-fluorouracil/leucovorin in vivo, suggesting a new therapeutic approach for this class of antibodies.

Adenocarcinoma↗

PubMed2006

Expression of the stress-related MHC class I chain-related protein MICA is an indicator of good prognosis in colorectal cancer patients.

The realization of targeted cancer therapy has driven the need to improve selection of patients with colorectal cancer for adjuvant therapy, leading to a search for potential new prognostic markers. There is accumulating evidence that immunosurveillance acts as an extrinsic tumor suppressor. As genetic instability is an early event in colorectal cancer, this can lead to altered expression of molecules conferring resistance to immune attack. Hence, molecules up or downregulated in this process may impact on patient survival. In our study, 449 colorectal tumors were screened for expression of the stress-related protein MICA, which functions as a ligand for the NKG2D receptor and whose expression confers susceptibility to both T- and NK-cell attack. Intensity of MICA expression was quantified using automated image analysis and MICA expression showed no correlation with conventional clinicopathological variables. In contrast, survival analysis showed a significant correlation between higher levels of MICA expression and improved disease-specific survival, with independent prognostic significance in multivariate analysis. Thus, patients with low levels of MICA and a poor prognosis may be good candidates for aggressive chemotherapy. In contrast, patients with high expression of MICA may be candidates for the antibody therapies, as they should be susceptible to NK killing by antibody dependent cellular cytotoxicity.

Aged↗

PubMed2006

Complement decay accelerating factor (DAF)/CD55 in cancer.

The complement system is a powerful innate mechanism involved in protection of the host against pathogens. It also has a role in the clearance of apoptotic cells and has been implicated in a range of pathologies including autoimmunity and graft rejection. The control of complement is mediated through the complement regulatory proteins (CRPs). These are present on most cells and protect normal cells from complement-mediated attack during innate activation. However, in a range of pathologies and cancer, these molecules are up or down regulated, sometimes secreted and even lost. We will review the expression of CRPs in cancer, focussing on CD55 and highlight other roles of the CRPs and their involvement in leukocyte function. We will also provide some data providing a potential mechanism by which soluble CD55 can inhibit T-cell function and discuss some of the implications of this data.

Antigens, CD↗

PubMed2006

The use of reverse immunology to identify HLA-A2 binding epitopes in Tie-2.

A potential target for a cancer vaccine would be receptors, such as Tie-2 which are over expressed on tumour endothelium. Using computer aided motif predictions for possible HLA class I epitopes, we have identified peptides from Tie-2 that should bind with a range of affinities to HLA-A*0201. No direct correlation between predicted values and actual binding affinities was observed. Although, the programs did produce a number of false positives, two epitopes were predicted that bound with relatively high affinity when compared with an influenza peptide. We have previously identified a Tie-2 epitope and shown that it was only immunogenic when we substituted preferred amino acids at key anchor residues to increase binding affinity. In this study we used a similar approach to generate modified epitopes. When HLA-A2 transgenic mice were immunised with peptides, CTL killing of the target cells was only achieved when the wild type epitope was presented at moderate levels. Moreover, the efficiency of immunisation was increased when we linked CD4 epitopes to CD8 epitopes. Caution should therefore be employed in the use of both reverse immunology and anchor modification of CTL epitopes in the identification of CTL epitopes for cancer vaccines.

Algorithms↗

PubMed2006

Immunosurveillance is active in colorectal cancer as downregulation but not complete loss of MHC class I expression correlates with a poor prognosis.

Many colorectal tumors lose or downregulate cell surface expression of MHC class I molecules conferring resistance to T-cell-mediated attack. It has been suggested that this phenomenon is due to in vivo immune-tumor interactions. However, evidence of the impact of MHC class I loss on outcomes from colorectal cancer is scarce. In our study of more than 450 colorectal cancers in tissue microarray format, we have shown that both high levels of MHC class I expression and absent MHC class I expression are associated with similar disease-specific survival times, possibly due to natural killer cell-mediated clearance of MHC class I-negative tumor cells. However, tumors with low level expression of MHC class I were found to confer a significantly poorer prognosis, retaining independent significance on multivariate analysis. The existence of these poor prognosis tumors, which may avoid both NK- and T-cell-mediated immune surveillance, has important implications for the design of immunotherapeutic strategies in colorectal cancer.

Aged↗

PubMed2005

Total loss of MHC class I is an independent indicator of good prognosis in breast cancer.

Tumours can be recognised by CTL and NK cells. CTL recognition depends on expression of MHC Class I loaded with peptides from tumour antigens. In contrast, loss of MHC Class I results in NK activation. In our study a large set of samples from patients with primary operable invasive breast cancer was evaluated for the expression of MHC Class I heavy and light by immunohistochemical staining of 439 breast carcinomas in a tissue microarray. Forty-seven percent (206 of 439) of breast carcinomas were considered negative for HLA Class I heavy chain (HC10), whereas lack of anti-beta2m-antibody staining was observed in 39% (167 of 424) of tumours, with only 3% of the beta2m-negative tumours expressing detectable HLA Class I heavy chain. Correlation with patient outcome showed direct relationship between patient survival and HLA-negative phenotype (log rank = 0.004). A positive relationship was found between the intensity of expression of MHC Class I light and heavy chains expression and histological grade of invasive tumour (p < 0.001) and Nottingham Prognostic Index (p < 0.001). To investigate whether HLA Class I heavy and light chains expression had independent prognostic significance, Cox multivariate regression analysis, including the parameters of tumour size, lymph node stage, grade and intensity of HC10 and anti-beta2m staining, was carried out. In our analysis, lymph node stage (p < 0.001), tumour grade (p = 0.005) and intensity of MHC Class I light and heavy chains expression were shown to be independent prognostic factors predictive of overall survival (p-values HC10 = 0.047 and beta2m = 0.018).

Adult↗

PubMed2005

Expression of the membrane complement regulatory protein CD59 (protectin) is associated with reduced survival in colorectal cancer patients.

It has been known for some time that the immune system can recognise growing tumours, and that tumours may respond by modulation of molecules, which make them resistant to further attack. Expression, over-expression, or loss of these molecules may function as markers of tumour progression and prognosis. Among such molecules are the membrane-bound complement regulatory proteins (mCRP), which protect cells from bystander attack by autologous complement. These include CD59 (protectin), which prevents formation of the MAC complex in the terminal stages of complement activation. In the present study, we evaluated immunohistochemical expression of CD59 in a series of over 460 well-characterised colorectal cancers using tissue microarrays (TMA), and related this information to known tumour and patient variables and to survival. The CD59 expression was observed in 69 (15%) of cases overall, and was significantly associated with tumour grade. In contrast, no associations were noted with tumour site, stage or histological type. On survival analysis, a further correlation was observed between expression of CD59 by the colorectal tumours and a reduction in disease-specific patient survival. This observation was strongest for patients with early stage disease. However, a negative impact on survival was also seen in those patients with late stage disease. These results indicate that TMA linked to good clinicopathological databases with good long term follow up are useful tools for determining new prognostic indicators that can be used in future patient management. Immune surveillance may result in immune-editing that induces variable expression of a range of target antigens, and these may be useful prognostic markers. This study has identified CD59 expression as a marker of poor prognosis in colorectal cancer patients.

Adenocarcinoma↗

PubMed2005

High expression of Lewis y/b antigens is associated with decreased survival in lymph node negative breast carcinomas.

INTRODUCTION: There is sufficient evidence that blood group related Lewis antigens are tumour-associated molecules. The Lewisy and Lewisb antigens are complex carbohydrates that are over-expressed by breast, lung, colon and ovarian cancers. The SC101 mAb is a unique Lewisy/b binding antibody that binds to native and extended Lewisy and Lewisb haptens, displaying no cross reactivity with H type 1, H type 2, Lewisx or normal blood group antigens. METHODS: Immunohistochemical detection of Lewisy/b was performed on 660 formalin-fixed, paraffin embedded breast tumour specimens using a streptavidin-biotin peroxidase technique. Tissue from these patients had previously been included in tissue microarrays. This cohort comprises a well characterized series of patients with primary operable breast cancer diagnosed between 1987 and 1992, obtained from the Nottingham Tenovus Primary Breast Carcinoma Series. This includes patients 70 years of age or less, with a mean follow up of 7 years. RESULTS: Of the breast carcinomas, 370 of 660 (56%) were negative for Lewisy/b expression, 110 (17%) cases showed a low level of expression (<25% of positive cells) and only 54 cases (8%) showed extensive expression of Lewisy/b (>75% of positive cells). We found significant positive associations between histological grade (p < 0.001), Nottingham Prognostic Index (p = 0.016), tumour type (p = 0.007) and the level of Lewis y/b expression. There was a significant correlation between the proportion of Lewisy/b positive tumour cells and survival in lymph-node negative patients (p = 0.006). CONCLUSION: The unique epitope recognised by SC101 mAb on Lewisy/b hapten is over-expressed on breast tumour tissue compared with normal breast. In this large series of invasive breast cancers, higher expression of Lewisy/b was more often found in high grade and poor prognosis tumours compared to good prognosis cancers. Moreover, in lymph node negative breast carcinomas, over-expression of Lewisy/b hapten was associated with significantly decreased patient survival.

Adult↗

PubMed2005

Evidence that the p53 negative / Bcl-2 positive phenotype is an independent indicator of good prognosis in colorectal cancer: a tissue microarray study of 460 patients.

BACKGROUND: Advances in our understanding of the molecular biology of colorectal cancer have fuelled the search for novel molecular prognostic markers to complement existing staging systems. Markers assessed in combination may perform better than those considered individually. Using high-throughput tissue microarray technology, we describe the prognostic value of combined p53 / Bcl-2 status in colorectal cancer. PATIENTS AND METHODS: Tumour samples from 462 patients who underwent elective surgery to resect a primary colorectal cancer between 1994 and 2000 (mean follow-up of 75 months) were assembled in tissue microarray format. Clinico-pathological data including tumour grade, stage, vascular invasion status along with disease specific survival data has been collected prospectively. Immunohistochemical analysis of p53 and Bcl-2 expression was performed using antibodies DO-7 (p53) and 124 (Bcl-2), and results correlated with known clinico-pathological variables and outcomes. RESULTS: Abnormal nuclear p53 accumulation and Bcl-2 overexpression were detected in 221/445 (49.6%) and199/437 (45.5%) tumours respectively, with a significant inverse correlation between the two markers (p = 0.023). On univariate analysis no correlations were found between either marker and standard clinico-pathological variables, however nuclear p53 expression was associated with a significantly reduced survival (p = 0.024). Combined analysis of the two markers indicated that 112/432 (24.2%) cases displayed a p53(-)/Bcl-2(+) phenotype, this occurring more frequently in earlier stage tumours. Kaplan-Meier analysis revealed a significant survival advantage in these p53(-)/Bcl-2(+) tumours compared with the remaining cases (p = 0.0032). On multivariate analysis using the Cox proportional hazards model, neither p53 expression nor Bcl-2 expression alone were of independent prognostic significance, however the combined p53(-)/Bcl-2(+) phenotype was significantly associated with a good prognosis in this series (HR 0.659, 95%CI 0.452-0.959, p = 0.029). CONCLUSION: Patient stratification by combined p53 / Bcl-2 phenotype provides stage-independent prognostic information in colorectal cancer. Specifically, that up to a quarter of patients display a good prognosis p53(-)/Bcl-2(+) phenotype. This may indicate a more clinically indolent phenotype and a subset of patients for whom less aggressive adjuvant treatment appropriate.

Journal Article↗

PubMed2004

Do poor-prognosis breast tumours express membrane cofactor proteins (CD46)?

UNLABELLED: CD46 or membrane cofactor protein (MCP) is a complement regulatory protein that has been identified on all nucleated cells and which protects them from attack by autologous complement. Breast carcinomas are reported to consistently express CD46. AIM AND METHODS: Our previous immunohistochemical study showed that in breast carcinomas, loss of CD59 and CD55 correlated with poor survival. This study aimed to investigate the prognostic significance of CD46 on breast tumours using a rabbit polyclonal anti-CD46 antibody with a standard immunohistochemistry method. A total of 510 breast tissues from patients with primary operable breast cancer diagnosed between 1987 and 1992 had previously been included in tissue microarrays. They included patients 70 years of age or less (mean = 54 years) with a long-term follow-up (median = 82 months). RESULTS: Immunohistochemical study revealed that 507/510 (99.4%) of breast tumours expressed CD46. Strong immunoreactivity was exhibited by 136/510 (27%) tumours, while moderate and weak staining was observed in 43% and 29% of tumours, respectively. Intensity of CD46 expression was significantly associated with tumour grade (p < 0.05), histological type of tumour (p < 0.001) and tumour recurrence (p < 0.05). There was no correlation with lymph node stage or the presence of vascular invasion, nor with patient age or menopausal status. Interestingly, as most tumours expressed CD46, it would appear that poor-prognosis tumours that lose CD55 and CD59 still express CD46. CONCLUSION: Breast tumours express high levels of CD46 that correlates with tumour grade and recurrence. It is therefore likely that loss of CD55 and CD59 could be compensated by expression of CD46. However, loss of CD55 and CD59, even for tumours that still express CD46, is still associated with a poor prognosis. This may suggest that CD46 alone can protect from complement lysis but that loss of CD55 and CD59 are associated with other roles in immune regulation.

Adult↗

PubMed2004

Identification of an HLA-A*0201 cytotoxic T lymphocyte epitope specific to the endothelial antigen Tie-2.

Tie-2 stabilises pericyte-endothelial interactions during angiogenesis and is highly expressed on endothelium during several diseases, including arthritis, age-related macular degeneration and cancer. A vaccine that targets endothelium overexpressing Tie-2 may result in vessel damage and stimulate an inflammatory cascade resulting in disease regression. We have identified a region unique to Tie-2 (amino acids 1-196) that is homologous in humans and mice. Using computer algorithms, several HLA-A*0201 epitopes that are identical in mice and humans were predicted within this region; however, binding assays showed that the majority of these epitopes were of low affinity. Modification of the anchor residues of 4 epitopes enhanced HLA binding. These epitopes were incorporated by site-directed mutagenesis into a Tie-2 DNA construct. Immunisation of HLA*0201 transgenic mice with one of the modified Tie-2 constructs stimulated CTLs that recognised both wild-type and modified peptide-pulsed target cells. In contrast, no CTLs were generated in mice immunised with wild-type Tie-2 construct, demonstrating that the modified epitope was necessary in the generation of CTLs. Moreover, CTLs from mice immunised with the modified construct killed HLA-A*0201 endothelial cells overexpressing Tie-2. Our study demonstrates that it is possible to break tolerance to the endothelial antigen Tie-2, suggesting that it may be feasible to design a vaccine to activate CTLs to kill endothelial cells overexpressing Tie-2.

Animals↗

PubMed2004

Comparison of the immune response to a self antigen after DNA immunisation of HLA*A201/H-2Kb and HHD transgenic mice.

HHD mice which express human HLA-A2 but no mouse class I, have been shown to have improved cytotoxic lymphocyte (CTL) responses to foreign antigens compared to HLA*A201/Kb transgenic mice. We have previously designed a DNA vaccine to a self antigen. Vaccination of A2.1/H-2Kb mice with this vaccine resulted in CTL in one third of the mice, but the frequency of antigen-specific cells was low. An increased frequency was observed in HHD mice, moreover CTL were obtained from all immunised mice. HHD mice are therefore useful for studying immunisation strategies for inducing and maintaining CD8 responses to over-expressed self antigens.

Animals↗

PubMed2004

Loss of CD55 is associated with aggressive breast tumors.

PURPOSE: CD55 is a complement regulatory protein expressed by cells to protect them from bystander attack by complement. CD55 is overexpressed on some tumor cell lines, and in colorectal carcinomas, it has been shown to be an indicator of poor prognostic. EXPERIMENTAL DESIGN: A large set of samples (480) from patients with primary operable breast cancer followed for 4-192 months were included in the present study. The prognostic significance of CD55 was then investigated in these tumors using an anti-CD55 monoclonal antibody (RM1) that we raised against a synthetic peptide and a standard immunohistochemistry method. RESULTS: Ninety-five percent of the breast carcinomas expressed CD55 (RM1) with intensity ranging from weak (51%) to strong (6%). High expression of CD55 was significantly associated with low-grade (grades 1 or 2; P = 0.001), lymph node negativity (P = 0.031), and good prognosis tumors (Nottingham Prognostic Index < 3.4; P < 0.001). Survival analysis showed CD55 overexpression was associated with a more favorable outcome and loss of CD55 being associated with poor survival (P = 0.001). Intensity of CD55 expression was significantly correlated (P = 0.002) with intensity of CD59 expression (as shown in a previous study) in these series of patients. CONCLUSIONS: In conclusion, we found that loss of both CD55 and CD59 in breast carcinomas is associated with a worse prognosis.

Animals↗