From pelvic radiation to social isolation: a qualitative study of survivors' experiences of chronic bowel symptoms after pelvic radiotherapy.

PURPOSE: We explored survivors' experiences of chronic bowel symptoms following pelvic radiotherapy, strategies employed in living with these symptoms, effects on daily activities, and roles at home and in the workplace. METHODS: Semi-structured interviews were conducted with 28 individuals (10 gynaecological, 14 prostate, four anal/rectal cancer survivors) who had completed pelvic radiotherapy at least six months prior to data collection and who had experience of bowel symptoms during this post-treatment period. Reflexive thematic analysis was undertaken. RESULTS: We propose four themes describing a process leading from experience of symptoms to withdrawal from activities and roles. These are (1) losing control (the experience of unintended anal leakage or discharge); (2) experiencing embarrassment and fear (the experience of embarrassment or fear of embarrassment as a result of discharge becoming public); (3) managing and reacting (acting to reduce the likelihood of discharge or to prevent this becoming public); and (4) restriction and withdrawal (avoiding specific activities or situations so as to reduce or remove the risk of embarrassment). Returning to the workplace presented additional challenges across these themes. CONCLUSIONS: Impacts of chronic bowel symptoms can be severe. Survivors employ a variety of methods and strategies in living with their symptoms. Some of these support continued role fulfilment but some constitute a withdrawal from pre-treatment roles. Current healthcare provision and statutory protections fail to fully meet needs following pelvic radiotherapy. IMPLICATIONS FOR CANCER SURVIVORS: There is a need to develop and implement evidence-based services and supported self-management programmes for survivors experiencing chronic bowel problems post-radiotherapy.

Understanding and addressing vaccine hesitancy in the context of COVID-19: development of a digital intervention.

OBJECTIVES: Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) was identified in late 2019, spreading to over 200 countries and resulting in almost two million deaths worldwide. The emergence of safe and effective vaccines provides a route out of the pandemic, with vaccination uptake of 75-90% needed to achieve population protection. Vaccine hesitancy is problematic for vaccine rollout; global reports suggest only 73% of the population may agree to being vaccinated. As a result, there is an urgent need to develop equitable and accessible interventions to address vaccine hesitancy at the population level. STUDY DESIGN: & Method: We report the development of a scalable digital intervention seeking to address COVID-19 vaccine hesitancy and enhance uptake of COVID-19 vaccines in the United Kingdom. Guided by motivational interviewing (MI) principles, the intervention includes a series of therapeutic dialogues addressing 10 key concerns of vaccine-hesitant individuals. Development of the intervention occurred linearly across four stages. During stage 1, we identified common reasons for COVID-19 vaccine hesitancy through analysis of existing survey data, a rapid systematic literature review, and public engagement workshops. Stage 2 comprised qualitative interviews with medical, immunological, and public health experts. Rapid content and thematic analysis of the data provided evidence-based responses to common vaccine concerns. Stage 3 involved the development of therapeutic dialogues through workshops with psychological and digital behaviour change experts. Dialogues were developed to address concerns using MI principles, including embracing resistance and supporting self-efficacy. Finally, stage 4 involved digitisation of the dialogues and pilot testing with members of the public. DISCUSSION: The digital intervention provides an evidence-based approach to addressing vaccine hesitancy through MI principles. The dialogues are user-selected, allowing exploration of relevant issues associated with hesitancy in a non-judgmental context. The text-based content and digital format allow for rapid modification to changing information and scalability for wider dissemination.

A Prospective Study of Diffusion-weighted Magnetic Resonance Imaging as an Early Prognostic Biomarker in Chemoradiotherapy in Squamous Cell Carcinomas of the Anus.

AIMS: The use of diffusion-weighted magnetic resonance imaging (DW-MRI) as a prognostic marker of treatment response would enable early individualisation of treatment. We aimed to quantify the changes in mean apparent diffusion coefficient (ΔADCmean) between a DW-MRI at diagnosis and on fraction 8-10 of chemoradiotherapy (CRT) as a biomarker for cellularity, and correlate these with anal squamous cell carcinoma recurrence. MATERIALS AND METHODS: This prospective study recruited patients with localised anal cancer between October 2014 and November 2017. DW-MRI was carried out at diagnosis and after fraction 8-10 of radical CRT. A region of interest was delineated for all primary tumours and any lymph nodes >2 cm on high-resolution T2-weighted images and propagated to the ADC map. Routine clinical follow-up was collected from Nation Health Service electronic systems. RESULTS: Twenty-three of 29 recruited patients underwent paired DW-MRI scans. Twenty-six regions of interest were delineated among the 23 evaluable patients. The median (range) tumour volume was 13.6 cm3 (2.8-84.9 cm3). Ten of 23 patients had lesions with ΔADCmean ≤ 20%. With a median follow-up of 41.2 months, four patients either failed to have a complete response to CRT or subsequently relapsed. Three of four patients with disease relapse had lesions demonstrating ΔADCmean <20%, the other patient with persistent disease had ΔADCmean of 20.3%. CONCLUSIONS: We demonstrated a potential correlation between patients with ΔADCmean <20% and disease relapse. Further investigation of the prognostic merit of DW-MRI change is needed in larger, prospective cohorts.

Native/citrullinated LL37-specific T-cells help autoantibody production in Systemic Lupus Erythematosus.

LL37 exerts a dual pathogenic role in psoriasis. Bound to self-DNA/RNA, LL37 licenses autoreactivity by stimulating plasmacytoid dendritic cells-(pDCs)-Type I interferon (IFN-I) and acts as autoantigen for pathogenic Th17-cells. In systemic lupus erythematosus (SLE), LL37 also triggers IFN-I in pDCs and is target of pathogenic autoantibodies. However, whether LL37 activates T-cells in SLE and how the latter differ from psoriasis LL37-specific T-cells is unknown. Here we found that 45% SLE patients had circulating T-cells strongly responding to LL37, which correlate with anti-LL37 antibodies/disease activity. In contrast to psoriatic Th17-cells, these LL37-specific SLE T-cells displayed a T-follicular helper-(TFH)-like phenotype, with CXCR5/Bcl-6 and IL-21 expression, implicating a role in stimulation of pathogenic autoantibodies. Accordingly, SLE LL37-specific T-cells promoted B-cell secretion of pathogenic anti-LL37 antibodies in vitro. Importantly, we identified abundant citrullinated LL37 (cit-LL37) in SLE tissues (skin and kidney) and observed very pronounced reactivity of LL37-specific SLE T-cells to cit-LL37, compared to native-LL37, which was much more occasional in psoriasis. Thus, in SLE, we identified LL37-specific T-cells with a distinct functional specialization and antigenic specificity. This suggests that autoantigenic specificity is independent from the nature of the autoantigen, but rather relies on the disease-specific milieu driving T-cell subset polarization and autoantigen modifications.

Post-translational modifications such as citrullination are excellent targets for cancer therapy.

Under conditions of cellular stress, proteins can be post-translationally modified causing them to be recognized by the immune system. One such stress-induced post-translational modification (siPTM) is citrullination, the conversion of arginine residues to citrulline by peptidylarginine deiminase (PAD) enzymes. PAD enzymes are activated by millimolar concentrations of calcium which can occur during apoptosis, leading to precipitation of proteins, their subsequent uptake by B cells and stimulation of antibody responses. Detection of anti-citrullinated protein antibodies (ACPAs) is a diagnostic of rheumatoid arthritis (RA), where immune complexes stimulate inflammation around the joints. More recently, autophagy has been shown to play a role in the presentation of citrullinated peptides on MHC class II molecules to CD4+ helper T cells, suggesting that citrullination may be a way of alerting immune cells to cellular stress. Additionally, inflammation-induced IFNγ and concomitant MHC class II expression on target cells contributes to immune activation. Stressful conditions in the tumor microenvironment induce autophagy in cancer cells as a pro-survival mechanism. Cancer cells also over express PAD enzymes and in light of this the hypothesis that citrullinated peptides stimulate CD4+ T cell responses that would recognize these siPTM's produced during autophagy has been investigated. The induction of potent citrullinated peptide-specific CD4 responses has been shown in both humans and HLA transgenic mouse models. Responses in mouse models resulted in potent anti-tumour responses against tumours expressing either constitutive or IFNγ-inducible MHC class II. The anti-tumour effect relied upon direct recognition of tumours by specific CD4 T cells suggesting that citrullinated peptides are attractive targets for cancer vaccines.

A qualitative study of cancer survivors' responses to information on the long-term and late effects of pelvic radiotherapy 1-11 years post treatment.

As more patients survive cancer for longer term, the long-term and late effects of treatments become increasingly important issues for cancer survivors and providing information to enable survivors to recognise and manage them becomes an increasingly pressing challenge for health care professionals. The aim of this study was to explore the experiences of cancer survivors regarding information given on potential long-term and late effects of pelvic radiotherapy. Semi-structured interviews were conducted with 28 cancer survivors who had had radiotherapy to the pelvic area for a range of cancers 1-11 years previously. Participants were recruited using maximum variation sampling from a larger questionnaire survey of patients treated at one hospital. Interviews were recorded, transcribed and analysed using Framework. Participants recognised the value of information to reassure and to inform action but also its potentially undesirable effects to frighten or raise anxieties about future problems and its inherent limitations in meeting their wider needs. They identified the timing, amount of information and context in which it was given as of particular importance. Information based on personal experience was also valued. These findings highlight the importance of appropriate, individualised information during treatment, at hospital discharge and subsequently in primary care.

The effects of pelvic radiotherapy on cancer survivors: symptom profile, psychological morbidity and quality of life.

AIMS: As cancer survival rates continue to increase, it is important to maximise the quality of life of cancer survivors. Pelvic radiotherapy is a common cancer treatment. Bladder, bowel and sexual dysfunction are recognised side-effects of treatment, and yet relatively little is known of the extent to which they remain problems in the longer term when patients are often managed by primary care, nor of the psychological impact of symptoms and effects on quality of life. Therefore, the aims of this study were to estimate the prevalence of bladder, bowel and sexual dysfunction late effects in a sample of cancer survivors; assess the impact of time since treatment on symptom prevalence; and explore the relationship between symptoms, psychological morbidity and quality of life. MATERIALS AND METHODS: A questionnaire was given to a sample of cancer survivors treated in Oxford who had pelvic radiotherapy 1-11 years previously. The questionnaire measured patient-reported toxicity (Common Toxicity Criteria of Adverse Events/Late Effects of Normal Tissues--Subjective, Objective, Management and Analytic Measure), psychological morbidity (Hospital Anxiety and Depression Scale) and quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30). RESULTS: In total, 418 (57.1%) completed questionnaires were received. Moderate/severe problems with bowel, urinary and sexual functioning were relatively common: bowel urgency (59% women, 45% men); urine urgency (49% women, 46% men); ability to have a sexual relationship affected (24% women, 53% men). Symptoms were just as frequent in those 6-11 years after treatment as in those 1-5 years after treatment. Symptom severity was significantly associated with poorer overall quality of life and higher levels of depression. CONCLUSIONS: Late effects are common among long-term cancer survivors who have had pelvic radiotherapy, and are associated with reduced quality of life and psychological morbidity. It is imperative due attention is paid to this issue during the follow-up phase--both in secondary and primary care. Health care professionals providing follow-up care need to be aware of the importance of assessing and monitoring symptoms, and need to be adequately informed on the most appropriate management strategies.

High levels of cleaved caspase-3 in colorectal tumour stroma predict good survival.

AIM: The primary aim was to determine the prognostic significance of apoptosis in colorectal tumour cells and tumour-associated stroma. A secondary aim was to determine whether apoptosis was related to immune surveillance. METHODS: Immunohistochemistry was performed using monoclonal antibodies recognising cleaved caspase-3 (CC3), cleaved poly (ADP-ribose) polymerase (PARP), p53, Bcl2, MHC-II, B cells (CD16), macrophages (CD68) and T cells (CD3), on a tissue microarray of 462 colorectal tumours. RESULTS: Kaplan-Meier analysis demonstrated that patients with high expression of CC3 in the tumour or CC3 or cleaved PARP in tumour-associated stroma have a good prognosis. This suggests that tumour stroma is promoting tumourigenesis and that high levels of death within the stroma breaks this link. CC3 levels in the tumour correlated with cleaved PARP and MHC-II expression but not with CD16, CD68, CD3, p53 or Bcl2 expression. CC3 levels on tumour-associated stroma also correlated with cleaved PARP and MHC-II expression but not with CD16, CD68, CD3, p53 or Bcl2 expression. Tumour cells express MHC-II in response to IFN-γ, suggesting that this may be one of the initiators of apoptosis within the good prognosis tumours. Although 73% of the MHC-II-positive tumour had high levels of apoptosis, many tumours had high levels of apoptosis in the absence of MHC-II, implying that this is only one of many causes of apoptosis within tumours. On multivariate analysis, using Cox's proportional hazards model, tumour stage, vascular invasion and expression of CC3 in tumour-associated stroma were shown to be independent markers of prognosis. CONCLUSION: This study shows that a high level of apoptosis within colorectal tumour-associated stroma is an independent marker of good prognosis.

Analysis and characterization of cultivable extremophilic hydrolytic bacterial community in heavy-metal-contaminated soils from the Atacama Desert and their biotechnological potentials.

AIMS: To isolate and characterize the cultivable community of hydrolase producers (amylase, protease, lipase, DNase, xylanase and pullulanase) inhabiting heavy-metal-contaminated soils in extreme conditions from the Atacama Desert. METHODS AND RESULTS: A total of 25 bacterial strains showing hydrolytic activities have been selected including halotolerants, extremely halotolerants and moderate halophiles. Most hydrolase producers were assigned to the family B acillaceae, belonging to the genera Bacillus (nine strains), Halobacillus (seven strains) and Thalassobacillus (five strains) and four isolates were related to members of the families Pseudomonadaceae, Halomonadaceae and Staphylococcaceae. The selected strains were then characterized for their tolerance pattern to six heavy metals, measured as minimal inhibitory concentrations (MICs). CONCLUSIONS: The diversity found in the cultivable bacterial community analysed is more limited than that detected in other ecological studies owing to the restrictive conditions used in the screening. The dominant bacteria were Firmicutes and particularly, species related to the genus Bacillus. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is focused on the characterization of extremophilic hydrolytic bacteria, providing candidates as a source of novel enzymes with biotechnological applications.

The chemokine, CXCL12, is an independent predictor of poor survival in ovarian cancer.

BACKGROUND: The chemokine CXCL12 and its cognate receptor, CXCR4, have been implicated in numerous tumour types where expression promotes tumour growth, angiogenesis, metastasis and suppresses tumour immunity. METHODS: Using a tissue microarray of 289 primary ovarian cancers coupled to a comprehensive database of clinicopathological variables, the expression of CXCL12 and CXCR4 was assessed by immunohistochemistry and its impact in terms of survival and clinicopathological variables was determined. RESULTS: Patients whose tumours expressed high levels of CXCL12 had significantly poorer survival (P=0.026) than patients whose tumours failed to produce this chemokine. Lack of CXCL12 expression within tumours was associated with a 51-month survival advantage for patients when compared with patients whose tumours expressed high levels of CXCL12. FIGO stage, adjuvant chemotherapy and the absence of macroscopic disease after surgery were all shown to predict prognosis independently of each other in this cohort of patients. CXCL12 was independently predictive of prognosis on multivariate analysis (P=0.016). There was no correlation between CXCL12 and any clinicopathological variable. CONCLUSION: The chemokine CXCL12 is an independent predictor of poor survival in ovarian cancer. High expression of CXCL12 was seen in only 20% of the tumours, suggesting a role for anti-CXCL12/CXCR4 therapy in the management of these patients.

Immunology in the clinic review series; focus on cancer: glycolipids as targets for tumour immunotherapy.

Research into aberrant glycosylation and over-expression of glycolipids on the surface of the majority of cancers, coupled with a knowledge of glycolipids as functional molecules involved in a number of cellular physiological pathways, has provided a novel area of targets for cancer immunotherapy. This has resulted in the development of a number of vaccines and monoclonal antibodies that are showing promising results in recent clinical trials.

Single shot tetanus vaccine manufactured by a supercritical fluid encapsulation technology.

Single shot vaccines of tetanus toxoid (TT) were manufactured using the NanoMix process - a low temperature solvent free encapsulation technology using supercritical fluids. The formulations were injected into mice, and compared to multiple injections of a commercially available alum adsorbed TT vaccine. After 5 months the antibody titres were found to be similar for both the alum adsorbed and microparticle formulations, demonstrating for the first time the potential of formulating antigens in PLA microparticles using the supercritical fluid (NanoMix) technique to produce single shot vaccines. The results are likely to be due to the maintenance of toxoid bioactivity and some degree of sustained release of the encapsulated antigens, resulting in repeated stimulation of antigen presenting cells eliminating the need for multiple immunisations. This demonstrates the potential of this supercritical fluid processing technique to reduce the need for booster doses in a vaccine regimen.

Cten signals through integrin-linked kinase (ILK) and may promote metastasis in colorectal cancer.

CTEN/TNS4 is an oncogene in colorectal cancer (CRC), which can induce cell motility although its mechanistic basis of activity and the clinical implications of Cten expression are unknown. As Cten is in complex with integrins at focal adhesions, we hypothesised that it may interact with integrin-linked kinase (ILK). Through forced expression and knockdown of Cten in HCT116 and SW620 (respectively, showing low and high Cten expression), we showed that Cten could regulate ILK. However, inhibition of ILK after forced expression of Cten abrogated the motility-inducing effects of Cten, thereby demonstrating that the Cten-ILK interaction was functionally relevant. Combined knockdown of Cten and ILK had no additive effects on cell motility compared with knockdown of each individually. In order to investigate the clinical implications of Cten expression, a series of 462 CRCs were evaluated by immunohistochemistry. High expression of Cten was associated with advanced Dukes' stage (P<0.001), poor prognosis (P<0.001) and distant metastasis (P=0.008). The role of Cten in metastasis was tested by (a) intrasplenic injection of CRC cells stably transfected with a Cten expression vector into nude mice and (b) testing a series of primary human CRCs and their metastases by immunohistochemistry. Compared with controls, mice injected with cells expressing Cten developed larger tumours in the spleen (P<0.05) and liver (P<0.05). In the human cases, compared with primary tumours, the metastatic deposits had a significantly higher frequency of nuclear localisation of Cten (P=0.002). We conclude that Cten expression is of prognostic significance in CRC, and we delineate a Cten-ILK pathway controlling cell motility and possibly promoting metastasis.

Identification of alpha-beta unsaturated aldehydes as sources of toxicity to activated sludge biomass in polyester manufacturing wastewater.

Wastewater generated in industrial production processes are often contaminated by hazardous chemicals. Characterization by means of toxicity-directed analysis is useful for identifying which fractions of a waste stream possess the most toxicity. We applied this approach to evaluate toxic components of a polyester manufacturing wastewater. Using the reduction in oxygen uptake rate of activated sludge as an indicator of toxicity, it was determined that increasing the pH from 3 to 11 followed by air stripping significantly reduced the toxicity of the wastewater. Comparative headspace GC/MS analysis of wastewater at different pHs selected a group of Volatile Organic Compounds (VOCs) associated with the observed effect of air stripping at pH 11. Ten of these compounds were identified as alpha,beta unsaturated aldehydes (acrolein (2-propenal) congeners); these compounds are known to be toxic as well as mutagenic. Confirmation that these compounds were a cause of toxicity was achieved by demonstrating that removal of these compounds by air stripping significantly reduced the wastewater mutagenic potency in a Salmonella mutagenicity assay. Formation of these volatile compounds by base catalyzed aldol condensation at pH 11 may account for the effectiveness of air stripping in reducing toxicity. To date there is no record in the literature about the toxicity and presence of acrolein congeners in polyester manufacturing wastewater.

CD24 shows early upregulation and nuclear expression but is not a prognostic marker in colorectal cancer.

BACKGROUND AND AIMS: The putative stem cell marker CD24 is a small, heavily glycosylated, cell surface molecule which was originally associated with tumour metastasis. Recently it has been reported to be upregulated and of prognostic importance in colorectal tumours. The study aims to study the prognostic value of CD24 in a large series of colorectal cancer (CRC). METHODS: CD24 protein expression was examined by immunohistochemistry. A total of 10 whole tissue sections (WTS) of adenoma and 345 CRCs arranged as tissue microarrays (TMAs) were evaluated. For comparison with non-neoplastic tissue, 10 WTS containing tumour with associated non-neoplastic tissue were also studied. RESULTS: None of the samples of normal tissue (adjacent to tumour) showed CD24 expression. In the tumours, CD24 expression was seen on the luminal surface of the cells, within the cytoplasm and, unexpectedly, also within the nucleus. Positive immunostaining was seen in 9/10 (90%) adenomas and 313/345 (91%) of CRCs. Weak statistical associations were found between CD24 expression and some clinicopathological features. In contrast to other published studies, however, the analysis did not show any association between CD24 expression and poor prognosis-if anything it was found that loss of CD24 expression appeared to be more related to poor outcome. CONCLUSION: Upregulation of CD24 is an early and common event during the development of CRC and it may be expressed in any cellular compartment, including the nucleus. CD24 is not, however, a good prognostic marker in CRC.

Human leukocyte antigen class I expression is an independent prognostic factor in advanced ovarian cancer resistant to first-line platinum chemotherapy.

BACKGROUND: Loss of HLA class I is important in ovarian cancer prognosis but its role as a prognostic indicator in relation to therapy remains unproven. We studied the prognostic potential of this antigen and its significance in relation to platinum therapy. METHODS: A total of 157 primary ovarian cancers were assessed for HLA class I immunohistochemically and linked to a comprehensive database of clinicopathological variables, treatment details, and platinum sensitivity. RESULTS: Tumours expressing high levels of HLA class I had significantly improved survival (P=0.044). There was a 19-month difference in the median overall survival between tumours with high and low antigen expression. HLA class I antigen expression, stage, and platinum sensitivity were independently predictive of prognosis on multivariate analysis. HLA class I antigen was shown to be expressed at higher levels in patients with good overall survival in platinum-resistant patients (P=0.042). HLA class I significantly correlated with overall survival on multivariate analyses (P=0.034). CONCLUSION: Low-level HLA class I expression is an independent prognostic indicator of poor clinical outcome in ovarian cancer. The survival advantage of patients with platinum-resistant tumours expressing high levels of HLA class I suggests that immunotherapy may be of use in these ovarian cancers resistant to standard chemotherapy.

Antibodies designed as effective cancer vaccines.

Antigen/antibody complexes can efficiently target antigen presenting cells to allow stimulation of the cellular immune response. Due to the difficulty of manufacture and their inherent instability complexes have proved inefficient cancer vaccines. However, anti-idiotypic antibodies mimicking antigens have been shown to stimulate both antibody and T cell responses. The latter are due to T cell mimotopes expressed within the complementarity-determining regions (CDRs) of antibodies that are efficiently presented to dendritic cells in vivo. Based on this observation we have designed a DNA vaccine platform called ImmunoBody, where cytotoxic T lymphocyte (CTL) and helper T cell epitopes replace CDR regions within the framework of a human IgG1 antibody. The ImmunoBody expression system has a number of design features which allow for rapid production of a wide range of vaccines. The CDR regions of the heavy and light chain have been engineered to contain unique restriction endonuclease sites, which can be easily opened, and oligonucleotides encoding the T cell epitopes inserted. The variable and constant regions of the ImmunoBody are also flanked by restriction sites, which permit easy exchange of other IgG subtypes. Here we show a range of T cell epitopes can be inserted into the ImmunoBody vector and upon immunization these T cell epitopes are efficiently processed and presented to stimulate high frequency helper and CTL responses capable of anti-tumor activity.

T-cell responses in osteosarcoma patients vaccinated with an anti-idiotypic antibody, 105AD7, mimicking CD55.

We assessed T-cell responses in young osteosarcoma patients vaccinated with 105AD7, 1-6 months after having received chemotherapy. 105AD7 is a human anti-idiotypic antibody mimicking CD55, a glycoprotein that protects from attack by complement and which is overexpressed on osteosarcoma cells. Seven out of 21 investigated patients made a IFN-gamma T-cell response against the vaccine, 105AD7 as assessed by ELISPOT. Cytokine secretion was analysed using Luminex assays and revealed TNF-alpha and GM-CSF responses not only to the vaccine but also towards the native antigen, CD55, in 5 / 14 (36%) of investigated patients. Importantly, the Luminex assay was found to be more sensitive than the more established T-cell assays (ELISPOT and proliferation assay), since responses towards the native antigen were recorded in this assay. Clinical responses and induction of immune responses to both the anti-idiotype and the native CD55 antigen support the use of CD55 as a target in cancer treatment.

Development of cancer vaccines to activate cytotoxic T lymphocytes.

Cancer vaccines have been shown to stimulate cytotoxic T lymphocyte (CTL) responses in a variety of cancer patients. However, the response is often of low frequency and moderate avidity, and does not result in objective clinical responses. This is related to the target antigens, which are usually over-expressed self-antigens that elicit tolerogenic and regulatory immune responses, resulting in deletion or inactivation of high-avidity T cells. Although moderate-avidity T cells can be efficient killers, tumours are often poor targets as they express a variety of molecules to protect them from cell-mediated immunity. Adoptive transfer of large numbers of high-avidity T cells has been shown to induce regression of bulky disease, proving that immune responses can effectively eradicate tumours. New approaches that target activated dendritic cells in vivo, resulting in cross-presentation of CTL epitopes and release of cytokines that suppress regulatory T cells, have resulted in the production of T cells with sufficient avidity to kill tumour target cells. These approaches in combination with regimes, such as cytokine therapy, chemotherapy or radiotherapy, that modulate effector costimulatory expression on tumour targets may result in more effective second-generation cancer vaccines.

Immune responses to the 105AD7 human anti-idiotypic vaccine after intensive chemotherapy, for osteosarcoma.

105AD7 is a human monoclonal antibody that mimics the complement regulatory protein, CD55, overexpressed by many solid tumours including osteosarcoma. This study was designed to assess the toxicity and efficacy of this vaccine in a young age group of patients within 1-6 months of myleosuppressive chemotherapy. Out of 28, 20 (71%, 95% CI 51-87%) patients showed a significant T-cell proliferation response in vitro to the 105AD7 protein but not to human IgG. Furthermore, 13 out of 22 (59%, 95% CI 36-79%) patients showed antigen-specific gammaIFN secretion (range 20-370 U/ml). Nine out of 28 (32%, 95% CI 16-52%) patients made weak antibody responses to CD55. This study showed that 105AD7 was well tolerated in younger patients with osteosarcoma. In addition, two patients with possible clinical responses were given compassionate permission to continue immunisation quarterly for 2 years. They both remain alive and disease free 5.8 and 6.5 years from original diagnosis of osteosarcoma and showed no adverse effects of repeated immunisation. In conclusion, the majority of patients showed measurable T helper responses when vaccination was commenced within a 6-month window of intensive chemotherapy with no clinically significant toxicity. Future clinical trials incorporating immune stimulation strategies should include early introduction of vaccines during the highest risk period for relapse.