L. K. Borysiewicz

Cytotoxic T cell immunity to human cytomegalovirus glycoprotein B

Human cytomegalovirus (HCMV) is associated with significant morbidity and mortality following immunosuppression and in pregnancy. HCMV infection may be accompanied by acute disease but persists asymptomatically. Cytotoxic T lymphocytes (CTL) appear to be an important immune effector mechanism in maintaining the normal host‐virus equilibrium. Glycoprotein B may be an important target for future subunit vaccines as it has been found to elicit both neutralising antibody and CTL responses.

Acute fatigue in chronic fatigue syndrome patients

BACKGROUND Chronic fatigue syndrome (CFS) patients often complain that they are more susceptible to acute mental fatigue. It is important to determine whether this is observed using objective tests of sustained attention and responding. METHODS Sixty-seven patients who fulfilled the criteria for CFS proposed by Sharpe et al. (1991) were compared with 126 matched healthy controls. Acute fatigue was assessed by comparing performance at the start and end of a lengthy test session and by examining changes over the course of individual tasks. RESULTS CFS patients showed impaired performance compared to the controls and these differences increased as the volunteers developed acute fatigue. In addition, differences between the two groups were larger at the end of the test session. CONCLUSIONS The present results show that CFS patients are more susceptible to acute fatigue than healthy controls. This could reflect motor fatigue or an inability to compensate for fatigue with increased effort. This profile is consistent with previous research on fatigue and suggests that interpretation of certain aspects of CFS may be helped by considering it as the end point of a continuum of fatigue rather than a distinct disease.

The relationship between subjective ratings of sleep and mental functioning in healthy subjects and patients with chronic fatigue syndrome

The present study examined the relationships between subjective reports of sleep and mental functioning. This was done both for healthy subjects and chronic fatigue syndrome patients, a group who frequently report sleep disorders. Sleep abnormalities were found to be related to personality and to state measures of physical and mental health. Distractability, as measured by the Stroop task, was also related to sleep disorder. The psychomotor slowing observed in the chronic fatigue syndrome patients was not modified by sleep status. However, the problems of memory and sustained attention found in the patients were restricted to those subgroups with sleep disorders.

Consequences of live poliovirus vaccine administration in chronic fatigue syndrome

The effect of live oral polio virus vaccination on chronic fatigue syndrome (CFS) patients was examined in a double-blind study. CFS patients were allocated randomly to placebo (N = 7) or vaccine (N = 7) conditions. All controls subjects received the vaccine (9). Vaccine administration was not associated with clinical exacerbation of CFS. However, objective responses to the vaccine revealed differences between patients and controls: increased poliovirus isolation, earlier peak proliferative responses, lower T-cell subsets on certain days post vaccination and a trend for reduced gamma-interferon in the CFS-vaccine group. Polio vaccination was not found to be clinically contraindicated in CFS patients, however, there was evidence of altered immune reactivity and virus clearance.

Clinical studies of human papilloma vaccines in cervical cancer

Cervical cancer is the second most common cause of cancer death world wide’ and is a particular problem in developing countries. Even with optimum treatment approximately 40% continue to die from this disease.2There is therefore a need for new strategies to reduce global mortality, including immunotherapeutic intervention.

Generation of in Vitro Autologous Human Cytotoxic T-Cell Response to E7 and HER-2/Neu Oncogene Products Using Ex-Vivo Peptide Loaded Dendritic Cells

Cytotoxic T-cells (CTL) have been shown to be capable of causing tumour-specific cell lysis when primed with tumour-specific antigenic peptides presented in conjunction with haplotype matched cell surface MHC class I molecules. For this approach to be successful for immunotherapy of tumours in vivo, it is essential that it is shown to be capable of generating adequate numbers of tumour-specific CTL either in vivo for active immunisation, or ex vivo for adoptive transfer therapy. A powerful means for ex vivo expansion of CTL has been recently shown to be antigen loaded autologous dendritic cells (DC)1. It has also become possible to generate large numbers of these cells from bone marrow or blood derived precursor cells cultured in the presence of GM-CSF and 1L42. Furthermore, murine studies have confirmed the efficacy of these cells to evoke significant ex vivo and in vivo responses against tumour specific antigenic peptides, in particular, HPV 16 E7 and HER-2/neu oncogene products3, thereby creating the possibility of using these antigenic targets4 for effective immunotherapy of gynaecological cancers such as cervical and ovarian carcinomas in which these tumour associated antigens are expressed with 93%5 and 30%6 frequency, respectively.

Therapeutic vaccines for cervical cancer: concept and clinical results

SummaryHuman papillomavirus (HPV) infection is associated with transformation and clonal expansion of infected epithelial cells, resulting in the production of a benign growth, i.e. a wart. Recently, however, HPV has emerged as the primary causative agent of cervical carcinoma, malignancy being associated with the presence of the viral genome (predominantly genotypes 16 and 18) in cancerous cells. The only HPV proteins reliably expressed in neoplastic lesions are the ‘oncogenic’ E6 and E7 proteins, that serve both as tumour-specific markers and potential targets for immunotherapeutic intervention. As intracellular (nuclear) proteins, the E6 and E7 gene products may be hidden from the humoral immune response. Attention has thus focused on the generation of a vaccine capable of inducing or stimulating a cellular immune response to HPV 16 and HPV 18 E6 and E7. Vaccine development has been constrained by the absence of an appropriate animal model, the oncogenic nature of E6 and E7 and technical difficulties associated with detection of cytotoxic T cell responses to these antigens. Despite these difficulties, vaccine strategies have now been devised based on immunisation with synthetic peptide, whole protein and a vaccinia virus recombinant. Phase I/II human clinical trials have been initiated, and preliminary results have demonstrated the induction of specific cellular immune responses after immunisation. The HPV-associated neoplasia in cervical cancer represents an excellent target for therapeutic intervention because the tumour-associated antigens are so clearly defined. As such, it provides an appropriate model for establishing the general principles of cancer immunotherapy in humans.

Infiltration of cervical cancer tissue with human papilloma virus-specific cytotoxic T-lymphocytes

CTLs specific for high-risk human papillomaviruses (HPVs) have recently been found in the peripheral blood of cervical cancer patients. Although cell-mediated immunity is thought to be important in the control of HPV infection, the functional relevance and site of activation of HPV-specific CTLs are unclear. We identified HLA-A*0201-restricted HPV-16 E7 peptide-specific CTLs in the peripheral blood (four of five patients), draining lymph nodes (three of four patients) and tumors (one of three patients) of cervical cancer patients. In four of four cancer patients, the frequency of CTLs specific for a recombinant vaccinia virus expressing HPV-16 and -18 E6/E7 gene products was found to be higher in tumors and lymph nodes compared with that of peripheral blood. HPV-specific CTLs were not identified in any of seven healthy controls, but primary responses could be generated by peptide-pulsed dendritic cells (four of four controls). In a non-HLA-A*0201 subject with invasive carcinoma, other HLA alleles also presented HPV antigens. This is the first demonstration that virus-specific CTLs infiltrate the virus-associated tumor, where they may play an important role in restricting disease progression.

Development and initial clinical studies of TA-HPV in cervical cancer

Cervical cancer is associated with human papillomavirus (HPV) infection in >94% of cases, usually HPV strain 16 or 18. In the transformed cells continued expression of two intra-cellular, non-structural viral proteins, termed E6 and E7, is required to maintain the malignant phenotype. These proteins are potential targets for immunotherapy, particularly by cytotoxic T cells.A recombinant (TA-HPV) was made, in which E6 and E7 genes of both strains were fused and inserted into Wyeth strain vaccinia. Furthermore E7 was modified to inactivate the Rb binding site, largely removing its oncogenic potentialThis construct has been used to vaccinate 8 patients with established cervical cancer, under contained environmental release conditions. Clinical follow up is still in progress but no side effects of vaccination have been observed, after up to a year, despite subsequent chemo- and radio-therapy. No environmental contamination has been detected and the recombinant is stable after human inoculation.Serological response to the inserted sequences has been observed in 3 of 3 patients. Assays for human HPV specific CTL are difficult but we have developed an assay, using adenovirus recombinants expressing HPV E6 & E7 for in vitro expansion of CTL from PBMC. Studies are in progress to determine if TA-HPV induces this specific response in vaccine recipients.