Identification of antigens presented by MHC for vaccines against tuberculosis

Mycobacterium tuberculosis (M.tb) is responsible for more deaths globally than any other pathogen. The only available vaccine, bacillus Calmette-Guérin (BCG), has variable efficacy throughout the world. A more effective vaccine is urgently needed. The immune response against tuberculosis relies, at least in part, on CD4+ T cells. Protective vaccines require the induction of antigen-specific CD4+ T cells via mycobacterial peptides presented by MHC class-II in infected macrophages. In order to identify mycobacterial antigens bound to MHC, we have immunoprecipitated MHC class-I and class-II complexes from THP-1 macrophages infected with BCG, purified MHC class-I and MHC class-II peptides and analysed them by liquid chromatography tandem mass spectrometry. We have successfully identified 94 mycobacterial peptides presented by MHC-II and 43 presented by MHC-I, from 76 and 41 antigens, respectively. These antigens were found to be highly expressed in infected macrophages. Gene ontology analysis suggests most of these antigens are associated to membranes and involved in lipid biosynthesis and transport. The sequences of selected peptides were confirmed by spectral match validation and immunogenicity evaluated by IFN-gamma ELISpot against peripheral blood mononuclear cell from volunteers vaccinated with BCG, M.tb latently infected subjects or patients with tuberculosis disease. Three antigens were expressed in viral vectors, and evaluated as vaccine candidates alone or in combination in a murine aerosol M.tb challenge model. When delivered in combination, the three candidate vaccines conferred significant protection in the lungs and spleen compared with BCG alone, demonstrating proof-of-concept for this unbiased approach to identifying new candidate antigens

Phase I Evaluation of Intravenous Ascorbic Acid in Combination with Gemcitabine and Erlotinib in Patients with Metastatic Pancreatic Cancer

Preclinical data support further investigation of ascorbic acid in pancreatic cancer. There are currently insufficient safety data in human subjects, particularly when ascorbic acid is combined with chemotherapy.14 subjects with metastatic stage IV pancreatic cancer were recruited to receive an eight week cycle of intravenous ascorbic acid (three infusions per week), using a dose escalation design, along with standard treatment of gemcitabine and erlotinib. Of 14 recruited subjects enrolled, nine completed the study (three in each dosage tier). There were fifteen non-serious adverse events and eight serious adverse events, all likely related to progression of disease or treatment with gemcitabine or erlotinib. Applying RECIST 1.0 criteria, seven of the nine subjects had stable disease while the other two had progressive disease.These initial safety data do not reveal increased toxicity with the addition of ascorbic acid to gemcitabine and erlotinib in pancreatic cancer patients. This, combined with the observed response to treatment, suggests the need for a phase II study of longer duration.Clinicaltrials.gov NCT00954525

A comparison of the WHO 2004 and 2010 classification systems in pancreatic neuroendocrine tumors (Pancreatic NET)

Pancreatic NETs are rare tumors with multiple classification systems. Previous classification systems included tumor size, histologic grade, mitoses, Ki67, and metastases. The current WHO 2010 system utilizes mitotic rate and Ki67% to assign a grade. We compared the WHO 2004 and 2010 classification systems in predicting mortality and metastasis. Pathologic parameters were used to classify 50 cases of Pancreatic NET according to the WHO 2004 and WHO 2010 systems. The relationship between the WHO 2004 and WHO 2010 grading was investigated using an exact Chi squared test. WHO grade categorization was next explored by vital status, by the exact method, in order to determine if there was a difference in survivorship and metastasis by grading system. Associations between death and categorical variables were tested using exact methods and between death and continuous variables by the Wilcoxon test. Survival was explored using Cox Proportional Hazards regression (Cox). The WHO grades were significantly associated with one another (

Peak plasma ascorbic acid concentrations in millimoles/L after the initial dose and final dose (measurements after the final dose were unavailable for patients 008 and 014).

<p>The green line represents the highest plasma concentration expected with maximally tolerated oral doses of ascorbic acid <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029794#pone.0029794-Padayatty3" target="_blank">[13]</a>.</p

Patient demographics and disease status.

<p>Bone = bone metastases.</p><p>Liver = liver metastases.</p><p>Locally adv = locally advanced spread of cancer.</p><p>Abdomen = Metastases within the abdomen distant from the pancreas.</p><p>Lung = lung metastases.</p><p>Media = mediastinal metastases.</p><p>Peritoneal = peritoneal metastases.</p><p>Retroper = retroperitoneal nodes or metastases.</p><p>*Patient died during study.</p><p>**Weights were obtained on the first and last day of the ascorbic acid infusions.</p

Adverse Event Chart for all 14 patients (based on standard NCI criteria).

<p>Adverse Event Chart for all 14 patients (based on standard NCI criteria).</p

Study CONSORT flow diagram.

<p>Study CONSORT flow diagram.</p

Response to ascorbic acid plus gemcitabine based on CT findings in patients with scans pre and post the 8 week ascorbic acid treatment cycle plus gemcitabine/erlotinib (these data only include patients that completed both pre and post-treatment CT imaging and not the additional five patients who terminated participation early).

<p>SD = Stable Disease.</p><p>PD = Progressive Disease.</p