Efficient mapping and characterization of a T cell epitope by the simultaneous synthesis of multiple peptides

Prediction, identification and analysis of T cell epitopes in protein antigens has become a central theme in fundamental and applied immunology. However, while for the characterization of linear B cell epitopes the so-called Pepscan procedure was found to be extremely effective, no such technique has so far been available for T cell studies. Recently, we described the identification and localization of a T cell epitope in a mycobacterial 65-kDa shock protein in the model of adjuvant arthritis. This was done by molecular cloning and conventional solid-phase synthesis techniques. We now show that the delineation of such a T cell epitope and its further characterization can be accomplished in a much more rapid and efficient manner by a modification of the existing Pepscan technique. We show for the first time that several hundreds of peptides, simultaneously synthesized in an automated way on activated polyethylene rods, can be easily recovered from these rods in adequate quantities, enabling a systematic analysis of T cell epitopes. Synthesis of sequentially overlapping peptides along the 65-kDa protein revealed that the adjuvant arthritis T cell clones are fully stimulated by peptides that comprise a minimal sequence of seven residues, corresponding to positions 180-186 in the sequence of the 65-kDa protein of M. bovis Bacillus Calmette Guerin (BCG). Detailed examination of the epitope by peptides containing a single amino acid substitution showed that, apart from one conservative replacement (Glu----Asp), the requirement for the native residue at all positions in peptide 180-186 was absolute for full T cell stimulation. Their indispensability was confirmed with deletion and insertion peptides. It is concluded that the occurrence of indifferent or spacer residues in a minimal stimulatory sequence, as observed by others, is not a general feature of T cell epitopes.     

17β-Estradiol protects the esophageal epithelium from IL-13–induced barrier dysfunction and remodeling

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French American British (FAB) morphological classification of childhood lymphoblastic leukaemia and its clinical importance

As part of the Medical Research Council Leukaemia Trial UKALL VIII, 738 unselected children with acute lymphoblastic leukaemia (ALL) had the morphology of their marrow blast cells reviewed by a panel of three haematologists. Ninety four (13%) showed appearances classifiable as type L2 by the French American and British (FAB) cooperative group's criteria, five (0.7%) were typed L3, and the remaining 639 (86%) as L1. Disregarding the patients classified as L3, those with the L2 variant showed an inferior disease free survival to that of the remainder (p less than 0.01), and more of them failed to remit after receiving "standard" remission induction treatment (p less than 0.01). They included an excess of older children (p less than 0.01) with less profound marrow failure at diagnosis, and fewer of them expressed the common ALL antigen (p = 0.05). There was no association between L2 morphology and the diagnostic white cell count, sex, or the presence of a mediastinal mass. These findings confirm earlier reports that FAB L2 ALL is associated with a poor prognosis and that it occurs more commonly in older children. The high remission failure rate is a recent observation and indicates that alternative early treatment may be appropriate for such patients.     

Improved fixation of the pigeon brain by transcardiac carotid catheterization

We describe a technique of selective and controlled fixation of the brain and upper spinal cord in the adult pigeon by in vivo transcardiac bilateral carotid catheterization and pump perfusion. We were unable to achieve adequate and repeated fixation of these structures for histochemical techniques in the pigeon using the conventional intracardiac perfusion techniques described for mammals. Our intracarotid technique yields a blood-free and well fixed brain and upper spinal cord. A series of intracarotid pump perfusions (saline, fixative, and sucrose buffer) has significantly reduced histochemical processing time by allowing immediate cryosectioning of the dissected brain.     

Breast conservation therapy confers survival and distant recurrence advantage over mastectomy for stage II Triple Negative Breast cancer

IntroductionRecent studies suggest survival benefit of breast conservation over mastectomy. We evaluated distant recurrence (DR) rates after breast-conservation therapy (BCT) versus mastectomy in our community-based cancer institute.MethodsA retrospective review of patients undergoing treatment of Stage 0–3 breast cancer from January, 2002 to December, 2011 was performed. We evaluated outcomes between those having BCT versus mastectomy.ResultsWe reviewed 4876 patients. There was no significant difference in DR between patients undergoing BCT versus mastectomy in DCIS (n = 904; BCS 521, mastectomy 383; DR = 1/521 vs 1/383; p = 0.09), Stage I (n = 2202; BCT 1505, mastectomy 697; DR = 6/1505 vs 17/697; p = 0.98) or Stage III cancer (n = 417; BCT 87, mastectomy 330; DR = 17/87 vs 59/330; p = 0.50). There was significantly less DR in Stage II patients (n = 1353) undergoing BCT vs mastectomy (32/645 vs 64/708; p = 0.003). Subgroup analysis of Stage II TNBC (n = 198) subgroup analysis showed 104 mastectomy and 94 BCT patients. Those in the BCT group had significantly lower rates of DR (6/94 vs 16/104; p= 0.03) and significantly higher survival (81/94 vs 69/104; p = 0.007) than those undergoing mastectomy. Of Stage II TNBC patients with DR there was no difference in age, lymph node status or tumor size (p > 0.05 for all) in BCT versus mastectomy groups; there was a significant difference in radiation status (94/94 vs. 28/104; p < 0.0001). Radiation was associated with worse outcomes in the mastectomy group (HR 2.32; p = 0.04).ConclusionsWe found significantly less DR in Stage II patients undergoing BCT vs mastectomy. This benefit includes a survival advantage in patients with TNBC undergoing BCT. We could not identify an explanatory factor. Until the difference is understood eligible patients with TNBC should be encouraged to undergo BCT.     

Neutrophil-to-Lymphocyte Ratio Predicts Recurrence Pattern in Patients with Resectable Colorectal Liver Metastases

Annals of Surgical Oncology - Studies have suggested that neutrophil-to-lymphocyte ratio (NLR) has value as a predictor of long-term outcomes in various cancer types. Its prognostic potential in...     

ASO Visual Abstract: Neutrophil-to-Lymphocyte Ratio Predicts Recurrence Pattern in Patients with Resectable Colorectal Liver Metastases

Annals of Surgical Oncology -