Validation of a new non-invasive blood pressure measurement method on mice via pulse wave propagation time measurement on a cuff.

In the present article, we describe the validation of a new non-invasive method for measuring blood pressure (BP) which also enables to determine the three BP values: systolic, diastolic and mean value. Our method is based on the pulse transit time (PTT) measurement along an artery directly at the BP cuff. The accuracy of this method was evaluated by comparison with the direct simultaneous measurement of blood pressure from 40 anesthetized female mice. Close correlation between the gained data from these two methods was observed.

Human CD4+ T lymphocytes recognize a vascular endothelial growth factor receptor-2-derived epitope in association with HLA-DR.

PURPOSE: Given the multiple escape mechanisms of tumor cells, immunotherapy targeting tumor-dependent stroma may be an effective cancer treatment strategy. Animal models indicate that inducing immunity to tumor endothelia engenders potent antitumor effects without significant pathology. Recently, the first human tumor endothelial antigen vascular endothelial growth factor receptor-2 (VEGFR-2) recognized by HLA class I-restricted CD8(+) T cells has been characterized. In this study, we sought to investigate specific recognition of this molecule by human CD4(+) T cells. EXPERIMENTAL DESIGN: To identify HLA-DR-restricted antigenic peptides on VEGFR-2 recognized by CD4(+) T cells of healthy donors and cancer patients. RESULTS: Nine candidate VEGFR-2 peptides with high binding probability to six common HLA-DRB1 alleles were synthesized using the SYFPEITHI algorithm. One 15-mer peptide (EKRFVPDGNRISWDS), mapping to the 167-181 region of VEGFR-2, stimulated CD4(+) T cells in association with several HLA-DR alleles, including DR4 and DR7. Importantly, the epitope could be naturally processed and presented both by HLA-DR-matched antigen-expressing proliferating endothelial cells and by dendritic cells loaded with the native antigen. Furthermore, circulating VEGFR-2-specific CD4(+) T cells were detected in 4 of 10 healthy donors and 12 of 40 cancer patients even after single-round peptide stimulation in short-term culture. Patient's T cells could recognize antigen-expressing proliferating endothelial cells in a HLA-DR-restricted fashion. CONCLUSION: These findings indicate an important role for the 167-181 region of VEGFR-2 in the stimulation of CD4(+) T cell responses to VEGFR-2 protein, and may be instrumental both for the development and monitoring of upcoming antitumor vessel vaccines against different cancers based on VEGFR-2 immunogens.

A novel strategy for the discovery of MHC class II-restricted tumor antigens: identification of a melanotransferrin helper T-cell epitope.

CD4+ helper T cells play a critical role in orchestrating host immune responses, including antitumor immunity. The limited availability of MHC class II-associated tumor antigens is still viewed as a major obstacle in the use of CD4+ T cells in cancer vaccines. Here, we describe a novel approach for the identification of MHC class II tumor-associated antigens (TAAs). By combining two-dimensional liquid chromatography and nanoelectrospray ionization tandem mass spectrometry, we developed a highly sensitive method for the detection of human leukocyte antigen (HLA)-DR-associated peptides of dendritic cells upon exposure to necrotic tumor cells. This approach led to the identification of a novel MHC class II-restricted TAA epitope derived from melanotransferrin. The epitope stimulated T cells derived from melanoma patients and healthy individuals and displayed promiscuity in HLA-DR restriction. Moreover, the same peptide was also presented by MHC class II-positive melanoma cells. This strategy may contribute to increase the number of tumor epitopes presented by MHC class II molecules and may support the development of more efficacious vaccines against cancer.