Immunological evaluation of personalized peptide vaccination for patients with histologically unfavorable carcinoma of unknown primary site
CANCER IMMUNOLOGY IMMUNOTHERAPY
Authors: Sakamoto, Shinjiro; Yutani, Shigeru; Shichijo, Shigeki; Morita, Michi; Yamada, Akira; Itoh, Kyogo; Noguchi, Masanori
Abstract
The immunological characteristics of carcinoma of unknown primary site (CUP) are not well established due to inclusion of heterogeneous types of metastatic tumors with the absence of any detectable primary site. We evaluated the immune responses in patients with histologically unfavorable CUP during personalized peptide vaccination (PPV). Ten patients with histologically unfavorable CUP who had been treated by PPV after chemotherapy failure were analyzed. In PPV treatment, up to four human leukocyte antigen-matched peptides of a total 31 peptides were selected according to preexisting host immunity before vaccination and administered subcutaneously. Peptides derived from the Lck antigen were most often chosen for use among all patients. CTL responses were increased in 8 of the 10 and 5 of the five patients tested at the end of the first and second PPV cycles, respectively. Increases in humoral responses after vaccination, including IgG, IgG1, IgG3, IgA, and IgM, were observed against not only the vaccinated peptides but also the non-vaccinated peptides. Severe adverse events due to PPV were not observed. Median overall survival was 13.9 months (95 % CI 4.0-22.5 months). PPV activated both cellular and humoral immune responses to short peptides derived from CTL epitopes in the majority of CUP patients. PPV with Lck-derived peptides may be a feasible, new treatment modality for histologically unfavorable CUP patients due to its safety and strong ability to boost immune responses, although its clinical efficacy remains to be investigated in larger-scale trials.
Spatiotemporal Regulation of Signaling: Focus on T Cell Activation and the Immunological Synapse
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Authors: Garcia, Esther; Ismail, Shehab
Abstract
In a signaling network, not only the functions of molecules are important but when (temporal) and where (spatial) those functions are exerted and orchestrated is what defines the signaling output. To temporally and spatially modulate signaling events, cells generate specialized functional domains with variable lifetime and size that concentrate signaling molecules, enhancing their transduction potential. The plasma membrane is a key in this regulation, as it constitutes a primary signaling hub that integrates signals within and across the membrane. Here, we examine some of the mechanisms that cells exhibit to spatiotemporally regulate signal transduction, focusing on the early events of T cell activation from triggering of T cell receptor to formation and maturation of the immunological synapse.