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Background/aims: Hepatocellular carcinoma (HCC) is a leading indication for liver transplantation (LT) worldwide. Early identification of patients at risk for HCC recurrence is of paramount importance since early treatment of recurrent HCC after LT may be associated with increased survival. We evaluated incidence of and predictors for HCC recurrence, with a focus on the course of AFP levels.
Methods: We performed a retrospective, single-center study of 99 HCC patients who underwent LT between January 28th, 1997 and May 11th, 2016. A multi-stage proportional hazards model with three stages was used to evaluate potential predictive markers, both by univariate and multivariable analysis, for influences on 1) recurrence after transplantation, 2) mortality without HCC recurrence, and 3) mortality after recurrence.
Results: 19/99 HCC patients showed recurrence after LT. Waiting time was not associated with overall HCC recurrence (HR = 1, p = 0.979). Similarly, waiting time did not affect mortality in LT recipients both with (HR = 0.97, p = 0.282) or without (HR = 0.99, p = 0.685) HCC recurrence. Log10-transformed AFP values at the time of LT (HR 1.75, p = 0.023) as well as after LT (HR 2.07, p = 0.037) were significantly associated with recurrence. Median survival in patients with a ratio (AFP at recurrence divided by AFP 3 months before recurrence) of 0.5 was greater than 70 months, as compared to a median of only 8 months in patients with a ratio of 5.
Conclusion: A rise in AFP levels rather than an absolute threshold could help to identify patients at short-term risk for HCC recurrence post LT, which may allow intensification of the surveillance strategy on an individualized basis.
In ischemic vascular diseases, leukocyte recruitment and polarization are crucial for revascularization and tissue repair. We investigated the role of vasodilator-stimulated phosphoprotein (VASP) in vascular repair. After hindlimb ischemia induction, blood flow recovery, angiogenesis, arteriogenesis, and leukocyte infiltration into ischemic muscles in VASP−/− mice were accelerated. VASP deficiency also elevated the polarization of the macrophages through increased signal transducer and activator of transcription (STAT) signaling, which augmented the release of chemokines, cytokines, and growth factors to promote leukocyte recruitment and vascular repair. Importantly, VASP deletion in bone marrow–derived cells was sufficient to mimic the increased blood flow recovery of global VASP−/− mice. In chemotaxis experiments, VASP−/− neutrophils/monocytes were significantly more responsive to M1-related chemokines than wild-type controls. Mechanistically, VASP formed complexes with the chemokine receptor CCR2 and β-arrestin-2, and CCR2 receptor internalization was significantly reduced in VASP−/− leukocytes. Our data indicate that VASP is a major regulator of leukocyte recruitment and polarization in postischemic revascularization and support a novel role of VASP in chemokine receptor trafficking.
Neoepitope-specific T-cell responses have been shown to induce durable clinical responses in patients with advanced cancers. We explored the recognition patterns of tumor-infiltrating T lymphocytes (TILs) from patients with glioblastoma multiforme (GBM), the most fatal form of tumors of the central nervous system. Whole-genome sequencing was used for generating DNA sequences representing the entire spectrum of ‘private’ somatic mutations in GBM tumors from five patients, followed by 15-mer peptide prediction and subsequent peptide synthesis. For each mutated peptide sequence, the wildtype sequence was also synthesized and individually co-cultured with autologous GBM TILs, which had been expanded in vitro with a combination of interleukin (IL)-2, IL-15 and IL-21. After seven days of culture, interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α) and/or IL-17A production was measured by ELISA in culture supernatants, and used as an epitope-specific immune response readout. Mutated peptides that induced a strong cytokine response were considered to contain legitimate neoepitopes. TILs from 5/5 patients with GBM exhibited specific immune reactivity profiles to the nominal target peptides, defined by IFN-γ and/or TNF-α production, as well as IL-17A. Neoepitopes, defined by mutated peptides inducing IFN-γ and/or TNF-α production without or only minimal reactivity to the wildtype sequences, were found for each individual patient. CD8+ TILs dominated the patients’ responses to private neoepitopes. The present study shows that neoepitope-specific TIL reactivity constitutes an important arm of anti-tumor immune responses in patients with GBM, and thus a powerful tool for developing next-generation personalized immunotherapies.
Although essential for T cell function, the identity of the T cell receptor (TCR) “inside-out” pathway for the activation of lymphocyte function-associated antigen 1 (LFA-1) is unclear. SKAP1 (SKAP-55) is the upstream regulator needed for TCR-induced RapL-Rap1 complex formation and LFA-1 activation. In this paper, we show that SKAP1 is needed for RapL binding to membranes in a manner dependent on the PH domain of SKAP1 and the PI3K pathway. A SKAP1 PH domain-inactivating mutation (i.e. R131M) markedly impaired RapL translocation to membranes for Rap1 and LFA-1 binding and the up-regulation of LFA-1-intercellular adhesion molecule 1 (ICAM-1) binding. Further, N-terminal myr-tagged SKAP1 for membrane binding facilitated constitutive RapL membrane and Rap1 binding and effectively substituted for PI3K and TCR ligation in the activation of LFA-1 in T cells.