T-lymphocytes from focused ultrasound ablation subsequently mediate cellular antitumor immunity after adoptive cell transfer immunotherapy.

Background: Our previous studies found that high-intensity focused ultrasound (HIFU) stimulated tumor-specific T cells in a mouse H22 tumor model, and adoptive transfer of the T cells from HIFU-treated mice could subsequently elicit stronger inhibition on the growth and progression of the implanted tumors. The aim of this study was to investigate the mechanism of T cells from focused ultrasound ablation in HIFU-mediated immunomodulation. Methods: Sixty H22 tumor-bearing mice were treated by either HIFU or sham-HIFU, and 30 naïve syngeneic mice served as controls. All mice were euthanized on day 14 after HIFU and splenic T cell suspensions were obtained in each group. Using an adoptive cell transfer model, a total of 1 × 106 T cells from HIFU treated-mice were intravenously injected into each syngeneic H22 tumor-bearing mouse twice on day 3 and 4, followed by the sacrifice for immunological assessments at 14 days after the adoptive transfer. Results: T cells from HIFU-treated mice could significantly enhance the cytotoxicity of CTLs (p < 0.001), with a significant increase of TNF-α (p < 0.001) and IFN-γ secretion (p < 0.001). Compared to control and sham-HIFU groups, the number of Fas ligand+ and perforin+ tumor-infiltrating lymphocytes (TILs) and apoptotic H22 tumor cells were significantly higher (p < 0.001) in the HIFU group. There were linear correlations between apoptotic tumor cells and Fas ligand+ TILs (r = 0.9145, p < 0.001) and perforin+ TILs (r = 0.9619, p < 0.001). Conclusion: T cells from HIFU-treated mice can subsequently mediate cellular antitumor immunity, which may play an important role in the HIFU-based immunomodulation.

Specific antitumour immunity of HIFU-activated cytotoxic T lymphocytes after adoptive transfusion in tumour-bearing mice.

PURPOSE: The aim of this study was to investigate the specific anti-tumour immunity of cytotoxic T lymphocytes (CTL) activated by high-intensity focused ultrasound (HIFU) after adoptive transfer in a murine tumour model. MATERIALS AND METHODS: H22 tumour-bearing mice were treated by either HIFU or sham-HIFU, while naïve syngeneic mice were used as controls. They were sacrificed and the spleens were harvested 14 days after HIFU. T lymphocytes were obtained from the spleens, and then adoptively transferred into 40 mice each bearing a 3-day implanted H22 tumour. On day 14 after adoptive transfer, 10 mice were sacrificed in each group for assessment of the number of tumour-infiltrating T lymphocytes and interferon-gamma (IFN-γ) secreting cells. The remaining 30 mice were continuously observed for 60 days, and tumour growth, progression and survival were recorded. RESULTS: HIFU significantly increased peripheral blood CD3(+), CD4(+) levels and CD4(+)/CD8(+) ratio (P < 0.05), CTL cytotoxicity (P < 0.01) and IFN-γ and TNF-α secretion (P < 0.01) in H22 tumour-bearing mice. Adoptive transfer of HIFU-activated T lymphocytes into the autologous tumour-bearing mice induced a significant increase of tumour-infiltrating T lymphocytes and IFN-γ-secreting cells (P < 0.001). Compared to the control and sham-HIFU groups, HIFU-activated lymphocytes elicited significant inhibition of in vivo tumour growth (P < 0.01) and progression (P < 0.0001), and longer survival time in the tumour-bearing mice (P < 0.001). CONCLUSIONS: HIFU could enhance CTL's specific antitumour immunity. Adoptive transfer of HIFU-activated T lymphocytes could increase local antitumour immunity, and elicit stronger inhibition on tumour growth and progression, with more survival benefit in the autologous tumour-bearing mice.

[Study on relationship between alfalfa canopy spectral reflectance and leaf water content].

In the present study, alfalfa canopy reflectance was researched at alfalfa squaring period under different irrigation amount at the hutubi county grassland ecological station. Determining the spectral diagnostic model of alfalfa leaf moisture content was determined by spectrometry. The results showed that (1) The spectral reflectance of alfalfa canopy gradually decreases with the increase in the leaf water content in the near infrared. (2) The spectral inversion model of alfalfa leaf moisture content established by normalized reflectance spectra is superior to the original reflectance spectra, and the prediction model established in the 1,344-1,660 nm band has the lowest average relative error (7.8%). (3) In this study, the spectral diagnostic model of the leaf moisture content is: Y=0.962 - 7.560X1451 + 5.295X1473. The spectral prediction model of the alfalfa leaf moisture content can provide a basis for decision making for scientific irrigation of alfalfa.

High-intensity focused ultrasound tumor ablation activates autologous tumor-specific cytotoxic T lymphocytes.

Previous studies have shown that high-intensity focused ultrasound (HIFU) ablation can enhance host antitumor immune response, though the mechanism is still unknown. In the present study, we investigated whether HIFU ablation could activate tumor-specific T lymphocytes and then induce antitumor cellular immunity. We studied 70 C57BL/6J mice bearing the H(22) tumor; they were randomly divided into a HIFU group and a sham-HIFU group. Of the mice, 35 in the HIFU group underwent HIFU ablation of the H(22) hepatic tumor, and the remaining 35 received a sham-HIFU procedure. In addition, 35 female, naïve syngeneic C57BL/6J mice were used as controls. All mice were sacrificed 14 days after HIFU, and the spleens were harvested. The function of T lymphocytes was determined. As a valuable tool for detecting and characterizing peptide-specific cells, the frequency of MHC class I tetramer/CD8-positive cells was quantified, which could help to determine the response and number of T lymphocytes. The therapeutic effect of the HIFU-activated lymphocytes on tumor-bearing mice was investigated after adoptive transfer of the lymphocytes. The results showed that compared to sham-HIFU and control groups, HIFU ablation significantly increased the cytotoxicity of cytotoxic T lymphocytes (p < 0.05), with a significant increase of IFN-γ and TNF-α secretion (p < 0.001). The frequency of the MHC class I tetramer/CD8-positive cells was significantly higher in the HIFU group (p < 0.05). A stronger inhibition of tumor progression and higher survival rates were observed to be significant after adoptive immunotherapy in the HIFU group as compared to the sham-HIFU and control groups (p < 0.01). It is concluded that HIFU ablation could activate tumor-specific T lymphocytes, thus inducing antitumor cellular immune responses in tumor-bearing mice.