In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: To determine the role of recipient lymphopenia state in the expansion and function of leukemia specific cytotoxic T lymphocytes (CTLs).', 'C57BL/6 mice were induced to lymphopenia with 6 Gy total body irradiation. Spleen T cells or leukemia specific T cells from EGFP+ transgenic C57BL/6-EGFP mice were adoptively transferred by intravenous injection. The mice were challenged subcutaneously with 1 x 10(6) FBL3 leukemic cells at day 2 after irradiation. The peripheral WBC count, percentage of EGFP+ cells, subsets of T cells and tumor sizes were monitored.', 'Both of the spleen T cell and leukemia specific CTL proliferated efficiently with the percentage of EGFP+ cells of 28. 81% and 42.24%, respectively, after infused into lymphopenic recipients. However, spleen T cells had no anti-leukemia effect regardless of its expansion. In contrast, leukemia specific CTLs showed a more rapid and extensive expansion under the condition of lymphopenia and a enhanced anti-leukemia immunity.\Question: Does [ Recipient lymphopenia state enhance the expansion and anti-leukemia effect of leukemia specific cytotoxic T lymphocytes ]?
[EX A]: Transfusion of leukemia specific CTLs under lymphopenia state could be a feasible strategy to expand leukemia specific CTLs and generate favorable anti-leukemia effect in vivo.

[EX Q]: Context: Patient-prosthesis mismatch has been identified as a risk factor for mortality after aortic valve replacement and for structural valve deterioration (SVD) in patients receiving a bioprosthetic aortic valve. The aim of the present study was to compare the incidence of aortic valve bioprosthesis replacement for SVD in patients with mismatch to a population without mismatch.', 'Three hundred eighty-seven adult patients who underwent aortic valve replacement with a bioprosthesis from 1974 to 2009 were retrospectively reviewed. Mismatch was considered to be present if the anticipated indexed effective orifice area was <0.70cm(2) /m(2) . The median follow-up period was 7.2 years. Follow-up was 97% complete.', "Patient-prosthesis mismatch was present in 12% of the study population (n=47). Ten-year freedom from reoperation for aortic bioprosthesis replacement was 74.33.2%. During follow-up, 111 patients underwent reoperation for aortic bioprosthesis replacement. Causes of aortic bioprosthesis replacement were SVD of the bioprosthesis (n=96), paravalvular leak (n=10), and acute endocarditis (n=5). According to unadjusted Kaplan-Meier analysis, patients with mismatch had a higher incidence of aortic bioprosthesis replacement for SVD when compared with patients without mismatch (log rank test: p 0.05). This result was confirmed by multivariable Cox regression analysis, which identified two independent predictors of aortic bioprosthesis replacement for SVD: patients' age (hazard ratio (HR) 0.967) and patient-prosthesis mismatch (HR 2.161).\Question: Does patient-prosthesis mismatch in patients undergoing bioprosthetic aortic valve implantation increase risk of reoperation for structural valve deterioration?
[EX A]: Patients suffering from mismatch were twice as likely to undergo reoperation for aortic bioprosthesis replacement for SVD than those without mismatch.

[EX Q]: Context: Specific and effective therapy for prevention or reversal of bronchiolitis obliterans (BO) is lacking. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF) gene modified mesenchymal stromal cells (MSCs) on BO.', 'A mouse model of experimental BO was established by subcutaneously transplanting the tracheas from C57BL/6 mice into Balb/C recipients, which were then administered saline, Ad-HGF-modified human umbilical cord-MSCs (MSCs-HGF) or Ad-Null-modified MSCs (MSCs-Null). The therapeutic effects of MSCs-Null and MSCs-HGF were evaluated by using fluorescence-activated cell sorting (FACS) for lymphocyte immunophenotype of spleen, enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (rt-PCR) for cytokine expression, and histopathological analysis for the transplanted trachea.', 'The histopathologic recovery of allograft tracheas was improved significantly after MSCs-Null and MSCs-HGF treatment and the beneficial effects were particularly observed in MSCs-HGF-treated mice. Furthermore, the allo-transplantation-induced immunophenotype disorders of the spleen, including regulatory T (Treg), T helper (Th)1, Th2 and Th17, were attenuated in both cell-treated groups. MSCs-HGF treatment reduced expression and secretion of inflammation cytokines interferon-gamma (IFN-), and increased expression of anti-inflammatory cytokine interleukin (IL)-4 and IL-10. It also decreased the expression level of the profibrosis factor transforming growth factor (TGF)-.\Question: Does hepatocyte growth factor enhance the inflammation-alleviating effect of umbilical cord-derived mesenchymal stromal cells in a bronchiolitis obliterans model?
[EX A]:
Treatment of BO with HGF gene modified MSCs results in reduction of local inflammation and promotion in recovery of allograft trachea histopathology. These findings might provide an effective therapeutic strategy for BO.