Vaccine-induced tumor regression requires a dynamic cooperation between T cells and myeloid cells at the tumor site.

Most cancer immunotherapies under present investigation are based on the belief that cytotoxic T cells are the most important anti-tumoral immune cells, whereas intra-tumoral macrophages would rather play a pro-tumoral role. We have challenged this antagonistic point of view and searched for collaborative contributions by tumor-infiltrating T cells and macrophages, reminiscent of those observed in anti-infectious responses. We demonstrate that, in a model of therapeutic vaccination, cooperation between myeloid cells and T cells is indeed required for tumor rejection. Vaccination elicited an early rise of CD11b+ myeloid cells that preceded and conditioned the intra-tumoral accumulation of CD8+ T cells. Conversely, CD8+ T cells and IFNγ production activated myeloid cells were required for tumor regression. A 4-fold reduction of CD8+ T cell infiltrate in CXCR3KO mice did not prevent tumor regression, whereas a reduction of tumor-infiltrating myeloid cells significantly interfered with vaccine efficiency. We show that macrophages from regressing tumors can kill tumor cells in two ways: phagocytosis and TNFα release. Altogether, our data suggest new strategies to improve the efficiency of cancer immunotherapies, by promoting intra-tumoral cooperation between macrophages and T cells.

Impact of postgrafting immunosuppressive regimens on nonrelapse mortality and survival after nonmyeloablative allogeneic hematopoietic stem cell transplant using the fludarabine and low-dose total-body irradiation 200-cGy.

The development of nonmyeloablative (NM) hematopoietic cell transplantation (HCT) has extended the potential curative treatment option of allografting to patients in whom it was previously contraindicated because of advanced age or comorbidity. Acute and chronic graft versus host disease (GVHD) and its consequent nonrelapse mortality (NRM), remains the major limitation of NM HCT. In this report, we analyzed the outcome of 67 patients (median age, 45 years) with hematologic diseases receiving NM conditioning with fludarabine 90 mg/m(2) and total body irradiation (TBI) 200-cGy, followed by filgrastim-mobilized peripheral blood stem cell transplant from HLA identical (n = 61), 5/6 antigen-matched related (n = 1), 6/6 antigen-matched unrelated (n = 3), and 5/6 antigen-matched unrelated (n = 2) donors. The first cohort of 21 patients were given cyclosporine (CSP) and mycophenolate mofetil (MMF) as postgrafting immunosuppression, whereas the subsequent cohort was given additional methotrexate (MTX) and extended duration of CSP/MMF prophylaxis in an attempt to reduce graft-versus-host disease (GVHD). Sixty-four (95%) patients engrafted and 3 (5%) had secondary graft failure. Myelosuppression was moderate with neutrophil counts not declining below 500/microL in approximately 25% of patients, and with more than half of the patients not requiring any blood or platelet transfusion. The 2-year cumulative interval (CI) of grade II-IV, grade III-IV acute GVHD and chronic GVHD were 49%, 30%, and 34%, respectively. The 2-year probability of NRM, overall (OS), and progression-free (PFS) survival were 27%, 43%, and 28%, respectively. GVHD-related death accounted for 85% of NRM. Compared with patients receiving CSP/MMF, patients receiving extended duration of CSP/MMF with additional MTX in postgrafting immunosuppression had a significantly lower risk of grade III-IV acute GVHD (CI 20% versus 52%; P = .009) and NRM (CI at 2 years: 11% versus 62%; P < .001), without any significant adverse impact on the risk of relapse (CI at 2 years: 59% versus 33%; P = .174) Subgroup analysis of a cohort of patients given MTX/CSP/MMF showed that patients with "standard risk" diseases (n = 21) had a 3-year OS and PFS of 85% and 65%, respectively. This compares favorably to the 41% (P = .02) and 23% (P = .03) OS and PFS, respectively, in patients with "high-risk" diseases (n = 25). In conclusion, the addition of MTX onto the current postgrafting immunosuppression regimen with extended CSP/MMF prophylaxis duration provides more effective protection against severe GVHD, and is associated with more favorable outcome in patients receiving NM fludarabine/TBI conditioning than in patients receiving fludarabine/TBI conditioning with CSP and MMF without MTX.

CYP1A1 polymorphisms and risk of lung cancer in non-smoking Chinese women: influence of environmental tobacco smoke exposure and GSTM1/T1 genetic variation.

OBJECTIVE: We examined whether polymorphisms of CYP1A1, which plays a role in the metabolic activation of polycyclic aromatic hydrocarbons (PAHs), confer an increased risk of lung cancer in lifetime non-smoking Chinese women. METHODS: A total of 126 incident lung cancer cases, of which 87.7 were pathologically confirmed, and 162 age-matched hospital controls were included. CYP1A1 MspI and Ile(462)Val polymorphisms were genotyped and tested for association with this disease. RESULTS: An elevated risk of lung cancer was observed among individuals with the MspI CC (OR=1.7, 95 CI=0.9-3.3) and Ile(462)Val ValVal genotypes (OR=2.8, 95 CI=1.1-7.6). After stratifying by environmental tobacco smoke (ETS) exposure, the risk of lung cancer associated with both polymorphisms was higher among individuals with lower exposure to ETS, compared with those who reported at least weekly exposure. Individuals with the MspI CC genotype showed a two-fold higher risk of lung cancer if they were also null for either GSTM1 or T1 (OR=2.3, 95CI=1.0-5.0 and OR=2.7, 95 CI=1.1-6.9, respectively, compared to other genotype combinations combined). CONCLUSIONS: CYP1A1 is a susceptibility gene for lung cancer among non-smoking Asian women and this association can be influenced by ETS exposure and genetic variation at GST genes.