| 摘要: | The increased populations of Treg cells in peripheral blood and gastric carcinoma
reflect compromised host immunity. It remains unclear, whether the Treg cells in the
lymphoid tissues contribute to the immune dysfunction in gastric cancer. In this
study, the murine model of benzo[a]pyrene(B[a]P)-induced forestomach carcinoma was
used to analyze the distribution of Treg cell populations in different lymphoid tissues. To
determine the enhancement of Treg cells on tumor growth, the Treg cells were depleted
by PC61 specific antibody. The proportions of Treg cells in the thymus, spleen, the
regional lymph nodes (nodes at the perigastric area and the mesentery, RLNs), and the
peripheral lymph nodes (nodes at the axillary, inguinal, brachial, and popliteal, PLNs),
were compared. The proportion of Treg cells in total CD4+ T cells is clearly increased in
RLNs compared with PLNs, spleen and thymus in B[a]P-treated mice as tumor grown.
Moreover, these cells express the Foxp3 transcript and were dramatically enhanced in
RLNs relative to PLNs at 32 weeks. After depletion, the proportion of Treg cells
decreased in the lymphoid tissues, especial in the RLNs, the tumor mass reduced
significantly, and massive infiltrating cells at the tumor sites and apoptosis of the tumor
masses were observed in the forestomach carcinomas of the B[a]p treated mice at 32
weeks. These results demonstrate that the accumulation of Treg cells in the regional
lymph nodes mediated suppressive immunity in progressive forestomach tumors. Treg
cells depletion reduces growth of tumor via effective local immunity. |
