Histological Analysis of Lymphocyte Subsets Infiltrated into Mouse Tumor Tissue Exposed to Local Irradiation

Abstract

The subsets of lymphocytes infiltrated into mouse tumor tissue exposed to irradiation were analyzed by the avidin-biotin-peroxidase procedure using monoclonal antibodies. The effect of PSK administration was also analyzed. Microscopic observation revealed the intense lymphocytic reactions in the exposed tumor, especially 7 days after irradiation of 20 Gy, which mainly consisted of anti-L3T4 positive cells, whereas the degree of infiltration was lower in the nonexposed tumor. PSK was found to enhance T lymphocyte subset infiltration into the exposed tumor tissue.therapy has not been analyzed clearly. Mention is also made of these mechanisms.

Local Radiation Therapy of B16 Melanoma Tumors Increases the Generation of Tumor Antigen-Specific Effector Cells That Traffic to the Tumor

“…Tumor-specific primed T cells were obtained from OT-1 (Rag Ϫ/Ϫ ) mice immunized with 20 g of OVA 257-264 peptide (SynPep) emulsified in CFA (Sigma-Aldrich) and injected s.c. into the left flank and at the nape of the neck, whereas control T cells were from P14 transgenic mice immunized in the same manner with lymphocytic choriomeningitis virus gp51 [33][34][35][36][37][38][39][40][41] peptide (gift from T. Mosmann). Seven days after priming, the mice were sacrificed by CO 2 inhalation, and the draining lymph nodes (iliac, inguinal, axillary, popliteal) and spleen were harvested.…”

“…OT-1 cells, which recognize the OVA 257-264 peptide via MHC class I, were used to measure trafficking of tumor Ag-specific cells into B16/OVA tumors. P14 cells recognize the lymphocytic choriomeningitis virus peptide gp51 [33][34][35][36][37][38][39][40][41] and were used to evaluate the trafficking of cells lacking tumor Ag specificity. Whole mount fluorescence microscopy of individual tumors revealed increased numbers of transferred OT-1 cells at 24 and 72 h in tumors of both irradiated and nonirradiated mice.…”

Interactions between radiation therapy and immunotherapy: the best of two worlds?

“…The authors were able to document an immunity‐related 20‐fold cell kill enhancement in immunocompetent mice when compared with immunosuppressed mice 4 . Increases in cytotoxic T‐cell infiltration and in situ CD8 T‐cell proliferation have been seen in irradiated tumour tissue when compared with unirradiated tumour tissue 5–7 , and the degree of inflammatory infiltrate after RT has been positively correlated to treatment outcome in humans with cervical carcinoma 8,9 . A study using coarsely fractionated RT before surgery in patients with carcinomas of the breast and stomach showed a significant increase in lymphoplasmacytic infiltrate compared with those patients receiving surgery alone 10 , showing the potential immunomodulatory effects of RT in a relevant human patient population.…”