Open AccessCytotoxic Activity of CD4 + T Cells against Autologous Tumor Cells
Author(s) -
Konomi Yasushi,
Sekine Teruaki,
Takayama Tadatoshi,
Fuji Masashi,
Tanaka Takashi
Publication year - 1995
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1995.tb03096.x
Subject(s) - cytotoxic t cell , microbiology and biotechnology , cd8 , biology , cytotoxicity , cell culture , chemistry , in vitro , immunology , antigen , biochemistry , genetics
The 51 Cr‐release assay is mostly applied to detecting the cytotoxic activity of CD8 + T cells, and little is known about the activity of CD4 + T cells. Therefore, the correlation between the cytotoxic activity of CD4 + or CD8 + T cells and the incubation period with autologous tumor cells was analyzed by two methods. The incubation periods were 4 and 20 h (4 h and 20 h assay) for the 51 Cr‐release assay. Eight pairs of tumor cells and T cells were assayed. T cells were fractionated into CD4 + and CD8 + T cells by using magnetic beads and panning methods, and those cells were activated by culture with recombinant interleukin‐2 and immobilized anti‐CD3 monoclonal antibody. In 6 out of 8 cases, no cytotoxic activity of CD4 + T cells was detected by the 4 h assay, whereas cytotoxic activity was detected in all cases in the 20 h assay. The cytotoxic activities in 20 h assay of CD4 + T cells were increased 67‐fold in comparison with the activities in 4 h assay (range: 5–197). In the case of CD8 + T cells, cytotoxic activities were detected in 6 out of 8 cases in the 4 h assay. The lytic unit ratio of CD4 + and CD8 + T cells was calculated as 1.5 in the 20 h assay (range: 0.2‐>7.2) versus 0.4 in the 4 h assay (range: < 0.1–1.3). Cytotoxic activities in colorimetric assay using Crystal Violet with a 24 h incubation were similar to those in the 20 h 51 Cr‐release assay in all eight cases. These results indicate that CD4 + T cells have cytotoxic activity as strong as that of CD8 + T cells towards autologous tumor cells.