Search results for "T cell mediated cytotoxicity"
showing 4 items of 4 documents
T cell-mediated cytotoxicity: discrimination between antigen recognition, lethal hit and cytolysis phase.
1974
Using a 51Cr release cytotoxicity assay, the cytotoxic effector phase of in vitro activated mouse T lymphocytes (killer cells) against 51Cr-labeled target cells has been investigated. It is shown that within 5–10 minutes of contact between killer cells and target cells, the target cells are already committed to lysis, therefore, antigen recognition and “lethal hit” must have taken place within this period of time. In contrast, target cell lysis (cytolysis phase) requires up to 3–4 h in order to be completed; it occurs independently of killer cells and it is highly temperature dependent. The killer cell-dependent phase (antigen-recognition and “lethal hit”) is dissociated into two consecutiv…
Chemotherapy Sensitizes Colon Cancer Initiating Cells to Vγ9Vδ2 T Cell-Mediated Cytotoxicity
2013
Colon cancer comprises a small population of cancer initiating stem cells (CIC) that is responsible for tumor maintenance and resistance to anti-cancer therapies, possibly allowing for tumor recapitulation once treatment stops. Combinations of immune-based therapies with chemotherapy and other anti-tumor agents may be of significant clinical benefit in the treatment of colon cancer. However, cellular immune-based therapies have not been experimented yet in the population of colon CICs. Here, we demonstrate that treatment with low concentrations of commonly used chemotherapeutic agents, 5- fluorouracyl and doxorubicin, sensitize colon CICs to Vc9Vd2 T cell cytotoxicity. Vc9Vd2 T cell cytotox…
Influenza virus-specific T cell-mediated cytotoxicity: integration of the virus antigen into the target cell membrane is essential for target cell fo…
1979
This study deals with the requirements for target cell recognition by influenza A virus-specific cytotoxic T lymphocytes (CTL). H-2-identical cells were incubated with infectious or UV light-inactivated influenza A virus expressing either cleaved or uncleaved hemagglutinin (HA). Thereafter, the treated cells were tested in a 4-h 51Cr assay for susceptibility to CTL-mediated cytolysis. Regardless whether the influenza virus was infectious, virions expressing cleaved HA were efficient in target cell formation. In contrast, cells incubated with either active or UV-inactivated virions expressing uncleaved HA were not lysed by virus-specific CTL. Yet, after mere trypsin-mediated cleavage of the …
T-cell-mediated cytotoxicity against herpes simplex virus-infected target cells
1977
THE control of herpes simplex virus (HSV) infection by immunological mechanisms seems to be complex and is poorly understood. Neutralising antibodies to HSV plus complement seem to have no effect on the propagation of HSV infection, because HSV spreads to adjacent cells by passing through intercellular bridges1–3. Anti-HSV antibodies plus complement, however, destroy virus-infected cells, but cannot prevent the spread of HSV, suggesting that the virus must be transferred to neighbouring cells before immune lysis occurs1,5. Therefore if lymphocyte-mediated cytolytic mechanisms are instrumental in blocking the spread of HSV in vivo, they ought to destroy infected cells at a very early stage i…