Related Experiment Video
Updated: Oct 11, 2026

Evaluation of Tumor-infiltrating Leukocyte Subsets in a Subcutaneous Tumor Model
Published on: April 13, 2015
Adherent neoplastic cells grown at confluence downregulate HLA class I expression and enhance their susceptibility to
G Ferlazzo1, C Semino, G Quartarone
1Servizio di Biotecnologie, Istituto Nazionale per la Ricerca sul Cancro, Italy.
Abstract:
The number of HLA class I molecules and the susceptibility to lysis mediated by natural killer (NK) cells were evaluated on cell targets obtained from confluent and sparsely plated cultures of both normal and tumor cell lines. Sparsely plated proliferating cells expressed high amounts of HLA class I molecules and were more resistant to NK cell-mediated lysis than confluent cells, which expressed low amounts of HLA class I antigens. This characteristic could be involved in the control of cancer progression and could also explain the wide variability of assays of lymphocyte-mediated cytotoxic activity.
Related Concept Videos
Cell-mediated Immune Responses
Cells of the Innate Immune Response
Phagocytes
Phagocytes police the peripheral tissues by removing cellular debris and responding to the invasion of foreign substances or pathogens. Many phagocytes attack and remove microorganisms even before lymphocytes detect them. The human body has two general...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Immune Response Against Viral Pathogens
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...

