Natural cytotoxicity of human lymphocytes against equine target cells in vitro.

The research article examines how human lymphocytes have a notable natural cytotoxicity towards equine dermal cells and tumor cells. It also explores the varying natural cytotoxicity in individual donors which may indicate spontaneous sensitization.

Objective of the Research

• The study aimed to investigate the action of human lymphocytes against equine cells, particularly normal equine dermal fibroblasts and equine tumor cells from a virus-infected cell line.
• The researchers also sought to measure human sera antibodies’ ability to instigate antibody-dependent cellular cytotoxicity (ADCC) against these equine cells.
• Lastly, they aimed to scrutinize the correlation between antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) activity, as well as the involvement of immunoglobulins in the NK reaction.

Methodology of the Research

• The researchers conducted in vitro experiments, with the human lymphocytes and equine cells derived from different donors.
• Both natural cytotoxicity and antibody-dependent cellular cytotoxicity were evaluated for each specimen.
• Through the process of cold target cell inhibition, they observed the selectivity of both ADCC and NK.
• They also utilized Fab fragments of anti-human IgG to test and confirm the involvement of immunoglobulins in the NK reaction.

Findings of the Research

• Results indicated strong cytotoxicity of human lymphocytes against equine dermal fibroblasts and virus-infected tumor cells.
• The researchers found that normal human sera contain antibodies that stimulate ADCC against these equine cells.
• They observed significant correlations in NK and ADCC against the two target cells for individual donors, implying a degree of selectivity in these actions.
• They confirmed that immunoglobulins play a role in the NK reaction as inhibition studies with Fab fragments of anti-human IgG displayed a marked immunoglobulin-dependent increase in NK and ADCC activity against the infected tumor cells.
• Lastly, they concluded that variations in natural cytotoxicity among donors might signify a process of spontaneous sensitization.