transfer factor Word Origin noun Immunology.
- a lymphocyte product that, when extracted from T cells of an individual with immunity to a particular antigen, can confer that immunity when administered to another individual of the same species.
Origin of transfer factor First recorded in 1955–60 transfer factor in Medicine transfer factor n.
- The transfer gene of a conjugative plasmid, especially of the resistance plasmid.
- A substance free of nucleic acid and antibody, that is obtained from the white blood cells of a person with a delayed-type sensitivity and will transfer the specific sensitivity to the recipient after injection into the skin of a nonsensitive person.