Species specificity of iron delivery in hybridomas.
Studies with Human X Human (H X H), Human X Mouse (H X M), and Mouse X Mouse (M X M) hybridomas have enabled us to define specific factors that affect hybridoma growth in a species-specific manner. Three transferrins and three lipophilic iron chelates have been tested for their ability to support hybridoma proliferation and antibody production. The results of these studies demonstrate that H X H hybridomas do not respond to bovine transferrin a+ concentrations up to 100 micrograms/ml and are approximately 100-fold less responsive to mouse transferrin than to human transferrin. H X M and M X M hybridomas respond equally to human or mouse transferrin but are 100-fold less sensitive to bovine transferrin. An antibody to the human transferrin receptor inhibited the growth-promoting activity of human or mouse transferrin on H X H hybridomas but was ineffective on H X M hybridomas. This demonstrated the functionality of the human transferrin receptor in H X H hybridomas and that human, mouse, and bovine transferrin were interacting through the mouse transferrin receptor in H X M hybridomas. H X H and H X M hybridomas respond similarly to three different iron chelates exhibiting 80 to 110% of the growth response to human transferrin. M X M hybridomas fail to respond to the iron chelates at similar concentrations, suggesting that the human genome present in the other hybridoma species confers a unique ability for utilizing iron when delivered in this form.
Ill
C R
CR
Department of In Vitro Antibody Production, Hybritech, Inc., San Diego, California 92121.
Brehm
T
T
Lydersen
B K
BK
Hernandez
R
R
Burnett
K G
KG
D000818:Animals; D002417:Cattle; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D006825:Hybridomas / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D051379:Mice; D011990:Receptors, Transferrin / Q000378:metabolism; D013045:Species Specificity; D014168:Transferrin / Q000494:pharmacology
D011990:Receptors, Transferrin; D014168:Transferrin; D007501:Iron