Quantitative analysis of interleukin-2-induced proliferation in the presence of inhibitors using a mathematical model.
The proliferative response of CTLL-2 cells to human recombinant interleukin-2 (IL-2) can be modeled mathematically using enzyme kinetic equations. This approach has been used to analyze dose-response curves (IL-2 concentration vs. level of proliferation) measured by MTT and [3H]TdR assays. The values of functional dissociation constants, equivalent to IL-2 concentrations giving 50% of the maximal response, depended on the cell concentration and increased from 4 to 60 pM for the [3H]TdR assay and from 40 to 140 pM for the MTT assay when the cell concentration was increased from 2 x 10(3) to 4 x 10(4) cells/well. The types of inhibition and dissociation constants for various inhibitors of IL-2-dependent proliferation such as mAbs against IL-2 receptor (7D4 and AMT13) and normal mouse serum (NMS) were also analyzed. Both mAbs exhibited competitive mechanisms of inhibition whereas NMS inhibited IL-2-driven proliferation in a mixed manner. Two gel-filtration fractions of NMS with inhibitory activity manifested different types of inhibition: purely competitive type of inhibition in the case of a 10-15 kDa fraction and a mixed type of inhibition for a 100-150 kDa fraction. The proposed model can also be used for quantitative analysis of the influence of various factors (pH, temperature, cultivation condition) on the level of proliferation.
Svirshchevskaya
E V
EV
Shemyakin Institute of Bioorganic Chemistry, Russian Acad. Sci., Moscow.
Sidorov
I A
IA
Viskova
N Y
NY
Dozmorov
I M
IM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D008433:Mathematics; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D051381:Rats; D017208:Rats, Wistar; D015375:Receptors, Interleukin-2 / Q000502:physiology; D011994:Recombinant Proteins / Q000494:pharmacology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins