Computer simulation of immune kinetic processes in vitro and light scattering on antigen-antibody reagent mixture

摘要

On the base of computer simulation the immune kinetic processes for in vitro analysis was carried out for two cases: (1) antigen (Ag) was polyvalent, antibody (Ab)- monovalent; and (2) both Ag and Ab were bivalent. The problem was solved by calculation of the differential equations system minding limitations naturally. The immune reaction was treated as a combination of two competing processes: the antigen-antibody aggregation and synchronous disaggregation of immune complexes. Such a combination is to be described by a system of nonlinear differential equations but for simplicity the equations were linearized. The solution of the differential equation system was carried out minding some limitations naturally. The kinetic curves of immune reaction were obtained for different initial Ag, Ab concentrations and two experimental procedures. Partially, the concentrational curves obtained occurred for some cases analogous to the well known experimental results -'zone of equivalence.' The results of in vitro immune reaction simulation were used for computer analysis of one of the widely used methods of immune biomedical diagnosis - light beam scattering (nephelometry). The light beam scattering by the 'Ag-Ab-complex' mixture during immune reaction was treated as a single light scattering on the spheres of different diameters less than the wavelength. So the scattering medium was the polydisperse system, when the scattering centers concentration and sizes were changing in time. The expression for intensity of scattered light induced by the immune reaction process for different experimental conditions was derived.