Mathematical modeling the radiation effects on humoral immunity
Abstract
One of the biological processes affecting the carcinogenesis is a response of humoral immune system to an antigen of malignant cells. Humoral immunity involves the production of protein molecules, antibodies, which can specifically bind to a certain antigen. This body system is radiosensitive. Therefore when simulating the radiation carcinogenesis, it is important to take into account the radiation effects on humoral immunity. To this end, a model of humoral immune response in irradiated mammals is developed. It is based on conventional theories and experimental facts. The model represents a system of nonlinear differential equations whose variables are the concentrations of antigen-sensitive immuno-competent cells carrying surface receptors and their bone-marrow precursor cells, as well as the concentrations of antibody-producing cells, antibodies, and an antigen. The dose of acute exposure and the dose rate of chronic exposure are the variable parameters in our approach. The model quantitatively reproduces the dynamics of the humoral immune response to the T-independent antigen (capsular antigen of Pasteurella pestis) in nonirradiated mammals (CBA mice). The model simulates the processes of the damage and recovery of the system of humoral immunity after acute exposure and predicts an adaptation of this system to low-level long-term chronic irradiation. These results give evidence that the developed model, after the appropriate identification, can be incorporated into a model of radiation carcinogenesis in humans. Together with a model of cellular immunity, such joined model will give capability to estimate the risk of radiation carcinogenesis for cosmonauts and astronauts on long space missions such as a voyage to Mars or a lunar colony.
- Publication:
-
35th COSPAR Scientific Assembly
- Pub Date:
- 2004
- Bibcode:
- 2004cosp...35...93S