1. A Cellular Automata Model on HIV Infection (2) Shiwu Zhang Based on [Pandey et al’s work]

2. Review: CA models on HIV(1) Characteristics –Local interactions –Inhomogeneous elements –Spatial structure –High workload Examples –Santos2001 –Hershberg2001

3. Review: CA models on HIV(1) –Santos’ CA model One type cell with 4 different states on one site No mutation 3-stage evolution: different time scale –Hershberg’s model in “shape space” Virtual space, 2 types of cells Mutation 3-stage evolution: different time scale

4. Pandey’s model: Introduction(1) Elements –2-dimension or 3-dimension lattice, –Four types of entities: Macrophage(M) Helper(H) Cytotoxic cells(C) Antigen/Viral carrier cells(V) –Entity States: 0: low concentration 1: high concentration

5. Pandey’s model: Introduction(2) Rules –Boolean expression(4) –viral mutation(10) –Fuzzy set –CA sum rules

6. Pandey’s model: Result Populations of Cells and virus –Initial immune response Influence factors: –Viral mutation rate –Initial concentrations of cells –Cellular mobility

7. Comparison: our model Method: Reasonable-> Convincing –Multi-type elements: T cells, B cells, HIV… –Spatial space& shape space –Accounting for important interactions HIV high mutation rate Immune cells stimulation Immune system’s global ability:memory Result: –3-stage dynamics of AIDS –HIV strain diversity –Mechanism influence

8. Related Papers R.B. Pandey. (1998). A stochastic cellular automata approach to cellular dynamics for HIV: effect of viral mutation. Theory in Bioscience: 117(32) H. Mannion et al. (2000). Effect of Mutation on Helper T-cells and Viral Population: A Computer Simulation Model for HIV. Theory in Bioscience: 119(10) H. Mannion et al. (2000). A Monte Carlo Approach to Population Dynamics of Cell in an HIV Immune Response Model. Theory in Bioscience: 119(94) A. Mielke and R.B. Pandey. (1998). A computer simulation study of cell population in a fuzzy interaction model for mutating HIV. Physica A:251 (430). R.B. Pandey et al. (2000). Effect of Cellular Mobility on Immune Response. Physica A:283 (447).