Chapter 40, Problem 4CHI

The initial, nonsymptomatic liver stage (LS) of Plasmodium spp. is considered very promising for prophylactic drug and vaccine development (figure 40.9). However, technical obstacles in obtaining LS protists has hindered analysis of gene and protein expression. Tarun and her colleagues developed a rodent model whereby LS protists could be studied. They identified a set of proteins expressed only in the LS, including enzymes involved in metabolic pathways active only in LS, as well as exported proteins.

Examine the P. vivax life cycle in figure 40.7. Why do you think the metabolic requirements of LS protists are so unique? Having identified these proteins, what would be the next step in identifying drugs that might be effective against LS protozoa? How might this information assist in vaccine development?