Strategies of Intracellular Pathogens for Obtaining Iron from the Environment

Figure 4

Iron acquisitions systems in Cryptococcus neoformans. C. neoformans infects alveolar macrophages; at this site, specifically in the acidic phagolysosome, free Fe²⁺ is released from the host Ft and Tf. The reductive high-affinity Fe uptake system mediated by Cft1 and Cfo1 plays a role in the reduction of Fe³⁺ at the cell surface by the reductase activity. In addition, C. neoformans is able to utilize Tf through the reductive high-affinity iron uptake system.Finally, for extracellular heme acquisition, C. neoformans relies on the complex Cft1/Cfo1, a xenosiderophore transporter (Sit1), and secreted and extracellular reductants (3-hydroxyanthranilic acid, melanin).