Interleukin-12, Dendritic Cells, and the Initiation of Host-protective Mechanisms against Toxoplasma gondii

The principal job of the immune system is to provide protection against infectious pathogens. One of the immunologist's goals is to determine how the cellular and cytokine components of the immune system are functionally organized to provide this protection. In vitro studies can suggest which components of the immune system may be involved in resistance to a given pathogen, but ultimately the immunologist must look in vivo to see whether these components truly contribute to protection. In recent years, this task has been made easier by the advent of gene knockout mice and antibodies that can be used to selectively deplete or neutralize components of interest from infected experimental animals so that the consequences of a missing entity can be observed. A more demanding task has been to identify where and under what circumstances an entity that may be important in host protection performs its functions. Reis e Sousa...