Immunology and vaccinology of tuberculosis: can lessons from the mouse be applied to the cow?

The nature of both innate and acquired immunity in the lungs are both still poorly understood, and how these two sets of mechanisms intersect with each other may have considerable bearing on the overall expression of host resistance. While the central role of CD4 T cells in the acquired phase is well established, cells bearing this marker may also contribute to innate immunity in the guise of both NK-positive and negative innate populations capable of secreting gamma interferon. In contrast, expansion of an antigen-specific memory T cell population is the purpose of current vaccine strategies, and several interesting and promising types of new candidates are briefly discussed.