ABSTRACT
Innate immunity is an ancient host defense system for the recognition of microorganisms (1). It is the first line of defense and functions during the early phase of infection, before the development of specific adaptive immune responses. The innate immune cells initially have effector functions, but act later as regulatory cells in adaptive immunity. Unlike the mechanisms of adaptive immunity, the innate immune cells do not use cell-surface immunoglobulins or T-cell receptors, they are not major histocompatibility complex (MHC) restricted and lack memory, which is essential in vaccination. An early, nonspecific protective response may limit microbial replication and dissemination, which allows adaptive immunity sufficient time to mount an effective protective response. The innate immune system can be characterized by a number of general features, which will be highlighted below (2,3). However, the role of innate immunity in controlling HIV infection has so far received only limited attention.
