Consequently, we are today limited to the default postulate that the regulation of class is determined solely by germline-selected processes [6, 8]. This can be rationalized in evolutionary terms as the origin of the effector mechanism that rids a pathogen is an outcome of the same interactive germline-selection pressures operating between pathogen and host that gave rise to the innate system. Using the Matzinger and Kamala [30] suggestion as a base, an effector class is defined here as the collection of compatible EPZ-6438 datasheet elements (cell

types, interleukins, chemokines, immunoglobulins, etc.) that synergize or cooperate to rid a given category of pathogen. This will be referred to as an ‘effector ecosystem’. The elements of an ecosystem act in concert and will eventually have to be detailed. In the end, the detritus produced by the biodestrucive effector activities is ridded by macrophage phagocytosis, requiring that all effector ecosystems feed into that mechanism. Therefore, each ecosystem must include a humoral component that arms phagocytosis. The cell-mediated system might stop

selleck the development of a pathogen, but cannot rid it. As a dead reckoning estimate to simplify the discussion, there are four effector ecosystems, an initially expressed or naive effector system and three systems to which the naive effector system can switch or differentiate in response to Eliminon-driven additional signalling. Adopting a simplified nomenclature based on that used for the humoral system, these four ecosystems would be M, G, A and E. Admittedly, this nomenclature might become misleading. One should

be cautious as there may not be a totally faithful concordance between the Ig-subtype and membership in a given ecosystem. The four effector ecosystems are, at least in part, incompatible with each other because they express activities that are mutually inhibitory. For example, IgA that does not activate C’-lysis can inhibit the activation of C’-lysis by IgM or IgG2 and eTh1 can inhibit the induction of eTh2 and vice versa. Therefore, keeping the ecosystems functionally separated when responding to multiple Eliminons interacting with or derived from a given tissue is a problem that must eventually be faced [6]. The antigen-responsive cells, iT/B, are born as part of the crotamiton M-ecosystem. It consists of virgin iTh0, iTc0, Bμ/δ and the eTh0 that are required to prime the response. Included, of course, in this ecosystem are the APCs, macrophages and several other cell types, as well as the interleukins and other factors required for induction to effectors and their functioning. As a minimum, no trauma signals need be postulated for the induction of the M-ecosystem to effectors. The M-ecosystem is the virgin or initial state. The virgin M-ecosystem has the potential to either respond as such or to differentiate to any one of the three other ecosystems, G, A or E.