Figure 1.

Elements of the adaptive immune system that are observed to be altered in GWI: The adaptive immune system involves antigen-presenting cells, such as dendritic cells, monocytes and macrophages (cells that also have a role in innate immunity). The humoral responses are largely mediated by B-cells which are capable of directly responding to antigens and producing antibodies to neutralize them. The cellular responses are mediated by CD4 + T-helper cells and cytotoxic CD8 + T-cells which mount a highly specific response against antigens. Ultimately, these cells can generate memory T-cells that recruit B-cells to produce antibodies for neutralizing foreign antigens. The long-term memory T-cells and B-cells are responsible for producing long-lasting immunity. Thus far, observations of CD4-mediated immune responses and humoral responses have been observed in animal models and/or in blood of veterans with GWI. However, activation of CD8-mediated cytotoxic T-cell responses remains to be observed in GWI.