Antigens nonself

The immune response is mediated by interactions among an array of specialized leukocytes and their associated proteins. T lymphocytes produce T-cell receptors. B lymphocytes produce immunoglobulins. All cells produce MHC proteins, which display host (self) or antigenic (nonself) peptides on the cell surface. In a process called clonal selection, helper T cells induce the proliferation of B cells and cytotoxic T cells that produce immunoglobulins or of T-cell receptors that bind to a specific antigen. 

The specific, or adaptive, immune system is characterized by memory, specificity, and the ability to distinguish self from nonself. The important cells of the adaptive immune system are the lymphocytes and antigen-presenting cells that are... 

Insertion of viral molecules into the host cell membrane results in the host cell becoming antigenically different in that nonself molecules are presented to the immune system. Expression of viral antigens in this way is a major factor in the development of antiviral immune responses. 

Pacholczyk R, Kern J, Singh N, Iwashima M, Kraj P, Ignatowicz L Nonself-antigens are the cognate specificities of Foxp3-H regulatory T cells. Immunity 2007 27 493-504. 

Tolerance prevents the immune system from attacking self-antigens. To understand tolerance we must appreciate how T cells work. T cells recognize a combination of self and nonself. The cell surface antigens rec-... 

As previously mentioned fetal and newborn mammals have immature immune systems that do not yet have the capacity to differentiate self and nonself. This lack of maturity can be harnessed to our advantage when working with antigens, which are naturally found along with closely related (cross-reacting) substances. This technique does not guarantee success but can swing the odds in favor... 

How do the cells in the immune system recognize an antigen as foreign or nonself ... 

Thus far, antigen has been depicted as the structures associated with a foreign substance that allow it to be recognized as nonself and to therefore provide the... 

Immune responses can be directed toward a foreign (i.e., nonself) antigen which has a similar chemical structure to an antigen which characterizes self. 

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