Immune response antigen recognition

FIGURE 2 Natural killer T (NKT) cells provide an innate-type immune response upon recognition of T-cell receptor with CDld-presented antigens such as KRN7000. 

Details on the cellular immune responses occurring following the recognition of xenobiotic haptens as antigens by the immune system are described in chapters 33-35 of this volume. Ultimately, a certain combination of mediators is selectively activated and subsequently helps determine and differentiate the characteristic immune response (e.g., Thl vs. Th2). For example, dermal sensitizing chemicals (e.g., oxazolone and dinitrochlorobenzene) elicit a higher proportion of Thl cytokines such as IFNy and... 

Tumor cells in the first metastasis escaped immune recognition due to selective loss of HLA haplotype, but maintain the expression of HLA-A2 antigen. In contrast, in the second metastasis immune escape from immune dominant antigen-specific T cell responses were mediated by HLA class I downregulation which results in the impaired presentation of this epitope, whereas another tumor antigen-specific epitope was presented. This resulted in the shift of the dominant T cell response to a subdominant targeted response. 

For the selectivity of the immune response (see p. 294), the cells involved must be able to recognize foreign antigens and proteins on other immune cells safely and reliably. To do this, they have antigen receptors on their cell surfaces and co-receptors that support recognition. 

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