Читать книгу Immunology - Richard Coico - Страница 81

1 D. Cellular proliferation, differentiation of lymphocytes, and cellular interactions can take place in bone marrow. However, antigen‐dependent responses occur in the secondary lymphoid organs, such as the spleen and lymph nodes.

2 C. The NLRs are a group of cytosolic innate receptors that recognize microbes that infect cells. Once ligated, they initiate a set of cellular activities that facilitate inflammatory responses and other host defense mechanisms.

3 D. NK cells are large granular lymphocytes. Their number does not increase in response to antigen. Their killing is extracellular, and their target cells are virus‐infected cells or tumor cells. They are not particularly effective against bacterial cells.

4 A. When immature dendritic cells are activated following their engulfment of pathogens (phagocytosis), they mature and become more efficient at antigen presentation and, in fact, can activate antigen‐specific naïve T cells.

5 B. NK cells express KIRs, which allow them to bind to MHC class I molecules expressed on all nucleated cells that would otherwise be targets for killing when infected with certain viruses that downregulate MHC class I expression.