binding site Antigen- binding site VH Hlnge reglon S-S Light chaln CHO CH CHO CH 1 FIGURE 7.3 Schematic models of an IgG antibody molecule and an Fab fragment. The IgG is made from two identical heavy chains (dark blue) and two identical light chains (light blue), all held together by disulfide bonds. Each chain contains both constant domains (C) and variable domains (V). Constant domains are the same in all antibody molecules of a given class (see Table 7.1), whereas variable domains confer specificity to a given antigenic determinant. Cleavage by certain proteolytic enzymes such as papain at the hinge regions allows production of two identical monovalent Fab fragments and one F, fragment (see Figure 7.4). The carbohydrate (CHO; red) attached to the heavy chains helps determine the destinations of antibodies in the tissues and in stimulating secondary responses such as phagocytosis. The crystal structure of an immunoglobulin molecule is shown in Figure 7.4. Heavy chaln Enzymatlc dleavage Fab fragments VH VL S-S ss CHO CH CH CHO Fe fragment Antigen-

Nearly all immune deficiency diseases that result in impaired TH17 and ILC3 function lead to chronic mucocutaneous candidiasis (CMC), usually accompanied by increased susceptibility to pyogenic bacterial infections. However, a subset of these patients also show increased susceptibility to intracellular bacterial infections, such as those caused by Mycobacteria species. What is the explanation for why some, but not all, of these patients have increased susceptibility to intracellular bacteria and which patients fall into this category?

What is the mechanism of the Contactin-BIG-1

You have synthesized an oligopeptide containing an RGD motif surrounded by other amino acids. What is the effect of this peptide when added to a fibroblast cell culture grown on a layer of fibronectin adsorbed to the tissue culture dish? Why does this happen?