an important component of antigen presentation for both MHC class I and MHC class II pathways, as it drives the preferential presentation of high-affinity binding peptides. For MHC class II peptide editing, HLA-DM plays a key role. In the absence of HLA-DM: MHC class II molecules traffic to the cell surface with CLIP in their binding sites.

The formation of the C3 convertase is a key step in complement activation that occurs in all three complement pathways. This enzyme cleaves C3 in blood plasma, leading to a conformational change in the C3b fragment that exposes its reactive thioester group. The activated C3b is potentially harmful to the host, if it becomes covalently attached to a host cell, rather than to the surface of a pathogen. This deleterious outcome is largely avoided by:  The inability of active C3b to diffuse away in the blood plasma. The inability of active C3b to covalently attach to the membranes of eukaryotic cells. The rapid hydrolysis of active C3b in solution, rendering it inactive. The tight binding of active C3b to the C3 convertase. The ability of active C3b to recruit phagocytic cells.

picture 1 shows the directed migration of two immune cell types, neutrophils (red) and macrophages (green) to a laser-induced injury in the ear of a mouse. As you can observe from the video, there are three stages to this process: 1) an initial phase characterized by fast recruitment of neutrophils (red) to the site of injury followed by 2) the slower recruitment of macrophages after which 3) the interaction between both cell types is stabilized. Recruitment to the injury site is mediated by leukotriene B4 (LTB4), a potent immune signaling molecule (Figure 1A). LTB4 binds to BLT1, a G-protein coupled receptor (GPCR), activating various signaling pathways and resulting in immune cell migration to the site of injury (Figure 1B). With this background information and your knowledge of cell and molecular biology, describe in detail in your own words, as many molecular processes as you can identify that must take place for the cell migration process depicted in the video to be achieved. For…

T cells in the thymus are determined to be T helper cells or T killer cells while undergoing maturation in the Choose from the folloiwng: (A) cortex of the thymus (B) medulla of the thymus