LIFE SCIENCE

Detailed explanation-1: -Phagocytosis, the process by which macrophages, dendritic cells and other myeloid phagocytes internalize diverse particulate targets, is a key mechanism of innate immunity. The molecular and cellular events underlying the binding and engulfment of targets in phagosomes have been extensively studied.

Detailed explanation-2: -Receptors on the cell surface bind ligand molecules on the target, such as a pathogen, dead cell, or bead. As receptors bind more and more ligand molecules, the cell membrane progressively engulfs the target. Upon full engulfment, a phagosome is formed, which fuses with lysosomes, leading to digestion of the target.

Detailed explanation-3: -Macrophages work as innate immune cells through phagocytosis and sterilization of foreign substances such as bacteria, and play a central role in defending the host from infection. However, residual macrophages in intestinal mucosa can potentially reduce inflammation to a greater extent than those in other tissues.