1. Name six types of blood cells that function in nonspecific immunity and specify the most important function of each.
1) Neutrophils: These are white blood cells that play some very important roles in our innate immune system. They circulate around our body in the bloodstream, and when they sense signals that an infection is present, they are the first cells to migrate to the site of the infection to begin killing the invading microbes. They function as Phagocytes
2) Basophils: contain anticoagulant heparin, which prevents blood from clotting too quickly. They also contain the vasodilator histamine, which promotes blood flow to tissues. They are involved in allergic reactions and eukaryotic parasitic infections
3) Eosinophils: They are found in many inflammatory processes, especially allergic disorders. They may also have a physiological role in organ formation. They are mainly involved in eukaryotic parasitic infections
4) Monocytes: They are the largest type of leukocyte and can differentiate into macrophages and myeloid lineage dendritic cells. As a part of the vertebrate innate immune system monocytes also influence the process of adaptive immunity.
They are Phagocytes found in blood
5) Macrophages: A large white blood cell that is an integral part of our immune system. Its job is to locate microscopic foreign bodies and ‘eat’ them. Macrophages use the process of phagocytosis to engulf particles and then digest them. They are Antigen presenting cells
6) Dendritic cells: These are antigen-presenting cells of the mammalian immune system. Their main function is to process antigen material and present it on the cell surface to the T cells of the immune system. They act as messengers between the innate and the adaptive immune systems. Basically, they are Antigen presenting cells found in lymph nodes
2. Why are pathogen-associated molecular patterns (PAMPs) necessary for Toll-like receptors (TLRs) to function?
PAMPs is a pathogen associated with molecular patterns. These are molecules of foreign pathogens that are essential for their survival. This includes bacterial lipopolysaccharides, flagella, bacterial cell membrane and many viral RNA molecules. The PAMPs are recognized the receptors (TLR) present on the cell membrane. TLRs are membrane-bounded receptors. They are a component of the innate immune system making it able to recognize different foreign pathogens. This is important to have PAMPs available on the pathogen because TLRs can only recognize these patterns through pattern recognizer receptors. TLRs are able to recognize the PAMPs present on the cell. Then they give a specific signal to the innate immune system making them able to destroy the antigens. TLRs act as sentinels, providing an immediate first line of defense against invading microbes leading to the activation of defense mechanisms of the innate immune system. They are also important for developing B and T cell-mediated, pathogen-specific adaptive immune system.