Chapter 17: Innate Immunity

What are toll-like receptors (TLRs) in phagocytes? How are they used to identify pathogens?

which bind to various PAMPs and communicate with the nucleus of the phagocyte to elicit a response. Many TLRs (and other PRRs) are located on the surface of a phagocyte, but some can also be found embedded in the membranes of interior compartments and organelles (Figure 17.20). These interior PRRs can be useful for the binding and recognition of intracellular pathogens that may have gained access to the inside of the cell before phagocytosis could take place

What are the 3 layers of the skin?

epidermis, dermis, hypodermis

What is hematopoiesis?

formation of blood cells from bone marrow stem cells

What other mechanical defenses do eyes have to defend against microbes (structural: blinking)?

he eyes also have physical barriers and mechanical mechanisms for preventing infections. The eyelashes and eyelids prevent dust and airborne microorganisms from reaching the surface of the eye. Any microbes or debris that make it past these physical barriers may be flushed out by the mechanical action of blinking, which bathes the eye in tears, washing debris away

What does the keratin in the hypodermis protect against microbes?

makes the skin's surface mechanically tough and resistant to degradation by bacterial enzymes.

Where are acute phase proteins produced and what response do they produce in the body?

Acute-phase proteins are primarily produced in the liver and secreted into the blood in response to inflammatory molecules from the immune system.

What are granulocytes?

neutrophils, eosinophils, basophils (smaller sections of leukocytes)

What structures does antimicrobial peptides (AMPs) destroy in microbes? How is it target specific?

1. AMPs may induce cell damage in microorganisms in a variety of ways, including by inflicting damage to membranes, destroying DNA and RNA, or interfering with cell-wall synthesis. 2. Depending on the specific antimicrobial mechanism, a particular AMP may inhibit only certain groups of microbes (e.g., gram-positive or gram-negative bacteria) or it may be more broadly effective against bacteria, fungi, protozoa, and viruses. Many AMPs are found on the skin, but they can also be found in other regions of the bod

What is the difference between Acute inflammation and Chronic inflammation? What are the signs/symptoms associated with acute inflammation? What are granulomas in Chronic inflammation and what infections are highlighted by chronic inflammation and what degenerative neurological diseases contain this inflammation?

1. Acute -immediate response to breach in physical barrier. Induces erythema (redness), edema (swelling), heat, pain. Vasodilation and increased vascular permeability are also associated with an influx of phagocytes at the site of injury and/or infection. During the period of inflammation, the release of bradykinin causes capillaries to remain dilated, flooding tissues with fluids and leading to edema. Increasing numbers of neutrophils are recruited to the area to fight pathogens. As the fight rages on, pus forms from the accumulation of neutrophils, dead cells, tissue fluids, and lymph 2. Chronic - occurs when short term (acute) inflammation is not enough. Infections sites may be walled off with WBCs (granulomas). Chronic inflammation is not just associated with bacterial infections. Chronic inflammation can be an important cause of tissue damage from viral infections. Additionally, chronic inflammation may be involved in the progression of degenerative neurological diseases such as Alzheimer's and Parkinson's, heart disease, and metastatic cancer.

Give a brief summary of the difference between the activation in: alternative, classical, and lectin pathways (what response does lectin caus in the body though)?

1. Alternative: The alternative pathway is initiated by the spontaneous activation of the complement protein C3. The hydrolysis of C3 produces two products, C3a and C3b. When no invader microbes are present, C3b is very quickly degraded in a hydrolysis reaction using the water in the blood... Once attached, C3b will recruit other complement proteins in a cascade 2. Classical: To initiate the classical pathway, a specific antibody must first bind to the pathogen to form an antibody-antigen complex. This activates the first protein in the complement cascade, the C1 complex. The C1 complex is a multipart protein complex, and each component participates in the full activation of the overall complex 3. Lectin: The lectin activation pathway is similar to the classical pathway, but it is triggered by the binding of mannose-binding lectin, an acute-phase protein, to carbohydrates on the microbial surface (are commonly upregulated in response to inflammatory signals received by the body during an infection)

What are the 5 types of chemical defenses?

1. Body fluids 2. Antimicrobial peptides 3. Plasma protein mediators 4. Cytokines 5. Inflammation eliciting mediators

What are pathogen-associated molecular patterns (PAMPs)? What are the 5 PAMPS and what microbes/bacteria are they found?

1. Common characteristics of pathogenic bacteria used for identification by phagocytes. Phagocytes get help in recognizing pathogens (complement factors, lectins, etc.) • peptidoglycan, found in bacterial cell walls; • flagellin, a protein found in bacterial flagella; • lipopolysaccharide (LPS) from the outer membrane of gram-negative bacteria; • lipopeptides, molecules expressed by most bacteria; and • nucleic acids such as viral DNA or RNA

How does cytokines kill cells (what happens to the non-self cells)? How do the 2 cytokine toxins, Perforin and granzymes, destroy target cells?

1. For example, it may express cytotoxic membrane proteins and cytokines that stimulate the target cell to undergo apoptosis, or controlled cell suicide. 2. perforin, a protein that creates pores in the target cell, and granzymes, proteases that enter through the pores into the target cell's cytoplasm, where they trigger a cascade of protein activation that leads to apoptosis

How is saliva an example of an endogenous mediated chemical (what antimicrobial enzyme does saliva contain)? How is the enzymes is the digestive tract (stomach, intestines) an example of endogenous mediated chemicals?

1. In the oral cavity, saliva contains mediators such as lactoperoxidase enzymes, and mucus secreted by the esophagus contains the antibacterial enzyme lysozyme 2. In the stomach, highly acidic gastric fluid kills most microbes. In the lower digestive tract, the intestines have pancreatic and intestinal enzymes, antibacterial peptides (cryptins), bile produced from the liver, and specialized Paneth cells that produce lysozyme.

How does resident microbiota defend against microbes (competition for nutrients on skin)? How is Candida albicans an example?

1. In various regions of the body, resident microbiota serve as an important first-line defense against invading pathogens. Through their occupation of cellular binding sites and competition for available nutrients, the resident microbiota prevent the critical early steps of pathogen attachment and proliferation required for the establishment of an infection 2. Ex. Resident flora of vaginal area keeps Candida albicans in check

what is the difference between macrophages and dendritic cells?

1. Macrophages and dendritic cells can reside in body tissues for significant lengths of time. Macrophages in specific body tissues develop characteristics suited to the particular tissue. 2. Dendritic cells are important sentinels residing in the skin and mucous membranes, which are portals of entry for many pathogens.

What organ are the macrophages found: 1. Microglial cells 2. Kupffer cells 3. Alveolar macrophages (dust cells) 4. Peritoneal cavity Peritoneal macrophages

1. Microglial cells: Brain and Central Nervous System 2. Kupffer cells: Liver 3. Alveolar macrophages (dust cells): Lungs 4. Peritoneal cavity Peritoneal macrophages: Peritoneal Cavity

What are the 4 steps of Pathogen degradation? Give a brief summary of what occurs in each step.

1. Pathogen engulfment: the pathogen is engulfed in a vesicle and brought into the internal compartment of the phagocyte 2. Formation of phagosome: To engulf the pathogen, the phagocyte forms a pseudopod that wraps around the pathogen and then pinches it off into a membrane vesicle 3. Pathogen particle degradation: In addition to the reactive oxygen species produced by the respiratory burst, reactive nitrogen compounds with cytotoxic (cell-killing) potential can also form. For example, nitric oxide can react with superoxide to form peroxynitrite, a highly reactive nitrogen compound with degrading capabilities similar to those of the reactive oxygen species 4. Expulsion of debris: Once degradation is complete, leftover waste products are excreted from the cell in an exocytic vesicle. However, it is important to note that not all remains of the pathogen are excreted as waste. Macrophages and dendritic cells are also antigen-presenting cells involved in the specific adaptive immune response. These cells further process the remains of the degraded pathogen and present key antigens (specific pathogen proteins) on their cellular surface.

What cell junctions are examples of physical barriers? How do they prevent microbes from entering the body? How do some microorganisms try to enter the junctions?

1. Physical barriers play an important role in preventing microbes from reaching tissues that are susceptible to infection. At the cellular level, barriers consist of cells that are tightly joined to prevent invaders from crossing through to deeper tissue. 2. Cells create tight junctions, desmosomes, or gap junctions (Desmosomes, tight junctions, gap junctions) •Invading pathogens may use enzymes to break junction (recall: hyaluronidase)

What are the 3 categories of nonspecific innate immunity?

1. Physical innate defense 2. Chemical innate defense 3. Cellular innate defense

What proteins does the Membrane attack complex (MAC) use? How does it affect microbe cells and what bacteria is only effective against (gram-positive/gram-negative)?

1. The complement proteins C6, C7, C8, and C9 assemble into a membrane attack complex (MAC), which allows C9 to polymerize into pores in the membranes of gram-negative bacteria. 2. However, the MAC is only effective against gram-negative bacteria; it cannot penetrate the thick layer of peptidoglycan associated with cell walls of gram-positive bacteria.

Why is the endothelia crucial to the blood-brain barrier? How is the Central Nervous System sensitive to microbes? How do the junctions maintain a sterile field for the CNS?

1. The endothelia of the blood-brain barrier, for example, protect the central nervous system (CNS), which consists of the brain and the spinal cord. 2. The CNS is one of the most sensitive and important areas of the body, as microbial infection of the CNS can quickly lead to serious and often fatal inflammation. 3. The cell junctions in the blood vessels traveling through the CNS are some of the tightest and toughest in the body, preventing any transient microbes in the bloodstream from entering the CNS. This keeps the cerebrospinal fluid that surrounds and bathes the brain and spinal cord sterile under normal conditions

What substance do epithelial cells produces to protect against microbes? What enzymes is this substance made out of?

1. The epithelial cells secrete a moist, sticky substance called mucus, which covers and protects the more fragile cell layers beneath it and traps debris and particulate matter, including microbes. 2. Mucus secretions also contain antimicrobial peptides

What do monocytes look like (nucleus and granulocytes)? What is significant about monocytes as a type of white blood cells? What is the other 2 names for monocytes?

1. The largest of the white blood cells, monocytes have a nucleus that lacks lobes, and they also lack granules in the cytoplasm 2. •Largest constituent of WBCs 3. •AKA phagocytes or macrophages

Why doesn't extravasation occur in the arteries or veins (Hint: structure and flow of blood)? (give 2 reasons)

1. These blood vessels are surrounded by thicker, multilayer protective walls, in contrast to the thin single-cell-layer walls of capillaries. Furthermore, the blood flow in arteries is too turbulent to allow for rolling adhesion. Also, some leukocytes tend to respond to an infection more quickly than others.

Inflammatory mediators of cytokines: How does Histamine affect breathing?

to cause bronchoconstriction

What is the mucociliary escalator? Where is it located and is it better to have no microbiota presents or small amount?

1. This system of removal 2. Only recently has research suggested that healthy lungs may have a small normal microbiota. Disruption of the mucociliary escalator by the damaging effects of smoking or diseases such as cystic fibrosis can lead to increased colonization of bacteria in the lower respiratory tract and frequent infections, which highlights the importance of this physical barrier to host defenses.

What are examples of mechanical defenses performed by the skin, digestive system, and Ciliated epithelial cells? What action flushes microbes out of our eyes? What organs does the urinary system prevent microbes from colonizing?

1. We have already discussed several examples of mechanical defenses, including the shedding of skin cells, the expulsion of mucus via the mucociliary escalator, and the excretion of feces through intestinal peristalsis. 2. Other important examples of mechanical defenses include the flushing action of urine and tears, which both serve to carry microbes away from the body. 3. The flushing action of urine is largely responsible for the normally sterile environment of the urinary tract, which includes the kidneys, ureters, and urinary bladder. Urine passing out of the body washes out transient microorganisms, preventing them from taking up residence.

What properties does the complement system have? How are complement proteins considered innate?

1. antimicrobial but also connects innate with adaptive immunity 2. Complement proteins are considered part of innate nonspecific immunity because they are always present in the blood and tissue fluids, allowing them to be activated quickly. Also, when activated through the alternative pathway (described later in this section), complement proteins target pathogens in a nonspecific manner.

Inflammatory mediators of cytokines: How does Prostaglandins affect the body? What other inflammatory mediators does it stimulate?

1. induce fever 2. promote the inflammatory effects of kinins and histamines

What is the difference interleukins, chemokines, and interferons (Type I and type II)?

1. originally thought to be produced only by leukocytes (white blood cells) and to only stimulate leukocytes, thus the reasons for their name. Although interleukins are involved in modulating almost every function of the immune system, their role in the body is not restricted to immunity. Interleukins are also produced by and stimulate a variety of cells unrelated to immune defenses. (help recruit immune cells to infection site) 2. are chemotactic factors that recruit leukocytes to sites of infection, tissue damage, and inflammation. 3. Type I interferons (interferon-α and interferon-β) are produced and released by cells infected with virus. These interferons stimulate nearby cells to stop production of mRNA, destroy RNA already produced, and reduce protein synthesis. These cellular changes inhibit viral replication and production of mature virus, slowing the spread of the virus. Type I interferons also stimulate various immune cells involved in viral clearance to more aggressively attack virus-infected cells. Type II interferon (interferon-γ) is an important activator of immune cells (released by cells with viral infection to recruit immune cells)

What type of phagocytes are leukocytes? What is extravasation/diapedesis and what effects does it have on the body?

1. phagocytes that travel to infection site 2. To reach pathogens located in infected tissue, leukocytes must pass through the walls of small capillary blood vessels within tissues. Similar to C5a, many of these cytokines are proinflammatory and chemotactic, and they bind to cells of small capillary blood vessels, initiating a response in the endothelial cells lining the inside of the blood vessel walls

What chemical does opsonization produce? What proteins (C proteins) are activated by this chemical and what reaction does it cause in the body?

1. the coating of a pathogen by a chemical substance (called an opsonin) that allows phagocytic cells to recognize, engulf, and destroy it more easily 2. Opsonins from the complement cascade include C1q, C3b, and C4b. Additional important opsonins include mannose-binding proteins and antibodies. The complement fragments C3a and C5a are well-characterized anaphylatoxins with potent proinflammatory functions. Anaphylatoxins activate mast cells, causing degranulation and the release of inflammatory chemical signals, including mediators that cause vasodilation and increased vascular permeability.

What is produced by a buildup of neutrophils? What does this signal (what does it mean)?

As neutrophils fight an infection, a visible accumulation of leukocytes, cellular debris, and bacteria at the site of infection can be observed. This buildup is what we call pus (also known as purulent or suppurative discharge or drainage). The presence of pus is a sign that the immune defenses have been activated against an infection; historically, some physicians believed that inducing pus formation could actually promote the healing of wounds.

What 2 categories come from Agranulocytes? What type of cells do they produce?

As their name suggests, agranulocytes lack visible granules in the cytoplasm. Agranulocytes can be categorized as lymphocytes or monocytes. Among the lymphocytes are natural killer cells, which play an important role in nonspecific innate immune defenses.

How do fatty acids on the skin's surface (epidermis) protect against microbes (What kind of environment does it create)?

Fatty acids on the skin's surface create a dry, salty, and acidic environment that inhibits the growth of some microbes and is highly resistant to breakdown by bacterial enzymes.

How does the productions of new cells and shedding of old cells help with defending against microbes?

In addition, the dead cells of the epidermis are frequently shed, along with any microbes that may be clinging to them. Shed skin cells are continually replaced with new cells from below, providing a new barrier that will soon be shed in the same way

What is the difference between autocrine, paracrine, and endocrine functions (in cytokines)?

In autocrine function, the same cell that releases the cytokine is the recipient of the signal; in other words, autocrine function is a form of self-stimulation by a cell. In contrast, paracrine function involves the release of cytokines from one cell to other nearby cells, stimulating some response from the recipient cells. Last, endocrine function occurs when cells release cytokines into the bloodstream to be carried to target cells much farther away.

What does the chemicals lysozyme and lactoferrin do to the bacteria in the eyes (is it more effective against gram-positive/gram-negative bacteria)?

In the eyes, tears contain the chemical mediators lysozyme and lactoferrin, both of which are capable of eliminating microbes that have found their way to the surface of the eyes. Lysozyme cleaves the bond between NAG and NAM in peptidoglycan, a component of the cell wall in bacteria. It is more effective against grampositive bacteria, which lack th

How can microbes enter through the skin?

Infections can occur when the skin barrier is compromised or broken. A wound can serve as a point of entry for opportunistic pathogens, which can infect the skin tissue surrounding the wound and possibly spread to deeper tissues

What is s transendothelial migration in extravasation/diapedesis? Where do leukocytes stick to and when do they begin phagocytosis?

Leukocytes passing through will stick slightly to the adhesion molecules, slowing down and rolling along the blood vessel walls near the infected area. When they reach a cellular junction, they will bind to even more of these adhesion molecules, flattening out and squeezing through the cellular junction in a process known as transendothelial migration. This mechanism of "rolling adhesion" allows leukocytes to exit the bloodstream and enter the infected areas, where they can begin phagocytosing the invading pathogens.

How does the low humidity or low sebum production affect the susceptibility to pathogens/microbes?

Low humidity or decreased sebum production, for example, could make the skin less habitable for microbes that produce oleic acid, thus making the skin more susceptible to pathogens normally inhibited by the skin's low pH

How can NK cells be viewed under the microscope (how are they stained)?

NK cells contain these toxic compounds in granules in their cytoplasm. When stained, the granules are azurophilic and can be visualized under a light microscope

What are agranulocytes and what do they lack?

Natural killer cells but lack granulocytes

Inflammatory mediators of cytokines: How does Leukotrines affect the body?

to induce coughing, vomiting, diarrhea

What 2 instances are antimicrobial peptides (AMPs) produced?

Some AMPs are produced routinely by the body, whereas others are primarily produced (or produced in greater quantities) in response to the presence of an invading pathogen.

What is the crisis phase after a fever?

The crisis phase occurs when the fever breaks. The hypothalamus stimulates vasodilation, resulting in a return of blood flow to the skin and a subsequent release of heat from the body. The hypothalamus also stimulates sweating, which cools the skin as the sweat evaporates.

What structures does endothelia line? and what does it protect against?

The epithelial cells lining the urogenital tract, blood vessels, lymphatic vessels, and certain other tissues are known as endothelia. These tightly packed cells provide a particularly effective frontline barrier against invaders.

How does the an exogenously produced chemicals: lactate, glycogen, and lactobacilli prevent the colonization of microbes in the vagina?

The female reproductive system employs lactate, an exogenously produced chemical mediator, to inhibit microbial growth. The cells and tissue layers composing the vagina produce glycogen, a branched and more complex polymer of glucose. Lactobacilli in the area ferment glycogen to produce lactate, lowering the pH in the vagina and inhibiting transient microbiota, opportunistic pathogens like Candida

What is perilstalsis performed by the digestive tract (what is its function)?

The mechanical action of peristalsis, a series of muscular contractions in the digestive tract, moves the sloughed mucus and other material through the intestines, rectum, and anus, excreting the material in feces.

What parts of the body are mucous membranes located? What kind of cells line the mucous membranes and what junction are they bound by?

The mucous membranes lining the nose, mouth, lungs, and urinary and digestive tracts provide another nonspecific barrier against potential pathogens. Mucous membranes consist of a layer of epithelial cells bound by tight junctions.

How does respiratory system use chemical mediators e.g., lysozyme, lactoferrin, lactoperoxidase)?

The respiratory tract uses various chemical mediators in the nasal passages, trachea, and lungs. The mucus produced in the nasal passages contains a mix of antimicrobial molecules similar to those found in tears and saliva (e.g., lysozyme, lactoferrin, lactoperoxidase). Secretions in the trachea and lungs also contain lysozyme and lactoferrin, as well as a diverse group of additional chemical mediators, such as the lipoprotein complex called surfactant, which has antibacterial properties

What are pattern recognition receptors (PRRs)?

The structures that allow phagocytic cells to detect PAMPs

What are the other names for red blood cells, white blood cells, and platelets?

The three major categories of formed elements are: red blood cells (RBCs), also called erythrocytes; platelets, also called thrombocytes; and white blood cells (WBCs), also called leukocytes

How do physical barriers prevent microbes from invading the host?

They include physical barriers to microbes, such as the skin and mucous membranes, as well as mechanical defenses that physically remove microbes and debris from areas of the body where they might cause harm or infection.

How do ciliated epithelial cells protect against debris, dirt, and microbes from entering the lungs?

This debris becomes trapped in the mucus lining the respiratory tract, a layer known as the mucociliary blanket. The epithelial cells lining the upper parts of the respiratory tract are called ciliated epithelial cells because they have hair-like appendages known as cilia. Movement of the cilia propels debris-laden mucus out and away from the lungs. The expelled mucus is then swallowed and destroyed in the stomach, or coughed up, or sneezed out

What are the 3 processes of complement activation?

alternative, classical, and lectin pathways.

What do cytokines stimulate?

communication proteins that can stimulate immune cells to produce chemical defenses

Inflammatory mediators of cytokines: How does Bradykinin affect fluid in the body?

contributes to edema, which occurs when fluids and leukocytes leak out of the bloodstream and into tissues. It binds to receptors on cells in the capillary walls, causing the capillaries to dilate and become more permeable to fluids.

What structures does the dermis contain? What structures does the hypodermis contain?

dermis: contains hair follicles, sweat glands, nerves, and blood vessels. Hypodermis: blood and lymph vessels

What are the 4 protective outcomes that alternative, classical, and lectin all have in common?

they all provide the same protective outcomes: opsonization, inflammation, chemotaxis, and cytolysis

Where are basophils activated (activation pathway) and what chemicals do the granules contain? What reaction does it cause in the body?

•Activated complement cascade induce degranulation of basophils •Granules contain histamine & cytokines - . This cell type is important in allergic reactions and other responses that involve inflammation

What are the 3 antimicrobial proteins found in blood plasma?

•Acute phase proteins •Complement proteins •Cytokines

What is the purpose of nonspecific innate immunity? What does each term mean (Nonspecific, Innate)?

•Body's 1st line of defense against foreign matter in a non-specific manner These defenses are described as nonspecific because they do not target any specific pathogen; rather, they defend against a wide range of potential pathogens. They are called innate because they are built-in mechanisms of the human organism. Unlike the specific adaptive defenses, they are not acquired over time and they have no "memory" (they do not improve after repeated exposures to specific pathogens).

What is the difference between chemical mediators: endogenously produced by exogenously produced?

•Chemicals produced to inhibit microbial growth •Can be produced by host (endogenous) or resident microbiota (exogenous)

How is Propionibacterium acnes an example of exogenous chemicals while sebum is an example fo endogenous chemicals?

•Exogenous Example: Propionibacterium acnes digest sebum to produce oleic acid and lower skin pH 2. Sebaceous glands in the dermis secrete an oil called sebum that is released onto the skin surface through hair follicles. This sebum is an endogenous mediator, providing an additional layer of defense by helping seal off the pore of the hair follicle, preventing bacteria on the skin's surface from invading sweat glands and surrounding tissue

what do eosinophils protect against? What chemicals do they produce in the granules?

•Good protection against protozoa & helminths •Granules contain histamine, degradative enzymes, and major basic protein (MBP)

What bacteria do neutrophils kill? What do they produce to kill the bacteria/microbes? What do the Neutrophil extracellular traps (NETs) do and what properties do they contain (what proteins are examples of NETs)?

•Involved with destruction of extracellular bacteria •Produce defensins & hydrolytic enzymes (process is called degradation) •Neutrophil extracellular traps (NETs) - mesh of chromatin with AMPs to trap pathogens - s. Proteins frequently associated with NETs include lactoferrin, gelatinase, cathepsin G, and myeloperoxidase. Each has a different means of promoting antimicrobial activity, helping neutrophils eliminate pathogens

What is the difference in appearance between neutrophils, eosinophils, and basophils?

•Neutrophils: 5 connected lobes & small, purple granules •Eosinophils: 2-3 lobes & large, orange granules •Basophils: 2 lobes & large, purple granules

Though Inflammation is associated with negative consequences, What makes it so important for the immune system and repair?

•Recruitment of immune cells •Additional elimination tactic •Initiate repair of host damage

Where do Natural Killer cells (NK cells) derive from? What type of cells do they target? What chemicals are produced to eliminate these harmful cells?

•Seek out non-self markers (i.e. tumors and viral infected host cells) •Can express cytokines, cytotoxic molecules stored in granules to kill non-self cell

What kind of response does a fever produce? What are pyrogens in a fever? How are pyrogen considered both exogenous or endogenous?

•Systemic inflammatory response that raises overall body temperature •Pyrogens - produced by pathogens that alter hypothalamus (regulator of body temp) 2. s. For example, the endotoxin lipopolysaccharide (LPS), produced by gram-negative bacteria, is an exogenous pyrogen that may induce the leukocytes to release endogenous pyrogens such as interleukin-1 (IL-1), IL-6, interferon-γ (IFN-γ), and tumor necrosis factor (TNF). •Exogenous pyrogen - LPS •Endogenous pyrogen - interleukins from leukocytes

What functions are triggered when PAMPs recognize a pathogen?

•When PAMP is recognized phagocyte activates genes for phagocytosis, cell proliferation, interferon production, and/or cytokines