Non specific responses

Infection

A condition in which pathogenic microorganisms penetrate host defenses, enter the tissues, and multiply

Obligate intracellular parasites

Multiply by taking control of host cells genetic material and regulating the synthesis and assembly of new viruses

What is a fully assembled infectious virus is called?

Virion

RNA viruses are … of all viruses

70%

What is the basic structure of a virus?

Protein shell surrounding a nucleic acid core which is a capsid with a DNA/RNA

What are the types of structure of virus

Enveloped, Naked, Complex

Viruses possess the genes needed to … a host cell and … its activity

invade a host cell and redirect its activity

Gag

is a polyprotein and an acronym from group antigens

Pol

is the reverse transcriptase

Env

the envelope protein

HIV

An enveloped retrovirus in the form of an mRNA genome uses its own reverse transcriptase enzyme to produce DNA from its RNA genome.

Provirus

DNA is then incorporated into the host cell genome by an integrase enzyme

Reverse transcriptase (RT)

An enzyme used to generate complementary DNA from an RNA template

Virions

Viruses released by infected cells that has the potential for rapid, large scale proliferation

What damage can virions do?

shut down the catabolism, genetic expression, destruction of cell membrane and organelles, release of lyosomes, cell death, latency

Synscytium

a mass of cytoplasm containing several nuclei and enclosed in a membrane but no internal cell boundaries

Inclusion

A body suspended in the cytoplasm, such as a granule

Salmonella

intracellular pathogens that are rod shaped, They only invade the GI tract usually

Gram negative bacteria can cause..

many types of infections and are spread to humans in a matter of ways obj as E. coli

Bacteria

Produce toxins that disrupt normal cell function by damaging a cell. They block the transmission of internal signals or stimulaing cells so they malfunction

Cholera toxin works by?

disrupting the ionic balance of cells’ membranes. This leads to the cells in the small intestine secreting large amounts of water into the intestine → diarrhea and dehydration

Types of Antibiotics

Penicillins, tetracyclines, and quinolones

Penicillins

Inhibit the formation of bacterial cell wall by blocking cross-linking of the cell wall structure.

Why do bacteria need cross-linking of the cell wall?

The cell wall is a protecting casing for the bacterial cell

Tertracylines

inhibit protein synthesis by binding to the subunit of the bacterial ribosome

Quinolones

Blocks DNA synthesis by inducting one of bacterial enzymes (DNA gyrase) needed in this process

What are the lines of defense in fighting an infection? (1,2,3)

1. Nonspecific: physical barrier, chemical, genetic

2. Nonspecific: Innate immune system

3. Specific: Adaptive/ Acquired Immune system

What occurs during the first line response to infection to the skin

Skin resists pathogen penetraction and replication

What occurs during the first line response to infection to the mucous membranes

Chemical viral inhibitors prevent attachment to cell and directly inactivate the virus

What occurs during the first line response to infection from the lysozyme

Damage bacterial cell walls, secretes an abundant amount of lysozymes like tears, saliva, human milk, and mucus

What occurs during the first line response to infection from the stain environment of the stomach?

The stomach kills many bacteria

What occurs during the first line response to infection to the specificity of viruses

They host cell receptors

What are the key players in the second line of defense in fighting an infection?

Inflammatory response, phagocytosis, complement, interferons, and cytokines

What are the key players in the third line of defense

Antibodies, T cells, B cells, accessory cells, cytokines

The innate immune system will… than specific response

Act sooner

The innate immune system responses are … spectrum

broad

The innate immune system will have … of lasting protective immunity

No memory

Pathogen associated molecular patterns PAMPs

found on pathogens such as lipopolysaccharide (LPS) that are found on the outer membrane of bacteria

Damage associated molecular patterns DAMPs

cell components that are released during cell damage or death such as the presence of DNA anywhere other than the nucleus or mitochondria → triggers responses mediated by TLR9

pattern recognition receptors PPRs

These will identify PAMPs and DAMPs and are found on particular immune cells like phagocytic cells such as Toll like receptors TLRs

Will like receptors TLRs

A PPR. A class of proteins that play a key role in the innate immune system. They are single, membrane spanning, non catalytic receptors that usually are expressed on sentinel cells. They mainly recognize structurally conserved molecules derived from microbes

Cytokine

Any of a number of substances that are secreted by certain cells of the immune system and have an effect on other cellsW

What are examples of cytokines?

Interferons (IFN), tumor necrosis factor (TNF), interleukin (IL), and growth factors

Pyrogen

A polypeptide that produces fever by causing metabolic changes in the hypothalamus. It raises the set point of the hypothalamic thermostat

What are types of Pyrogens

exogenous and endogenous

What produces exogenous peptides

infectious agents

What produces endogenous peptides

Cells in the body like macrophages

Why are fevers important

they inhibit the multiplication of temperature sensitive viruses and stimulate immune reactions of phagocytosis

What are temperature sensitive viruses

poliovirus, cold viruses, herpes zoster virus

What can stem cells in the bone marrow become?

granulocytes, monocytes, and T/B lymphocytes

Granulocytes

A class of white blood cell that has granules in the cytoplasm

Monocytes

A type of white blood cells clear cytoplasm that are larger and migrate to site of infection and divide into macrophages and dendritic cells

Lymphocytes

A broader term for three types, NK cells, T cells, and B cell. These are found in the lymph and have no granules in their cytoplasm

Where are B cells located?

bone marrow

Where are T cells located

thymus

Where do natural killer cells function?

In innate immunity or adaptive immunity

What conditions are T cells used?

Cell mediates, cytotoxic adaptive immunity

What conditions are B cells used?

humoral, antibody-driven adaptive immunity

Monocytes differentiate into…

macrophages and dendritic cells

Inflammation

The response is activated by cell and tissue damage that is induced by pathogens. This response interferes with further pathogen replication/multiplication

What are the three stags of inflammation?

Vacular changes, swelling, production of chemical mediators

What occurs during vascular changes in inflammation

increased circulation, vasodilation, redness and warmth

What occurs during swelling

This occurs due to the leakage of macular fluid such as pus which is formed at the site of inflammation

What occurs as the production of chemical mediators rise?

Fever is inducted and stimulates the white blood cells to prevent the spread of the pathogen

What are examples of chemical medicators?

TNF via chemotaxis and phagocytosis, INF via inhibiting virus replication, and IL via activation of wbc

Exudate

A mass of cells and blood that has seeped out of blood vessels or an organ. Occurs during inflammation

Transudate

An extravascular fluid with a low protein content because of the increase fluid pressures or diminished colloid oncotic forces in the plasma

What occurs during inflammation at stage 1?

A break in the skin induces bacteria

What occurs during inflammation at stage 2

activated mast cells release histamine

What occurs during inflammation at stage 3

histamine and cytokines dilate local blood vessels

What occurs during inflammation at stage 4

chemokines attract neutrophils, which pass between cells of the blood vessel wall

What occurs during inflammation at stage 5

Neutrophils engulf the pathogens and destroy theCm

Chemokine

Type of cytokine that induces directed chemotaxis in nearby responsive cells

Histamine

A part of an immune response to freedom pathogens, this is produced via basophils and mast cells in the near by connective tissue.

Histamine increases the … of the capillaries to… and some proteins. This allows the to.. in the infected tissues

permeability of the capillaries to the exc and some proteins to allow them to engage pathogens in the infected tissues

Phagocytosis

Type of endocytosis where the cell membrane actively insults large particles or cells into vesiclesC

Antihistamines

Drugs that treat allergic rhinitis and other allergiesw

What symptoms and antihistamines help with?

Nasal congestion, sneezing, hives

Rhinitis

Inflammation and swelling of the mucous membrane of the nose that is characterized by a runny nose and stuffiness. This occurs typically because of a common cold or a seasonal allergy

Chemotaxis

Tendency of cells to migrate in response to a chemical stimulus

What are the main types of phagocyte

Neurtrophils, monocytes, macrophagesN

Neutrophils are

a type of granulocyte and are short livedm

Monocytes

Large and agranulated

Macrophages differentiate from

monocytes

Monocytes

Are attracted to a damaged site by chemical substances through chemotaxis and are triggered by. Range of stimuli including damaged cells, pathogens, and cytokines that help release by macrophages already at the site

Interferon (IFN)

A glycoprotein produced primarily by fibroblasts, NK lymphocytes, macrophages, epithelial cells, t-cells. It’s not virus specific

What initiates IFN synthesis

the binding of a virus to a host cell initiates

Where will IFN be secreted>

Into the extracellular space

When IFN binds to another host cell, what occurs?

It induces the production of proteins and degrades the viral RNA or prevents translation of viral proteins.

What is a benefit of the IFN not being antiviral specific?

IFN can be used a general treatment in combination with another to treat a viral infection before they find a better alternative

Complement

A Nonspecific group of proteins found in the blood plasma that form a membrane attack complex that kills cells via creating holes in the membrane. This is nonspecific and specific immunity

Cascade

sequential series of events in which the first substance activates the next

what are the three types of complement cascades?

classical, alternative, lectin

RNA interference (RNAi)

Cellular mechanism, destroys viral dsRNA, inhibits virus life cycle

How do Natural killer cells help in nonspecific defense

They can be activated by interferons and they can secrete orthotic and enzymes in response to infection

What does perforin do

creates pore in target cells and ruptures infected cells

What does secreted enzymes do

to degrade DNA, trigger apoptosis (programmed cell death)