Influenza and Immunology Lecture Review

Vocabulary and key concepts regarding viral characteristics, life cycles, evolution, and the human immune response to Influenza.

Capsid

The protein shell that surrounds the genetic material of a simple parasite (virus).

RNA viruses

Viruses that use RNA as genetic material and require a special enzyme for copying RNA, which typically makes numerous mistakes.

DNA viruses

Viruses that use DNA as genetic material and require the host cell to divide to provide enzymes for copying DNA; these can potentially cause cancer.

Lytic life cycle

A 5-step viral process consisting of attachment to host cell, penetration, synthesis of components, assembly of new particles, and release.

Lysogenic life cycle

A viral cycle where the virus goes dormant inside the host.

Evolution

Changes in the genetics or traits of a population, which can create a new species and implies all life is related by shared ancestry.

Natural selection

The process that causes undesirable traits to become less common and desirable traits to become more common based on the environment.

Mutations

The primary source of genetic diversity.

Homologous traits/structures

Evidence for evolution including examples like arm bones, genetic similarities, and gills in embryos.

Vestigial traits

Inherited traits that have lost their original function, such as the tailbone, serving as evidence for evolution.

1st line of defense

The initial immune barrier consisting of the skin and mucous membranes.

Innate immunity

The 2nd line of defense that is nonspecific, fast, and characterized by inflammation.

Adaptive immunity

The 3rd line of defense that is specific, slow, utilizes antibodies, and remembers pathogens.

4 cardinal signs of inflammation

Redness, heat, swelling, and pain.

Helper T cells

Adaptive immune cells that activate the other adaptive immune cells.

Killer T cells

Adaptive immune cells responsible for killing cells infected with a pathogen.

B cells

Adaptive immune cells that function to make antibodies.

Memory cells

Cells that remember past pathogens and allow for a quick response during future encounters.

Primary adaptive immune response

The slower response occurring the first time a pathogen is encountered, resulting in fewer antibodies for a shorter duration and the creation of memory cells.

Secondary adaptive immune response

The faster response occurring the second time a pathogen is encountered, requiring memory cells and resulting in more antibodies for a longer duration.

Vaccines

Preparations that use an antigen to generate memory cells so a person has a stronger, faster secondary immune response upon real-life exposure.

Antigen

The component from a pathogen that is required within a vaccine to trigger an immune memory.

Influenza evolution mechanism

Rapid evolution due to being an RNA virus with its own copying enzyme that makes many mistakes.