Life Cycle of HIV and Immunology Concepts

These flashcards cover key concepts in the life cycle of HIV, immunology, and disease transmission.

Binding (attachment)

HIV binds to receptors on the surface of CD4 cells.

Fusion

The HIV envelope and CD4 cell membrane fuse, allowing HIV to enter the CD4 cell.

Reverse transcription

HIV uses reverse transcriptase to convert its RNA to DNA inside the CD4 cell.

Integration

HIV releases integrase to insert its viral DNA into the CD4 cell's DNA.

Replication

HIV uses the machinery of the CD4 cell to create long chains of HIV proteins.

Assembly

New HIV proteins and RNA assemble into immature HIV at the surface of the CD4 cell.

Budding

A piece of the CD4 cell membrane wraps around the HIV proteins to form the viral envelope.

A-B Toxins

Toxins with an active (A) and binding (B) component, e.g., diphtheria toxin.

Membrane-disrupting toxins

Toxins that disrupt plasma membranes, causing cell lysis.

Superantigens

Toxins that provoke strong immune responses, leading to cytokine release.

Stages of Inflammation

1. Vasodilation, 2. Phagocyte migration, 3. Tissue repair.

Phagocytosis Steps

1. Identification and binding, 2. Engulfment, 3. Destruction with lysosomes, 4. Waste expulsion.

Siderophores

Molecules that bind iron, allowing pathogens to steal it from hosts.

Lactoferrin

A protein that sequesters iron found in mucosal secretions and breast milk.

TLR

Toll-like receptors, a type of pattern recognition receptor.

Incidence

Number of new cases of an infection within a specified period.

Prevalence

Percentage of total cases of infected individuals in a population.

Morbidity

Percentage of infected people showing symptoms.

Mortality

Percentage of infected individuals who die from an infection.

Case Fatality Ratio (CFR)

Percentage of symptomatic individuals who die from an infection.

Herd immunity

When a significant portion of a population is immune, hindering disease spread.

Zoonotic disease

A disease that has transferred from non-human animals to humans.

Vector

A living organism that carries a disease-causing agent from an infected host to a new host.