Immunology easy

The interaction between microorganisms and macroorganisms (e.g., bacteria and humans).

A type of symbiosis where both organisms benefit from the interaction.

E. coli living in the human digestive tract, aiding in nutrient breakdown and protection.

A type of symbiosis where one organism benefits, and the other is neither harmed nor helped.

A type of symbiosis where one organism benefits, and the other is harmed.

The invasion, replication, and host reaction to a causative agent and its toxins, in human tissues.

The resulting condition when an infection weakens the body's defenses.

A parasite that can exist both inside and outside a host.

A parasite that needs a host for survival and has a very limited time outside of a host.

A parasite that can only survive inside a host cell.

Toxic protein secreted by a bacterium.

Toxic component of the bacterial cell wall, released upon cell lysis.

Bacteria can control the production and release of exotoxins.

Released only when the bacterial cell breaks down (lysis).

Exotoxins are highly antigenic (trigger an immune response).

Endotoxins are weakly antigenic.

Endotoxins activate Kupffer cells, triggering inflammation and fever.

Molecules (like IL-1, TNF) that induce inflammation and fever.

An infection that occurs randomly and independently in different locations. It's not linked to a common source or outbreak.

An infection that is consistently present in a specific geographic region or population. It's expected and often occurs at a relatively steady rate.

A widespread occurrence of an infectious disease in a community or region within a specific time period. It involves a significant increase in cases beyond what is normally expected.

A global outbreak of an infectious disease, spreading across multiple continents or worldwide.

The potential result of an infection, which can be recovery, death, or becoming a carrier of the disease.

An infection process involves a source, the presence of a pathogen, transmission, a point of entry, stages of the disease, and an immune response.

The body's ability to resist and defend against harmful agents, particularly those with foreign genetic elements that trigger an immune response.

The body's first line of defense against infection, involving non-specific mechanisms that are always present and ready to act.

Sporadic infections occur randomly and independently, while endemic infections are consistently present in a specific region or population.

Most infections involve stages like incubation, prodromal, illness, decline, and convalescence, though not all stages are necessarily apparent.

Specialized receptors on immune cells that detect and bind to molecular patterns associated with pathogens (PAMPs) and damaged cells (DAMPs).

Pathogen-associated molecular patterns, molecules found on microbes that are recognized by PRRs. Example: Lipoteichoic acids on Gram-positive bacteria.

Damage-associated molecular patterns, molecules released from damaged or dying cells that are recognized by PRRs. Example: Heat shock proteins.

A type of PRR that plays a crucial role in recognizing a variety of microbial products and triggering immune responses.

A TLR that recognizes lipoteichoic acids, a component of Gram-positive bacteria cell walls.

TLRs that recognize multiple diacyl peptides, typically found on Mycoplasma bacteria.

TLRs that recognize products of viral replication, like double-stranded RNA.

Phagocytic cells that engulf and destroy pathogens and cellular debris, also expressing TLRs.

Cells that present antigens to T cells, triggering adaptive immune responses, also expressing TLRs.

Phagocytic cells that act as the first line of defense against invading pathogens, also expressing TLRs.

Proteins expressed on the surface of antigen-presenting cells (like macrophages and dendritic cells) that display fragments of foreign proteins (antigens) to T cells.

A process where a phagocytic cell engulfs and destroys a pathogen.

The movement of phagocytic cells towards a site of infection, guided by chemical signals.

The process of coating a pathogen with antibodies or complement proteins, making it more easily recognized and engulfed by phagocytes.

A vesicle formed within a phagocyte that encloses the engulfed pathogen.

A vesicle formed by the fusion of a phagosome with a lysosome, where the pathogen is destroyed.

Small proteins produced by phagocytes that kill pathogens.

Highly reactive molecules produced by phagocytes to kill pathogens, such as superoxide, hydrogen peroxide, and singlet oxygen.

Phagocytosis can be complete, resulting in pathogen destruction, or incomplete, leaving pathogens inside the cell.

A group of genes responsible for immune recognition and controlling tissue compatibility. It helps the body identify "self" from "non-self" cells.

MHC Class I proteins present short peptides, typically 8-10 amino acids long, derived from intracellular proteins. These peptides can be from normal cellular proteins, viral proteins, or other pathogens.

MHC Class II proteins present longer peptides, typically 13-18 amino acids long, derived from extracellular proteins. These peptides are usually from pathogens like bacteria or viruses that have been engulfed by APCs.

Cells specialized in capturing and processing antigens, then presenting them to T cells via MHC molecules. Examples include macrophages, dendritic cells, and B cells.

MHC Class II molecules have a groove that can bind peptides of around 10-20 amino acids. This binding is specific and helps in antigen presentation.