Question

How do cytokines function?

1) They bind directly to microbes to enhance their chance of being ingested (phagocytosed).
2) They are secreted in the phagolysosomes of neutrophils to effect killing of ingested microbes.
3) They are secreted by one cell type. They then bind to a receptor on target cell causing a signal within that cell that turns on (or off) certain genes to achieve a response.
4) They work as a series of serum proteins to produce a hole in microbes to directly lyse them.

Answer 1

Cytokines are signaling molecules that regulate immune responses, guiding leukocytes to infection sites and influencing gene expression in target cells to facilitate the body's defense mechanisms.

Step-by-step explanation:

Cytokines are integral to the immune system, serving as signaling molecules secreted by various cells, including leukocytes and macrophages. They play a pivotal role in cell communication, signaling immune responses by binding to receptors on target cells which in turn activate or deactivate gene expression.

Early in immune reactions, they promote inflammation, characterized by redness and swelling, facilitating the arrival of leukocytes to the infection site. Cytokines such as interleukins and chemokines also participate in chemotaxis, guiding phagocytes to sites of infection. Once there, these leukocytes, like neutrophils, engulf and eliminate pathogens through phagocytosis, utilizing lysosomes to digest the microbe.