Word: Helper T Cell
Definition: A helper T cell is a type of white blood cell that plays a crucial role in the immune system. It has a special receptor called CD4. Helper T cells recognize harmful substances (called antigens) on the surface of virus-infected cells. When they recognize these antigens, they produce signals (called lymphokines) that help activate other immune cells, like B cells and killer T cells, to fight off infections.
Usage Instructions:
Context: You will often hear about helper T cells in discussions about the immune system, health, and diseases, especially in relation to HIV/AIDS.
Sentence Structure: You can use "helper T cell" in sentences to talk about health, biology, or medicine.
Example Sentence: The doctor explained how helper T cells are important for fighting infections.
Advanced Usage:
In more advanced discussions, you might hear about how helper T cells interact with various immune pathways and their role in diseases like HIV/AIDS, where they are specifically targeted and destroyed by the virus.
Word Variants:
T Cell: A broader category that includes all types of T cells, not just helper T cells.
CD4: The specific receptor found on helper T cells.
Lymphokines: The signaling molecules released by helper T cells.
Different Meanings:
While "helper T cell" has a specific meaning in biology and medicine, "helper" in other contexts can refer to someone who assists or supports another person in various tasks (e.g., a helper in a classroom).
Synonyms:
T lymphocyte: Another term for T cell, although it is more general.
Immune helper cell: Sometimes used to describe the function of helper T cells.
Idioms and Phrasal Verbs:
There are no specific idioms or phrasal verbs directly related to "helper T cell," but you might hear phrases like "fight off an infection," which refers to the action that helper T cells help other immune cells perform.
Summary:
Helper T cells are essential for a strong immune response. They help other immune cells recognize and fight infections.