Question

What are the components of acquired immunity?

Short answer

The components of acquired immunity are B cells, T cells, and antibodies.

Step-by-step solution

Title - Define Acquired Immunity

Acquired immunity, also known as adaptive immunity, is the immunity that develops with exposure to various antigens. It is specific to each pathogen and has a memory component.

Title - Identify Components

The main components of acquired immunity are B lymphocytes (B cells) and T lymphocytes (T cells). B cells produce antibodies that neutralize pathogens, whereas T cells can kill infected host cells or help activate other immune cells.

Title - Explain B Cells

B cells mature in the bone marrow. When activated by an antigen, they differentiate into plasma cells, which produce antibodies specific to that antigen. They also form memory B cells that provide long-term immunity.

Title - Explain T Cells

T cells mature in the thymus. They are divided into different types: Helper T cells (CD4+), which assist other white blood cells in immunologic processes, and Cytotoxic T cells (CD8+), which destroy virus-infected cells and tumor cells. There are also regulatory T cells that help control the immune response.

Title - Discuss Antibodies

Antibodies, or immunoglobulins, are proteins produced by plasma cells. They specifically recognize and bind to antigens, neutralizing them or marking them for destruction by other immune cells.

Title - Summarize Functions

In summary, B cells and T cells are the main components of acquired immunity. B cells produce antibodies, while T cells either help coordinate the immune response or directly kill infected cells. Memory cells provide long-term immunity.

Key concepts

B lymphocytes

B lymphocytes, also called B cells, are a crucial part of the acquired immune system. They mature in the bone marrow, and their primary role is to produce antibodies. When a B cell encounters its specific antigen, it gets activated and transforms into a plasma cell. Plasma cells are like factories that churn out large amounts of antibodies against the antigen. This response helps neutralize the pathogen. Another important feature of B lymphocytes is the formation of memory B cells. These cells remember the antigen they encountered, providing long-term immunity and allowing for a faster and more effective response if the pathogen invades again.

T lymphocytes

T lymphocytes, or T cells, mature in the thymus. They come in different types, each with a unique function in the immune response.
Helper T cells (CD4+ T cells) are like the alarm system of the immune response. They assist other immune cells by releasing signaling molecules called cytokines, which help activate B cells and other T cells.
Cytotoxic T cells (CD8+ T cells) are the body's defense force. They directly attack and kill cells that are infected with viruses or have turned cancerous. There are also regulatory T cells, which help control and maintain the immune system's response, preventing it from becoming overactive and causing damage to the body.

Antibodies

Antibodies, also known as immunoglobulins, are specialized proteins produced by plasma cells which are derived from B cells. These proteins play a critical role in the immune response by specifically targeting antigens.
Each antibody has a unique structure that allows it to bind precisely to its specific antigen, much like a lock and key. This binding can neutralize the pathogen directly or mark it for destruction by other immune cells. Antibodies can also activate other immune components, such as the complement system, to further aid in eliminating the pathogen.

Adaptive immunity

Adaptive immunity, also known as acquired immunity, is the body's tailored defensive response against specific pathogens. This system is highly specialized and remembers the pathogens it encounters. The adaptive immune system relies on B cells and T cells to provide this precise response.
Unlike the innate immune system, which provides a general defense, adaptive immunity develops over time and improves with repeated exposure to the same pathogen. This means that the body becomes better at fighting off an infection each time it encounters the same antigen.

Memory cells

Memory cells are a vital part of the adaptive immune system. Both B cells and T cells can develop into memory cells after an initial encounter with an antigen.
Memory B cells remain in the body for years and can quickly produce antibodies if the same pathogen invades again. Similarly, memory T cells can promptly respond to the same antigen, providing faster and more efficient protection. This long-term immunity is why vaccines are so effective—they simulate an infection and generate memory cells without causing illness.