3020 Lecture 23
Amber Stokes・32 minutes read
Inflammatory response enables phagocytes to eliminate bacteria, with the complement system activating in the presence of pathogens to cause them to burst. Edward Jenner's vaccination study in 1796 led to the understanding of immunity, while memory cells allow for swift immune responses to familiar antigens.
Insights
- Inflammatory responses are triggered by cell injuries, causing blood vessels to dilate and become more permeable, allowing phagocytes to eliminate bacteria. This process is accompanied by an acute phase response that includes fever to enhance immune activity and impede microbial growth.
- Edward Jenner's observation of milkmaids' immunity to smallpox due to exposure to cowpox marked the beginning of vaccination, showcasing how exposure to related pathogens can confer immunity without severe symptoms upon subsequent exposure.
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Recent questions
What is the purpose of the complement system?
The complement system consists of proteins that circulate in the blood and become activated in the presence of pathogens. When activated, it forms a membrane attack complex that causes pathogens to swell and burst, aiding in their elimination from the body.
How did Edward Jenner contribute to immunity studies?
Edward Jenner initiated the scientific study of immunity in 1796 by observing that milkmaids rarely contracted smallpox due to exposure to cowpox. This observation led to the development of the first form of vaccination, as exposure to cowpox provided immunity against smallpox.
What are primary lymphoid organs responsible for?
Primary lymphoid organs, such as the bone marrow and thymus, play critical roles in the immune system. They facilitate the maturation of B cells in the bone marrow and T cells in the thymus, ensuring the development of functional immune cells.
What are antigens and their role in immune responses?
Antigens are molecules that provoke specific immune responses by signaling the immune system to react. Typically found on the surface of invaders or microorganisms, antigens can have multiple antigenic determinants called epitopes, stimulating distinct immune responses in the body.
How do memory cells contribute to the immune system?
Memory cells play a crucial role in the immune system by enabling rapid responses to previously encountered antigens. Similar to how individuals remember past interactions, memory cells allow for swift and efficient immune responses upon re-exposure to familiar antigens, enhancing the body's ability to fight off infections.
Related videos
Summary
00:00
"Immune Response: Inflammation, Antigens, Memory Cells"
- Inflammatory response occurs when cells are injured, releasing chemical alarms that make blood vessels more permeable and dilate, allowing phagocytes to enter and eliminate bacteria.
- Inflammation is accompanied by an acute phase response, leading to fever as macrophages release interleukin one, signaling the hypothalamus to raise body temperature to enhance phagocyte activity and impede microbial growth.
- The complement system, consisting of 30 proteins, circulates in the blood in an inactive form and becomes activated in the presence of pathogens, forming a membrane attack complex that causes pathogens to swell and burst.
- Edward Jenner initiated the scientific study of immunity in 1796 by observing that milkmaids rarely contracted smallpox due to exposure to cowpox, leading to the first form of vaccination.
- Primary lymphoid organs, such as bone marrow and thymus, play critical roles in the immune system by facilitating B cell maturation and T cell maturation, respectively.
- Secondary lymphoid organs like lymph nodes, spleen, and mucosal-associated lymphoid tissue filter antigens, activating B and T cells to initiate immune responses.
- Antigens are molecules that provoke specific immune responses, typically components of microorganisms or proteins found on the surface of invaders, signaling the immune system to respond.
- Antigens can have multiple antigenic determinants called epitopes, stimulating distinct immune responses, with each epitope recognized independently by the immune system.
- Immune cells, like helper T cells and cytotoxic T cells, are characterized by their specificity in recognizing antigens, wide diversity of antigens recognized, and the presence of memory cells for rapid responses to previously encountered antigens.
- Memory cells enable the immune system to respond quickly to familiar antigens, akin to how individuals remember past interactions and conversations, allowing for swift and efficient immune responses.
30:08
"Immune Cells Differentiate Self from Non-Self"
- Immune cells can differentiate between self and non-self cells, crucial for the adaptive immune system.
- Self cells are the body's own cells, while non-self cells include bacteria, viruses, or foreign cells.
- Lymphocytes, like B and T cells, have surface receptors specific to antigens, initiating immune responses.
- Naive lymphocytes encounter antigens for the first time, activating through clonal selection.
- Activated lymphocytes can become memory cells or immediately respond to antigens.
- B cells secrete antibodies in response to antigens, known as immunoglobulins (IG).
- T cells regulate immune cells or attack cells with specific antigens, like altered self cells or foreign peptides.
- Cytotoxic T cells undergo clonal expansion, inducing apoptosis in specific cells.
- Helper T cells secrete cytokines to activate or differentiate immune cells in response to foreign antigens.
- Humoral immunity involves B cells encountering antigens, leading to clonal expansion, memory cell production, and antibody secretion.
01:03:41
"IGG Antibodies: Immune Response and Vaccination"
- IGG antibodies neutralize antigens and promote phagocytosis by binding to receptors on phagocytes.
- IGG is the most abundant antibody in body secretions and binds to mast cells and basophils, triggering allergic reactions.
- The difference between primary and secondary immune responses is illustrated through the production of IGM and IGG antibodies after exposure to cowpox.
- Vaccination introduces antigens into the body, stimulating a primary immune response that can lead to immunity without experiencing severe symptoms upon subsequent exposure.
