Antibody Dependent Cell Mediated Cytotoxicity (ADCC) | Effector cells in ADCC response

Summary

In this video, the concept of Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) is explained as a crucial mechanism in the immune response. ADCC involves effector cells, such as natural killer (NK) cells, recognizing antibodies bound to pathogens or abnormal cells, leading to their destruction. The video discusses ADCC's role in combating viral infections, bacterial infections, and hypersensitivity reactions like blood transfusion mismatches. It also explores ADCC's potential in cancer treatment by targeting tumor cells. The video concludes with a call to support the channel and a reminder about available courses on an educational platform.

Takeaways

• 😀 ADCC (Antibody Dependent Cell Mediated Cytotoxicity) is a cell-mediated immunity mechanism that helps eliminate pathogens like bacteria and viruses.
• 😀 ADCC involves effector cells, which recognize antibodies bound to pathogens, enabling the destruction of those pathogens.
• 😀 The primary effector cells in ADCC are Natural Killer (NK) cells, along with others like neutrophils, dendritic cells, and macrophages, which have FC receptors.
• 😀 ADCC plays a critical role in the immune response to viral infections by neutralizing the virus and preventing it from entering host cells.
• 😀 Antibodies produced against viruses can block the virus from entering cells, and effector cells can destroy the virus through ADCC.
• 😀 ADCC is linked to type II hypersensitivity reactions, which involve immune responses like those seen in blood transfusion mismatches.
• 😀 A mismatch blood transfusion between a person with blood group A and another with blood group B results in ADCC leading to RBC destruction.
• 😀 Complement-mediated lysis also contributes to the destruction of RBCs in a mismatch blood transfusion, alongside ADCC.
• 😀 ADCC principles can be applied in cancer treatment, where monoclonal antibodies target tumor-specific antigens on cancer cells.
• 😀 NK cells, through ADCC, can help reduce tumor volume by recognizing and destroying tumor cells bound by monoclonal antibodies.
• 😀 ADCC is an area of active research in cancer immunotherapy, focusing on harnessing the immune system to target and destroy tumor cells more effectively.

Q & A

What is antibody-dependent cell-mediated cytotoxicity (ADCC)?

ADCC is a mechanism of cell-mediated immunity where effector cells recognize a portion of an antibody that has bound to a pathogen, such as a virus or bacteria. These effector cells then engulf and destroy the pathogen, a process known as cytotoxicity.

What role do effector cells play in ADCC?

Effector cells are immune cells that have receptors for the Fc portion of antibodies. These cells, such as natural killer (NK) cells, neutrophils, macrophages, and dendritic cells, recognize the antibody bound to a pathogen and initiate the destruction of the pathogen.

How does ADCC contribute to fighting viral infections?

In viral infections, antibodies are produced to neutralize the virus. If the virus is neutralized by antibodies, effector cells like NK cells can recognize the antibody-coated virus and destroy it, helping to clear the infection.

What are the types of effector cells involved in ADCC?

Effector cells that can mediate ADCC include natural killer (NK) cells, neutrophils, macrophages, and dendritic cells. The most important of these in viral infections are NK cells.

Can ADCC occur in bacterial infections as well?

Yes, ADCC can also occur in bacterial infections. Antibodies bind to bacteria, and effector cells such as NK cells can recognize the antibody-coated bacteria and destroy them.

What is the relationship between ADCC and type II hypersensitivity reactions?

ADCC is associated with type II hypersensitivity reactions, where immune cells destroy cells or tissues that have been targeted by antibodies. An example is a mismatched blood transfusion, where antibodies bind to the donor red blood cells, leading to their destruction by effector cells.

How does a mismatched blood transfusion trigger ADCC?

In a mismatched blood transfusion, the antibodies in the recipient's blood bind to antigens on the donor's red blood cells. This binding attracts effector cells like NK cells or macrophages, which destroy the transfused red blood cells.

How is ADCC applied in cancer treatment?

In cancer treatment, monoclonal antibodies are designed to target tumor-specific antigens on cancer cells. These antibodies then bind to the tumor cells, and effector cells like NK cells can destroy the cancer cells through ADCC, reducing the tumor volume.

What are tumor antigens, and why are they important in ADCC-based cancer treatment?

Tumor antigens are specific proteins or markers found on the surface of tumor cells. These antigens are targeted by monoclonal antibodies in cancer treatments. Since normal cells do not express these antigens, the treatment selectively targets and destroys tumor cells through ADCC.

What is the significance of NK cells in ADCC?

NK cells (natural killer cells) play a crucial role in ADCC because they have Fc receptors that recognize the antibody-coated pathogens or tumor cells. NK cells are especially important in viral infections and cancer treatments, where they help eliminate infected or cancerous cells.