Anticorpos Policlonais e Monoclonais

Summary

In this lesson, Professor Ana Cristina explains the difference between polyclonal and monoclonal antibodies, delving into how these antibodies are produced and their various applications. The process of creating monoclonal antibodies through the fusion of B lymphocytes with immortalized myeloma cells, resulting in hybridomas, is described in detail. The video also covers their significance in medical diagnostics, cancer treatments, and transplant rejection therapies. Additionally, the limitations of using animal-derived antibodies in humans and advancements in biotechnology to overcome these challenges are discussed, alongside the practical uses of immunoassays.

Takeaways

• 😀 Polyclonal antibodies are produced by multiple B lymphocytes and target different epitopes of an antigen, making them diverse in their properties.
• 😀 Monoclonal antibodies are derived from a single B lymphocyte and are identical in their chemical and biological properties, targeting only one epitope.
• 😀 The production of monoclonal antibodies involves fusing B lymphocytes from an immunized animal with immortalized myeloma cells to create hybridomas.
• 😀 Hybridomas are cultured in a selective medium, ensuring that only the hybrid cells, which produce monoclonal antibodies, survive and proliferate.
• 😀 Monoclonal antibodies have numerous applications in medical diagnostics, cancer therapies, organ transplant rejection prevention, and more.
• 😀 The hybridoma technique for producing monoclonal antibodies was first developed by César Milstein and George Köhler in 1975.
• 😀 There are potential limitations to monoclonal antibodies, including immune responses in humans due to their animal origin, leading to HAMA (human anti-mouse antibody) reactions.
• 😀 Biotechnological advancements have led to the development of chimeric and humanized monoclonal antibodies, which reduce immunogenicity and side effects.
• 😀 Antibodies are classified into different isotypes (IgG, IgA, IgM, etc.), each with distinct properties based on their heavy chain structure.
• 😀 Immunoassays, such as those using monoclonal antibodies, are crucial for diagnosing diseases by detecting specific antigens or antibodies in patient samples.

Q & A

What are polyclonal antibodies?

Polyclonal antibodies are produced by various B lymphocytes, each recognizing a different epitope of a specific antigen. These antibodies are generated in response to an antigen invading the body, and each B cell produces antibodies targeting different parts of the antigen.

How are monoclonal antibodies different from polyclonal antibodies?

Monoclonal antibodies are derived from a single B lymphocyte that has been selected and replicated, producing identical antibodies with the same specificity. In contrast, polyclonal antibodies come from different B cells and recognize different epitopes on the same antigen.

Who were the scientists behind the first procedure to produce monoclonal antibodies?

The procedure to produce monoclonal antibodies was first described in 1975 by César Milstein and George Köhler.

What is the key process involved in producing monoclonal antibodies?

The key process involves fusing B lymphocytes from an immunized animal, typically a mouse, with immortalized myeloma cells. The resulting hybrid cells, known as hybridomas, are capable of producing monoclonal antibodies.

What are hybridomas and how are they used in monoclonal antibody production?

Hybridomas are cells created by fusing B lymphocytes with myeloma cells. These hybrid cells are immortal and produce monoclonal antibodies that are identical in structure and specificity.

What challenge arises when using monoclonal antibodies from animals in humans?

Monoclonal antibodies derived from animals, particularly mice, can provoke an immune response in humans, known as an 'anti-animal response' or 'human anti-mouse antibody' (HAMA) reaction, which can reduce the effectiveness of the antibody and lead to adverse effects.

What solution has been developed to address the problem of human immune reactions to monoclonal antibodies?

To address the problem of immune reactions, researchers developed chimeric antibodies. These antibodies combine the variable regions from animal antibodies with the constant regions from human antibodies, reducing immune reactions.

What are 'humanized' monoclonal antibodies?

Humanized monoclonal antibodies have been further engineered to minimize the mouse-derived components. The variable regions responsible for specificity are from the animal source, but most of the antibody structure is human, reducing the risk of immune reactions.

What are some common uses of monoclonal antibodies?

Monoclonal antibodies are widely used in research, diagnostic tests, cancer treatment, and therapies for transplant rejection and other medical conditions.

What is the significance of monoclonal antibodies in diagnostics and therapies?

Monoclonal antibodies are highly specific and can be used in various diagnostic tests, such as detecting antigens or antibodies in blood tests. They also play a crucial role in targeted therapies, particularly in cancer treatment and autoimmune diseases.