Immune System Mechanisms: Lymphocytes, Antibodies, and Vaccines

Specific Mechanisms of the Immune System

Lymphocytes, a type of white blood cell, are the most important component of the immune system. These cells recognize microorganisms or foreign substances that enter our body. There are two primary types: B lymphocytes and T lymphocytes, each functioning differently.

All organisms possess proteins or molecules on their surface that differ from those found in our own body. These molecules are called antigens and can trigger an immune response.

B Cells and Antibodies

B cells produce antibodies, also known as immunoglobulins, which bind specifically to antigens. Microorganisms covered with antibodies are marked, signaling other white blood cells to destroy them.

T Lymphocytes

When a virus infects a cell, it leaves behind proteins that form its outer shell. T lymphocytes recognize these proteins as antigens and destroy the infected cells, preventing the virus from reproducing. T cells are essential to our defense as they regulate the overall functioning of the immune system.

The Cat and Mouse Game: AIDS

Vaccines are not available for all diseases due to two main factors:

• Social Measures: Research often prioritizes diseases affecting the developed world.
• Scientific Challenges: Microorganisms utilize complex defensive strategies, making vaccine development difficult.

For example, creating an AIDS vaccine is challenging because the HIV virus mutates rapidly, constantly changing its protein envelope to evade antibodies. Scientists Sloboda and Julia Karen Hurwitz have proposed a new vaccine, PolyEnv, which contains over one hundred types of HIV envelope proteins to combat viral diversity.

Genetics and Vaccines

DNA vaccines are currently being evaluated. This process involves:

• Inserting DNA from an infectious agent into a plasmid.
• Injecting the plasmid into the individual.
• The plasmid carries a gene that encodes a protein, which muscle cells then express.
• This expressed antigen triggers an immune response, inducing the production of antibodies and memory cells without the plasmid replicating.