Which of the following is NOT a consequence of the immune system lacking an immune tolerance?

• A. The immune system cells will only recognize and attack foreign antigens.
• B. The immune system cells will recognize and attack foreign and self-antigens.
• C. The immune system will attack self-cells causing autoimmune diseases.
• D. The immune system will not remove T and B lymphocytes that bind to self-antigens.

Answer: (A)

Verified step by step guidance

1. Understand the concept of immune tolerance: Immune tolerance is the ability of the immune system to recognize self-antigens and not mount an immune response against them. This prevents the immune system from attacking the body's own cells.
2. Identify the consequences of lacking immune tolerance: When immune tolerance is absent, the immune system may fail to distinguish between self and non-self antigens, leading to potential autoimmune reactions.
3. Analyze each option: Consider what happens when immune tolerance is lacking. The immune system may attack self-cells, leading to autoimmune diseases, and may fail to remove T and B lymphocytes that bind to self-antigens.
4. Evaluate the correct answer: The statement 'The immune system cells will only recognize and attack foreign antigens' implies that the immune system is functioning normally, recognizing only non-self antigens, which is not a consequence of lacking immune tolerance.
5. Conclude by identifying the option that does not fit: Since the lack of immune tolerance leads to the immune system attacking both foreign and self-antigens, the correct answer is the option that suggests the immune system will only attack foreign antigens, which is not a consequence of lacking immune tolerance.