Final answer:
B-cells that make antibodies against self molecules are usually eliminated or made inactive through tolerance mechanisms to prevent autoimmunity. They undergo processes in the bone marrow and peripheral immune system to ensure they do not react against the body's own tissues. If these B-cells are mistakenly activated, they can lead to autoimmune diseases.
Step-by-step explanation:
B-cells that make antibodies specific for self molecules are typically identified and deleted during the immune response, due to a process known as tolerance. Tolerance ensures that B-cells, which produce antibodies against the body's own tissues, are rendered nonfunctional or are eliminated to prevent autoimmune diseases. B-cells mature in the bone marrow, where they undergo negative selection to ensure self-tolerance.
If B-cells that react to self molecules escape the tolerance mechanisms, peripheral tolerance helps in keeping them inactive, often thanks to T cell tolerance. However, when B-cells are activated by binding to antigens not identified as self, they undergo differentiation into plasma cells. These plasma cells are essentially antibody factories, secreting large quantities of antibodies over a specific period until they eventually die off as terminally differentiated cells.