Several viruses are implicated in the development or progression of various autoimmune diseases by triggering or exacerbating immune responses. These viruses can play a role in how the immune system mistakenly attacks healthy tissues in the body.
Viruses Implicated in Autoimmune Conditions
The interaction between specific viruses and an individual's genetic predisposition can lead to a breakdown in immune tolerance, resulting in autoimmune disease. For example, certain viruses are associated with conditions like rheumatoid arthritis and Sjogren syndrome.
The table below highlights some autoimmune conditions and the viruses that have been linked to them, along with their proposed mechanisms:
| Autoimmune Disease | Virus | Proposed Mechanism |
|---|---|---|
| Rheumatoid arthritis | Epstein–Barr virus | Epitope spreading |
| Rheumatoid arthritis | Cytomegalovirus | Epitope spreading |
| Pulmonary inflammation in lupus-prone mice | Influenza A virus | Bystander activation & epitope spreading |
| Sjogren syndrome | Hepatitis C virus | Bystander activation |
How Viruses May Trigger Autoimmunity
Viruses can contribute to autoimmunity through several proposed mechanisms:
- Epitope Spreading: This occurs when an initial immune response to a viral antigen broadens to include self-antigens, leading to an autoimmune attack.
- Bystander Activation: Viral infections can create an inflammatory environment that activates self-reactive immune cells that would otherwise remain dormant, thus initiating or worsening autoimmune disease.
These mechanisms illustrate how a viral infection, rather than directly causing the disease, can act as a trigger or amplifier for autoimmune processes in susceptible individuals.
