New Hopes to Patients Suffering from Autoimmune Disease Are On the Way.

Approximately 24 million (7%) people in the United States are suffering from autoimmune diseases, among which women have a higher incidence rate than men.

The immune system of human body generates antibodies to attack and eliminate foreign antigens or abnormal cells in the body (such as tumor cells), which is a physiological mechanism to protect the body. Autoimmune disease (abbreviation: AID) is an autoimmune problem caused by abnormal immunity, which refers to the phenomena that human immune system treats normal cells or cell components as viruses or bacteria attack, causing excessive inflammation or tissue damage, to affect health and causes disease.

At present, there are more than 80 known autoimmune diseases that may occur in any part of the body.

The pathogenesis of autoimmune diseases mainly relates to the ineffectiveness of immune recognition and immune response, in terms of pathogenic mechanism. The immune recognition and immune response require the full participation of antigen presenting cells (APC) and T cells, which can be divided into 3 stages: initial T cells specifically recognizing the antigen presented by APC; T cell activation, proliferation and differentiation; effector T cell generation and effective stage. Within the 3 phases, initial T cells can be effectively activated, proliferated, and differentiated to take effects. It is necessary for initial T cells to effectively recognize the antigen presented by APC, which is based on the dual signal transmission between APC and T cells. APC presents the major compatible MHC II to T cells, and the T cell receptor (TCR) specifically recognizes the antigen peptide to achieve preliminary activation of T cells, which get fully activated after interaction with multiple pairs of costimulatory molecules on the surface of APC. If the second signal (costimulatory signal) is missing, the first signal will not only fail to effectively activate T cells, but will disable T cells.

Common Immune Diseases

1. Systemic lupus erythematosus (SLE)

SLE is a systemic autoimmune disease related to anti-nuclear antibodies, whose comprehensive clinical manifestations are skin rash, thrombocytopenia, serous inflammation, and nephritis.

2. Rheumatoid arthritis (RA)

RA is a systemic autoimmune disease characterized by automatic antibody production, synovial inflammation and hyperplasia, multi-articular cartilage and bone destruction, cardiovascular and pulmonary diseases. The early manifestation of RA is local inflammation of the joints, which then develops into a systemic autoimmune disease due to the loss of immune tolerance.

3. Multiple sclerosis (MS)

MS is an organ-specific autoimmune disease. Its pathological characteristic is that immune inflammatory cells infiltrate the brain and spinal cord, which leads to progressive demyelination and neurodegeneration of the central nervous system.

4. Type I diabetes (T1D)

T1D, also known as juvenile diabetes, is a chronic autoimmune disease. Although various immune cells are involved in the disease, autoreactive CD4+ and CD8+ T cells are the key driving factors. The main causes are destruction of insulin-secreting pancreatic islet B cells by self-reactive T cells, and the consequent imbalance of blood glucose regulation.

At present, the main clinical drugs to treat autoimmune diseases are glucocorticoids and immunosuppressants, which are currently facing bottlenecks, such as high prices and large side effects (causing osteoporosis and cardiovascular diseases). Therefore, there is an urgent need to find safe and effective drug targets to alleviate autoimmune diseases.

In view of the pathogenesis of autoimmune diseases, how to restore the normalization of the immune system is a crucial strategy for the treatment of AID, which is also a hot spot in the R&D of drugs for the treatment of autoimmune diseases. Recent studies that autoantibodies with agonistic or antagonistic function towards numerous cell types can shut down detrimental immune responses and make immune system to normal state of tolerance if properly controlled, which therefore make agonistic antibody therapy in immune diseases a promising candidate.

A fan of biotechnology who likes to post articles in relevant fields regularly