Recombinant Mouse Oligodendrocyte-myelin glycoprotein (Omg)

What is BIA1 Antibody

The term "BIA1 Antibody" can refer to a few different things, based on the context. It is most commonly associated with an antibody that targets the protein TRIM11, but it can also refer to B-1a cells, a unique subset of B lymphocytes .

BIA1 as an Anti-TRIM11 Antibody:

• BIA1 can refer to an antibody that targets TRIM11 (Tripartite Motif Containing 11) . TRIM11, also known as BIA1 or RNF92 (RING finger protein 92), is an E3 ubiquitin-protein ligase . Antibodies against BIA1 (TRIM11) can be used to detect and measure the BIA1 antigen in biological samples .

BIA1 as B-1a Cells:

• B-1a cells are a unique subset of B lymphocytes that play a key role in the early innate immune response against viral, bacterial, and acute inflammatory diseases . They release polyreactive natural immunoglobulin M (IgM), which non-specifically recognizes and neutralizes microbes . B-1a cells also produce anti-inflammatory cytokines such as interleukin (IL)-10 and IL-35, and the immune-bolstering factor granulocyte-monocyte colony-stimulating factor (GM-CSF) .

• B-1a cells are characterized by specific markers: low expression of CD23 (CD23dim/−), high expression of CD19 (CD19bright), and the presence of CD43 . Depending on the expression of CD5, B-1 cells are further classified into either CD5+ (B-1a) or CD5− (B-1b) . B-1a cells primarily perform innate-like functions, providing an initial defense against infection by secreting natural antibodies (Abs) that protect the host against acute infection or lower bacterial load .

Research Findings on B-1a Cells

B-1a cells have demonstrated therapeutic potential in various contexts, particularly in mitigating acute viral and bacterial infections.

• Role in COVID-19 and Similar Conditions: B-1a cells have been shown to ameliorate influenza virus infection, sepsis, and pneumonia, conditions with similarities to COVID-19 . B-1a cell therapy may also alleviate acute respiratory distress syndrome (ARDS) associated with COVID-19 .

• Function and Location: B-1a cells are predominantly found in serosal spaces like the peritoneal and pleural cavities . They are also present in the spleen and bone marrow but are hardly detectable in the blood and lymph nodes . These cells spontaneously secrete natural IgM, which constitutes a significant portion of the immunoglobulin levels in healthy individuals, providing an initial line of defense against infection .

• Comparison with Other B Cells: B-1a cells differ from B-2 cells, which play an adaptive immune function by recognizing soluble antigens via the B-cell receptor (BCR) and undergoing V(D)J recombination, class switch, and differentiation into plasma cells . While B-1b and B-2 cells mount adaptive immune responses specific to each pathogen over weeks after infection, B-1a cells neutralize a broad range of pathogens through their immediate release of natural IgM . B-1a cells are long-lived, self-renewing, and resistant to apoptosis, making them excellent sources of sustainable protective immunity .

• Natural Antibody Characteristics: Natural antibodies produced by B-1a cells differ from B-2 cell adaptive antibodies in that they display little or no somatic hypermutation and minimal N-region addition, thus preserving their germline sequences . Murine B-1a cell natural IgM is characteristically repertoire skewed, low affinity, and polyreactive . These natural IgMs can recognize phosphorylcholine (PC), a constituent of the cell wall of gram-positive bacteria, membranes of other bacterial pathogens, apoptotic cells, and oxidized low-density lipoprotein .

Therapeutic Applications and Significance

BIA1 antibodies, particularly concerning B-1a cells, hold promise in therapeutic applications due to their role in immune response and pathogen neutralization.

• Broadly Neutralizing Antibodies (bNAbs) in HIV-1 Therapy: While not directly related to BIA1, research on broadly neutralizing antibodies (bNAbs) in HIV-1 therapy provides a context for antibody-based therapeutic strategies . Studies suggest that a combination of three bNAbs targeting different epitope regions may be necessary to overcome viral variants with pre-existent escape mutations and provide sufficient control of the virus to prevent the development of novel resistance .

• Implications for Autoimmunity and Inflammation: B-1a cell-derived natural IgM can recognize surface molecules of dead and dying cells, aiding in the elimination of dead cells and their debris . This process helps prevent uncontrolled immune cell activation that could cause tissue injury, highlighting their role in modulating autoimmunity and inflammation .

• Tracking Broadly Reacting Antibodies: New methods are being developed to isolate and amplify rare antibodies that can target a wide range of different viruses, which is relevant to the broader field of antibody research and development .