nonCD22expressing

NonCD22expressing is a term used in immunology and clinical diagnostics to describe cells or cell populations that do not express the CD22 protein on their surface, as detected by methods such as flow cytometry or immunohistochemistry. CD22, also known as Siglec-2, is a lectin-like receptor primarily expressed on mature B cells and many B-cell malignancies. It functions as a regulator of B-cell receptor signaling and is commonly used as a marker to identify B-lineage cells.

Non-CD22-expressing cells can include non-B-lineage cells such as T cells and other myeloid populations, which typically lack CD22. Among B-lineage cells, CD22 expression can vary with developmental stage, disease state, or therapeutic exposure. Some B-cell precursors or certain malignant subclones may show low or absent CD22 expression, depending on biology or prior treatment.

Clinically, the absence of CD22 has implications for therapies that target CD22, such as antibody-drug conjugates or other CD22-directed strategies. Tumor or cell populations that are non-CD22expressing may be resistant to such therapies, highlighting the need for alternative targets or combination approaches. In research and diagnostics, identifying non-CD22expressing populations helps in characterizing B-cell development, lineage assignment, and minimal residual disease assessments, and it requires careful consideration of antibody clone, assay sensitivity, and sample quality.