CD19CD24hiCD27

CD19CD24hiCD27 refers to a human B cell phenotype defined by the surface markers CD19, CD24 at high expression, and CD27. This combination is commonly described as a regulatory B cell (Breg) subset within the broader B cell compartment. CD19 marks B lineage cells; high CD24 is associated with a regulatory state, and CD27 is typically a marker of memory B cells, but in this context helps identify a functionally distinct population with anti-inflammatory properties.

Phenotype and identification: These cells are identified by flow cytometry as CD19+ CD24hi CD27+. The population can be enriched by additional markers (e.g., CD38, CD1d) depending on tissue and activation status; marker expression can vary with maturation and disease state.

Function and mechanisms: The core feature attributed to CD19+ CD24hi CD27+ B cells is the production of anti-inflammatory cytokines, especially interleukin-10 (IL-10). Through IL-10 and other mediators they can suppress CD4+ T cell proliferation and cytokine production, reduce dendritic cell activation, and influence regulatory T cell responses. The regulatory activity is context dependent and can be induced in vitro by stimuli such as CD40 ligation, toll-like receptor agonists, or CpG DNA.

Clinical and research relevance: Alterations in this Breg subset have been reported in various conditions, including autoimmune diseases and infectious diseases. Reduced numbers or impaired function have been linked with autoimmunity in some studies, while other contexts show expansion in tolerance settings or after certain therapies. Overall, CD19+ CD24hi CD27+ B cells are a widely used, but not universally defined, marker set for human regulatory B cells, reflecting ongoing research into their biology and clinical significance.