IL-21 Protein, Human (HEK293)

IL-21 Protein, a cytokine with immunoregulatory activity, serves as a pivotal mediator in orchestrating the interplay between innate and adaptive immunity. Notably, it induces the production of IgG(1) and IgG(3) in B-cells, emphasizing its role in shaping humoral immune responses. Additionally, IL-21 is intricately involved in the generation and maintenance of T follicular helper (Tfh) cells, playing a crucial part in the formation of germinal centers—an essential process in adaptive immunity. Collaborating with IL6, it contributes to the early generation of Tfh cells, proving critical for mounting an effective antibody response during acute viral infections. Furthermore, IL-21 may play a role in the proliferation and maturation of natural killer (NK) cells, particularly in synergy with IL15. Its regulatory influence extends to mature B- and T-cells, modulating their proliferation in response to activating stimuli. In concert with IL15 and IL18, IL-21 stimulates interferon gamma production in T-cells and NK cells, highlighting its multifaceted impact on immune responses. During T-cell-mediated immune responses, IL-21 exhibits the potential to inhibit dendritic cells (DC) activation and maturation, adding another layer to its regulatory repertoire.