All kit components of this kit are stable at 2 to 8°C. Any unused reconstituted standard should be discarded or frozen at -70°C. Standard can be frozen and thawed one time only without loss of immunoreactivity.
Interleukin 4, abbreviated IL-4, is a cytokine that induces differentiation of naive helper T cells (Th0 cells) to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4. The cell that initially produces IL-4, thus inducing Th0 differentiation, has not been identified, but recent studies suggest that basophils may be the effector cell. It is closely related and has functions similar to Interleukin 13. Its receptor is the Interleukin-4 receptor. It has many biological roles, including the stimulation of activated B-cell and T-cell proliferation, and the differentiation B cells into Plasma Cells. It is a key regulator in humoral and adaptive immunity. IL-4 induces B-cell class switching to IgE, and up-regulates MHC class II production. It also induces B cell class switching to IgG4. IL-4 decreases the production of Th1 cells, macrophages, IFN-gamma, and dendritic cell IL-12. Overproduction of IL-4 is associated with allergies.
Background reference :
1) Apte SH, Baz A, Kelso A, Kienzle N (2008). "Interferon-gamma and interleukin-4 reciprocally regulate CD8 expression in CD8+ T cells". Proc Natl Acad Sci U S A. 105 (45): 17475–80.
2) Kay AB, Barata L, Meng Q, et al. (1997). "Eosinophils and eosinophil-associated cytokines in allergic inflammation". Int. Arch. Allergy Immunol. 113 (1–3): 196–9.
3) Marone G, Florio G, Petraroli A, de Paulis A (2001). "Dysregulation of the IgE/Fc epsilon RI network in HIV-1 infection". J. Allergy Clin. Immunol. 107 (1): 22–30.
4) Marone G, Florio G, Triggiani M, et al. (2001). "Mechanisms of IgE elevation in HIV-1 infection". Crit. Rev. Immunol. 20 (6): 477–96.