Human IL-2 ELISA Kit

Interleukin 2 (IL-2), även känd som T-cellstillväxtfaktor (TCGF), är en 15-18 kDa variabelt glykosylerad alfa -helixpolypeptid som är en medlem av den gemensamma gammakedjan (gamma c) cytokinfamiljen. Den existerar som en monomer och har en anmärkningsvärt kort halveringstid (< 30 minutes). Human IL-2 is synthesized as a 153 amino acid (aa) precursor that contains a 20 aa signal sequence plus a 133 aa mature region. The mature region is alpha -helical in nature, and contains one utilized O-linked glycosylation site at Thr3 plus three cysteines, two of which form an intrachain disulfide bond that is essential for activity. Mature human IL-2 shares 73%, 66%, 78% and 97% aa identity with canine, rat, feline and rhesus monkey IL-2, respectively. Although human IL-2 shares only approximately 60% aa identity with the highly polymorphic mouse IL-2, human IL-2 is known to be active on mouse IL-2 responsive cells. Cells reported to secrete IL-2 include gamma δ T cells, activated conventional CD4+ and CD8+ T cells, neurons, microglia, and hematopoietic stem cells. The receptor for IL-2 (IL-2 R) is composed of three subunits, the 55 kDa CD25/IL-2 R alpha chain, the 70 kDa IL-2 R beta chain, and the 65 kDa Common gamma Chain. IL-2 first binds to CD25, the binary complex then recruits IL-2 R beta and gamma c to form the quaternary signaling complex. In addition to IL-2, IL-2 R beta is used by IL-15 in its quaternary signaling complex. gamma c also serves as a signaling receptor for IL-4, -7, -9, -15, and -21. In vitro studies have shown an important role for IL-2 in T cell activation and expansion. In vivo, IL-2 is critical for the development, maintenance and function of regulatory T cells (Treg) which provide protection against autoimmune disease. On the other hand, IL-2 can also promote autoimmune inflammation in target organs through its roles in regulating the expression of T cell trafficking genes, and production of Th2 cytokines. Within the CD8+ T cell subset, IL-2 is essential for optimal primary responses and differentiation into terminal effector cells. IL-2 also promotes the development of activated CD8+ T cells into memory cells.

pg/ml	O.D.		Genomsnittlig	Rättad
0.00	0.0112	0.0111	0.0112
6.86	0.0212	0.0173	0.0193	0.0085
20.58	0.0301	0.0282	0.0292	0.0175
61.73	0.0671	0.0623	0.0647	0.0530
185.19	0.2142	0.1983	0.2063	0.1955
555.56	0.8721	0.7723	0.8222	0.8105
1666.67	2.4952	2.4073	2.4513	2.4401
5000.00	4.2972	4.3173	4.3073	4.2961

	Intra-assay Precision			Inter-assay Precision
Provnummer	S1	S2	S3	S1	S2	S3
	22	22	22	6	6	6
Genomsnitt (pg/ml)	92.1	407.5	1540.9	102.1	502.1	1990.9
Standardavvikelse	4.7	23.4	86.4	6	29.1	119.09
Variationskoefficient (%)	5.1	5.7	5.6	5.9	5.8	6

Intra-assayprecision (precision inom en analys) Tre prover med känd koncentration testades tjugo gånger på en platta för att bedöma intra-assayprecisionen.

Inter-assayprecision (precision mellan analyser) Tre prover med känd koncentration testades sex gånger på en platta för att bedöma intra-assayprecisionen.

Spike-återvinningen utvärderades genom att spika 3 nivåer av humant IL-2 i ett hälsoprov av humant serum. Det otillsatta serumet användes som blank i detta experiment.
Återvinningen varierade från 85 % till 115 % med en total genomsnittlig återhämtning på 103 %.

Provmatris	Prov utvärderat	Område (pg/ml)	Detekterbar (%)	Medelvärde för detekterbar (pg/ml)
Serum	30	n.d.	0	0

Serum/plasma – Trettio prover från till synes friska frivilliga utvärderades med avseende på närvaron av IL-2 i denna analys. Ingen medicinsk historia var tillgänglig för donatorerna. n.d. = ej-detekterbar. Prover uppmätta under känsligheten anses vara omöjliga att detektera.