Description

Nori Porcine Pentraxin 3 ELISA Kit Summary

Alternative names for pentraxin 3: PTX3, TNF-inducible gene 14 protein (TSG-14), TNFAIP5,

Alternative names for porcine: pig, swine,

Standard Curve

Kit Components
1. Pre-coated 96-well Microplate
2. Biotinylated Detection Antibody
3. Streptavidin-HRP Conjugate
4. Lyophilized Standards
5. TMB One-Step Substrate
6. Stop Solution
7. 20 x PBS
8. Assay Buffer

Other Materials Required but not Provided:
1. Microplate Reader capable of measuring absorption at 450 nm
2. Log-log graph paper or computer and software for ELISA data analysis
3. Precision pipettes (1-1000 µl)
4. Multi-channel pipettes (300 µl)
5. Distilled or deionized water

Protocol Outline
1. Prepare all reagents, samples and standards as instructed in the datasheet.
2. Add 100 µl of Standard or samples to each well and incubate 1 h at RT.
3. Add 100 µl of Working Detection Antibody to each well and incubate 1 h at RT.
4. Add 100 µl of Working Streptavidin-HRP to each well and incubate 20 min at RT.
5. Add 100 µl of Substrate to each well and incubate 5-30 min at RT.
6. Add 50 µl of Stop Solution to each well and read at 450 nm immediately.

Background:

Pentraxin 3 (PTX3) is a member of the pentraxin superfamily. Pentraxin-related protein PTX3 also known as TNF-inducible gene 14 protein (TSG-14) is a protein that in humans is encoded by the PTX3 gene.^[1] PTX3 is rapidly produced and released by several cell types, in particular by mononuclear phagocytes, dendritic cells (DCs), fibroblasts and endothelial cells in response to primary inflammatory signals [e.g., toll-like receptor (TLR) engagement, TNFα, IL-1β].^[2] PTX3 binds with high affinity to the complement component C1q, the extracellular matrix component TNFα induced protein 6 (TNFAIP6; also called TNF-stimulated gene 6, TSG-6) and selected microorganisms, including Aspergillus fumigatus and Pseudomonas aeruginosa.^[3] PTX3 activates the classical pathway of complement activation and facilitates pathogen recognition by macrophages and DCs.^[2][3] PTX3 behaves as an acute phase response protein, as the blood levels of PTX3, low in normal conditions (about 25 ng/mL in the mouse, < 2 ng/mL in humans), increase rapidly (peaking at 6–8 h after induction) and dramatically (200–800 ng/mL) during endotoxic shock, sepsis and other inflammatory and infectious conditions, correlating with the severity of the disease. Under these conditions, PTX3 is a rapid marker for primary local activation of innate immunity and inflammation.^[4] Similar to other members of the pentraxin family PTX3 binds apoptotic cells, thereby inhibiting their recognition by DCs. Binding occurs late in the apoptotic process and enhances cytokine production by DCs. In addition, preincubation of apoptotic cells with PTX3 enhances C1q binding and C3 deposition on the cell surface, suggesting a role for PTX3 in the complement-mediated clearance of apoptotic cells.^[5] Moreover, in the presence of dying cells, PTX3 restricts the cross presentation of antigens derived from dying cells. These results suggest that PTX3 has a dual role: protection against pathogens and control of autoimmunity.^[5]

References

1. Breviario F, et al. (1992). J Biol Chem. 267(31): 22190–7.
2. Garlanda C, et al. (2005). Annu. Rev. Immunol. 23: 337–66.
3. Diniz SN, et al. (2004). J. Leukoc. Biol. 75(4): 649–56.
4. Muller B, et al. (2001Crit. Care Med. 29(7): 1404–7.
5. Rovere P, et al. (2000). Blood. 96(13): 4300–6.

Product Citation