Technical datasheet
Description
The monoclonal antibody 12D11 (also known as clone M4d3) recognizes an epitope on the alpha 2 chain of human C4d. Complement factor C4 (MW 41 kDa), formerly known as Gg protein, consists of an alpha-, beta- and gamma-chain. The classical pathway of complement and the mannose binding lectin (MBL) activation pathway converge at C4. Activated C1, MASP-1 and MASP-2 cleave C4 resulting in the formation of C4a and C4b. The latter can be cleaved by factor I resulting in C4c and C4d, in which step all functional sites are lost.
The C4d activation fragment of C4 is an excellent marker for classical complement pathway and MBL pathway activation. The thioester formed between the side chains of Cys1010 and Gln1013 within the C4d region of the α-chain mediates covalent attachment to the target surface bearing activated forms of C1s or MASP.
Furthermore, C4d is highly homologous to C3d with over 35% shared amino acid sequence.
In a number of diseases such as rheumatoid arthritis (RA), hereditary angioedema (HAE), systemic lupus erythematosus (SLE) and chronic urticaria with hypercomplementemia levels of C4d are significantly elevated in serum or plasma. C4d levels may also be elevated in plasma from patients with a variety of humoral autoimmune diseases in which complement activation is known to occur. Deposition of C4d in peritubular capillaries has been shown to be a sensitive marker for antibody-mediated (humoral) rejection in renal transplant biopsies.
The monoclonal antibody 12D11 recognizes C4, C4b and C4d. Antibody 12D11 cross reacts with pig, bovine, baboon and rhesus monkey.
Cross Reactivity
| Cross reactant |
Reactivity |
| Banoon |
Yes |
| Bovine |
Yes |
| Rhesus monkey |
Yes |
| Swine |
Yes |
Formulation
1 ml (100 µg/ml) 0.2 µm filtered antibody solution in PBS, containing 0.1% bovine serum albumin and 0.02% sodium azide.
Species
Mouse IgG1
Application
The monoclonal antibody 12D11 can be used for immunohistology on frozen sections and Western blotting. Furthermore, the monoclonal antibody 12D11 is useful for immuno assays.
Use
For immunohistology and Western blotting dilutions to be used depend on detection system applied. It is recommended that users test the reagent and determine their own optimal dilutions. The typical starting working dilution is 1:50.
Storage and stability
Product should be stored at 4°C. Under recommended storage conditions, product is stable for one year.
References
- Zwirner, J et al; Classical pathway of complement activation in normal and diseased human glomeruli. Kidney Int 1989, 36: 1069.
- Zwirner, J et al; Classical pathway of complement activation in mammalian kidneys. Immunology 1993, 80: 162.
- Feucht, H et al; Capillary deposition of C4d complement fragment and early renal graft loss. Kidney Int 1993, 43: 1333.
Precautions
For research use only. Not for use in or on humans or animals or for diagnostics. It is the responsibility of the user to comply with all local/state and federal rules in the use of this product. Hycult Biotech is not responsible for any patent infringements that might result from the use or derivation of this product.
Also available
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HM2230
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C4d, Human, mAb 7H4
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HM2198
|
C3d, Human, mAb 3
|
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HM2199
|
C3g, Human, mAb 9
|
|
HM2200
|
C3c, Human, mAb 4
|
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HM2167
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TCC, Human, mAb aE11
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Scientific info
C4d: a versatile marker for allograft dysfunction
C4d is an element of the complement system. It is released from complement protein 4 (C4) during activation of the classical complement pathway by the antigen-antibody complex. However, C4d formation can also occur in an antibody-independent fashion, via complement activation through the mannose-binding lectin (MBL) pathway. The MBL-pathway can be triggered by microbial infection and also in the setting of solid-organ transplantation.
C4d binds covalently to tissue elements at the site of activation and has been shown to be useful as a durable marker of antibody-mediated antidonor humoral response. For that reason, C4d was included in the 2003-Banff scoring criteria for assessment of renal transplant pathology.
C4d and allografts:
• C4d has proven to be a useful adjunct marker of antibody-mediated rejection (AMR), both in early and late renal and cardiac post-transplant periods.1,2
• The immunohistochemical detection of C4d early after lung transplantation (< 3 months) is clearly indicative for primary graft dysfunction and airway infection.3
• C4d is a valuable marker for assisting the diagnosis of chronic graft-versus-host-disease (GVHD) in patients with bone marrow transplantation (BMT). GVHD was identified in colon biopsies in which dilated capillaries stained all positive for C4d, 4 months – 2 years following BMT.4
In conclusion, C4d remains a well-established immunohistochemical marker for AMR in renal and cardiac transplants. In addition, the complement factor is becoming increasingly important as a versatile marker for allograft dysfunction.
References:
1. Feucht, H; Complement C4d in graft capillaries – the missing link in the recognition of humoral alloreactivity. Am J Transplant 2003, 3: 646
2. Crespo-Leiro, M et al; Humoral heart rejection (severe allograft dysfunction with no signs of cellular rejection or ischemia): incidence, management, and the value of C4d for diagnosis). Am J Transplant 2005, 5: 2560
3. Westall, G et al; C3d and C4d deposition early after lung transplantation. J Heart Lung Transplant 2008, 27: 722
4. Zhang, P et al; C4d staining is a valuable marker in identifying chronic GVHD in colonic biopsies following BMT. Bone Marrow Transplant 2008, 42: 209