Talk:Complement system

message: I'm going through the complement system and comparing it to an Immunology text book (specifically, Immunology, Infection, and Infection by Pier, Lyczak, and Wetzler, copyright 2004) and the Alternative pathway could use some work, both for clarity and accuracy.                                                                                                                            
                                                                                                                        
Major Points:  C3 spontaneously breaks and activates because of a breakdown in a thioester bond via a condensation reaction.  In short, it's mildly unstable in water.  This results in C3(H20).  C3(H20) is then capable of covalently binding to a membrane surface if it is near enough.  Upon binding with a cellular membrane C3(H20) is capable of being bound by Factor B.  Upon being bound, Factor B is then cleaved by Factor D into components Bb and Ba, Bb is the larger of the two components and stays attached to C3(H20) to form C3(H20)Bb, a C3 convertase which cleaves further C3 molecules to amplify the effect.  Ba diffuses away. C3 convertase cleaves C3 molecules into C3b and C3a, of which C3b is the larger of the two and can bind to C3(H20)Bb to form C3(H20)Bb3b, which has C5 convertase activity.   
Protection/Dissociation of C3(H20):
Since C3(H20) formation is spontaneous, there is a greater chance of it causing a Membrane Attack Complex (MAC for short) to form on a host cell.  This is prevented by several ways.  First, Factor H in the blood causes the dissociation of C3(H20)Bb.  Second, C3(H20)Bb is inherently unstable and eventually will dissociate on its own.  Furthermore, mammalian cell membranes have both sialic acid and heparin, which promote binding of factor H.  Factor H, in addition to destabilizing the C3(H20)Bb molecule, acts as a cofactor to allow Factor I to cleave C3(H20)Bb and inactivate it.  In addition to this, mammalian cells also have structurally homologous proteins to Factor H embedded in their membranes, which have the same effect.  
Stabilization of C3(H20):
C3(H20) can be stabilized by the protein properdin, which is present in the blood stream.  
That's enough on the alternative pathway for now, I'll also work on a more detailed diagram of the 3 pathways and how they intertwine.  Let me know if I should go ahead and work these changes into the page.  
~Richard, e-mail Kinnin@gmail.com  —Preceding unsigned comment added by 157.62.190.17 (talk) 21:39, 22 October 2007 (UTC)
thread_title: Overhaul of Alternative Pathway

message: I agree the page needs work on the complement cascade. I compared what's here to a couple textbooks and found mistakes galore. I wouldn't trust it until someone does some serious work. As far as I can tell, the classical C3 convertase is NOT C3b2a, but rather, C3b2b. I changed the mistakes I found, but there may be more, But I'm just a medical student.134.84.152.128 (talk) 03:51, 21 January 2009 (UTC)
thread_title: Work Needed

message: Typo in "This binding leads to *cnformational* changes in C1q molecule..."
I assume it should read conformational but I'm savvy enough on this matter to be sure... someone else please correct it and delete this.--nunocordeiro
:Be bold! JFW | T@lk 22:20, 19 January 2006 (UTC)
replies: text:  But don't be reckless Your right though... I'll be a little bolder in the future. :) --nunocordeiro 03:14, 28 March 2006 (UTC)
thread_title: Spelling

message: There is need for this article to be both in :Category:Complement system and its parent :Category:Immune system - parent/grandparent conflict (P/G-C). So i removed the grandparent link. I also added :Category:Complement system to :Category:Acute phase proteins b/c it doesn't make sence to have the article "Complement system" in the "Acute phase proteins" tree structure and not have :Category:Complement system, as a result of that change i had to remove the direct link from here to "Acute phase proteins" b/c of another P/G-C. -- Boris 17:12, 9 February 2006 (UTC)
thread_title: Categories

message: I came across the diagram I have inserted into the article while looking for diagrams for the Immune system. I added the detailed information to the diagram, hopefully it suits your needs. If more info is needed I can add it, relatively easily, to the existing diagram, let me know.--DO11.10 21:19, 5 September 2006 (UTC)
thread_title:  Complement system diagram 

message: I can't work out from reading the article if the complement system is only found in mammals such as humans, or if it is present in other organisms. TimVickers 23:32, 30 December 2006 (UTC)
replies: text: Complement definatly exists in organisms outside of Chordates like Echinoderms, Arthropods, Urochordates, and possibly Annilids. Maybe someone more knowledgable in this could add a small section on non-mammalian complement? This should at least be mentioned somewhere in the page. JosephJP (talk) 19:21, 15 March 2008 (UTC)
thread_title: Other organisms?

message: Caption currently reads, "A complement protein attacking an invader", which is incorrect - it is a Membrane attack complex, causing cell lysis. It is made of several different complement protein and you cannot tell if it is a host cell or a foreign cell.  —Preceding unsigned comment added by 82.16.95.94 (talk) 21:47, 3 December 2007 (UTC)
thread_title:  The Caption on the MAC Complex 

message: In the paragraph about the classical pathway, it is explained that the C3 convertase complex should now correctly be called C4b2b. But in the paragraph "Alternative pathway", it still says that C4b and C2a combine to make C3 convertase. I think this should be changed to "C4b and C2b etc. ..." 85.127.84.16 (talk) 14:04, 7 February 2008 (UTC)
replies: text: You're right that it's confusing and that if all complement proteins followed the regular nomenclature, then the fragment in question would be C2b; however, the scientific community seems to be just as confused about it as we are. The newest version of the Janeway textbook (7th edition) reverts to calling it C2a even after explaining that the nomenclature would call it C2b. I don't have my old text, but I'm fairly certain the 6th edition did call it C2b, so it's a confused protein fragment. I'm in favor of calling it C2b, but that does put Wikipedia at odds with what's widely considered the premier immunology text. JosephJP (talk) 19:15, 15 March 2008 (UTC)

text: Due to the comments in some textbooks of immunology that only 'old' texts assigned C2a to be a larger fragment, C2a was changed to C2b. The comments found in the textbooks were put into the box. Was it right?  --Tossh eng (talk) 09:03, 23 August 2008 (UTC)
thread_title:  differnt names in "Classical" and "alternative" 

message: I think that this article should at least mention lab tests commonly used to measure parameters of this system, for example the total hemolytic complement (CH50). Thomas.Hedden                                                                                                                                                                                                                                                =============== For god’s sake, why put an image in an important article like this one in French? English is the universal scientific language – deal with it, and stop wasting people’s time. ======================
:On both counts, the best approach may be for you to be bold and fix it!  --Scray (talk) 11:07, 13 October 2008 (UTC)
thread_title:  Should mention tests, including "total hemolytic complement" (CH50)

message: I would like to suggest that this article on the Complement system be merged with its subdivisions (the three pathways: classical complement pathway, alternative complement pathway, mannose-binding lectin pathway).  I don't think it is necessary to have 3 short articles about each pathway when it can all be incorporated under the common theme of the complement system.  Furthermore, it is unnecessary to name an article "mannose-binding lectin pathway" (too focused, wikipedia is not a dictionary); instead, these links should be re-directed to Complement system.
--comcc (talk) 10:14, 27 November 2009 (UTC)
thread_title: Suggestion to merge [[Complement System]] with all the complement pathways

message: The following sentence in the lede could use some work: "It is part of the immune system called the innate immune system that is not adaptable and does not change over the course of an individual's lifetime." The innate immune system certainly changes over time and is in some respects "adaptable". Just a thought. Keepcalmandcarryon (talk) 23:49, 15 March 2011 (UTC)
thread_title: Lede

message: There seems to be no evidence that Jackie Stanley exists. Can someone please link to their work on opsonization? From the history of the page, it appears that these two edits got the name into the history section but neither the original "RR Stanley" nor the changed "Jackie Stanley" seem to be searchable terms nor is any cited article provided to attest to the existence of this "renowned" researcher:
(cur | prev) 16:51, 9 May 2010‎ 193.63.36.54 (talk)‎ . . (21,255 bytes) (+4)‎ . . (→‎History) (undo)
(cur | prev) 13:05, 9 May 2010‎ 193.63.36.12 (talk)‎ . . (21,251 bytes) (+297)‎ . . (→‎History) (undo)  — Preceding unsigned comment added by 173.8.123.205 (talk)  
:You may have misread KK as RR, but your point is valid—good pickup. The description resembles the work of Duke and Wallace, working in Uganda. I'm a little too distracted to follow up on it this week. If no one has followed up in a timely manner, someone give me a kick.Novangelis (talk) 23:05, 21 August 2012 (UTC)
thread_title:  Jackie Stanley 

message: The first two paragraphs of the article were copied and pasted directly from the introduction of a paper authored by Vahid Afshar-Kharghan titled "The role of the complement system in cancer", copyright © 2017, American Society for Clinical Investigation. A copy of the paper can be found on the National Institutes of Health website at this URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5330758/ . I will try to tag the paragraphs in the article as soon as I leave this post. Metrowestjp (talk) 22:36, 29 April 2021 (UTC)
thread_title: Copyright violation

message: Prior content in this article duplicated one or more previously published sources. The material was copied from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5330758/. Copied or closely paraphrased material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.)
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thread_title:  Copyright problem removed 

message: Suggest using plasma in place of serum.  Serum only exists after blood completely clots, while plasma is "unclotted" and contains all coagulation factors and is what exists in vivo. 2603:9001:670A:9C18:B0BB:AFF6:4186:70CE (talk) 11:51, 22 November 2021 (UTC)
thread_title:  Term correction suggestion