Lectin Pathway of Complement System

The lectin pathway is a type of cascade reaction in the complement system, similar in structure to the classical complement pathway, in that, after activation, it proceeds through the action of C4 and C2 to produce activated complement proteins further down the cascade. In contrast to the classical complement pathway, the lectin pathway does not recognize an antibody bound to its target. The lectin pathway starts with mannose-binding lectin (MBL) or ficolin binding to certain sugars.
In this pathway, mannose-binding lectin binds to mannose, glucose, or other sugars with 3- and 4-OH groups placed in the equatorial plane, in terminal positions on carbohydrate or glycoprotein components of microorganisms including bacteria such as Salmonella, Listeria, and Neisseria strains.
Mannan-binding lectin, also called mannose-binding protein, is a protein belonging to the collectin family that is produced by the liver and can initiate the complement cascade by binding to pathogen surfaces.
MBL forms oligomers of subunits, which are trimers (6- to 18-heades correspond to a dimer and a hexamer, respectively). Multimers of MBL form a complex with MASP1 (Mannose-binding lectin-Associated Serine Protease), MASP2 and MASP3, that are protease zymogens. The MASPs are very similar to C1r and C1s molecules of the classical complement pathway, respectively, and are thought to have a common evolutionary ancestor. When the carbohydrate-recognising heads of MBL bind to specifically arranged mannose residues on the surface of a pathogen, MASP-1 and MASP-2 are activated to cleave complement components C4 and C2 into C4a, C4b, C2a, and C2b

[@anukshyarath3069]

Nice video... But the classical pathway isn't antibody independent. Alternative pathway is antibody independent.

[@hussainbiology]

Yes...I agree i have said it mistakenly there in the beginning but rest of the pathway is all right...Thanks for ur feedback

[@Medico_5647]

So it's similar to alternative pathways not classical

[@bunneenee5867]

@@Medico_5647 you need to study more and review the different videos on the complement system, then you will realize that the lectin pathway is very similar to the classical pathway

[@aaqibzyt]

Alternate can be activated by LPS or IgA

[@prarthana.07]

Activation of classical pathway is depends on antibodies

[@hannahs7662]

All 3 videos on complement pathways were so helpful, THANK YOU!

[@hussainbiology]

thanks for appreciation..... Glad it helps

[@YNWAOASIS]

I was studying/preparing for my work on 'classical/alternative/lectin pathway', and your video files were immensely informative and easy to understand. Just great! thank you so much for your efforts!

[@hussainbiology]

Glad it was helpful!

[@eldrienadsilva3385]

Thank you so much for your efforts on this! It was clear, concise and very helpful. God bless you.

[@hussainbiology]

thanks for appreciation..Glad it helps

[@annesharoy06]

all the three pathways in ur explanations were nicest ❣️ you saved me🙏🏻

[@snehamondal4460]

Sir the full form of MASP 1 is Mannose binding lactin Associated Serine Protease 1 . But this video is help me a lot. Thank you sir❤

[@hussainbiology]

thanks for appreciation..Glad it helps....✌️

[@sheratajayasinghe448]

Helllo!! This demonstration was very clear and was easy to digest. Thank you . 😊

[@hussainbiology]

thanks for appreciation.. Glad it helps ✌️

[@andrearussell2712]

Thank you for a clear and concise explanation of the lectin pathway.

[@hussainbiology]

thanks for appreciation...

[@manarsmaan2624]

very Helpful video for ASCP board exam takers . Thank you so much

[@hussainbiology]

Happy to help

[@welpitsnoemi]

Isn’t classical pathway dependent on antibody antigen complex? I thought alternative pathway was Ab independent.

[@alnooralnoor6419]

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[@hussainbiology]

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[@rahulgaikwad6053]

Thank you so much sir 🙏🙏🙏🙏 really really i am learned a lot from you make more interesting and short explanation videos for me😢

[@hussainbiology]

So nice of you

[@SerinSagayaraj]

Well explained..👍👍

[@handam3725]

Great..... Thanks for the explanation 🌷🌷

[@amysami5839]

just one note, the C3 convertase is C4bC2b
other than that great video

[@hussainbiology]

Recent change that is why it is not in the video...

[@safesoundequine8511]

You are the best!

[@zxii.1]

Which one of the following is cleaved by MASP-1 of Lectin pathway of complement system?
a. C2
b. C3
C. C4
d. Factor D

[@zxii.1]

Please what is the answer?

[@hussainbiology]

C2

[@zxii.1]

@@hussainbiology thank you 😊

[@zxii.1]

@@hussainbiology What is the role of Factor H as a regulatory protein of complement system?

[@zxii.1]

Do you know his answer?

[@SidraHaseen-cv5rs]

This video is very helpful thanks much sir

[@hussainbiology]

Thanks for appreciation.. Glad it helps

[@ratandevda1981]

Bhai bohot khub samghaya🙏🙏🙏🙏❤️❤️❤️

[@gagandalal5233]

Excellent one, thanks

[@57594651]

You're movies are awesome!

[@hussainbiology]

thanks for appreciation..Glad to know that it helps ✌️

[@nayabkhan1746]

Great Video! Incredibly helpful, thank you for sharing!

[@hussainbiology]

thanks for appreciation..Glad to know that it helps

[@osaidtanbouz4217]

Amazing explanation 🔥

[@krishnatejachowdary1590]

Excellent explanation

[@barnalisinha4705]

Thank you sir for amazing explanation

[@hussainbiology]

So nice of you

[@tripti2173]

Your video... are very helpful for me due to this am able to complete my assignments at time thank u 😊😊 for making such video. Keep helping 😊😊.

[@hussainbiology]

thanks for appreciation..Glad to know that it helps ✌️

[@noorali3110]

What happens if bacteria do not contain mannose ?

[@ManishYadav-id7wl]

Hey bro please tell me answer I am confused I think e will answer but I am not sure please tell me answer correct . Which of statements is correct?
A The complement system belongs to the adaptive immune system.
B
The complement system has two activation routes in human
C
The complement components are produced, with no stimulation by antigen.
D
The C3 only involves in the classic pathway but not in the MBL pathway
E
The complement components were E only produced with stimulation by antigen.

[@RTSProfessionalStudy]

Nice video bhai , I am from Rts professional studies

[@hussainbiology]

Thanks Suraj bhai ..... Bohat acha din raha

[@lasyasri457]

Great explanation. U make my complicated subjects easy. Thank u.

[@hussainbiology]

thanks for appreciation

[@shaifalipatel379]

Thank you so much

[@hussainbiology]

thanks for appreciation..Glad it helps....✌️

[@حسانصهيبعبدالمجيد]

بربي احسن من د.احمد عالاقل البنج يمك مستقر ❤❤

[@hussainbiology]

Thanks for appreciation

[@marionmumbi8889]

Thank you so much..the videos are so easy to understand

[@hussainbiology]

You are welcome!

[@adnanm4069]

Thank you , but isn't the C3 convertase is made of ( C2b and C4b )?

[@itzmeerfaheem6137]

In case of C2 molecule, it is C2a which is active form,,,so C3 convertase is made of C4b2a
But Some books now write composition of C3 convertase as C4b2b (wikipedia also mentions that,,,)It has been recently changed.

[@TheSigneA]

it is the new way.. C4b2a is the original way..

[@swapnilombale4329]

C4b C2a is C3 converse, C2 is the only complement where "b" is released!

[@exenasza8554]

Wonderful comment and replies ,thanks

[@nebilmuhammedsha]

thank you🙏

[@hussainbiology]

You're welcome 😊

[@priyakunwaranandsingh8537]

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[@monikaswami8438]

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[@hussainbiology]

thanks for appreciation

[@Sophie23456]

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[@hussainbiology]

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Glad to know that it helps ✌️

[@zoiecjarenereyno9167]

very helpful! thank you. :)

[@hussainbiology]

Most welcome.. Glad it helps

[@krishnatejachowdary1590]

Super sir

[@hussainbiology]

thanks for appreciation

[@sahanajfirdoushi7303]

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[@miniminati291]

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[@prajwalareddy2603]

Thank u so much Sir

[@hussainbiology]

Most welcome

[@siyabendunus6443]

Thank u very much!

[@hussainbiology]

Welcome!

[@Sunset-zw6zs]

Helpful thank you!

[@dynamicbiotech6736]

Wonderful explanation ☺️ thanks

[@hussainbiology]

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[@hajer9546]

thanx alot

[@hussainbiology]

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[@tanu6464]

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[@連祐暘]

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[@hussainbiology]

Glad it was helpful!

[@nachoman2910]

Thank you for this good explanation :D

[@hussainbiology]

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[@tahzeebfatima3006]

Speed is soo fast PLZZ explain slowly

[@hussainbiology]

thanks for appreciation.. Glad to know that it helps
Surely i will slow down the speed

[@addhyaaishwaryadash5305]

In MASP-1 What does S stand for?

[@hussainbiology]

Serine ✌️

[@addhyaaishwaryadash5305]

@@hussainbiology Thank you 😂

[@saranadeem8567]

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[@hussainbiology]

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[@qamar997]

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[@muktakukreja1620]

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[@hussainbiology]

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[@lovanlovan70]

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[@hussainbiology]

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[@xiaodansun3805]

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[@noornena470]

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[@hussainbiology]

You are welcome ✌️

[@prajaktamansuke9015]

Thank u so much

[@hussainbiology]

My pleasure