Immunological Perspective of Complement

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Published: 2023-03-15

Page: 43-45

Nnodim Johnkennedy *

Department of Medical Laboratory Science, Imo State University, Owerri, Nigeria.

Uzah Glad

Department of Physiology, Madonna University, Elele Rivers State, Nigeria.

*Author to whom correspondence should be addressed.


The complement system functions as a link between innate and acquired immunity and is a crucial component of the innate immune response. It is made up of a number of proteins that are mostly synthesized in the liver and exist as precursors only in plasma and on cell surfaces. Through a coordinated sequential enzyme cascade that clears foreign cells through pathogen detection, opsonization, and lysis, complement mediates responses to inflammatory stimuli. Additionally, complement has anti-inflammatory properties. It binds to immune complexes and apoptotic cells and helps remove them from the bloodstream and injured tissues. IgG and IgM antibodies activate and collaborate with complement proteins, giving rise to the term "complement." Numerous complement proteins are present in a "precursor" state and become active when there is inflammation. The creation of successive non-covalently linked activated protein fragments makes the complement system more complicated than many enzyme cascades.

Keywords: Immunological, perspective, complement, C3, C3b, alternative pathway, classic pathway

How to Cite

Johnkennedy, N., & Glad, U. (2023). Immunological Perspective of Complement. Asian Journal of Research in Biology, 6(1), 43–45. Retrieved from


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Janeway CA Jr, Travers P, Walport M. The complement system and innate immunity. Immunobiology: The Immune System in Health and Disease. New York: Garland Science; 2001.

Haplin H. "Review: the burgeoning history of the complement system 1888-2005". Immunohematology. 2020;21(3):85–93.

Nesargikar PN, Spiller B, Chavez R. "The complement system: History, pathways, cascade and inhibitors". European Journal of Microbiology & Immunology. 2012;2(2): 103–11.

Rooijakkers SH, Wu J, Ruyken M, van Domselaar R, Planken KL, Tzekou A. "Structural and functional implications of the alternative complement pathway C3 convertase stabilized by a staphylococcal inhibitor". Nature Immunology. 2009;10(7): 721–7.

Frank K, Atkinson JP. Complement system. In Austen KF, Frank K, Atkinson JP, Cantor H (eds.). Samter's Immunologic Diseases. Vol. 1 (6th ed.). Philadelphia: Lippincott Williams & Wilkins. 2001;281–298.

Janeway Jr CA, Travers P, Walport M, Shlomchik MJ. The complement system and innate immunity. Immunobiology (5th ed.). Garland Publishing; 2001.

Stoermer KA, Morrison TE. "Complement and viral pathogenesis". Virology. 2011; 411(2):362–73

Bajic G, Degn SE, Thiel S, Andersen GR. "Complement activation, regulation, and molecular basis for complement-related diseases". The EMBO Journal. 2015; 34(22):2735–2757.

Sacks SH, Chowdhury P, Zhou W. Role of the complement system in rejection". Current Opinion in Immunology. 2003; 15(5):487–92.

Ram S, Lewis LA, Rice PA. "Infections of people with complement deficiencies and patients who have undergone splenectomy". Clinical Microbiology Reviews. 2010;23(4):740–80.

Lewis LA, Ram S. Meningococcal disease and the complement system. Virulence. 2014;5 (1): 98–126.

Gomez-Arboledas A, Acharya MM, Tenner AJ. The role of complement in synaptic pruning and neurodegeneration". Immuno Targets and Therapy. 2021;10:373–386.