You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which of the following activates the classical complement pathway? and explain in detail?
Ans: A (Immune complex) Ref: Ananthnarayan R, Partiker CKJ. Textbook of Microbiology. 8th Edition. Hyderabad: Universities Press: 2009.Explanation:Complement-pathwaysClassic pathway - Acquired immunity (Activated by antigen antibody complex)Alternate complement pathway - Innate immunity (Activated by various substances like bacterial endotoxins, fungal cell wall components like zymosan)Mannan/Mannose Binding Lectin pathway (MBL Pathway) - Innate immunity (Activated by the binding of mannose-binding lectin (MBL) to mannose residues on glycoproteins or carbohydrates on the surface of microorganisms including certain Salmonella, Listeria, and Neisseria strains, as well as Cryptococcus neoformans and Candida albicans.)Sources of ComplementClassical pathwayC1-epithelium & fibroblastsC3, C4. C6 -C9 -LiverCl -C5 -Macrophages (stimulated by phagocytic events)CI esterase -LiverAlternate pathwayFactor B. D. H. I. P -Macrophages (stimulated by phagocytic events)