In this article we will discuss about the classical and alternative pathways of complement system. 1. The Classical Pathway of Complement: The classical pathway of complement is initiated by the interaction of antibody with antigen directly (soluble antigen-antibody complexes or immune complexes). The gradual progress of classical pathway can be mediated by these successive stages called: (i) Activation of C1 [...]
In this article we will discuss about the features of adaptive immune responses. 1. Specificity: It ensures that distinct microbes elicit specific responses. It exists because individual lymphocyte expresses membrane receptors that are able to distinguish subtle differences in structure between different antigens. 2. Diversity: It enables immune system to respond to a large variety of microbes. The total no. [...]
On the basis of principal biologic actions; cytokines are grouped under three basic categories: (i) Mediators and regulators of innate immunity: These are produced mainly by mononuclear phagocytes in response to infectious agents: Pathogen-associated molecular patterns; like bacterial lipopolysaccharides (LPS) and viral double stranded RNA (dsRNA), also bind to Toll like receptors (TLRs) on the cell surface or in endosomes [...]