Complement is a set of small, circulating proteins that are activated by foreign materials and antibodies. Once activated, complement proteins insert into cell membranes forming a membrane attack complex that creates pores that cause cytolysis and death of the cell.
Interferons are released by virus-infected cells. These proteins bind to receptors on uninfected neighboring cells and restrains the spread of the viral infection by reducing the ability of cells to produce more virus particles.
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