The complement (C) system participates in the immune response against pathogenic microorganisms.
C3 protein plays a crucial role because its activation supports the course of the three pathways
of the C cascade: the alternative pathway (AP), the classical pathway (CP), and the lectin pathway
(LP) leading to the destruction of microorganisms and limitation of the infection. This paper attempts to
highlight the role of outer membrane proteins (OMPs) in C components binding, as there are porins able
to alter the course of C activation. Additionally, we present molecular methods adapted to C3 activation
in human serum upon a contact with Salmonella cells and their OMPs. We demonstrate our achievements
by using Salmonella strains as an exemplary microorganism of the public importance. The most
severe outcomes of the presence of vital Salmonella rods in human body is sepsis. Therefore, it is desirable
to do research on the C evasion mechanisms developed by pathogens, to understand the principles
of bacteremia caused by other pathogens. We propose four techniques that may be useful in studying interactions
between bacterial surfaces and C components: electrophoretic resolution of OMPs under denaturing
and non-denaturing conditions, western blotting, and sandwich ELISA.