Complement-subcomponent-C1̅-inhibitor synthesis by human monocytes

Biosynthesis in vitro of complement subcomponents C1q, C1s and C1 inhibitor by resting and stimulated human monocytes.

The capacity of cultured human monocytes to synthesize and to secrete the subcomponents of C1 and C1 inhibitor was examined. Non-stimulated monocytes secreted C1q and C1s from day 5 of culture. C1s reached a plateau immediately at its maximum level, whereas C1q secretion increased progressively until the end of the second week. Between day 12 and day 25, C1q secretion remained nearly constant (...

C1 inhibitor-dependent dissociation of human complement component C1 bound to immune complexes.

The interaction of C1 inhibitor with complement component C1 bound to immune complexes was examined by using 125I-labelled C1 subcomponents. The inhibitor binds rapidly to subcomponent C1s, and more slowly to subcomponent C1r. Formation of the C1r-C1 inhibitor complex causes rapid dissociation of subcomponents C1r and C1s from the antibody-antigen-component C1 aggregate. The rate and extent of ...

Complement C 1 q subcomponent subunit A

Synthesis of the second component of complement by long-term primary cultures of human monocytes

A method has been developed for preparation of confluent monolayers of human monocytes from small volumes of blood and for maintenance of these pure monocyte cultures for up to 16 wk in vitro. These cells phagocytosed 5.7 mum diameter latex beads, rosetted with erythrocytes coated with IgG or with C3, killed Listeria monocytogenes, and synthesized both lysozyme and the second component of compl...

Synthesis and expression of C1 inhibitor by human umbilical vein endothelial cells.

The biologic activity of C1 esterase, activated forms of factor XII and kallikrein at sites of vascular inflammation may be regulated by C1 inhibitor (C1 INH) elaborated by endothelial cells. Therefore, we investigated whether human umbilical vein endothelial cells (HUVEC) in culture produce C1 INH. Passaged HUVEC contain 1.6 +/- 0.8 micrograms of C1 INH/10(8) cells (mean +/- S.D.; n = 7) which...