C5-deficient mice differed from C5-sufficient mice both quantitatively and qualitatively in C5 protein, C5 mRNA, and the C5 gene. C5-deficient protein was present as decreased amounts of an unprocessed, single-chain precursor. C5-deficient mRNA was decreased in amount and present in two forms, the smaller of which was the same as the single form in normal cells. Nuclei from both normal and defi...

The fifth component of complement, C5, can form fragments that cause neutrophil chemotaxis, oxygen radical production, and lysosomal enzyme release. The purpose of this study was to determine if C5 and these fragments contribute to the inflammation seen in pulmonary oxygen toxicity as defined by histology and analysis of bronchoalveolar lavage fluid (BALF). In addition, the role of C5 in produc...

Complement activation is involved in the initiation of Ab-mediated inflammatory demyelination in experimental autoimmune encephalomyelitis (EAE). At a sublytic dose, the C5b-9 membrane attack complex protects oligodendrocytes (OLG) from apoptosis. Using C5-deficient (C5-d) mice, we previously showed a dual role for C5: enhancement of inflammatory demyelination in acute EAE, and promotion of rem...

C5-deficient mice grafted with thymus from C5-sufficient donors and immunized with C5 failed to make humoral antibody to C5, suggesting that the transfer of thymus had induced tolerance. Irradiated C5-deficient hosts repopulated with lymphoid cells from thymectomized C5-deficient mice grafted with C5-sufficient thymus also failed to respond to immunization with C5, thus showing that the state o...

The data presented here indicate that the C5 reaction step may proceed via the specific attachment of C5 to EAC1,4,2,3 and the formation of a hemolytically active C5 intermediate complex. During this process only a minor proportion (less than 4%) of C5 offered to EAC1,4,2,3 becomes bound, although the remaining C5 also participates in the reaction as evidenced by its inactivation in the fluid p...

Hydrosalpinx is a pathological hallmark of tubal infertility associated with chlamydial infection. However, the mechanisms of hydrosalpinx remain unknown. Here, we report that complement factor 5 (C5) contributes significantly to chlamydial induction of hydrosalpinx. Mice lacking C5 (C5(-/-)) failed to develop any hydrosalpinx, while ∼42% of the corresponding wild-type mice (C5(+/+)) did so fol...

Sexual dimorphism of mouse complement component 5 (C5) was detected by isoelectric focusing of desialated ethylenediamine tetraacetic acid (EDTA)-plasma on agarose gel, followed by immunofixation with anti-mouse C5. Male plasma displayed two C5 bands, basic and acidic, while female plasma had only a basic C5 band. In all mouse strains tested except C5-deficient strains, the identical patterns o...