Complement C5-deficient (C5(-/-)) macrophages derived from B.10 congenic mice were found to be defective in killing intracellular Mycobacterium tuberculosis (MTB). They were bacteriostatic after activation with IFN-gamma alone but bactericidal in the combined presence of IFN-gamma and C5-derived C5a anaphylatoxin that was deficient among these macrophages. Reduced killing correlated with a decr...

Congenic C5-deficient and C5-sufficient mice were infected with group B streptococci (GBS) to determine if the polymorphonuclear leukocyte (PMNL) chemoattractant C5a contributes to PMNL recruitment in GBS infection and if GBS C5a-ase reduces C5a-induced PMNL recruitment in vivo. PMNL accumulation was greater in the peritoneum and air spaces of C5-sufficient mice than in C5-deficient mice. Admin...

The sex-dependent differences in serum levels of complement components have been reported concerning C4 (1), C5 (2, 3), C6 (3), C4-binding protein (C4-bp) ~ (4), and sex-limited protein (Slp) (5) in the mouse complement system. The serum levels o f these components in adult mice are always higher in males than in females within each inbred strain and are strongly under hormonal control. With re...

Skin allografts survived longer on ALS-treated, complement-deficient (C5 negative) recipients than on ALS-treated, complement-competent (C5 positive) recipients. Administration of C5-positive serum to C5-negative, ALS-treated recipients resulted in reduced graft survival. A percentage of grafts from ALS-treated, C5-positive donors was rejected when transferred to untreated syngeneic recipients;...

The central serine esterase of the alternative pathway of complement (APC) activation, activated factor B (Bb), has been shown recently to induce murine macrophages and human monocytes to become spread on a glass substrata. It has also been established that to induce the spreading reaction, the catalytic site of the Bb enzyme must be structurally intact since treatment of Bb with heat (56 degre...

Fasting gluconeogenesis (GNG) is often quantified using the 2H2O technique, which is based on plasma 2H2O enrichment and ensuing enrichment of plasma glucose at the C5 and C2 positions. Fractional (fr)GNG can be calculated using the ratio of C5 to C2 enrichment or the ratio of C5 to plasma 2H2O enrichment. For the latter, equilibration of 2H2O and C2 is required. The optimal equilibration perio...

The serum complement system is a major mediator of inflammation reactions. Two of the complement proteins, the third (C3) and fifth (C5) components, are precursors of potent phlogistic molecules, C3a and C5a. C5a has potent chemotactic activity and plays an active role in pulmonary inflammation. We present evidence suggesting that several complement proteins, including C5, are synthesized local...

Experimental infection of mice with Plasmodium berghei ANKA (PbA) provides a powerful model to define genetic determinants that regulate the development of cerebral malaria (CM). Based on the hypothesis that excessive activation of the complement system may confer susceptibility to CM, we investigated the role of C5/C5a in the development of CM. We show a spectrum of susceptibility to PbA in a ...