Chemical definition of serum anaphylatoxins has progressed rapidly in recent years. Structure-function studies are proposed here to further define the active site and mechanisms of action of these factors. Anaphylatoxins are low molecular weight polypeptides released from complement components in the course of activation. Complete primary structures of three human anaphylatoxins (e.g., C3a, C5a and C5a) have recently been elucidated in my laboratory. Quantitative data has also been collected regarding numerous biological activities associated with these purified anaphylatoxins in assays designed to assess their actions both in vitro and in vivo. An additional humoral factor, human C3e, will be examined both chemically and biologically. Recently it was suggested that C3e may be the C3-derived factor that inhibits mitogen-induced lymphocyte blastogenesis. If C3e proves to have immunoregulatory activities, in addition to leukocyte mobilizing activity, then this factor will be recognized as a very important factor in host defense. The anaphylatoxins have been shown to elicit acute responses in lung tissue. Severe lung injury involving complement activation fragments has never been examined in erms of chronic effects on pulmonary tissue. We now realize that introduction of anaphylatoxins to the airway side of lung tissue causes dramatic changes in the appearance of the lung's architecture. Complex lipid mediators are released as a direct result of anaphylatoxin action on pulmonary tissue. The C3a anaphylatoxin reportedly release vasoamines and prostaglandins while C5a is known to release vasoamines and leukotrienes. A main focus of this proposal is to examine the potential of anaphylatoxins for inducing chronic damage in pulmonary tissue from repeated insult. Purified anaphylatoxins will be administered repeatedly to both the airway and vascular sides of the lung tissue and both immediate and long-term effects will be assessed by histochemical and histological examination. Advantage will be taken of specific inhibitors of the anaphylatoxin inactivator (carboxypeptidase N), as well as antihistamines and inhibitors of the arachidonate pathways in estimating the role of anaphylatoxins in lung damage.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL025658-08
Application #
3338171
Study Section
Allergy and Immunology Study Section (ALY)
Project Start
1980-04-01
Project End
1989-03-31
Budget Start
1988-04-01
Budget End
1989-03-31
Support Year
8
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
City
San Diego
State
CA
Country
United States
Zip Code
92037
Ni, F; Carpenter, K A; Ripoll, D R et al. (1996) Stabilization of an isolated helical capping box in solution by hydrophobic interactions: evidence from the NMR study of bioactive peptides from the C-terminus of human C5a anaphylatoxin. Biopolymers 38:31-41
Discipio, R G; Daffern, P J; Kawahara, M et al. (1996) Cleavage of human complement component C5 by cysteine proteinases from Porphyromonas (Bacteroides) gingivalis. Prior oxidation of C5 augments proteinase digestion of C5. Immunology 87:660-7
Daffern, P J; Pfeifer, P H; Ember, J A et al. (1995) C3a is a chemotaxin for human eosinophils but not for neutrophils. I. C3a stimulation of neutrophils is secondary to eosinophil activation. J Exp Med 181:2119-27
Reed, S L; Ember, J A; Herdman, D S et al. (1995) The extracellular neutral cysteine proteinase of Entamoeba histolytica degrades anaphylatoxins C3a and C5a. J Immunol 155:266-74
Jagels, M A; Chambers, J D; Arfors, K E et al. (1995) C5a- and tumor necrosis factor-alpha-induced leukocytosis occurs independently of beta 2 integrins and L-selectin: differential effects on neutrophil adhesion molecule expression in vivo. Blood 85:2900-9
Buchner, R R; Hugli, T E; Ember, J A et al. (1995) Expression of functional receptors for human C5a anaphylatoxin (CD88) on the human hepatocellular carcinoma cell line HepG2. Stimulation of acute-phase protein-specific mRNA and protein synthesis by human C5a anaphylatoxin. J Immunol 155:308-15
Jagels, M A; Hugli, T E (1994) Mechanisms and mediators of neutrophilic leukocytosis. Immunopharmacology 28:1-18
Hetland, G; del Zoppo, G J; Mori, E et al. (1994) Uptake of C5a by polymorphonuclear leukocytes (PMNs) after focal cerebral ischemia. I. Effect of tirilazad mesylate intervention on C5a uptake by PMNs. Immunopharmacology 27:191-8
Cui, L; Carney, D F; Hugli, T E (1994) Primary structure and functional characterization of rat C5a: an anaphylatoxin with unusually high potency. Protein Sci 3:1169-77
Ember, J A; Sanderson, S D; Hugli, T E et al. (1994) Induction of interleukin-8 synthesis from monocytes by human C5a anaphylatoxin. Am J Pathol 144:393-403

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