Immunological and genetic characterization of the deficiency of the component C5 of the human complement system (2006)
- Authors:
- Autor USP: ISAAC, LOURDES - ICB
- Unidade: ICB
- Assunto: IMUNOLOGIA
- Language: Inglês
- Abstract: Introduction and Objectives: The deficiency of the C5 component of the complement system is rare, with approximately 50 described cases in the literature. This deficiency is frequently associated with severe and recurrent infections, especially caused by Neisseria. These patients have less bactericidal activity, reduced production of chemotactic factors and fail to properly activate the complement system in the serum. We observed complete absence of C5 in the serum of 3 members of a Brazilian family with history of consanguinity, which had suffered from recurrent episodes of meningitis, and other less severe infections. Our general objective is to characterize immunologically and genetically this deficiency, the first of its type described in the Brazilian population. Methods and Results: While other complement proteins were found to be present within the normal range by ELISA, we detected only 0,91; 0,99 and 1,27 µg/ml of C5 in the 3 deficient sera (normal range: 75-150 µg/ml).This data was confirmed by Western blot analysis in which when neither C5 á or â chains could be visualized in any of the 3 deficient sera. The proband sera were also unable to mediate the hemolytic activity by the classical and alternative pathways. When purified C5 was added to the deficient serum at approximately physiological concentrations, hemolytic activity was restored to close to normal levels in dosedependent manner. Furthermore, the father's serumpresented only 50% of hemolytic activity mediated by the classical pathway and followed normal activity mediated by the alternative pathway. The father's sera presented normal levels of C1s and C4. Using RT-PCR of mRNA obtained from the fibroblasts of one of C5 deficient brothers, we detected a deletion in the C5 cDNA between nucleotides 3877 - 4029. This deletion is apparently due to a splicing error which completely excludes exon 30. This proband also carried a silent ACC498 to ACT498 mutation in his C5 gene. Conclusion: This C5 deficiency is produced by a splicing error that deletes 153 bp (exon 30) from the mature mRNA. This deletion would be expected to produce an unstable and non-functional protein, destined for degradation.
- Imprenta:
- Source:
- Título: Abstracts
- Conference titles: Meeting of the Brazilian Society for Immunology
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ABNT
AGUILAR, P R et al. Immunological and genetic characterization of the deficiency of the component C5 of the human complement system. 2006, Anais.. São Paulo: Instituto de Ciências Biomédicas, Universidade de São Paulo, 2006. . Acesso em: 17 out. 2024. -
APA
Aguilar, P. R., Florido, M. P. C., Reis, E. S., Costa-Carvalho, B., Kierstman, D., & Isaac, L. (2006). Immunological and genetic characterization of the deficiency of the component C5 of the human complement system. In Abstracts. São Paulo: Instituto de Ciências Biomédicas, Universidade de São Paulo. -
NLM
Aguilar PR, Florido MPC, Reis ES, Costa-Carvalho B, Kierstman D, Isaac L. Immunological and genetic characterization of the deficiency of the component C5 of the human complement system. Abstracts. 2006 ;[citado 2024 out. 17 ] -
Vancouver
Aguilar PR, Florido MPC, Reis ES, Costa-Carvalho B, Kierstman D, Isaac L. Immunological and genetic characterization of the deficiency of the component C5 of the human complement system. Abstracts. 2006 ;[citado 2024 out. 17 ] - Ultrastructural aspects of alpha - 2 - macroglobulin activited mouse macrophages
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