C4b-binding protein and factor h compensate for the loss of membrane-bound complement inhibitors to protect apoptotic cells against excessive complement attack
Trouw, Leendert LU ; Bengtsson, Anders LU ; Gelderman, Kyra LU ; Dahlbäck, Björn LU ; Sturfelt, Gunnar LU and Blom, Anna LU
(2007)
In Journal of Biological Chemistry
282(39).
p.28540-28548
- Abstract
- Apoptotic cells have been reported to down- regulate membrane-bound complement regulatory proteins ( m- C- Reg) and to activate complement. Nonetheless, most apoptotic cells do not undergo complement- mediated lysis. Therefore, we hypothesized that fluid phase complement inhibitors would bind to apoptotic cells and compensate functionally for the loss of m- C- Reg. We observed that m- C- Reg are down- regulated rapidly upon apoptosis but that complement activation follows only after a gap of several hours. Coinciding with, but independent from, complement activation, fluid phase complement inhibitors C4b- binding protein ( C4BP) and factorH( fH) bind to the cells. C4BP and fH do not entirely prevent complement activation but strongly limit... (More)
- Apoptotic cells have been reported to down- regulate membrane-bound complement regulatory proteins ( m- C- Reg) and to activate complement. Nonetheless, most apoptotic cells do not undergo complement- mediated lysis. Therefore, we hypothesized that fluid phase complement inhibitors would bind to apoptotic cells and compensate functionally for the loss of m- C- Reg. We observed that m- C- Reg are down- regulated rapidly upon apoptosis but that complement activation follows only after a gap of several hours. Coinciding with, but independent from, complement activation, fluid phase complement inhibitors C4b- binding protein ( C4BP) and factorH( fH) bind to the cells. C4BP and fH do not entirely prevent complement activation but strongly limit C3 and C9 deposition. Late apoptotic cells, present in blood of healthy controls and systemic lupus erythematosus patients, are also positive for C4BP and fH. Upon culture, the percentage of late apoptotic cells increases, paralleled by increased C4BP binding. C4BP binds to dead cells mainly via phosphatidylserine, whereas fH binds via multiple interactions with CRP playing no major role for binding of C4BP or fH. In conclusion, during late apoptosis, cells acquire fluid phase complement inhibitors that compensate for the downregulation of m- C- Reg and protect against excessive complement activation and lysis. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/656580
- author
- Trouw, Leendert
LU
; Bengtsson, Anders
LU
; Gelderman, Kyra
LU
; Dahlbäck, Björn
LU
; Sturfelt, Gunnar
LU
and Blom, Anna
LU
- organization
- publishing date
- 2007
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Biological Chemistry
- volume
- 282
- issue
- 39
- pages
- 28540 - 28548
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- wos:000249642100028
- scopus:35348980673
- pmid:17699521
- ISSN
- 1083-351X
- DOI
- 10.1074/jbc.M704354200
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Clinical Chemistry, Malmö (013016000), Medical Inflammation Research (013212019), Department of Rheumatology (013036000)
- id
- 3d772f28-3944-4e38-a792-1c52d5c62ae6 (old id 656580)
- date added to LUP
- 2016-04-01 12:17:31
- date last changed
- 2022-05-07 00:29:04
@article{3d772f28-3944-4e38-a792-1c52d5c62ae6,
abstract = {{Apoptotic cells have been reported to down- regulate membrane-bound complement regulatory proteins ( m- C- Reg) and to activate complement. Nonetheless, most apoptotic cells do not undergo complement- mediated lysis. Therefore, we hypothesized that fluid phase complement inhibitors would bind to apoptotic cells and compensate functionally for the loss of m- C- Reg. We observed that m- C- Reg are down- regulated rapidly upon apoptosis but that complement activation follows only after a gap of several hours. Coinciding with, but independent from, complement activation, fluid phase complement inhibitors C4b- binding protein ( C4BP) and factorH( fH) bind to the cells. C4BP and fH do not entirely prevent complement activation but strongly limit C3 and C9 deposition. Late apoptotic cells, present in blood of healthy controls and systemic lupus erythematosus patients, are also positive for C4BP and fH. Upon culture, the percentage of late apoptotic cells increases, paralleled by increased C4BP binding. C4BP binds to dead cells mainly via phosphatidylserine, whereas fH binds via multiple interactions with CRP playing no major role for binding of C4BP or fH. In conclusion, during late apoptosis, cells acquire fluid phase complement inhibitors that compensate for the downregulation of m- C- Reg and protect against excessive complement activation and lysis.}},
author = {{Trouw, Leendert and Bengtsson, Anders and Gelderman, Kyra and Dahlbäck, Björn and Sturfelt, Gunnar and Blom, Anna}},
issn = {{1083-351X}},
language = {{eng}},
number = {{39}},
pages = {{28540--28548}},
publisher = {{American Society for Biochemistry and Molecular Biology}},
series = {{Journal of Biological Chemistry}},
title = {{C4b-binding protein and factor h compensate for the loss of membrane-bound complement inhibitors to protect apoptotic cells against excessive complement attack}},
url = {{http://dx.doi.org/10.1074/jbc.M704354200}},
doi = {{10.1074/jbc.M704354200}},
volume = {{282}},
year = {{2007}},
}