Isoelectric Focusing of Components of the Complement System and Certain Related Proteins in Human Serum (1)

1974 ◽  
Vol 3 (2) ◽  
pp. 109-132
Author(s):  
Robert Nelson ◽  
Eva Brebner
Keyword(s):  
Human Serum ◽  
Isoelectric Focusing ◽  
Complement System ◽  
Related Proteins ◽  
The Complement System

scholarly journals Simple Method To Distinguish between Primary and Secondary C3 Deficiencies

2003 ◽  
Vol 10 (2) ◽  
pp. 216-220
Author(s):  
Marlene Pereira de Carvalho Florido ◽  
Patrícia Ferreira de Paula ◽  
Lourdes Isaac
Keyword(s):  
Human Serum ◽  
Complement System ◽  
Factor H ◽  
Normal Human Serum ◽  
Alternative Complement Pathway ◽  
Complement Pathway ◽  
Factor B ◽  
Alternative Complement ◽  
Normal Human ◽  
The Complement System

ABSTRACT Due to the increasing numbers of reported clinical cases of complement deficiency in medical centers, clinicians are now more aware of the role of the complement system in the protection against infections caused by microorganisms. Therefore, clinical laboratories are now prepared to perform a number of diagnostic tests of the complement system other than the standard 50% hemolytic component assay. Deficiencies of alternative complement pathway proteins are related to severe and recurrent infections; and the application of easy, reliable, and low-cost methods for their detection and distinction are always welcome, notably in developing countries. When activation of the alternative complement pathway is evaluated in hemolytic agarose plates, some but not all human sera cross-react to form a late linear lysis. Since the formation of this linear lysis is dependent on C3 and factor B, it is possible to use late linear lysis to routinely screen for the presence of deficiencies of alternative human complement pathway proteins such as factor B. Furthermore, since linear lysis is observed between normal human serum and primary C3-deficient serum but not between normal human serum and secondary C3-deficient serum caused by the lack of factor H or factor I, this assay may also be used to discriminate between primary and secondary C3 deficiencies.

scholarly journals The Impact of Graphite Oxide Nanocomposites on the Antibacterial Activity of Serum

2021 ◽  
Vol 22 (14) ◽  
pp. 7386
Author(s):  
Katarzyna Dorota Morka ◽  
Maciej Wernecki ◽  
Anna Kędziora ◽  
Marta Książczyk ◽  
Bartłomiej Dudek ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Human Serum ◽  
Complement System ◽  
Graphite Oxide ◽  
Galleria Mellonella ◽  
Serum Proteins ◽  
Normal Human Serum ◽  
Normal Human ◽  
The Impact ◽  
The Complement System

Nanoparticles can interact with the complement system and modulate the inflammatory response. The effect of these interactions on the complement activity strongly depends on physicochemical properties of nanoparticles. The interactions of silver nanoparticles with serum proteins (particularly with the complement system components) have the potential to significantly affect the antibacterial activity of serum, with serious implications for human health. The aim of the study was to assess the influence of graphite oxide (GO) nanocomposites (GO, GO-PcZr(Lys)2-Ag, GO-Ag, GO-PcZr(Lys)2) on the antibacterial activity of normal human serum (NHS), serum activity against bacteria isolated from alveoli treated with nanocomposites, and nanocomposite sensitivity of bacteria exposed to serum in vitro (using normal human serum). Additionally, the in vivo cytotoxic effect of the GO compounds was determined with application of a Galleria mellonella larvae model. GO-PcZr(Lys)2, without IR irradiation enhance the antimicrobial efficacy of the human serum. IR irradiation enhances bactericidal activity of serum in the case of the GO-PcZr(Lys)2-Ag sample. Bacteria exposed to nanocomposites become more sensitive to the action of serum. Bacteria exposed to serum become more sensitive to the GO-Ag sample. None of the tested GO nanocomposites displayed a cytotoxicity towards larvae.

scholarly journals Systems Biology Modeling of the Complement System Under Immune Susceptible Pathogens

2021 ◽  
Vol 9 ◽  
Author(s):  
Nehemiah T. Zewde ◽  
Rohaine V. Hsu ◽  
Dimitrios Morikis ◽  
Giulia Palermo
Keyword(s):  
Complement System ◽  
Membrane Attack Complex ◽  
Factor H ◽  
Immunoglobulin M ◽  
The Body ◽  
Complement Components ◽  
Invasive Pathogens ◽  
Time Profiles ◽  
Related Proteins ◽  
The Complement System

The complement system is assembled from a network of proteins that function to bring about the first line of defense of the body against invading pathogens. However, complement deficiencies or invasive pathogens can hijack complement to subsequently increase susceptibility of the body to infections. Moreover, invasive pathogens are increasingly becoming resistant to the currently available therapies. Hence, it is important to gain insights into the highly dynamic interaction between complement and invading microbes in the frontlines of immunity. Here, we developed a mathematical model of the complement system composed of 670 ordinary differential equations with 328 kinetic parameters, which describes all three complement pathways (alternative, classical, and lectin) and includes description of mannose-binding lectin, collectins, ficolins, factor H-related proteins, immunoglobulin M, and pentraxins. Additionally, we incorporate two pathogens: (type 1) complement susceptible pathogen and (type 2) Neisseria meningitidis located in either nasopharynx or bloodstream. In both cases, we generate time profiles of the pathogen surface occupied by complement components and the membrane attack complex (MAC). Our model shows both pathogen types in bloodstream are saturated by complement proteins, whereas MACs occupy <<1.0% of the pathogen surface. Conversely, the MAC production in nasopharynx occupies about 1.5–10% of the total N. meningitidis surface, thus making nasal MAC levels at least about eight orders of magnitude higher. Altogether, we predict complement-imbalance, favoring overactivation, is associated with nasopharynx homeostasis. Conversely, orientating toward complement-balance may cause disruption to the nasopharynx homeostasis. Thus, for sporadic meningococcal disease, our model predicts rising nasal levels of complement regulators as early infection biomarkers.

scholarly journals Complement-Mediated Neutralization of a Potent Neurotropic Human Pathogen, Chandipura Virus, Is Dependent on C1q

2019 ◽  
Vol 93 (19) ◽  
Author(s):  
Umerali Kunnakkadan ◽  
Joydeep Nag ◽  
Nisha Asok Kumar ◽  
Reshma Koolaparambil Mukesh ◽  
Sreenath Muraleedharan Suma ◽  
...  
Keyword(s):  
Human Serum ◽  
Complement System ◽  
Virus Neutralization ◽  
Host Immune System ◽  
Classical Pathway ◽  
Human Pathogen ◽  
Clinical Prognosis ◽  
Complement Proteins ◽  
Chandipura Virus ◽  
The Complement System

ABSTRACT Among the innate immune sentinels, the complement system is a formidable first line of defense against pathogens, including viruses. Chandipura virus (CHPV), a neurotropic vesiculovirus of the family Rhabdoviridae, is a deadly human pathogen known to cause fatal encephalitis, especially among children. The nature of interaction and the effect of human complement on CHPV are unknown. Here, we report that CHPV is a potent activator of complement and, thus, is highly sensitive to complement proteins in normal human serum (NHS). Utilizing a panel of specific complement component depleted/reconstituted human serum, we have demonstrated that CHPV neutralization is C3, C4, and C1q dependent and independent of factor B, suggesting the importance of the classical pathway in limiting CHPV. Employing a range of biochemical approaches, we showed (i) a direct association of C1q to CHPV, (ii) deposition of complement proteins C3b, C4b, and C1q on CHPV, and (iii) virus aggregation. Depletion of C8, an important component of the pore-forming complex of complement, had no effect on CHPV, further supporting the finding that aggregation and not virolysis is the mechanism of virus neutralization. With no approved vaccines or treatment modalities in place against CHPV, insights into such interactions can be exploited to develop potent vaccines or therapeutics targeting CHPV. IMPORTANCE Chandipura virus is a clinically important human pathogen of the Indian subcontinent. The rapidity of death associated with CHPV infection in addition to the absence of an effective vaccine or therapeutics results in poor clinical prognosis. The biology of the virus and its interaction with the host immune system, including the complement system, are understudied. Our investigation reveals the susceptibility of CHPV to fluid phase complement and also dissects the pathway involved and the mechanism of virus neutralization. Direct binding of C1q, an important upstream component of the classical pathway of complement to CHPV, and the strong dependency on C1q for virus neutralization highlight the significance of identifying such interactions to better understand CHPV pathogenesis and devise strategies to target this deadly pathogen.

scholarly journals Involvement of C3a and C5a in Interleukin-8 Secretion by Human Polymorphonuclear Cells in Response to Capsular Material of Cryptococcus neoformans

1998 ◽  
Vol 66 (9) ◽  
pp. 4324-4330 ◽  
Author(s):  
Anna Vecchiarelli ◽  
Cinzia Retini ◽  
Arturo Casadevall ◽  
Claudia Monari ◽  
Donatella Pietrella ◽  
...  
Keyword(s):  
Human Serum ◽  
Cryptococcus Neoformans ◽  
Complement System ◽  
Interleukin 8 ◽  
Polymorphonuclear Cells ◽  
Complement Components ◽  
Combined Use ◽  
Normal Human ◽  
The Complement System ◽  
Capsular Material

ABSTRACT In a previous paper we demonstrated that human polymorphonuclear cells (PMN) in the presence of normal human serum (NHS) secrete proinflammatory cytokines in response to Cryptococcus neoformans or its major capsular component, glucuronoxylomannan (GXM). The hypothesis that activation of the complement system could be responsible for the observed phenomenon is supported by the fact that encapsulated and acapsular C. neoformans isolates are activators of the complement system and, in particular, large encapsulated isolates are powerful activators. In the present study we demonstrate that (i) interleukin-8 (IL-8) release in response to acapsular or encapsulated strains of C. neoformans is significantly reduced in the presence of heat-inactivated serum rather than NHS and is completely abrogated in the absence of human serum; (ii) GXM-induced IL-8 release is strictly dependent on the presence of NHS, is inhibited by specific antibodies to either C3a and C5 complement components, and is completely abrogated by the combined use of these antibodies; (iii) the addition of purified C3a and C5a directly stimulates IL-8 release by PMN; and (iv) monoclonal antibody to GXM in combination with GXM or encapsulated C. neoformans potentiates IL-8 release by PMN. These data shed light on the mechanism involved in GXM-induced IL-8 secretion by PMN, provide an additional potential role for complement in the control of C. neoformans infections, and suggest a complex interplay between the complement system, humoral immunity, and cytokine regulation.

scholarly journals Human genes for three complement components that regulate the activation of C3 are tightly linked.

1985 ◽  
Vol 161 (5) ◽  
pp. 1189-1195 ◽  
Author(s):  
S Rodriguez de Cordoba ◽  
D M Lublin ◽  
P Rubinstein ◽  
J P Atkinson
Keyword(s):  
Major Histocompatibility Complex ◽  
Linkage Disequilibrium ◽  
Complement System ◽  
Complement Components ◽  
Factor B ◽  
Histocompatibility Complex ◽  
Human Genes ◽  
Related Proteins ◽  
The Complement System ◽  
Family Segregation

A new cluster of complement component genes, including C4BP, C3bR, and FH, is described. Family segregation data indicate that FH is linked to the genes for C4-bp and C4bR, previously reported to be linked and to maintain linkage disequilibrium. This cluster is not linked to the major histocompatibility complex, which contains the genes for the complement components, C4, C2, and factor B, or to the C3 locus. These data further suggest that the organization of genes for functionally related proteins in clusters may be a rule for the complement system.

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