Effect of liposome surface modification with water-soluble phospholipid polymer chain-conjugated lipids on interaction with human plasma proteins

Author(s):  
Anna Adler ◽  
Yuuki Inoue ◽  
Kristina N Ekdahl ◽  
Teruhiko Baba ◽  
Kazuhiko Ishihara ◽  
...  

Alternative liposome surface coatings for PEGylation to evade the immune system, particularly the complement system, have garnered significant interest. We previously reported poly(2-methacryloyloxyethyl phosphorylcholine) (MPC)-based lipids (PMPC-lipids) and investigated the...

Author(s):  
Marina Botto ◽  
Mark J. Walport

The complement system consists of over 20 distinct proteins and is an essential component of the innate immune system. It is a major effector mechanism of host defence against infection and inflammatory responses, has an important role in the physiological removal of immune complexes and dying cells, and plays an accessory role in the induction of antibody responses....


2020 ◽  
Vol 19 (1) ◽  
pp. 131-138
Author(s):  
A. A. Butilin ◽  
A. E. Filippova ◽  
S. S. Shakhidzhanov ◽  
F. I. Ataullakhanov

Complement system is a part of the immune system that provides organism cells with protection against foreign pathogens. Various kinds of defects in the complement system can induce development of serious diseases. This review summarizes different malfunctions of the complement system and also shows how these defects can result in development of severe diseases.


2021 ◽  
Vol 10 (22) ◽  
pp. 5251
Author(s):  
Anna Sobuś ◽  
Bartłomiej Baumert ◽  
Monika Gołąb-Janowska ◽  
Piotr Kulig ◽  
Edyta Paczkowska ◽  
...  

ALS remains a fatal, neurodegenerative motor neuron disease. Numerous studies seem to confirm that innate immune system is involved in the pathophysiology of ALS. Hence, the assessment of the complement system and attempts to modify its activity remain the target of medical intervention in ALS. In the present study, three intrathecal administrations of autologous bone marrow-derived lineage-negative (Lin–) cells were performed every 6 weeks in 20 sporadic ALS patients. The concentrations of various complement components in the cerebrospinal fluid and plasma at different time points after cell injection were quantified using a Luminex multiplex. The results of the complement system were correlated with the level of leukocytes, neutrophils, lymphocytes, fibrinogen and CRP in the peripheral blood and the functional status of ALS patients using Norris and ALS-FRSr scales. The study showed a statistically significant decrease in plasma C3b concentration in all 7th days after cell application. In parallel, a peak decrease in neutrophil count and CRP level was observed on days 5–7, with a simultaneous maximum clinical improvement on days 7–28 of each Lin– cell administration. Adjuvant Lin– cell therapy appears to have the silencing potential on the complement-mediated immune system and thus suppress pro-inflammatory reactions responsible for neurodegeneration. However, further in-depth studies are necessary to address this issue.


2019 ◽  
Vol 21 (4) ◽  
pp. 773-780
Author(s):  
E. G. Cheremnykh ◽  
P. A. Ivanov ◽  
M. I. Factor ◽  
E. Yu. Chikina ◽  
S. G. Nikitina ◽  
...  

It is known that functional activity of complement system depends not only on balance and concentration of components participating in formation of the system end products, but also on levels of inhibitory activities. Numerous relations with hemostasis also substantially contribute to general level of complement system activity. Changes in complement system functioning are inevitable during chronic diseases accompanied with immune system dysregulation. All mental diseases tend to be chronic and are they aggravated by patients’ immune system changes. Autism spectrum disorders in children is a group of mental disorders. Immune system dysregulation is usually detected in such patients, manifesting as excessive susceptibility to viral and bacterial infections. Therefore, the level of its functional activity is diagnostically and prognostically significant in this pathology, since the complement system is a key element of immune system.We have evaluated functional activity of complement system in patients with autistic spectrum disorders, using the method which was developed earlier. It is based on the reaction of the protozoa (Tetrahymena pyriformis) which are both targets and activators for the complement system. The complement system capacity (cSC) was used as the main parameter of complement evaluation. The half-time of protozoa survival (T50) was defined using the BioLat device for each serum specimen added at four concentrations (1/20, 1/40, 1/80, 1/160 dilution). The complement capacity was calculated as the area enclosed by influence curve of the reciprocals of T50 and the serum dilution. According to Mann–Whitney U test, the difference between patients’ and healthy volunteers’ groups was established as Z = 4.43 (by T50 at 1/160 dilution), p < 0.001 and by cSCas Z = 5.8, p < 0.001. cSC was calculated from the results obtained at each serum concentration measured. The difference between the two groups according to Mann–Whitney U test appeared to be more significant than the difference according to T50. Therefore, cSC was taken as the main characteristic of complement system function.The contribution of hemostasis plasma components to complement system functional activity level was estimated by determination of complement capacity in plasma and serum of each blood sample from 6 patients with autism spectrum disorders and 5 healthy donors. All healthy donors showed small difference between plasma and serum complement capacity, and their complement activity was higher in plasma. In patients’ group, the complement capacity levels in plasma and serum differed significantly. The cSC levels of two patients were higher in serum than in plasma, and the cSC levels of three other patients were significantly higher in plasma than in serum. Differential involvement of coagulation into the complement system activation may be indicative for the immune system dysfunction which is observed in patients with autistic spectrum disorders of different etiology.


2021 ◽  
Vol 12 ◽  
Author(s):  
Kristina Zlatina ◽  
Sebastian P. Galuska

The function of antibodies, namely the identification and neutralization of pathogens, is mediated by their antigen binding site (Fab). In contrast, the subsequent signal transduction for activation of the immune system is mediated by the fragment crystallizable (Fc) region, which interacts with receptors or other components of the immune system, such as the complement system. This aspect of binding and interaction is more precise, readjusted by covalently attached glycan structures close to the hinge region of immunoglobulins (Ig). This fine-tuning of Ig and its actual state of knowledge is the topic of this review. It describes the function of glycosylation at Ig in general and the associated changes due to corresponding glycan structures. We discuss the functionality of IgG glycosylation during different physiological statuses, like aging, lactation and pathophysiological processes. Further, we point out what is known to date about Ig glycosylation in farm animals and how new achievements in vaccination may contribute to improved animal welfare.


2021 ◽  
Vol 11 ◽  
Author(s):  
Sivan Livson ◽  
Hanna Jarva ◽  
Ilkka Kalliala ◽  
A. Inkeri Lokki ◽  
Jenni Heikkinen-Eloranta ◽  
...  

BackgroundHuman pregnancy alters profoundly the immune system. The local involvement and mechanisms of activation of the complement system in the cervicovaginal milieu during pregnancy and delivery remain unexplored.ObjectivesTo determine whether normal pregnancy and delivery are associated with local activation of complement or changes in the immunoglobulin profile in the cervix.Study DesignThis study was designed to assess IgA, IgG, and complement activation in the cervicovaginal area in three groups of patients: i) 49 pregnant women (week 41+3–42+0) not in active labor, ii) 24 women in active labor (38+4–42+2), and iii) a control group of nonpregnant women (n=23) at child-bearing age. We collected mucosal samples from the lateral fornix of the vagina and external cervix during routine visits and delivery. The Western blot technique was used to detect complement C3 and its activation products. For semiquantitative analysis, the bands of the electrophoresed proteins in gels were digitized on a flatbed photo scanner and analyzed. IgA and IgG were analyzed by Western blotting and quantified by ELISA. One-way ANOVA and Tukey’s Multiple Comparison tests were used for statistical comparisons.ResultsA higher abundance but lower activation level of C3 in both the external cervix (P&lt;0.001) and lateral fornix of the vagina (P&lt;0.001) was observed during delivery (58 ± 22, n= 24) in comparison to the groups of nonpregnant (72 ± 13%; mean ± SD, n=23) and pregnant women (78 ± 22%, n=49). Complement activating IgG was detected in higher abundance than IgA in the cervicovaginal secretions of pregnant women. In a small proportion samples also C3-IgG complexes were detected.ConclusionsOur results reveal an unexpectedly strong activation of the complement system and the presence IgG immunoglobulins in the cervicovaginal area during pregnancy, active labor, and among nonpregnant women. In contrast to the higher amounts of C3 in the cervicovaginal secretions during labor, its activation level was lower. Complement activating IgG was detected in higher concentrations than IgA in the mucosal secretions during pregnancy and labor. Taken together our results imply the presence a locally operating humoral immune system in the cervicovaginal mucosa.


2019 ◽  
Vol 18 (3) ◽  
pp. 130-144
Author(s):  
S. S. Shakhidzhanov ◽  
A. E. Filippova ◽  
A. A. Butilin ◽  
F. I. Ataullakhanov

Complement is a part of the immune system which provides host cells with protection against pathogen cells and particles. It is activated when a pathogen invasion is detected. The results of numerous investigations have led to growing realization of the important role of this system in maintaining normal organism homeostasis. This review summarizes a modern view on the complement system.


2019 ◽  
Vol 32 (2) ◽  
pp. 247-250
Author(s):  
Stanislava Popova ◽  
Mariela Geneva

Introduction: The complement system adds antibodies and helps phagocytic cells to destroy pathogens from the body. This is part of a congenital immune system that is not adaptive and does not change over the individual life. However, complement can be "triggered" by the adaptive immune system. The complement system is the main effector of the humoral patr of the immune system. Activation of complement results in opsonization, chemotaxis and cytolysis. Regulation of the complement system can control inflammatory diseases including psoriatic arthritis and vice versa, complement fixation disorders can lead to illness. Treatment with anti-TNF blokers complement activity in patients with inflammatory joint diseases.Objective: To investigate C3, C4 fractions of complement, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and complement the response prediction and monitoring of anti-TNF treatment in patients with psoriatic arthritis.Materials and Methods: 36 patients were included sequentially before treatment with TNF-a-blokers. C3, C4, ESR, CRP were assessed at baseline at 6 and 12 months after initiation of treatment with TNF-α blockers. The activity of the disease is measured by the DARSA disease activity scale, the responses being compared with a control group of persons similar in gender and age. Statistical data processing was performed using the SPSS v25.Results and conclusions: According to the results obtained, C3 and C4 were significantly higher than controls at initiation of treatment (C3 111.3 ± 30.8, C4 91.9 ± 12.4 mg / dl, controls 19.1 ± 8.3 mg / dl, 10.2 ± 5.6 mg / dl p = 0.001, p = 0.001). At 6 and 12 months of follow-up, 76.2% of patients had a reduction in the level of C3 and C4 (p = 0.002, 0.001, respectively). It was found that higher baseline levels of C3 were associated with higher DARSA values at 6 and 12 months.Conclusion: The study of the C3 and C4 complement fractions can be used as biomarkers to estimate the prognosis of TNF-blocker therapy.


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