The role of serum in leucocyte adherence to the plerocercoid of Ligula intestinalis (Cestoda: Pseudophyllidea)

Parasitology ◽  
1986 ◽  
Vol 92 (2) ◽  
pp. 413-424 ◽  
Author(s):  
P. Hoole ◽  
C. Arme
Keyword(s):  
Rutilus Rutilus ◽  
Immune Serum ◽  
Adherent Cells ◽  
Percoll Gradient ◽  
Serum Dilution ◽  
Ligula Intestinalis ◽  
Discontinuous Percoll Gradient ◽  
Leucocyte Adherence

SUMMARYThe role of serum in the adherence of roach (Rutilus rutilus) leucocytes to the plerocercoid of Ligula intestinalis has been investigated in vitro. Roach plerocercoids, either untreated, cultured or killed (fixation in 0·5 % buffered glutaraldehyde or heat at 50°C for 45 mm), were exposed to serum and 4×106 leucocytes obtained from the pronephros of non-infected roach using a discontinuous Percoll gradient. At normal roach serum (NRoS) dilutions of 1:5000 to 1:100, leucocyte adherence was observed on all living parasites but was negligible in killed parasites or in complement-depleted NRoS assays. The number of adherent cells increased with increasing NRoS concentration. Leucocytes bound more avidly in the presence of heat-inactivated immune serum (hi IRoS); at a serum dilution of 1:5000 the percentage of the parasite surface covered by leucocytes was approximately 3 times greater in hi IRoS than in NRoS. Ultrastructural observations on parasites revealed that plerocercoids exposed to cells and hi IRoS had, in some areas, abnormal inclusions in their tegument and lacked a microthrix border and distal cytoplasm. In addition, the efflux of radioactivity from [14C] cycloleucine-labelled worms was greater in parasites incubated in the presence of hi IRos.

Mechanisms involved in the loss or antibody-mediated adherence of macrophages to lung-stage schistosomula of Schistosoma mansoni in vitro

Parasitology ◽  
1993 ◽  
Vol 106 (5) ◽  
pp. 463-469 ◽  
Author(s):  
B. W. L. Lawson ◽  
Q. D. Bickle ◽  
M. G. Taylor
Keyword(s):  
Protein Synthesis ◽  
Immune Evasion ◽  
Actinomycin D ◽  
Cell Loss ◽  
Immune Serum ◽  
Adherent Cells ◽  
Cell Adherence ◽  
Rapid Loss ◽  
Antigen Loss

SUMMARYSera from rabbits vaccinated with irradiated cercariae mediated cell (P388D1 or mouse peritoneal macrophage) adherence to lung-stage schistosomula (LS) but such antibody-mediated cell adherence was short-lived in contrast to cell adherence to mechanically transformed schistosomula (MS). Thus LS lost 50% of their adherent cells within 3–6 h in culture and up to 90% by 24 h, whereas adherence to MS was undiminished during this time. Rapid loss of adherent cells was unique to schistosomula that had developed to the lung stage because schistosomula recovered from the skin up to 3 days post-infection did not exhibit the rapid cell loss shown by 3-day LS. To determine whether cell loss was caused by loss of surface antigenicity during culture LS were cultured on their own for up to 24 h and at various intervals samples of schistosomula were tested for antigenicity by addition of immune serum and cells. Levels of adherence to both MS and LS were maintained throughout the incubation period. When antibody-opsonized schistosomula were washed and indicator cells added at progressive intervals, persistence of adherence was again demonstrated, showing that antibody binding to LS had not promoted surface antigen loss or degradation of bound antibody. It was then shown, by adding fresh macrophages to cultures up to 24 h old that LS which had lost their adherent cells nevertheless retained bound antibody, and comparison of adherence of ‘used’ and ‘fresh’ cells to MS and LS showed that the cytoadherence properties of macrophages were not significantly reduced during their culture with LS from which cells had been lost. Cell loss was shown to be dependent upon protein synthesis by LS since cell loss was significantly reduced when the schistosomula were pre-incubated in puromycin or actinomycin D. Transient cell adherence to LS may comprise an important immune evasion stratagem by schistosomula.

scholarly journals The Vi Capsular Polysaccharide Prevents Complement Receptor 3-Mediated Clearance ofSalmonella entericaSerotype Typhi

2010 ◽  
Vol 79 (2) ◽  
pp. 830-837 ◽  
Author(s):  
R. Paul Wilson ◽  
Sebastian E. Winter ◽  
Alanna M. Spees ◽  
Maria G. Winter ◽  
Jessalyn H. Nishimori ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Immune Serum ◽  
Complement Receptor ◽  
Immune Recognition ◽  
Bacterial Binding ◽  
Intraperitoneal Infection ◽  
Complement Receptor 3 ◽  
Vi Capsular Polysaccharide

ABSTRACTCapsular polysaccharides are important virulence factors of invasive bacterial pathogens. Here we studied the role of the virulence (Vi) capsular polysaccharide ofSalmonella entericaserotype Typhi (S.Typhi) in preventing innate immune recognition by complement. Comparison of capsulatedS.Typhi with a noncapsulated mutant (ΔtviBCDE vexABCDEmutant) revealed that the Vi capsule interfered with complement component 3 (C3) deposition. Decreased complement fixation resulted in reduced bacterial binding to complement receptor 3 (CR3) on the surface of murine macrophagesin vitroand decreased CR3-dependent clearance of Vi capsulatedS.Typhi from the livers and spleens of mice. Opsonization of bacteria with immune serum prior to intraperitoneal infection increased clearance of capsulatedS.Typhi from the liver. Our data suggest that the Vi capsule prevents CR3-dependent clearance, which can be overcome in part by a specific antibody response.

scholarly journals In Vitro Production and Immunogenicity of a Clostridium difficile Spore-Specific BclA3 Glycopeptide Conjugate Vaccine

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 73 ◽  
Author(s):  
Annie Aubry ◽  
Wei Zou ◽  
Evguenii Vinogradov ◽  
Dean Williams ◽  
Wangxue Chen ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Immune Responses ◽  
Keyhole Limpet Hemocyanin ◽  
Immune Serum ◽  
In Vitro Assays ◽  
Enzyme Linked Immunosorbent Assay ◽  
In Vitro Production ◽  
Vitro Production

The BclA3 glycoprotein is a major component of the exosporangial layer of Clostridium difficile spores and in this study we demonstrate that this glycoprotein is a major spore surface associated antigen. Here, we confirm the role of SgtA glycosyltransferase (SgtA GT) in BclA3 glycosylation and recapitulate this process by expressing and purifying SgtA GT fused to MalE, the maltose binding protein from Escherichia coli. In vitro assays using the recombinant enzyme and BclA3 synthetic peptides demonstrated that SgtA GT was responsible for the addition of β-O-linked GlcNAc to threonine residues of each synthetic peptide. These peptide sequences were selected from the central, collagen repeat region of the BclA3 protein. Following optimization of SgtA GT activity, we generated sufficient glycopeptide (10 mg) to allow conjugation to KLH (keyhole limpet hemocyanin) protein. Glycosylated and unglycosylated versions of these conjugates were then used as antigens to immunize rabbits and mice. Immune responses to each of the conjugates were examined by Enzyme Linked Immunosorbent Assay ELISA. Additionally, the BclA3 conjugated peptide and glycopeptide were used as antigens in an ELISA assay with serum raised against formalin-killed spores. Only the glycopeptide was recognized by anti-spore polyclonal immune serum demonstrating that the glycan moiety is a predominant spore-associated surface antigen. To determine whether antibodies to these peptides could modify persistence of spores within the gut, animals immunized intranasally with either the KLH-glycopeptide or KLH-peptide conjugate in the presence of cholera toxin, were challenged with R20291 spores. Although specific antibodies were raised to both antigens, immunization did not provide any protection against acute or recurrent disease.

scholarly journals In Vitro Activities of Daptomycin Combined with Fosfomycin or Rifampin on Planktonic and Adherent Linezolid-resistant Enterococcus faecalis

2018 ◽  
Author(s):  
Jin-xin Zheng ◽  
Xiang Sun ◽  
Zhi-wei Lin ◽  
Guo-bin Qi ◽  
Hao-peng Tu ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Adherent Cells ◽  
Planktonic Cells ◽  
Bactericidal Activities ◽  
High Concentrations

AbstractThis study aimed to explore daptomycin combined with fosfomycin or rifampin against the planktonic and adherent linezolid-resistant isolates of Enterococcus faecalis. Four linezolid-resistant isolates of E. faecalis which formed biofilms were collected for this study. Biofilm biomasses were detected by crystal violet staining. The adherent cells in the mature biofilms were counted by CFU numbers and observed by confocal laser scanning microscope (CLSM). In time-killing studies, daptomycin combined with fosfomycin or rifampin (4xMIC) demonstrated bactericidal activities on the planktonic cells, and daptomycin combined with fosfomycin killed more planktonic cells (at least 2-log10 CFU/ml) than daptomycin or fosfomycin alone. Daptomycin alone showed activities against the mature biofilms, and daptomycin combined with fosfomycin (16xMIC) demonstrated significantly more activity than daptomycin or fosfomycin alone against the mature biofilms in three of the four isolates. Daptomycin alone effectively killed the adherent cells, and daptomycin combined with fosfomycin (16xMIC) killed more adherent cells than daptomycin or fosfomycin alone in these mature biofilms. The high concentrations of daptomycin (512 mg/L) combined with fosfomycin indicated more activity than 16xMIC of daptomycin combined with fosfomycin on the adherent cells and the mature biofilms. The addition of rifampin increased the activity of daptomycin against the biofilms and the adherent cells of FB-14 and FB-80 isolates, but was not observed in FB-1 and FB-2 isolates. In conclusion, daptomycin combined with fosfomycin works effectively against the planktonic and adherent linezolid-resistant isolates of E. faecalis. The role of rifampin in these linezolid-resistant isolates is discrepant and needs more studies.

scholarly journals The regulatory role of interleukin 2-responsive T lymphocytes on human marrow granulopoiesis

Blood ◽  
1987 ◽  
Vol 69 (4) ◽  
pp. 1161-1166 ◽  
Author(s):  
Z Estrov ◽  
C Roifman ◽  
G Mills ◽  
T Grunberger ◽  
EW Gelfand ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Interleukin 2 ◽  
Colony Growth ◽  
Adherent Cell ◽  
Adherent Cells ◽  
Dependent Manner ◽  
Recombinant Interleukin 2 ◽  
Dose Dependent

Abstract The effect of recombinant interleukin 2 (IL2) on marrow CFU-C colony formation was evaluated to define the role for T lymphocytes in human marrow granulopoiesis. The colony-stimulating factor (CSA) used in our experiments was found to contain IL2. IL2 depletion from CSA resulted in a reduction in CFU-C colony proliferation. Addition of exogenous IL2 caused an increase in CFU-C colony numbers in a dose-dependent manner. This increase could be prevented by anti-Tac, a monoclonal antibody (MoAb) to the IL2 receptor. Moreover, anti-Tac in the absence of exogenous IL2 resulted in an overall decrease in colony numbers. Depletion of either adherent cells or T lymphocytes abolished the effect of IL2 and anti-Tac on colony growth. In the presence of IL2, re- addition of T lymphocytes to the T-depleted marrow or adherent cells to adherent cell-depleted marrow resulted in a significant increase in CFU- C colony numbers, whereas no significant effect was found when IL2- depleted CSA was used. Although T lymphocytes were not themselves essential for CFU-C colony growth, our studies indicate that IL2 and IL2-responsive T cells can regulate in vitro granulopoiesis.

scholarly journals The regulatory role of interleukin 2-responsive T lymphocytes on human marrow granulopoiesis

Blood ◽  
1987 ◽  
Vol 69 (4) ◽  
pp. 1161-1166
Author(s):  
Z Estrov ◽  
C Roifman ◽  
G Mills ◽  
T Grunberger ◽  
EW Gelfand ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Interleukin 2 ◽  
Colony Growth ◽  
Adherent Cell ◽  
Adherent Cells ◽  
Dependent Manner ◽  
Recombinant Interleukin 2 ◽  
Dose Dependent

The effect of recombinant interleukin 2 (IL2) on marrow CFU-C colony formation was evaluated to define the role for T lymphocytes in human marrow granulopoiesis. The colony-stimulating factor (CSA) used in our experiments was found to contain IL2. IL2 depletion from CSA resulted in a reduction in CFU-C colony proliferation. Addition of exogenous IL2 caused an increase in CFU-C colony numbers in a dose-dependent manner. This increase could be prevented by anti-Tac, a monoclonal antibody (MoAb) to the IL2 receptor. Moreover, anti-Tac in the absence of exogenous IL2 resulted in an overall decrease in colony numbers. Depletion of either adherent cells or T lymphocytes abolished the effect of IL2 and anti-Tac on colony growth. In the presence of IL2, re- addition of T lymphocytes to the T-depleted marrow or adherent cells to adherent cell-depleted marrow resulted in a significant increase in CFU- C colony numbers, whereas no significant effect was found when IL2- depleted CSA was used. Although T lymphocytes were not themselves essential for CFU-C colony growth, our studies indicate that IL2 and IL2-responsive T cells can regulate in vitro granulopoiesis.

scholarly journals Studies on the Nature of Immunity to Homologous Grafted Skin, With Special Reference to the Use of Pure Epidermal Grafts

1954 ◽  
Vol 31 (1) ◽  
pp. 16-39 ◽  
Author(s):  
R. E. BILLINGHAM ◽  
ELIZABETH M. SPARROW
Keyword(s):  
Fibrous Tissue ◽  
Immune Serum ◽  
Prolonged Treatment ◽  
Histological Changes ◽  
Skin Homograft ◽  
Probable Role ◽  
Derivatives Of

1. Homografts of pure epidermis, i.e. of skin freed from all dermal elements, survive their orthotopic transplantation between unrelated rabbits for 10-15 days. They elicit and succumb to a transplantation immunity reaction just as ordinary skin homografts do. 2. The distinctive sequence of histological changes that take place in the dermis of a skin homograft during the course of its breakdown take place in the host's own young fibrous tissue when this forms the bed underlying pure epidermal homografts. 3. Although the breakdown of pure epidermal homografts is accelerated when they are transplanted to specifically immunized recipients, they normally survive for from 4-6 days. It is inferred that the serum and tissue exudates present in the bed to which such grafts are transplanted have no immediate inimical effect on the susceptible Malpighian cells when these are intimately exposed to them. 4. The possible application of pure epidermal grafts, and more particularly of dissociated epidermal cells, has been investigated in attempts to demonstrate a specific toxic action against a donor's cells of the blood, serum, and other derivatives of specifically immunized animals. After treatment in vitro, the ‘vitality’ of the epidermal grafts or cells was tested by transplanting them back to the animal from which they originated. 5. It was found that epidermal melanocytes of guinea-pig's skin are unaffected by prolonged treatment in vitro with ‘immune’ blood and serum, with or without the addition of lymphocytes or spleen cells. 6. The capacity of dissociated Malpighian cells in the rabbit to give rise to epithelium after grafting was completely or partially inhibited by treating them in vitro with excess immune serum for 22 hr. or longer at either 5° C. or 37° C. 7. It is suggested that this effect indicates the presence of a protective iso-antibody in the serum of rabbits which have reacted against skin homografts. The probable role of this antibody in the breakdown of skin homografts in vivo is discussed.

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