The attachment of IgG to cell components: a reconsideration of Brambell’s receptor hypothesis of protein transmission

1974 ◽  
Vol 187 (1087) ◽  
pp. 209-219 ◽  

Nuclear, mitochondrial and microsomal fractions were prepared from rabbit yolk-sac splanchnopleur and rabbit chorio-allantoic placenta, and tested in vivo and in vitro for attachment of labelled rabbit and bovine IgG. Similar fractions were prepared from small intestinal scrapings of neonatal rats, and tested in vivo and in vitro for attachment of labelled rat and sheep IgG. In all cases the attachment of the homologous and heterologous proteins was substantially equal. Digestion experiments on the labelled organelle pellets of rabbit yolk-sac were carried out with the proteases of the macerated tissue (the cell sap or final supernatant) at optimum pH. The nuclear pellet gave rise to a higher proportion of breakdown products derived from bovine than from rabbit IgG, showing the existence of a mechanism whereby selection between the two proteins might be brought about.

Development ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 159-174
Author(s):  
Nelly Bennett

The detection of a specific enzyme (cysteine lyase) of the yolk-sac endoderm by a very sensitive method is employed to characterize cell differentiation during the early stages of endoderm organogenesis in the chick. The first cells to contain active cysteine lyase are found in the germ wall at the primitive streak stage. In vivo observations establish a relation between the morphological specialization and organization of endodermal cells, their loss of mitotic activity and the increase in cysteine lyase activity. They suggest an influence of the mesoderm on endoderm differentiation. In vitro experiments confirm the existence in the yolk-sac endoderm of an incompatibility between cell proliferation and differentiation, as well as the action of the mesoderm on both the structural organization of the endoblast and the appearance of cysteine lyase; this last action seems to be due mainly to blood cells; chicken and rabbit blood cells are equally active. The problems of the origin of the endoderm and of the interactions occurring during the organogenesis of the yolk-sac endoderm are discussed.


2021 ◽  
Vol 95 ◽  
Author(s):  
E.S. El-Wakil ◽  
H.F. Abdelmaksoud ◽  
T.S. AbouShousha ◽  
M.M.I. Ghallab

Abstract Our work aimed to evaluate the possible effect of Annona muricata (Graviola) leaf extract on Trichinella spiralis in in vitro and in vivo studies. Trichinella spiralis worms were isolated from infected mice and transferred to three culture media – group I (with no drugs), group II (contained Graviola) and group III (contained albendazole) – then they were examined using the electron microscope. In the in vivo study, mice were divided into five groups: GI (infected untreated), GII (prophylactically treated with Graviola for seven days before infection), GIII (infected and treated with Graviola), GIV (infected and treated with albendazole) and GV (infected and treated with a combination of Graviola plus albendazole in half doses). Drug effects were assessed by adults and larvae load beside the histopathological small intestinal and muscular changes. A significant reduction of adult and larval counts occurred in treated groups in comparison to the control group. Histopathologically, marked improvement in the small intestinal and muscular changes was observed in treated groups. Also, massive destruction of the cultured adults’ cuticle was detected in both drugs. This study revealed that Graviola leaves have potential activity against trichinellosis, especially in combination with albendazole, and could serve as an adjuvant to anti-trichinellosis drug therapy.


2004 ◽  
Vol 186 (20) ◽  
pp. 6983-6998 ◽  
Author(s):  
Aneta A. Bartosik ◽  
Krzysztof Lasocki ◽  
Jolanta Mierzejewska ◽  
Christopher M. Thomas ◽  
Grazyna Jagura-Burdzy

ABSTRACT The par genes of Pseudomonas aeruginosa have been studied to increase the understanding of their mechanism of action and role in the bacterial cell. Key properties of the ParB protein have been identified and are associated with different parts of the protein. The ParB- ParB interaction domain was mapped in vivo and in vitro to the C-terminal 56 amino acids (aa); 7 aa at the C terminus play an important role. The dimerization domain of P. aeruginosa ParB is interchangeable with the dimerization domain of KorB from plasmid RK2 (IncP1 group). The C-terminal part of ParB is also involved in ParB-ParA interactions. Purified ParB binds specifically to DNA containing a putative parS sequence based on the consensus sequence found in the chromosomes of Bacillus subtilis, Pseudomonas putida, and Streptomyces coelicolor. The overproduction of ParB was shown to inhibit the function of genes placed near parS. This “silencing” was dependent on the parS sequence and its orientation. The overproduction of P. aeruginosa ParB or its N-terminal part also causes inhibition of the growth of P. aeruginosa and P. putida but not Escherichia coli cells. Since this inhibitory determinant is located well away from ParB segments required for dimerization or interaction with the ParA counterpart, this result may suggest a role for the N terminus of P. aeruginosa ParB in interactions with host cell components.


1986 ◽  
Vol 34 (7) ◽  
pp. 847-853 ◽  
Author(s):  
D R Abrahamson

Ultrastructural distribution of laminin within renal glomerular (GBM) and tubular basement membranes (TBM) was investigated using post-embedding immunolocalization with colloidal gold. Rat kidneys were fixed with 4% formaldehyde and embedded at 4 degrees C in Lowicryl K4M medium. Thin sections were then sequentially treated with affinity-purified rabbit anti-laminin IgG and anti-rabbit IgG conjugated to 10 nm diameter colloidal gold. Gold bound specifically to the GBM and TBM with particle densities of 690/micron2 and 731/micron2, respectively. In the GBM, the number of gold particles bound/micron2 of lamina densa greater than lamina rara externa greater than lamina rara interna. Closely similar binding patterns were found when kidneys were fixed with 0.5% glutaraldehyde plus 3% formaldehyde and embedded at 60 degrees C in L.R. White resin, but slightly less gold bound to sections overall than that seen with formaldehyde alone and Lowicryl. Taken together, these results illustrate that anti-laminin IgG, whether applied to fixed sections in vitro or introduced in vivo, bound to the lamina rara interna, lamina densa, and lamina rara externa of the GBM and throughout the TBM.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Dongsun Park ◽  
Kyungha Shin ◽  
Ehn-Kyoung Choi ◽  
Youngjin Choi ◽  
Ja-Young Jang ◽  
...  

Objective. Since oligodendrocyte progenitor cells (OPCs) are the target cells of neonatal hypoxic-ischemic encephalopathy (HIE), the present study was aimed at investigating the protective effects ofN-acetyl-L-cysteine (NAC), a well-known antioxidant and precursor of glutathione, in OPCs as well as in neonatal rats.Methods. Inin vitrostudy, protective effects of NAC on KCN cytotoxicity in F3.Olig2 OPCs were investigated via MTT assay and apoptotic signal analysis. Inin vivostudy, NAC was administered to rats with HIE induced by hypoxia-ischemia surgery at postnatal day 7, and their motor functions and white matter demyelination were analyzed.Results. NAC decreased KCN cytotoxicity in F3.Olig2 cells and especially suppressed apoptosis by regulating Bcl2 and p-ERK. Administration of NAC recovered motor functions such as the using ratio of forelimb contralateral to the injured brain, locomotor activity, and rotarod performance of neonatal HIE animals. It was also confirmed that NAC attenuated demyelination in the corpus callosum, a white matter region vulnerable to HIE.Conclusion. The results indicate that NAC exerts neuroprotective effectsin vitroandin vivoby preserving OPCs, via regulation of antiapoptotic signaling, and that F3.Olig2 human OPCs could be a good tool for screening of candidates for demyelinating diseases.


2001 ◽  
Vol 281 (5) ◽  
pp. G1140-G1150 ◽  
Author(s):  
Lynn Edde ◽  
Ronaldo B. Hipolito ◽  
Freda F. Y. Hwang ◽  
Denis R. Headon ◽  
Robert A. Shalwitz ◽  
...  

Lactoferrin is a milk protein that reportedly protects infants from gut-related, systemic infection. Proof for this concept is limited and was addressed during in vivo and in vitro studies. Neonatal rats pretreated orally with recombinant human lactoferrin (rh-LF) had less bacteremia and lower disease severity scores ( P < 0.001) after intestinal infection with Escherichia coli. Control animals had 1,000-fold more colony-forming units of E. coli per milliliter of blood than treated animals ( P < 0.001). Liver cultures from control animals had a twofold increase in bacterial counts compared with cultures from rh-LF-treated pups ( P < 0.02). Oral therapy with rh-LF + FeSO4did not alter the protective effect. In vitro studies confirmed that rh-LF interacted with the infecting bacterium and rat macrophages. An in vitro assay showed that rh-LF did not kill E. coli, but a combination of rh-LF + lysozyme was microbicidal. In vitro studies showed that rat macrophages released escalating amounts of nitric oxide and tumor necrosis factor-α when stimulated with increasing concentrations of rh-LF. The in vitro studies suggest that rh-LF may act with other “natural peptide antibiotics” or may prime macrophages to kill E. coli in vivo.


2001 ◽  
Vol 281 (4) ◽  
pp. G899-G906 ◽  
Author(s):  
Robert C. De Lisle ◽  
Kathryn S. Isom ◽  
Donna Ziemer ◽  
Calvin U. Cotton

The exocrine pancreas of the cystic fibrosis (CF) mouse ( cftrm1UNC ) is only mildly affected compared with the human disease, providing a useful model to study alterations in exocrine function. The CF mouse pancreas has ∼50% of normal amylase levels and ∼200% normal Muclin levels, the major sulfated glycoprotein of the pancreas. Protein biosynthetic rates and mRNA levels for amylase were not altered in CF compared with normal mice, and increases in Muclin biosynthesis and mRNA paralleled the increased protein content. Stimulated pancreatic amylase secretion in vitro and in vivo tended to be increased in CF mice but was not statistically significant compared with normal mice. We show for the first time that the CF mouse duodenum is abnormally acidic (normal intestinal pH = 6.47 ± 0.05; CF intestinal pH = 6.15 ± 0.07) and hypothesize that this may result in increased signaling to the exocrine pancreas. There were significant increases in CF intestinal mRNA levels for secretin (310% of normal, P < 0.001) and vasoactive intestinal peptide (148% of normal, P < 0.05). Furthermore, CF pancreatic cAMP levels were 147% of normal ( P < 0.01). These data suggest that the CF pancreas may be chronically stimulated by cAMP-mediated signals, which in turn may exacerbate protein plugging in the acinar/ductal lumen, believed to be the primary cause of destruction of the pancreas in CF.


1982 ◽  
Vol 242 (1) ◽  
pp. G65-G75
Author(s):  
E. A. Swabb ◽  
R. A. Hynes ◽  
W. G. Marnane ◽  
J. S. McNeil ◽  
R. A. Decker ◽  
...  

The mechanism of changes in small intestinal transport due to acutely increased intraluminal hydrostatic pressure (IHP) was investigated in detail using perfused in vivo rabbit intestinal segments. IHP affected passive transport in vivo by increasing effective mucosal surface area in the small intestine (indicated by 3HOH transport and tissue architectural changes) and increasing small intestinal permeability (indicated by a proportionately greater increase in mannitol than erythritol secretory clearance). IHP did not alter ileal blood flow rate measured by radioactive microspheres, despite grossly evident venous dilatation, or active intestinal transport in the ileum as measured by a) in vitro ion transport in the absence of elevated hydrostatic pressure, b) mucosal adenylate cyclase or Na-K-ATPase activities, and c) glucose-stimulated water and electrolyte absorption. Acutely increased IHP appears to influence the hydrodynamics of the mucosal microcirculation in the rabbit ileum to produce a driving force for passive filtration-secretion, which is associated with and possibly augmented by increased tissue permeability and effective surface area.


Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 488-495 ◽  
Author(s):  
Hiroyuki Fujita ◽  
Yoshimi Hashimoto ◽  
Susan Russell ◽  
Barbara Zieger ◽  
Jerry Ware

Abstract We have performed a systematic in vivo evaluation of gene expression for the glycoprotein (GP) Ibα subunit of the murine platelet adhesion receptor, GP Ib-IX-V. This study is warranted by in vitro observations of human GP Ibα expression in cells of nonhematopoietic lineage and reports of regulation of the GP Ibα gene by cytokines. However, an in vivo role for a GP Ib-IX-V receptor has not been established beyond that described for normal megakaryocyte/platelet physiology and hemostasis. Our Northern analysis of mouse organs showed high levels of GP Ibα mRNA in bone marrow with a similar expression pattern recapitulated in mice containing a luciferase transgene under the control of the murine GP Ibα promoter. Consistently high levels of luciferase activity were observed in the two hematopoietic organs of mice, bone marrow (1,400 relative light units/μg of protein [RLUs]) and spleen (500 RLUs). Reproducible, but low-levels of luciferase activity were observed in heart, aorta, and lung (30 to 60 RLUs). Among circulating blood cells, the luciferase activity was exclusively localized in platelets. No increase in GP Ibα mRNA or luciferase activity was observed after treatment of mice with lipopolysaccharides (LPS) or tumor necrosis factor-α (TNF-α). We conclude the murine GP Ibα promoter supports a high level of gene expression in megakaryocytes and can express heterologous proteins allowing an in vivo manipulation of platelet-specific proteins in the unique environment of a blood platelet.


PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Dory Gómez ◽  
Natalia Muñoz ◽  
Rafael Guerrero ◽  
Orlando Acosta ◽  
Carlos A. Guerrero

Rotavirus infection has been reported to induce an inflammatory response in the host cell accompanied by the increased expression or activation of some cellular molecules including ROS, NF-κB, and COX-2. PPARγstimulation and N-acetylcysteine (NAC) treatment have been found to interfere with viral infections including rotavirus infection. Small intestinal villi isolated fromin vivoinfected mice with rotavirus ECwt were analyzed for the percentage of ECwt-infected cells, the presence of rotavirus antigens, and infectious virion yield following treatment with pioglitazone. Isolated villi were also infectedin vitroand treated with PPARγagonists (PGZ, TZD, RGZ, DHA, and ALA),all-transretinoic acid (ATRA), and NAC. After treatments, the expression of cellular proteins including PPARγ, NF-κB, PDI, Hsc70, and COX-2 was analyzed using immunochemistry, ELISA, immunofluorescence, and Western blotting. The results showed that rotavirus infection led to an increased accumulation of the cellular proteins studied and ROS. The virus infection-induced accumulation of the cellular proteins studied and ROS was reduced upon pioglitazone treatment, causing also a concomitant reduction of the infectious virion yield. We hypothesized that rotavirus infection is benefiting from the induction of a host cell proinflammatory response and that the interference of the inflammatory pathways involved leads to decreased infection.


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