scholarly journals REGULATION OF THE IMMUNE SYSTEM BY SYNTHETIC POLYNUCLEOTIDES

1972 ◽  
Vol 135 (1) ◽  
pp. 45-67 ◽  
Author(s):  
Robert D. Stout ◽  
Arthur G. Johnson

Addition of polyadenylic-polyuridylic acid in complex form (poly A:U) without antigen to a suspension of spleen cells obtained from BALB/Aj mice primed 6 wk previously with human γ-globulin (HGG) resulted in an immediate fourfold increase over background number of anti-HGG rosette-forming cells (RFC). Culture of similar cells in the presence of puromycin for 1–6 hr before poly A:U did not significantly reduce the response. Continued culture of primed spleen cells in the presence of poly A:U, resulted in a decrease of RFC to background levels within an hour followed by an increase again 6 hr later. This later increase in RFC was inhibited by addition of puromycin to the culture medium. The nonspecific stimulation by poly A:U of antibody production by primed spleen cells also was induced in vivo. Increases in splenic RFC were detectable 6 hr after intravenous injection of poly A:U alone, without antigen, into primed mice. The response peaked at 18 hr and had dissipated completely within 3 days. A second injection of poly A:U 24 hr or later after the first injection resulted in a second response, similar to the first with respect to kinetics and intensity. Rosette formation by poly A:U-stimulated cells could not be inhibited by mitotic poisons, but was inhibited by treatment of the cells with goat anti-mouse γ-globulin serum, suggesting that the antibody involved was a 7S γ-globulin. The decrease in RFC induced by culture of primed cells for 1 hr in poly A:U paralleled a decrease in secondary responsiveness of the cells to antigen. This poly A:U-induced inhibition of secondary responsiveness could be reversed by suspending the treated cells in supernatant fluids derived from poly A:U-stimulated cultures. The reversal was specific in that supernatant fluids removed from bovine serum albumin (BSA)-primed cells by poly A:U did not stimulate the response of HGG-primed cells to HGG. However supernatant fluids from BSA-primed cells caused the production of anti-HGG RFC if BSA rather than HGG was used as triggering antigen. The active factor in the supernatant fluids appeared to be a 7S γ-globulin since activity was lost after 45 min incubation of the supernatant fluids in the presence of goat anti-mouse 7S γ-globulin serum.

1963 ◽  
Vol 117 (6) ◽  
pp. 1053-1062 ◽  
Author(s):  
Thomas F. O'Brien ◽  
Maria C. Michaelides ◽  
Albert H. Coons

The in vitro anamnestic antibody response of popliteal lymph node fragments to additions of antigen closely resembles the in vivo anamnestic antibody response in its sensitivity to antigen, in the time course of antibody production, and in the sequence of appearance and the morphology of the antibody containing cells. Most of the cells responsible for antibody synthesis remain in the explant and do not migrate, although a few can be found in the outgrowing sheet of cells. The smallest concentration of bovine serum albumin which stimulates an anamnestic response in vitro is about 1 x 10–9 gm/ml.


1974 ◽  
Vol 140 (1) ◽  
pp. 172-184 ◽  
Author(s):  
Judith A. Kapp ◽  
Carl W. Pierce ◽  
Baruj Benacerraf

Although nonresponder, H-2s and H-2q, mice fail to develop GAT-specific PFC responses to GAT, they do develop GAT-specific PFC responses when stimulated by GAT complexed to an immunogenic carrier such as methylated bovine serum albumin. The studies described in this paper show that injection of nonresponder mice with GAT specifically decreases their ability to develop anti-GAT PFC responses to a subsequent challenge with GAT-MBSA. Addition of GAT to cultures of spleen cells from nonresponder mice also prevents development of the GAT-specific PFC responses stimulated by GAT-MBSA. Thus, interaction of nonresponder spleen cells with GAT leads to the induction of unresponsiveness in vivo and in vitro. Various parameters of the tolerance induction have been investigated and described. A comparison of the effects of GAT on B cells indicates that nonresponder B cells are more readily rendered unresponsive by soluble GAT than are responder B cells. The significance of these data for our understanding of Ir gene regulation of the immune response is discussed.


2021 ◽  
Author(s):  
Chao Zhang ◽  
Xusheng Guo ◽  
Xuwen Da ◽  
Yishan Yao ◽  
Haihua Xiao ◽  
...  

Ru(II)-based photoactivated chemotherapy (PACT) agents are promising, however, the short wavelength absorption (generally < 550 nm) and poor tumor accumulation ability limit their in vivo applications. Herein bovine serum albumin...


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Songtao Zhang ◽  
Longhai Jin ◽  
Jianhua Liu ◽  
Yang Liu ◽  
Tianqi Zhang ◽  
...  

AbstractIn spite of the tumor microenvironments responsive cancer therapy based on Fenton reaction (i.e., chemodynamic therapy, CDT) has been attracted more attentions in recent years, the limited Fenton reaction efficiency is the important obstacle to further application in clinic. Herein, we synthesized novel FeO/MoS2 nanocomposites modified by bovine serum albumin (FeO/MoS2-BSA) with boosted Fenton reaction efficiency by the synergistic effect of co-catalyze and photothermal effect of MoS2 nanosheets triggered by the second near-infrared (NIR II) light. In the tumor microenvironments, the MoS2 nanosheets not only can accelerate the conversion of Fe3+ ions to Fe2+ ions by Mo4+ ions on their surface to improve Fenton reaction efficiency, but also endow FeO/MoS2-BSA with good photothermal performances for photothermal-enhanced CDT and photothermal therapy (PTT). Consequently, benefiting from the synergetic-enhanced CDT/PTT, the tumors are eradicated completely in vivo. This work provides innovative synergistic strategy for constructing nanocomposites for highly efficient CDT.


Nature ◽  
1968 ◽  
Vol 220 (5174) ◽  
pp. 1350-1352 ◽  
Author(s):  
H. F. JEEJEEBHOY ◽  
A. G. RABBAT

2008 ◽  
Vol 90 (5) ◽  
pp. 2013.e17-2013.e19 ◽  
Author(s):  
Juan A. Pagán ◽  
Idoia Postigo ◽  
Jorge R. Rodríguez-Pacheco ◽  
Maribel Peña ◽  
Jorge A. Guisantes ◽  
...  

2017 ◽  
Vol 9 (21) ◽  
pp. 3099-3104 ◽  
Author(s):  
Dong Li ◽  
Minghui Hua ◽  
Kun Fang ◽  
Rong Liang

Bovine serum albumin-Fe3O4 nanoparticles with undoubted biosafety and robust dual-modal T1 and T2 MR imaging ability were fabricated using a biomineralization approach in a facile way under mild conditions for in vivo MR imaging.


1983 ◽  
Vol 212 (2) ◽  
pp. 249-257 ◽  
Author(s):  
M J Imber ◽  
S V Pizzo

These studies explore the role of carbohydrate recognition systems and the direct involvement of terminal alpha 1-3-linked fucose in the clearance of lactoferrin from the murine circulation and in the specific binding of lactoferrin to receptors on murine peritoneal macrophages. As previously reported, radiolabelled lactoferrin cleared very rapidly (t1/2 less than 1 min) after intravenous injection into mice. However, competing levels of ligands specific for the hepatic galactose receptor (asialo-orosomucoid), the hepatic fucose receptor (fucosyl-bovine serum albumin), and the mononuclear-phagocyte system pathway recognizing mannose, N-acetylglucosamine and fucose (mannosyl-, N-acetylglucosaminyl- and fucosyl-bovine serum albumin) did not block radiolabelled lactoferrin clearance in vivo or binding to mouse peritoneal macrophage monolayers in vitro. Almond emulsin alpha 1-3-fucosidase was used to prepare defucosylated lactoferrin in which 88% of the alpha 1-3-linked fucose was hydrolysed. No difference in clearance or receptor binding was observed between radiolabelled native and defucosylated lactoferrin. Fucoidin, a fucose-rich algal polysaccharide, completely inhibits the clearance in vivo and macrophage binding in vitro of lactoferrin. This effect, however, is probably not the result of competition for binding to the fucose receptor, since gel-filtration studies demonstrated formation of a stable complex between lactoferrin and fucoidin. The present results indicate that the lactoferrin-clearance pathway is distinct from several pathways mediating glycoprotein clearance through recognition of terminal galactose, fucose, N-acetylglucosamine or mannose. Furthermore, alpha 1-3-linked fucose on lactoferrin is not essential for lactoferrin clearance in vivo or specific binding to macrophage receptors in vitro.


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