scholarly journals IMMUNOCHEMICAL STUDIES ON THE SPECIFICITY OF CELLULAR HYPERSENSITIVITY

1968 ◽  
Vol 128 (6) ◽  
pp. 1451-1459 ◽  
Author(s):  
John R. David ◽  
Stuart F. Schlossman

The immunochemical specificity of antigen-induced inhibition of peritoneal exudate cell migration was studied in animals sensitized to chemically defined α,DNP(Lys)18 peptides. It was shown that sensitized peritoneal exudate cells could discriminate between various DNP-oligolysines. Only immunogenic members of the homologous series of α,DNP-L-lysines equal to or larger in size than the heptamer inhibited the migration of specifically sensitized peritoneal exudate cells. In contrast, nonimmunogenic α,DNP-L-lysines, a D-lysine containing stereoisomer of α,DNP L(Lys)9 (α,DNP-L4DL4) and (Lys)9ϵ, DNP were not inhibitory to the migration of peritoneal exudate cells derived from animals immunized to α,DNP(Lys)18. The exquisite specificity of the in vitro reaction of sensitized cells with antigen contrasts with the previously observed in vivo or in vitro specificity of anti-α,-DNP(Lys)n antibody, but parallels the specificity of the in vivo delayed or anamnestic response. These results suggest the presence of a still undefined but highly specific binding site, which functions as the cellular receptor for antigen on the sensitized lymphoid cell or on some "processing" cell.

1980 ◽  
Vol 152 (5) ◽  
pp. 1184-1193 ◽  
Author(s):  
T Boon ◽  
J Van Snick ◽  
A Van Pel ◽  
C Uyttenhove ◽  
M Marchand

Tumor cell variants that were rejected by syngeneic mice (tum-) were obtained from mastocytoma P815 by mutagenesis (as described in the accompanying report (13). A considerable T lymphocyte-mediated lysis was observed upon incubation of these tum- variants with peritoneal exudate cells collected a few days after an intraperitoneal challenge of immune animals. Spleen cells from these animals were cytolytic after stimulation in vitro with the immunizing variant. New antigens, absent from the original P815 tum+ cells, were detected on 15 of the 21 tum- variants that were tested. All these antigens appeared to be different. No new antigen was detected on any of 10 mutagenized P815 clones that had retained their ability to form tumors. We compared the evidence obtained in vivo and in vitro for the presence of specific antigens on five tum- variants. Three variants were shown both in vivo and in vitro to carry an individual antigen. One showed no specificity either in vivo or in vitro. However, for one variant, no specificity was observed in vivo, although cytolysis tests demonstrated the existence of a singular antigenic specificity.


1960 ◽  
Vol 111 (4) ◽  
pp. 573-600 ◽  
Author(s):  
John M. McKenna ◽  
Kingsley M. Stevens

Cells from peritoneal exudates of rabbits sacrificed 3 days after an intraperitoneal injection of sterile mineral oil were grown in tissue cultures in medium 199 (75 per cent); normal rabbit serum (25 per cent). Antibody produced by the cells was assayed by an hemagglutination technique in which the antigens used were adsorbed to formalinized tanned sheep erythrocytes. These sensitized cells agglutinate in the presence of antibody specific to the adsorbed antigen. It has been demonstrated that: Peritoneal exudate cells produced hemagglutinating antibody to bovine gamma globulin (BGG) in a replicating tissue culture system for approximately 3 weeks when taken from animals given either primary or secondary injections of BGG. The mean hemagglutinating titer was 30 for the primary and 32 for the secondary systems. Since the other cell types did not persist, it is felt that monocytes were responsible for these results. Monocytes taken from normal rabbits and exposed to either BGG or egg albumen (EA) in vitro produced titers of 28 for about 2 weeks. Monocytes taken from rabbits given hyperimmunizing injections of BGG produced titers of 147 for about 1 week. Endotoxin from Salmonella typhosa caused the monocytes to form antibody as if they had been taken from hyperimmunized rabbits. This was true both when the antigen was given in vivo together with the endotoxin as well as when the cells were exposed to antigen in vitro. The titers were 223 and 97, respectively. Neither freshly harvested nor cultured monocytes were phagocytic for carbon particles or bacteria in vitro. Monocytes in tissue culture appeared to assume the morphology of fibroblasts, but did not stain with the characteristics of fibroblasts. The morphologic changes and staining characteristics of monocytes in tissue culture have been described. The implications of these findings have been discussed and an attempt made to integrate them into general biological theory.


2019 ◽  
Vol 19 (12) ◽  
pp. 950-960
Author(s):  
Soghra Farzipour ◽  
Seyed Jalal Hosseinimehr

Tumor-targeting peptides have been generally developed for the overexpression of tumor specific receptors in cancer cells. The use of specific radiolabeled peptide allows tumor visualization by single photon emission computed tomography (SPECT) and positron emission tomography (PET) tools. The high affinity and specific binding of radiolabeled peptide are focusing on tumoral receptors. The character of the peptide itself, in particular, its complex molecular structure and behaviors influence on its specific interaction with receptors which are overexpressed in tumor. This review summarizes various strategies which are applied for the expansion of radiolabeled peptides for tumor targeting based on in vitro and in vivo specific tumor data and then their data were compared to find any correlation between these experiments. With a careful look at previous studies, it can be found that in vitro unblock-block ratio was unable to correlate the tumor to muscle ratio and the success of radiolabeled peptide for in vivo tumor targeting. The introduction of modifiers’ approaches, nature of peptides, and type of chelators and co-ligands have mixed effect on the in vitro and in vivo specificity of radiolabeled peptides.


Author(s):  
Thu Hang Lai ◽  
Magali Toussaint ◽  
Rodrigo Teodoro ◽  
Sladjana Dukić-Stefanović ◽  
Daniel Gündel ◽  
...  

Abstract Purpose The adenosine A2A receptor has emerged as a therapeutic target for multiple diseases, and thus the non-invasive imaging of the expression or occupancy of the A2A receptor has potential to contribute to diagnosis and drug development. We aimed at the development of a metabolically stable A2A receptor radiotracer and report herein the preclinical evaluation of [18F]FLUDA, a deuterated isotopologue of [18F]FESCH. Methods [18F]FLUDA was synthesized by a two-step one-pot approach and evaluated in vitro by autoradiographic studies as well as in vivo by metabolism and dynamic PET/MRI studies in mice and piglets under baseline and blocking conditions. A single-dose toxicity study was performed in rats. Results [18F]FLUDA was obtained with a radiochemical yield of 19% and molar activities of 72–180 GBq/μmol. Autoradiography proved A2A receptor–specific accumulation of [18F]FLUDA in the striatum of a mouse and pig brain. In vivo evaluation in mice revealed improved stability of [18F]FLUDA compared to that of [18F]FESCH, resulting in the absence of brain-penetrant radiometabolites. Furthermore, the radiometabolites detected in piglets are expected to have a low tendency for brain penetration. PET/MRI studies confirmed high specific binding of [18F]FLUDA towards striatal A2A receptor with a maximum specific-to-non-specific binding ratio in mice of 8.3. The toxicity study revealed no adverse effects of FLUDA up to 30 μg/kg, ~ 4000-fold the dose applied in human PET studies using [18F]FLUDA. Conclusions The new radiotracer [18F]FLUDA is suitable to detect the availability of the A2A receptor in the brain with high target specificity. It is regarded ready for human application.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Merricka C. Livingstone ◽  
Alexis A. Bitzer ◽  
Alish Giri ◽  
Kun Luo ◽  
Rajeshwer S. Sankhala ◽  
...  

AbstractPlasmodium falciparum malaria contributes to a significant global disease burden. Circumsporozoite protein (CSP), the most abundant sporozoite stage antigen, is a prime vaccine candidate. Inhibitory monoclonal antibodies (mAbs) against CSP map to either a short junctional sequence or the central (NPNA)n repeat region. We compared in vitro and in vivo activities of six CSP-specific mAbs derived from human recipients of a recombinant CSP vaccine RTS,S/AS01 (mAbs 317 and 311); an irradiated whole sporozoite vaccine PfSPZ (mAbs CIS43 and MGG4); or individuals exposed to malaria (mAbs 580 and 663). RTS,S mAb 317 that specifically binds the (NPNA)n epitope, had the highest affinity and it elicited the best sterile protection in mice. The most potent inhibitor of sporozoite invasion in vitro was mAb CIS43 which shows dual-specific binding to the junctional sequence and (NPNA)n. In vivo mouse protection was associated with the mAb reactivity to the NANPx6 peptide, the in vitro inhibition of sporozoite invasion activity, and kinetic parameters measured using intact mAbs or their Fab fragments. Buried surface area between mAb and its target epitope was also associated with in vivo protection. Association and disconnects between in vitro and in vivo readouts has important implications for the design and down-selection of the next generation of CSP based interventions.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2204
Author(s):  
Meng-Die Yang ◽  
Yang Sun ◽  
Wen-Jun Zhou ◽  
Xiao-Zheng Xie ◽  
Qian-Mei Zhou ◽  
...  

Triple-negative breast cancer (TNBC) is a refractory type of breast cancer that does not yet have clinically effective drugs. The aim of this study is to investigate the synergistic effects and mechanisms of resveratrol combined with cisplatin on human breast cancer MDA-MB-231 (MDA231) cell viability, migration, and invasion in vivo and in vitro. In vitro, MTS assays showed that resveratrol combined with cisplatin inhibits cell viability as a concentration-dependent manner, and produced synergistic effects (CI < 1). Transwell assay showed that the combined treatment inhibits TGF-β1-induced cell migration and invasion. Immunofluorescence assays confirmed that resveratrol upregulated E-cadherin expression and downregulated vimentin expression. Western blot assay demonstrated that resveratrol combined with cisplatin significantly reduced the expression of fibronectin, vimentin, P-AKT, P-PI3K, P-JNK, P-ERK, Sma2, and Smad3 induced by TGF-β1 (p < 0.05), and increased the expression of E-cadherin (p < 0.05), respectively. In vivo, resveratrol enhanced tumor growth inhibition and reduced body weight loss and kidney function impairment by cisplatin in MDA231 xenografts, and significantly reduced the expressions of P-AKT, P-PI3K, Smad2, Smad3, P-JNK, P-ERK, and NF-κB in tumor tissues (p < 0.05). These results indicated that resveratrol combined with cisplatin inhibits the viability of breast cancer MDA231 cells synergistically, and inhibits MDA231 cells invasion and migration through Epithelial-mesenchymal transition (EMT) approach, and resveratrol enhanced anti-tumor effect and reduced side of cisplatin in MDA231 xenografts. The mechanism may be involved in the regulations of PI3K/AKT, JNK, ERK and NF-κB expressions.


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