[Effect of prolonged administration of low doses of essential oils on the immune response and sensitivity of mice to the action of ionizing radiation]

The effect of ionizing radiation (1 Gy) on the immunological characteristics of spleen in the mice that consumed essential oils of oregano, clove bud and the mixture of lemon oil with ginger extract at low doses with drinking water for 6 months was studied. It was found that the essential oils increased the content of antibody forming lymphocyte cells in the spleen. The maximal effect in comparison with control was found for essential oil of clove bud.

Assessing antibody microarrays for space missions: effect of long-term storage, gamma radiation, and temperature shifts on printed and fluorescently labeled antibodies

Antibody microarrays are becoming frequently used tools for analytical purposes. A key factor for optimal performance is the stability of the immobilized (capturing) antibodies as well as those that have been fluorescently labeled to achieve the immunological test (tracers). This is especially critical for long-distance transport, field testing, or planetary exploration. A number of different environmental stresses may affect the antibody integrity, such as dryness, sudden temperature shift cycles, or, as in the case of space science, exposure to large quantities of the highly penetrating gamma radiation. Here, we report on the effect of certain stabilizing solutions for long-term storage of printed antibody microarrays under different conditions. We tested the effect of gamma radiation on printed and freeze- or vacuum-dried fluorescent antibodies at working concentrations (tracer antibodies), as well as the effect of multiple cycles of sudden and prolonged temperature shifts on the stability of fluorescently labeled tracer antibody cocktails. Our results show that (i) antibody microarrays are stable at room temperature when printed on stabilizing spotting solutions for at least 6 months, (ii) lyophilized and vacuum-dried fluorescently labeled tracer antibodies are stable for more than 9 months of sudden temperature shift cycles (-20°C to 25°C and 50°C), and (iii) both printed and freeze- or vacuum-dried fluorescent tracer antibodies are stable after several-fold excess of the dose of gamma radiation expected during a mission to Mars. Although different antibodies may exhibit different susceptibilities, we conclude that, in general, antibodies are suitable for use in planetary exploration purposes if they are properly treated and stored with the use of stabilizing substances.

Investigation of neutron radiation effects on polyclonal antibodies (IgG) and fluorescein dye for astrobiological applications

Detecting life in the Solar System is one of the great challenges of new upcoming space missions. Biochips have been proposed as a way to detect organic matter on extraterrestrial objects. A biochip is a miniaturized device composed of biologically sensitive systems, such as antibodies, which are immobilized on a slide. In the case of in situ measurements, the main concern is to ensure the survival of the antibodies under space radiation. Our recent computing simulation of cosmic ray interactions with the martian environment shows that neutrons are one of the dominant species at soil level. Therefore, we have chosen, in a first approach, to study antibody resistance to neutrons by performing irradiation experiments at the Applications Interdisciplinaires des Faisceaux d'Ions en Région Aquitaine (AIFIRA) platform, a French ion beam facility at the Centre d'Etudes Nucléaires de Bordeaux-Gradignan in Bordeaux. Antibodies and fluorescent dyes, freeze-dried and in buffer solution, were irradiated with 0.6 MeV and 6 MeV neutrons. Sample analyses demonstrated that, in the conditions tested, antibody recognition capability and fluorescence dye intensity are not affected by the neutrons.

Biophotonic hydrogen peroxide production by antibodies, T cells, and T-cell membranes

Rapidly accumulating evidence indicates that inflammatory T cells sensitively respond to their redox environment by activating signal transduction pathways. The hypothesis that T-cell receptors have the potential to catalytically transform singlet oxygen into H(2)O(2) attracted our attention since the biophysical regulation of this process would provide a new tool for therapeutically directing T cells down a preferred signaling pathway. Light-dependent production of H(2)O(2) was first described in antibodies, and we reproduced these findings. Using a real-time H(2)O(2) sensor we extended them by showing that the reaction proceeds in a biphasic way with a short-lived phase that is fast compared to the slow second phase of the reaction. We then showed that Jurkat T cells biophotonically produce about 30nM H(2)O(2)/min/mg protein when pretreated with NaN(3). This activity was concentrated 4 to 5 times in T-cell membrane preparations. The implications of these observations for the development of new therapeutic tools for inflammatory diseases are discussed.

Modified and simplified western blotting protocol: use of intermittent microwave irradiation (IMWI) and 5% skim milk to improve binding specificity

A modified western blotting protocol was developed to increase the binding specificity of antigens and antibodies, using intermittent microwave irradiation (IMWI) with seven antibodies and two cell lines. The method was based on IMWI of the blotting membrane in the immunoblotting step using 5% skim milk as the diluting buffer. For some antibodies against p53, CDK4 and cyclinE, there were no distinct differences between the IMWI(+) and IMWI(-) counterparts; but improvement over the standard protocol was noted in both. For some antibodies, such as the polyclonal antibody against tubulin and the monoclonal antibodies against beta-tubulin, cyclinA and cyclinB1 (which were otherwise difficult to obtain good results with), IMWI was extremely effective, resulting in clear, specifically binding bands and a clean background. Moreover, the times were reduced from 8 to 3 h. Both the IMWI(+) and IMWI(-) protocols can be applied as simple, rapid and highly specific detection techniques for applications with various antigens, reducing background 'noise' to a minimum.

Delayed hypersensitivity. V. The effect of x-irradiation on the development of delayed hypersensitivity and antibody formation

The capacity to develop the delayed type of hypersensitivity to diphtheria toxoid and ovalbumin may persist in guinea pigs and rabbits that have received doses of x-ray sufficient to eliminate a detectable antibody response. Larger doses of x-irradiation can prevent development of delayed-type hypersensitivity in rabbits.

Effect of microwave irradiation on antibody labeling efficiency when applied to ultrathin cryosections through fixed biological material

To study the effect of microwaves on immunolabeling, ultrathin cryosections or diluted antibodies were irradiated prior to antibody application, and gold labeling was quantified. In addition, affinity purified, polyclonal antibodies and protein A-gold were applied to ultrathin cryosections of aldehyde-fixed material in the presence and absence of microwaves. Amylase, a soluble protein secreted by pancreatic acinar cells, MHC class II, an integral membrane protein, and 3-(2,4-dinitroanilino)-3-amino-N-methyldipropylamine (DAMP), an exogenously added antigen, were localized with monospecific antibodies. Each was chosen for their contrasting subcellular characteristics. Results demonstrated that for some antigens, antibody labeling efficiency was quantitatively improved by microwave irradiation of sections prior to antibody application. Irradiation of diluted antibodies prior to their application also resulted in improved labeling. In contrast, the results obtained using rapid immunolabeling protocols in the presence of microwaves resulted in labeling levels similar to those obtained in the absence of microwaves. We conclude that microwave irradiation can improve the labeling efficiency of some antibodies. However, improvements in labeling density are dependent on the antigen under study and on variable irradiation times, unique to each antibody. This suggests that the routine use of microwaves to reduce incubation times may not be a viable alternative to bench protocols.

Light activatable antibodies: models for remotely activatable proteins

The ability to activate biological macromolecules remotely, at specific locations and times, will allow the manipulation of a wide range of cellular activities and give rise to many practical applications. Interest has been shown in the theoretical possibility of accomplishing this by means of photochemical approaches. Photochemical changes of the guest-binding cavity of cyclodextrins has been suggested; however, these changes require organic solvent. What is needed is a widely and readily applicable method allowing activation under physiological conditions. We have developed such a method. This is based on our demonstration that relatively large amounts of the a-methyl substituted 2-nitrobenzyl alcohol, namely, 1-(2-nitrophenyl)ethanol (NPE) can be coupled to proteins using diphosgene. Previous work involved "caging" of small molecules such as ATP (ref. 5-9) and blocking amino acids in peptide synthesis with 2-nitrobenzyl compounds. For large molecules, site-specific reversible inactivation of T4-lysozyme has been reported following introduction of an aspartyl beta-nibenzyl ester into its active site by mutagenesis. In contrast, the present simple procedure allows an existing protein to be deactivated and then, when and where required, reactivated by exposure to ultraviolet-A (UV-A) light. We have employed antibodies as models for both receptors and ligands and have successfully modulated: antibody binding sites for antigen; antigen binding sites for antibody, and antibody Fc binding sites for Protein A.

Selective laser-induced inactivation of proteins (SLIP) by labelling with chromophores

Coupling a fluorochrome (e.g. fluorescein-isothiocyanate, FITC) to a molecule can enhance specific laser light absorption, thus leading to alteration or even destruction of the molecule itself. Therefore antibodies were labelled with FITC (absorption maximum 480 nm) and irradiated with laser light (488 nm) under various conditions. Inactivation of antibodies could only be achieved at the absorption maximum of FITC (as measured by direct and indirect immunofluorescence). Positive linear correlation exists between the amount of destruction and both exposure time and energy. Similar destructive effects were obtained when FITC-labelled peroxidase was irradiated. In these cases, enzyme activities measured by absorption photometry also showed a positive correlation to the total amount of energy transferred. Non-labelled proteins were not affected by irradiation. So we conclude that labelling of proteins with fluorochromes provides a highly specific means of selection of target molecules to be destroyed or inactivated. The method is based upon the laws of linear optics and is different from photodynamic or photochemical actions. The destructions observed are most likely caused by thermally induced changes of the molecules' tertiary structure.

[The activation of the immunosorptive properties of blood during its UV irradiation at therapeutic doses]

UV irradiation of donor rhesus-positive blood in apparatus, applied in Soviet hospitals for autotransfusion of UV-irradiated blood produces a 2-fold increase of the blood capacity to bind antirhesus antibodies in blood or serum from sensibilized women. The above data can be used for increase in therapeutic effect of blood exchange transfusion in children with rhesus-conflict hemolytic disease.