scholarly journals THE STRUCTURE OF ANTIGEN-ANTIBODY COMPLEXES

1963 ◽  
Vol 118 (3) ◽  
pp. 327-340 ◽  
Author(s):  
June Almeida ◽  
Bernhard Cinader ◽  
Allan Howatson

Negatively stained aggregates of antigen (polyoma or verruca vulgaris virus) and antibody (from rabbit or goat) were examined in the electron microscope. The antibody molecules appeared as cylindrical rods (often, but not always, showing a beaded appearance) with a long axis of 250 to 270 A and a short axis of 35 to 40 A. The combining sites were at the opposite short ends of the antibody molecules separated by the length of 250 to 270 A of the antibody molecule. Aggregates of antigen and antibody showed regions of orderly arrangements and frequently ring structures of five or more linked virus particles. Sometimes a virus particle in the center of these ring structures was linked to the peripheral particles. In extreme antibody excess, cross-linking was only rarely observed and virus particles were surrounded by a dense aura of antibody molecules. The specificity of the two combining sites of most antibody molecules is identical. This was utilized to examine the antigenic relation between the normal (icosahedral) and aberrant forms of polyoma virus.

Author(s):  
Wagh Sopan Ganpatrao ◽  
Pohare Manoj Baliram ◽  
Daspute Abhijit Arun ◽  
Wadekar Hanumant Baburao ◽  
Bhor Sachin Ashok

Rice, particularly grows in tropical and subtropical areas, is one of the most important crops worldwide. Rice necrosis mosaic virus (RNMV) was first reported in Japan and causes necrotic lesions on leaf and yellowing. This virus has been classified as member of the Potyviridae family's Bymovirus genus. The fungus, Polymixa graminis, transmits RNMV. In this study, the methodology first explained RNMV virus particle - purification by ultra-centrifugation along with sucrose and cesium chloride gradient is described. Further, confirmation of purified RNMV particles under the electron-microscope is discussed. In the last RNMV RNA isolation from the purified RNMV particles were explained.


Author(s):  
M. F. Miller ◽  
G. D. Gagne ◽  
R. Lesniewski ◽  
D. A. Peterson

Polycarbonate filters (Nuclepore Corporation, Pleasanton, CA) have beep used for sizing particulates such as virus particles and liposomes. Unlike nitrocellulose, polyester and other types of filters which are comprised of a relatively thick meshwork of interwoven fibers, polycarbonate filters are thin and contain precisely sized, straight-bore holes (Fig. 1). These features suggest that loss of particles due to nonspecific adsorption or entrapment in the filter matrix might be less for polycarbonate filters. In the present study, we have devised a purification technique based on the sequential filtration of blood plasma through a series of polycarbonate filters. The technique was evaluated by seeding chimpanzee blood plasma with human rotavirus (65-70 nm dia.) and determining recovery of purified virus using a sensitive electron microscope virus particle counting technique.Whole normal blood plasma (10 ml) was seeded with highly purified rotavirus to a final concentration of about 1010 particles per ml.


Author(s):  
W. G. Banfield ◽  
G. Kasnic ◽  
J. H. Blackwell

An ultrastructural study of the intestinal epithelium of mice infected with the agent of epizootic diarrhea of infant mice (EDIM virus) was first performed by Adams and Kraft. We have extended their observations and have found developmental forms of the virus and associated structures not reported by them.Three-day-old NLM strain mice were infected with EDIM virus and killed 48 to 168 hours later. Specimens of bowel were fixed in glutaraldehyde, post fixed in osmium tetroxide and embedded in epon. Sections were stained with uranyl magnesium acetate followed by lead citrate and examined in an updated RCA EMU-3F electron microscope.The cells containing virus particles (infected) are at the tips of the villi and occur throughout the intestine from duodenum through colon. All developmental forms of the virus are present from 48 to 168 hours after infection. Figure 1 is of cells without virus particles and figure 2 is of an infected cell. The nucleus and cytoplasm of the infected cells appear clearer than the cells without virus particles.


Author(s):  
Elizabeth S. Priori ◽  
T. Shigematsu ◽  
B. Myers ◽  
L. Dmochowski

Spontaneous release of type C virus particles in long-term cultures of mouse embryo cells as well as induction of similar particles in mouse embryo cell cultures with IUDR or BUDR have been reported. The presence of type C virus particles in cultures of normal rat embryos has not been reported.NB-1, a culture derived from embryos of a New Zealand Black (NB) rat (rats obtained from Mr. Samuel M. Poiley, N.C.I., Bethesda, Md.) and grown in McCoy's 5A medium supplemented with 20% fetal calf serum was passaged weekly. Extracellular virus particles similar to murine leukemia particles appeared in the 22nd subculture. General appearance of cells in passage 23 is shown in Fig. 1. Two budding figures and one immature type C virus particle may be seen in Fig. 2. The virus particles and budding were present in all further passages examined (currently passage 39). Various stages of budding are shown in Figs. 3a,b,c,d. Appearance of a mature virus particle is shown in Fig. 4.


Author(s):  
John H. Luft

With information processing devices such as radio telescopes, microscopes or hi-fi systems, the quality of the output often is limited by distortion or noise introduced at the input stage of the device. This analogy can be extended usefully to specimen preparation for the electron microscope; fixation, which initiates the processing sequence, is the single most important step and, unfortunately, is the least well understood. Although there is an abundance of fixation mixtures recommended in the light microscopy literature, osmium tetroxide and glutaraldehyde are favored for electron microscopy. These fixatives react vigorously with proteins at the molecular level. There is clear evidence for the cross-linking of proteins both by osmium tetroxide and glutaraldehyde and cross-linking may be a necessary if not sufficient condition to define fixatives as a class.


Author(s):  
Ruchama Baum ◽  
J.T. Seto

The ribonucleic acid (RNA) of paramyxoviruses has been characterized by biochemical and physiochemical methods. However, paramyxovirus RNA molecules have not been studied by electron microscopy. The molecular weights of these single-stranded viral RNA molecules are not known as yet. Since electron microscopy has been found to be useful for the characterization of single-stranded RNA, this investigation was initiated to examine the morphology and length measurements of paramyxovirus RNA's.Sendai virus Z strain and Newcastle disease virus (NDV), Milano strain, were used. For these studies it was necessary to develop a method of extracting RNA molecules from purified virus particles. Highly purified Sendai virus was treated with pronase (300 μg/ml) at 37°C for 30 minutes and the RNA extracted by the sodium dodecyl sulfate (SDS)-phenol procedure.


1953 ◽  
Vol 98 (2) ◽  
pp. 157-172 ◽  
Author(s):  
William H. Gaylord ◽  
Joseph L. Melnick

The intracellular development of three pox viruses has been studied with the electron microscope using thin sections of infected tissue. Cells infected with vaccinia, ectromelia, and molluscum contagiosum viruses all form developmental bodies preliminary to the production of mature virus. Developmental bodies, believed to be virus precursors, are round to oval, slightly larger than mature virus particles, less dense to electrons, and have a more varied morphology. It is suggested as a working hypothesis that the process of maturation of a virus particle takes place as follows. In the earliest form the developmental bodies appear as hollow spheres, imbedded in a very dense cytoplasmic mass constituting an inclusion body, or in a less dense matrix near the nucleus in cells without typical inclusion bodies. The spheres become filled with a homogeneous material of low electron density. A small, dense granule appears in each developmental body and grows in size at the expense of the low density material. Following growth of the granule, particles are found with the dimensions of mature virus and having complex internal structure resembling bars or dumbells. Mature virus is ovoid and very dense to electrons. An "empty" interior may be found within its thick walls.


1965 ◽  
Vol 24 (1) ◽  
pp. 57-78 ◽  
Author(s):  
J. F. David-Ferreira ◽  
R. A. Manaker

Samples taken at different intervals of time from suspension cultures of the NCTC 1469 line of mouse liver—derived (ML) cells infected with a mouse hepatitis virus have been studied with the electron microscope. The experiments revealed that the viruses are incorporated into the cells by viropexis within 1 hour after being added to the culture. An increasing number of particles are found later inside dense cytoplasmic corpuscles similar to lysosomes. In the cytoplasm of the cells from the samples taken 7 hours after inoculation, two organized structures generally associated and never seen in the controls are observed: one consists of dense material arranged in a reticular disposition (reticular inclusion); the other is formed by small tubules organized in a complex pattern (tubular body). No evidence has been found concerning their origin. Their significance is discussed. With the progression of the infection a system of membrane-bounded tubules and cisternae is differentiated in the cytoplasm of the ML cells. In the lumen of these tubules or cisternae, which are occupied by a dense material, numerous virus particles are observed. The virus particles which originate in association with the limiting membranes of tubules and cisternae are released into their lumen by a "budding" process. The virus particles are 75 mµ in diameter and possess a nucleoid constituted of dense particles or rods limiting an electron transparent core. The virus limiting membrane is sometimes covered by an outer layer of a dense material. In the cells from the samples taken 14 to 20 hours after inoculation, larger zones of the cell cytoplasm are occupied by inclusion bodies formed by channels or cisternae with their lumens containing numerous virus particles. In the samples taken 20 hours or more after the inoculation numerous cells show evident signs of degeneration.


1971 ◽  
Vol 17 (7) ◽  
pp. 993-1000 ◽  
Author(s):  
A. E. Kelen ◽  
A. E. Hathaway ◽  
D. A. McLeod

A simple and practical method is presented for demonstrating the presence of the Australia/SH antigen and its corresponding antibody in serum specimens, both qualitatively and quantitatively. The method is based on the electronmicroscopic visualization of characteristic aggregates of antigen–antibody complexes formed in the mixture of a serum specimen and the appropriate Australia/SH detector reagent. It involves the use of a microtechnique requiring minute amounts of reagents and provides, as a result of diffusion and filtration through agar gel, partially purified and concentrated preparations, ready for electronmicroscopic examination in less than an hour. The method is highly specific and yields reproducible results. Its sensitivity was found to be greater than that of the crossover electrophoresis test and closely approximates that of the complement fixation test, with the added advantage of not being affected by the "prozone phenomenon." The method can be recommended for use in laboratories equipped with electronmicroscopic facilities to establish a differential diagnosis of viral hepatitis cases, perform rapid screening of blood samples (blood products) for the presence of Australia/SH antigen, and clarify equivocal results obtained by other methods. It is expected that the agar–diffusion–filtration technique will also prove useful, in general, for enhancing the chances of detecting virus particles in suspensions of relatively low virus concentrations.


1963 ◽  
Vol 118 (2) ◽  
pp. 295-306 ◽  
Author(s):  
Wesley C. Wilcox ◽  
Harold S. Ginsberg

Type 5 adenovirus was purified by fluorocarbon (freon 113) treatment followed by banding in a CsCl equilibrium density gradient. This method permitted separation of virus from normal host cell materials and virus-specific soluble antigens. Virus banded in CsCl with a mean bouyant density of 1.3349 gm/cm3. The three virus-specific soluble antigens (group- and type-specific antigens and toxin) banded together with a mean bouyant density of 1.2832 gm/cm3. The group-specific antigen was the predominant antigen of the purified virus particle, whereas the group- and type-specific antigens were present in equal titers in the antigen band. Infectious virus particles were inactivated by prolonged dialysis at pH 10.5. Centrifugation of inactivated virus preparations in a CsCl equilibrium density gradient resulted in separation of virus DNA from specific antigen: the antigens banded with a mean bouyant density of 1.2832 gm/cm3 and the DNA sedimented to the bottom of the tube. The predominant antigen derived from purified virus particles was the group-specific antigen and it was in the same relative proportion to the type-specific antigen as measured in intact particles. The antigens derived from disrupted virus were immunologically identical with the soluble virus antigens present in infected cells.


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