Protides of the Mustelidae: immunoresponse of mustelids to Aleutian mink disease virus

Members of North American Mustelidae were tested for their response to inoculation with 10(6) infective doses of Aleutian disease virus. In subfamily Mustelinae, 3 species in the genus Mustela (M vision, M erminea, and M putorius) and 2 species in genus Martes (Ma pennanti and Ma americana) responded immunologically with some features resembling Aleutian disease in mink. In subfamily Mephitinae, only Mephitis mephitis responded, and others of the subfamily did not, nor did members of subfamilies Melinae and Lutrinae. The responses observed ranged from development of detectable antibody levels determined by counterimmunoelectrophoresis to histopathologic changes typical of Aleutian disease.

Immunological response to infection with human reovirus-like agent: measurement of anti-human reovirus-like agent immunoglobulin G and M levels by the method of enzyme-linked immunosorbent assay

The report describes the development of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against the human reovirus-like agent of infantile gastroenteritis (HRVLA). This ELISA system proved to be four times as sensitive as the standard anti-HRVLA fluorescent-antibody assay and ten times as sensitive as the standard anti-HRVLA complement fixation assay. In addition, the ELISA was capable of determining immunoglobulin G (IgG) and IgM subclasses of anti-HRVLA antibody using a single dilution os serum. With this assay, it was discovered that 11 of 21 infected children had anti-HRVLA IgM in their acute sera before the appearance of anti-HRVLA IgG. ELISA is a useful tool in the evaluation of immunological response to HRVLA infection.

Solid-phase microtiter radioimmunoassay for detection of the Norwalk strain of acute nonbacterial, epidemic gastroenteritis virus and its antibodies

The development of microtiter solid-phase radioimmunoassays for the detection of Norwalk antigen and its antibody is described. The tests are simple to perform and are sensitive and specific. The test for antigen can be used on crude stool filtrates and suspensions. Both tests are at least as sensitive as immune electron microscopy and more sensitive than immune adherence assay.

Eradication of Aleutian disease of mink by eliminating positive counterimmunoelectrophoresis test reactors

The counterimmunoelectrophorsis test was applied on three Aleutian disease virus-infected mink ranches for the detection of specific Aleutian disease virus antibody. All mink on the ranches were tested during the pelting season and before the breeding season for 4 consecutive years. Aleutian disease has been eliminated from the three commercial mink ranches by culling out all mink that were positive for Aleutian disease virus antibody.

Experimental infection of chimpanzees with the Norwalk agent of epidemic viral gastroenteritis

A fecal filtrate of human origin containing the Norwalk agent of epidemic viral gastroenteritis was administered by stomach tube to chimpanzees in an attempt to induce diarrheal disease. Significant postchallenge serum antibody rises against Norwalk viral antigens were demonstrated in all animals using the techniques of immune electron microscopy and radioimmunoassay. In addition, viral antigens were detected in feces from five of nine animals using radioimmunoassay. Clinical illness characterized by diarrhea and/or vomiting did not occur. Infection was transmitted subsequently by feeding four additional chimpanzees a fecal filtrate prepared from one of the previously infected animals. Development of an antibody response in four animals and detection of viral antigen in two animals that received this passage filtrate indicated that viral replication had occurred in the absence of clinical illness. The availability of the chimpanzee as an experimental animal host susceptible to infection with the Norwalk agent should facilitate the study of epidemic viral gastroenteritis.

Prevalence of antibody to the Norwalk agent by a newly developed immune adherence hemagglutination assay

An immune adherence hemagglutination assay (IAHA) for the detection of antibody to the Norwalk agent of acute epidemic nonbacterial gastroenteritis was developed using as antigen virus purified from stool from an experimentally infected volunteer. The assay was sensitive and specific and was efficient for detecting Norwalk antibody seroresponses. The prevalence of Norwalk antibody in various groups in the United States was studied. Antibody to the Norwalk agent was acquired gradually, beginning slowly in childhood and accelerating in the adult period so that by the fifth decade 50% possessed antibody. This pattern of antibody acquisition contrasted sharply with that for the human rotavirus of infantile gastroenteritis. Rotavirus antibody was acquired during early childhood by almost all individuals in the pediatric groups studied. Antibody to the Norwalk agent was also found in rural Bangladesh; in a small prevalence survey of 39 children and adults 21% possessed Norwalk IAHA antibody, whereas 95% possessed antibody to the human rotavirus.

Serological relationships between rotaviruses from different species as studied by complement fixation and neutralization

Human, piglet, mouse, foal, lamb, calf and rabbit rotaviruses all infected, but could not readily be subcultured in LLC MK2 cells. Cells infected with mouse and calf rotaviruses reacted by indirect immunofluorescence (FA) with convalescent serum from children, piglets, mice, foals, lambs, calves or rabbits, taken after rotavirus infection. Human, calf, piglet, mouse and foal rotaviruses reacted with human, calf, mouse, foal and lamb convalescent serum by complement fixation (CF). It was not possible to distinguish between different rotaviruses by CF or FA. Neutralization tests, however, detected species-specific rotavirus antigens. Any virus was neutralized by a much higher dilution of homologous species convalescent serum than by any heterologous serum. With the exception of the mouse virus there was very little cross reaction. However, in sera with a very high neutralizing titre for the homologous virus the titre was proportionately raised against heterologous virus. It is, therefore, now possible to type to species an unknown rotavirus by a neutralization test in LLC MK2 cells using convalescent serum from each species.

Clinical immunity in acute gastroenteritis caused by Norwalk agent

To examine immunity in viral gastroenteritis, we challenged and then rechallenged 12 volunteers with Norwalk agent and evaluated symptoms, jejunal biopsies and serum antibody. With the first challenge, gastroenteritis developed in six volunteers but not in the others. When rechallenged 27 to 42 months later, the six who became ill initially again had gastroenteritis with jejunal lesions; in the six previously immune volunteers illness or jejunal lesions did not develop. Four of five ill volunteers had increases in serum antibody to Norwalk agent after both challenges. Serum antibody did not increase in three immune volunteers after either challenge. Four volunteers who had twice become ill underwent a third challenge four to eight weeks after their second illness. In one gastroenteritis developed; in three, it did not. These findings indicate two forms of immunity for viral gastroenteritis, one of short and the other of long duration. Factors other than serum antibody appear important in immunity to Norwalk gastroenteritis.

Rapid diagnosis of rotavirus infections: comparison of electron microscopy and immunoelectroosmophoresis for the detection of rotavirus in human infantile gastroenteritis

Eighty-seven faecal samples from infants and children suffering from acute gastroenteritis were investigated for the presence of rotavirus by immunoelectroosmophoresis (IEOP) and electron microscopy (EM). Sixty-one % of the samples contained rotavirus antigens when examined by IEOP whereas only 50% were diagnosed as positive EM. However, where it was possible to perform EM within the same day that the sample was received it took 24 h to establish the diagnosis by IEOP. The high sensitivity of the IEOP method was achieved by application of antiserum produced in rabbits to rotavirus immunoprecipitates. The specificity and sensitivity of the diagnostic antiserum produced were tested by application of different immunoelectrophoretic methods.

A comparative study of detection methods for Aleutian disease viral antibody

Four methods of detecting and quantitating mink antibody against Aleutian disease (AD) virus were compared. Counterelectrophoresis, modified, counterelectrophoresis, immunofluorescence, and complement fixation were performed blindly on 274 serum samples. All four methods were reliably specific for AD antibody. Immunofluorescence was less reproducible than the other systems. Immunofluorescence complement fixation were 4- to 8-fold more sensitive than regular or modified counterelectrophoresis, but were limited by background staining and anti-complementary activity, respectively, when used to detect small amounts of antibody in undiluted sera.

Reovirus-like agent in acute epidemic gastroenteritis in Japanese infants: fecal shedding and serologic response

The reovirus-like agent, sometimes referred to as duovirus or rotavirus, was visualized by electron microscopy in stool extracts from Japanese infants and young children with acute epidemic gastroenteritis. The virus particles measured 70 nm in diameter and had double-shelled capsids. One hundred ten (89%) of 124 patients with the gastroenteritis had such virus particles in stools obtained during the acute phase. The virus particles were excreted in the stools usually during the first eight days of illness. Agglutination of virus particles by antibody present in convalescent-phase sera was demonstrated by immune electron microscopy. Complement-fixing antibody was detected as early as day 3 of illness, and antibody titers peaked during the second and third weeks of the disease. The antibody appearing in the acute and early convalescent phases was sensitive to 2-mercaptoethanol. Antibody resistant to 2-mercaptoethanol was produced approximately 10 days after the onset of the symptoms. The serologic evidence suggests that a primary infection with the reovirus-like agent was responsible for the clinical attack of acute gastroenteritis.

Antigenic relationship between human and simian rotaviruses

The simian rotavirus, SA 11, and the murine rotavirus, EDIM, were investigated for antigenic relatedness to the human rotavirus, by immunoelectron-microscopy. These studies led to the recognition of two types of rotavirus antibody. One agglutinated "rough" virus particles only and was group-reactive; it appears to be widely distributed in various animal species, including human infants. The second antibody agglutinated "smooth" virus particles and was more species-specific, demonstrating only a one-way cross-reaction between the simian and human viruses; it was found only in convalescent-phase human sera and in hyperimmune rabbit sera and is probably protective. The simian rotavirus is easy to propagate in primary cell culture and in cell lines and should prove useful for serodiagnosis of human gastroenteritis. It may be a candidate for immunoprophylaxis.

Complement-fixing antibody response to rotavirus infection

A human rotavirus complement-fixing (CF) antigen, prepared by purification of large volumes of fluid feces collected from children with winter diarrhea, was used to study the development and persistence of antibody in children with diarrhea and the prevalence of rotavirus antibody in Melbourne. In children with diarrhea, antibody rises were detectable within 4 to 6 weeks of the onset of illness, and the titers usually remained elevated for the next 1 to 2 years. CF antibody did not develop in two children with proven rotavirus infection aged less than 6 months, an age at which poor CF responses to other viruses have also been observed. A study of CF antibody levels in the general community showed that in Melbourne, most children have been infected with human rotavirus by the age of 3 years.

Expression of Aleutian mink disease antigen in cell culture

Infection of CRFK feline kidney cells with Aleutian disease vurus leads to production of virus-induced antigen(s) in the nucleus which could be demonstrated by the fluorescent-antibody technique. The number of fluorescent nuclei was lineraly dependent on the dilution of the inoculum, but rarely exceeded 20% of the cells. Aleutian disease nuclear antigen was only transiently detectable. The virus-induced antigen was detected after infection of cells of several divergent species; however, the CRFK line of feline kidney cells was the most susceptible. Inhibitor studies indicated that deoxyribonucleic acid synthesis, ribonucleic acid synthesis, and protein synthesis were required for viral antigen production. Cell growth was also a requirement for synthesis of viral antigen, An in situ radioimmune assay was used to measure binding of 125I-labeled mink anti-Aleutian disease virus to infected cells and competition with unlabeled sera. The system is suitable for quantitation of infectivity.

Virus-like particles in bovine sera for tissue culture

Virus-like particles were found in nine different bovine sera for tissue culture from commercial suppliers. These particles were spherical with an overall diam. between 70 and 95 nm. After negative staining, surface projections of about 11 to 12 nm were clearly seen. One of the nine sera was positive in an Ouchterlony test with antisera against bovine viral diarrhoea virus.

Preparation of antigen for the counterimmunoelectrophoretic test for plasmacytosis in mink

Counterimmunoelectrophoresis as a test method for making the diagnosis of plasmacytosis in mink demands the specific virus antigen. The method for preparation of the antigen according to Cho & Ingram (1972 a, b) with minor modifications is described in details, and results obtained at 62 antigen preparations are presented. In addition an ultrafiltration method is outlined which may be useful as a replacement for ultracentrifugation procedures used in the technique described by Cho & Ingram (1974).

The influence of genotype on the development of glomerular lesions in mink with Aleutian disease virus

In an attempt to document progression rate differences in the development of glomerular lesions in mink infected with Aleutian disease virus (ADV), the glomeruli of Aleutian and non-Aleutian mink experimentally infected with ADV were evaluated by light, fluorescent, and electron microscopy. The animals were also examined for the presence of interstitial infiltrate, neutrophils, and arterial lesions. One hundred percent of the Aleutian mink had glomerular cell proliferation and interstitial infiltrate, while 95% of the Aleutian and 41% of the non-Aleutian mink had neutrophilic infiltrates and arteritis, respectively. Of the non-Aleutian mink, 91, 83, 42, and 12.5% had glomerular cell proliferations, glomerular neutrophils, interstitial infiltrate, and arterial lesions in, that order. All the Aleutian mink had glomerular depositions of gamma-globulin (IgG) and complement (C3), whereas 75% of non-Aleutian mink had deposits of IgG and C3. One hundred percent of both genotypes had glomerular deposits of immunoglobulin M (IgM). Ultrastructural glomerular changes consisting primarily of depositions of granular electron-dense material on basement membranes were observed in Aleutian mink 6 weeks after infection and 12 weeks after infection in non-Aleutian mink. These findings document progression rate differences in the development of glomerular lesions in Aleutian disease-affected Aleutian and non-Aleutian mink. Further, they emphasize the need for exploration of pathogenetic mechanisms involved in progression rate differences in lesion development.

Aleutian disease of mink: the antibody response of sapphire and pastel mink to Aleutian disease virus

The specific antiviral antibody response of sapphire and pastel mink to Pullman strain of ADV has been examined. Sapphire mink inoculated with from 300,000-3 LD50 developed high levels of specific antibody and AD. Pastel mink inoculated with parallel doses of ADV also produced antibody but did not develop AD. The low incidence of AD in pastel mink inoculated with Pullman strain of ADV is probably related to factors other than antiviral antibody.

Competition radioimmunoassay for mason-pfizer monkey virus: comparison with recent isolates

The major core protein of Mason-Pfizer monkey virus was purified by DEAE ion exchange column chromatography and shown to be 27,000 daltons (p27). Following the characterization of monospecific antisera prepared against p27, a radioimmunoassay was developed with these reagents and competition experiments were done with come of the recent M-PMY-like isolates as well as with other oncornaviruses. Results suggest that three of the viruses tested, AO, X-381 and FTP-1, are similar to M-PMV while J-96 virus is related, but not identical, to M-PMV. It is also shown that competition RIA can be used successfully to detect the presence of viral proteins in tissue homogenates and cell extracts.