Respiratory viral antigens in autopsy lung tissue specimens from patients with cancer or myocardial infarction.

Using immunoenzyme histochemical analysis, we retrospectively examined lung tissue specimens obtained at autopsy from 118 patients with cancer who had received chemotherapy and 20 patients who had died after myocardial infarction. Respiratory viral antigens were demonstrated in lung tissue specimens from eight of 118 cancer patients and two of 20 myocardial infarction patients. Most of the patients with demonstrable viral antigens were febrile and had signs of pulmonary infection, but in no case was pulmonary viral infection considered clinically. The following viral antigens were demonstrated: influenza A virus (6 patients), respiratory syncytial virus (2), influenza B virus (1), and parainfluenza virus type 1 (1).

Pathogenesis of human parainfluenza virus 3 infection in two species of cotton rats: Sigmodon hispidus develops bronchiolitis, while Sigmodon fulviventer develops interstitial pneumonia.

Human parainfluenza virus 3 replicates well in the noses and lungs of two species of cotton rats, Sigmodon hispidus and Sigmodon fulviventer. Peak viral titers of nearly 10(6) PFU/g are reached 2 days after infection in both tissues, are maintained through day 5, and are equivalent in the two species. Infectious virus is eliminated by day 8 after infection. Both species produce a strong neutralizing antibody response with titers of 1:10,000 4 weeks after infection. Viral replication in the nasal epithelium results in only minor histological changes, and viral antigen is found only in the apical portion of epithelial cells. Infection of S. hispidus causes a bronchiolitis with a peribronchiolar lymphoid cell infiltration that reaches a peak 6 days after infection, and there is only a minor component of interstitial pneumonia. In contrast, infection of S. fulviventer causes an interstitial pneumonia, and this lesion reaches its maximal extent by 6 days after infection. There is minimal peribronchiolar lymphoid cell infiltration in infected S. fulviventer. Lung lesions in both species of cotton rats are largely healed 9 days after infection, and the lungs are indistinguishable from those of uninfected controls 16 days after infection. These species of cotton rats offer separate models for the two major pulmonary manifestations of human parainfluenza virus 3 infection. The models may be useful for basic studies of the pathogenesis of this infection and for initial evaluation of candidate vaccines.

Aleutian disease parvovirus infection of mink and ferrets elicits an antibody response to a second nonstructural viral protein.

A second nonstructural protein of the Aleutian disease parvovirus was predicted from nucleotide sequence analysis and a detailed transcription map. Western immunoblotting analysis showed that infected mink and ferrets show an antibody response to this predicted protein.

Restricted viral antibody specificity in many ferrets infected with the ferret Aleutian disease parvovirus. Brief report.

The majority of ferrets infected with a ferret strain of Aleutian disease virus (ADV) produce antibody only to a detergent-sensitive common determinant on the two closely related virion proteins. Ferrets with high antibody titers and mink infected with this virus also produce antibody to one or more virion immunogenic determinants unaffected by detergent.

Immunoenzyme Western blotting analysis of antibody specificity in Aleutian disease of mink, a parvovirus infection.

Aleutian disease virus (ADV), an autonomous parvovirus, persistently infects mink and induces very high levels of virus-specific antibody. All strains of ADV infect all mink, but only highly virulent strains cause progressive disease in non-Aleutian mink. The development of antibody to individual ADV proteins was evaluated by Western blotting by using the sera of 22 uninfected mink and 163 naturally or experimentally infected mink. ADV has virion proteins of 86,000 and 78,000 daltons that are closely related. A new, possibly nonvirion protein of 143,000 daltons was observed, as well as a known nonvirion protein of 71,000 daltons. Sera from mink experimentally or naturally infected with ADV of high or low virulence generally reacted about equally with all four proteins. The only exceptions noted were that 8 of 15 sera of mink infected transplacentally preferentially reacted with the two virion proteins and sera from mink with the monoclonal gammopathy of Aleutian disease reacted preferentially with either virion (10 of 12) or nonvirion (2 of 12) proteins.

A glucose oxidase immunoenzyme stain for the detection of viral antigen or antibody on nitrocellulose transfer blots.

Separation of mixtures of proteins by polyacrylamide gel electrophoresis followed by transfer of the proteins to support media such as nitrocellulose and detection by immunologic procedures provides a powerful analytic tool for assaying the antibody specificity of antisera or for following the purification of antigens. This technique requires fewer assumptions about antigenic solubility or antibody reactivity than immunoprecipitation methods. We present a glucose oxidase immunoenzyme staining procedure for protein blots and illustrate its use for detecting antibody to several viruses. The glucose oxidase immunoenzyme stain has a lower background than some peroxidase stains. We have detected as little as 1 microgram/ml of antiviral antibody using this stain.

Immunoglobulin classes of Aleutian disease virus antibody.

Aleutian disease virus (ADV) persistently infects mink and causes marked hypergammaglobulinemia. Immunoglobulin class-specific antisera were used to define the total immunoglobulin of each class by radial immunodiffusion and the immunoglobulin class of ADV-specific antibody by immunofluorescence in experimentally and naturally infected mink. Electrophoretic gamma globulin closely reflects the immunoglobulin G (IgG) level in mink, and the majority of the increased immunoglobulin and ADV antibody in infected mink is IgG. IgM becomes elevated within 6 days after infection, reaches peak levels by 15 to 18 days, and returns to normal by 60 days after infection. The first ADV antibody demonstrable is IgM, and most mink have virus-specific IgM antibody for at least 85 days postinfection. Serum IgA levels in normal mink are not normally distributed, and ADV infection causes a marked elevation of IgA. Low levels of ADV-specific IgA antibody can be shown throughout the course of infection. Failure of large amounts of virus-specific IgG antibody to inhibit the reaction of virus-specific IgM and IgA antibodies suggests that the various classes of antibodies are directed against spatially different antigenic determinants. The IgM and IgA were shown not to be rheumatoid factors.

Much of the increased IgG in Aleutian disease of mink is viral antibody.

Aleutian disease (AD) is caused by a persistent infection of mink with an autonomous parvovirus. Chronically infected mink develop widespread plasmacytosis, a marked elevation of their serum IgG, and immune complex disease. A substantial fraction of the IgG in the serum of mink with Aleutian disease may be specifically absorbed by monolayer cell cultures infected with Aleutian disease virus. The maximum percentage of absorption of IgG found was 81% in a mink with 5.4 g/dl of IgG. Mink with the monoclonal gammopathy of Aleutian disease had a particularly large percentage of the IgG absorbed. The percentage of IgG absorbed from serums of mink with Aleutian disease is directly proportional to the serum IgG level and to the Aleutian disease viral antibody titer. The amount of IgG which can be absorbed by infected cell monolayers increases during the course of experimental infection, and the absorption is immunologically specific. Thus, it appears that much of the hypergammaglobulinemia in mink with Aleutian disease represents virus-specific antibody.

Aleutian disease in ferrets.

When 32 antibody-free ferrets were inoculated with the highly mink-virulent Utah-1 strain of Aleutian disease virus (ADV), most developed ADV antibody starting 15 days after infection, but the antibody titers were much lower than those seen in mink. Relatively small amounts of ADV were demonstrated in CRFK cell culture, using ferret spleen and lymph node homogenates only 4 to 10 days after experimental infection, but low-level viral persistence for 180 days was shown by mink inoculation. The ferrets inoculated with the Utah-1 strain of ADV did not develop elevated gamma globulin levels, but did have mild tissue lesions. Forty-two percent of a group of 214, approximately 1-year-old, recently pregnant, female ferrets were found to have antibody to ADV. An analysis of the serum proteins of the ferrets with ADV antibody showed that they had a significant, but mild, elevation of their serum gamma globulin. Serial ferret-to-ferret transmission of a ferret strain of ADV by inoculation of spleen homogenates was demonstrated, and some of these ferrets developed liver lesions. Mink inoculated with ferret ADV made antibody, but did not develop hypergammaglobulinemia or tissue lesions. Although both ferret and mink strains of ADV replicate and persist in the ferret, they fail to cause severe disease of the type usually seen in the closely related mink. Mink and ferret ADV strains appear to be biologically distinct.

Reduced severity of lesions in mink infected transplacentally with Aleutian disease virus.

Inoculation of mink late in the second trimester of pregnancy with Aleutian disease virus (ADV) produces a persistent infection in the offspring. When these mink were analyzed at 83 days of age and compared with adolescent mink infected for a similar length of time, the transplacentally infected mink show: 1) a marked reduction in plasmacytosis, immunoglobulin level and specific ADV antibody; 2) increased amounts of infectious ADV and numbers of cells containing viral antigen; 3) a marked reduction in immune complex glomerulonephritis and absence of immune complex arteritis; 4) free ADV antigen in the glomeruli; and 5) a striking accumulation of eosinophils in the tissues. The findings suggest that the degree of ADV expression is partially immunologically controlled.

Isolation of Aleutian disease virus of mink in cell culture.

Aleutian disease virus, the causative agent of a persistent infection in mink, was isolated in a continuous line of feline renal cells when the cultures were maintained at reduced temperature (31.8 degrees). After serial in vitro passage of the virus at this temperature it had an optimum replication temperature of 37 degrees. An immunofluorescence focus assay was found to be suitable for virus quantitation. The cultured virus reproduced Aleutian disease in mink, and the virus could be reisolated from the mink 10--180 days after inoculation. The properties of the virus suggest that it is a member of the parvovirus group.

The pathogenesis of Aleutian disease of mink. 3. Immune complex arteritis.

Mink chronically infected with Aleutian disease virus develop a severe necrotizing arteritis affecting muscular arteries. Acute, subacute and healing lesions may be found. Extracellular deposits of host immunoglobulin and complement and, after acid elution, viral antigen can be shown by immunofluorescence technics in areas of fibrinoid necrosis and between proliferating endothelial cells. No intracellular viral antigen was found, indicating that the virus probably does not replicate in vascular structures. The arteritis of Aleutian disease appears to be the result of immune complex deposits in vessel walls.

The pathogenesis of Aleutian disease of mink. I. In vivo viral replication and the host antibody response to viral antigen.

Mink inoculated with 1 x 10(5)ID(50) of Aleutian disease virus revealed very high virus titers in the tissues 8-18 days later. The highest virus titers observed were 5 x 10(8)ID(50) per g of spleen and 1 x 10(9)ID(50) per g of liver 10 days after inoculation. Concomitant with the increase in infectious virus titers, viral antigen(s) was found in the cytoplasm of macrophages in the spleen and lymph nodes and in Kupffer cells in the liver. Antiviral antibody was assayed by indirect immunofluorescence, using sections of infected liver as the source of antigen. A few mink infected for 9 days and all those infected 10 days or more developed antibody to Aleutian disease virus antigen(s). By 60 days after infection, when hypergammaglobulinemia was marked, the mink had an exceptionally high mean antibody titer of 100,000. The pathogenesis of the glomerulonephritis of Aleutian disease is apparently related to formation of viral antigen-antibody-complement complexes which lodge in glomerular capillaries. No evidence was found that viral infection of the kidney took place, and no autoimmune responses were found. In this "slow-virus" disease the virus replicates rapidly and the morphologic and biochemical manifestations of disease are apparently due to the continuing interplay between a replicating antigen and the host immune response.