测定呼吸道合胞病毒抗体方法敏感性的比较

用ELISA、间接免疫荧光和中和试验三种方法测定兔免疫血清的呼吸道合胞病毒抗体。结果中和试验测定的免疫血清几何平均抗体滴度为1:32;间接免疫荧光试验为1:508,比中和试验高16倍;ELISA测得的抗体滴度1:4,000～1:5,000,为中和试验的125～156倍。以ELISA敏感性最高,间接免疫荧光试验次之,中和试验景差。     

Immunodiffusion test in avian encephalomyelitis. II. Detection of precipitating antibody in infected chickens in comparison with neutralizing antibody.

The sensitivities of double-immunodiffusion (DID) and neutralization tests to detect avian encephalomyelitis (AE) antibody in chickens were studied. Two antigens were employed in the tests. Concentrated antigen gave a higher titer of antiserum than crude antigen, which reacted only to serum having a neutralization log-index (NI) of 3.4approximately4.0 or more. Antibody responses were examined in four growing chick groups inoculated with AE virus by the intracerebral, subcutaneous and oral routes by the DID test with concentrated antigen and by the neutralization test for 1 or over 2 years after inoculation. When concentrated antigen was used, most sera having an NI of over 1.0 were positive for precipitating antibody. Therefore, the sensitivity of the DID test was nearly equal to that of the neutralization test. The DID test was considered to be applicable to the diagnosis of AE and an antibody survey in the field.     

Enhanced neutralization of flavivirus by monoclonal antibodies against Negishi virus

Ten monoclonal antibodies against Negishi virus were classified into 3 groups and 7 types according to the reaction patterns to Negishi virus by the hemagglutination inhibition (HI) test and by several kinds of neutralization tests. When kinetic neutralization was applied to these monoclonal antibodies at the same HI titer of 1:64, the initial slope and the persistent fraction of the kinetic curve was varied in each antibody. In the double-kinetic neutralization test, neutralization did not proceed further when the second antibody was the same type as the first one. When the second antibody was a different type from that of the first one, neutralization proceeded further. The mixtures of 4 monoclonal antibodies classified as different groups and types remarkably enhanced neutralization in the kinetic assay. These results suggested that an assortment of antibodies is needed for effective neutralization of Negishi virus and that a multi-hit model is likely operating in the neutralization of Negishi virus.     

Use of the toxin-binding inhibition test for estimation of tetanus antitoxin in serum

The usefulness of the toxin binding inhibition test (ToBI) for the titration of tetanus antibody in human sera was assessed. Sera from 80 healthy people with different vaccination histories that had been previously tested by the in vivo toxin neutralization (TN) test were retested by the ToBI test. The lowest tetanus antibody titre which could be detected by using 0.1 Lf/ml tetanus toxin was 0.01 IU/ml. Comparison between the estimates obtained by the ToBI test and those obtained by the TN test (r = 0.93 and r = 0.7 for titration low titre sera) showed good correlation. No overestimation of antibody content was seen in titrating low titre sera by the ToBI test. It is concluded that the ToBI-test is a reliable alternative to toxin neutralization test in mice.     

Human rabies immunoglobulin assayed by the rapid fluorescent focus inhibition test suppresses active rabies immunization

The rabies antibody content of each of ten lots of human rabies immunoglobulin was titrated by both the mouse neutralization test and the rapid fluorescent focus inhibition test. The two tests did not give comparable results, the antibody titres obtained by the mouse neutralization test being 1·4–9·6 times higher than those obtained by the rapid fluorescent focus inhibition test. This titre difference was associated with a consistently lower antibody response in human volunteers who had received post-exposure rabies vaccine treatment which included the administration of RIG assayed by the RFFIT.     

Indirect Hemagglutinating Antibody Response to Herpesvirus hominis Types 1 and 2 in Immunized Laboratory Animals and in Natural Infections of Man

Indirect hemagglutinating (IHA) antibody responses to Herpesvirus hominis types 1 and 2 (HVH-1 and HVH-2) were compared to complement-fixing and neutralizing antibody responses in immunized laboratory animals (rabbits, guinea pigs, and hamsters) and in natural infections of man. With the immunized animals, type specificity was seen only in the IHA test and only with antisera produced in hamsters and in the rabbits immunized with HVH-2. In human nongenital infections (considered to be caused predominately by HVH-1), IHA and neutralizing antibodies developed at about the same rate and reached approximately the same levels for HVH-1 and HVH-2. IHA titers tended to be higher than neutralizing antibody titers for both virus types. In genital infections (considered to be caused predominately by HVH-2), there was a rapid IHA antibody response to HVH-2, and the early HVH-2 antibody demonstrable by IHA, but not by neutralization tests, was found to be immunoglobulin M in nature. In genital infections, IHA titers for HVH-2 were markedly higher than neutralization titers, but there was no pronounced difference in neutralizing the IHA antibody titers for HVH-1. Several patients with genital infections fialed to develop IHA antibody for HVH-1. The IHA test possessed no greater sensitivity than did complement fixation or neutralization tests for serodiagnosis of HVH infections. Despite the fact that a number of patients with genital infections produced IHA antibody only for HVH-2, the test was no more effective than the neutralization test in providing a type-specific serodiagnosis of infection, due largely to the fact that the rapid IHA antibody response to HVH-2 prevented demonstration of a further, significant antibody titer increase in a number of cases.     

Antigenic variation in foot-and-mouth disease: studies based on the virus neutralization reaction

The neutralization reaction is the most appropriate in vitro reference test system for assessing intratypic antigenic variation as it involves the antigenic determinants responsible for virus strain specificity and evoking protective antibody. Antigenic relationships determined in different neutralization test systems were independent of the system used and were assumed to truly reflect antigenic variation. The two-dimensional microneutralization test was found to be appropriate for foot and mouth disease (FMD) virus strain differentiation. To minimize test to test variation, comparisons are performed as matched pairs. The pooled variance of the test system is used to assess the significance of the relationships obtained. Antisera from convalescent animals were less specific than those from vaccinates. Serum quality seemed less critical for the virus neutralization than the complement fixation reaction. A system for FMD virus strain differentiation based on the use of the virus neutralization reaction taking into account the statistical and biological significance of observed r values is recommended.     

Micro Indirect Hemagglutination Test for Cytomegalovirus

In an effort to obtain the flexibility and ease of performance of a rapid, serological test for detection of cytomegalovirus antibody, the indirect hemagglutination (IHA) technique was investigated by using a microserological system. Antigens were prepared from tissue cultures of infected human fibroblasts. The specificity of the cytomegalovirus antibody response detected by the IHA test correlated well with the standard neutralization test. The IHA method was more sensitive than the complement fixation test in detecting antibody in congenitally infected newborns. There appeared to be some heterologous antibody response with Herpesvirus hominis or varicella virus infections. The IHA test pattern was found to be very stable with excellent persistence of agglutination.     

Use of monoclonal antibodies in immunoenzyme analysis for demonstrating antigenic monovalency

To prove the monovalence of the antigen a method has been developed consisting of ELISA with the use of monoclonal antibodies in combination with the antibody neutralization test. Yersinia pestis capsular antigen was disintegrated by heating at 100 degrees C for a short time and subsequently passed through a column packed with Sephadex G-50. The portions of the eluate, showing high activity in the antibody neutralization test and low activity in ELISA (the double antibody sandwich scheme), contained mainly the monovalent antigen. This antigen was replaced by the polyvalent antigen from the antibody complex, but if such complex had been previously fixed by treatment with glutaraldehyde, no replacement of the monovalent antigen by the polyvalent one occurred.     

Detection of antibodies to Herpesvirus simiae and Herpesvirus hominis in nonhuman primates

Sera from nonhuman primates, predominantly Macaca species, were assayed by a serum neutralization test for antibodies to antigenically related Herpesvirus simiae (B virus) and Herpesvirus hominis type 1. The data indicate that there would have been approximately 50% error in the diagnosis of Herpesvirus simiae infection if these sera had been tested only against Herpesvirus hominis antigen. The role of active guinea pig complement in the serum neutralization test was also evaluated and found to be required by many of the sera for reproducible and enhanced virus neutralization, particularly for B virus antibody determination. A plaque reduction assay was found to be highly sensitive, especially when complement (2.5-5.0 hemolytic units) was added, but impractical for large-scale serum surveys.     

Antibody neutralization test in brucellosis]

The authors present the results of study of the antibody neutralization test in brucellosis with the use of erythrocytes sensitized with lipopolysaccharide. This test was shown to be highly specific and sensitive in detection of brucellae and brucellosis antigen in pathological material, food and objects of external environment.     

Serology of Rubella—Comparison of Fluorescent Antibody,Complement Fixation and Neutralization Tests for Diagnosis of Current Infections and Determination of Sero-immunity

Neutralization, complement fixation (CF) and indirect fluorescent antibody (FA) assays for rubella virus were compared for sensitivity in the serologic diagnosis of infection, for demonstrating antibody in the sera of infants with suspected rubella syndrome, and in the detection of antibody elicited by past infection (determination of immunity status). The combination of CF and FA tests was shown to be the most useful for serologic diagnosis of infection, largely eliminating the need for the slower and more cumbersome interference neutralization test.Neutralizing antibodies were found to appear rapidly in the course of infection, antibodies demonstrable by immunofluorescent staining appeared slightly later, and CF antibodies were rarely demonstrable in sera collected earlier than 14 days after onset of illness. Antibodies detected by all three techniques showed good correlation in infants with clinical evidence of rubella syndrome and corresponding maternal sera. The indirect FA technique compared favorably with the neutralization test for the detection of antibody elicited by past infection (determination of immunity status) and offered distinct advantages in ease of technical performance and more rapid results. In both current and past infections, FA titers tended to be higher than neutralizing antibody titers.     

Detection of postvaccination mumps virus antibody by neutralization test, enzyme-linked immunosorbent assay and sensitive hemagglutination inhibition test

A group of 251 children aged 2-3 years given live attenuated mumps virus vaccine PAVIVAC of Czechoslovak production were tested for antiparotitis antibody levels in pre- and postvaccination sera by neutralization test (NT), enzyme-linked immunosorbent assay (ELISA) and sensitive hemagglutination inhibition test, enhanced by heterologous antibody to human immunoglobulin G (E-HIT). The prevaccination findings were as follows: positive ELISA IgG titres, neutralization antibodies and hemagglutination inhibition antibodies were present in, respectively, 35%, 25.9% and 27.9% of the sera. Postvaccination seroconversions were evaluated in 159 susceptible vaccinees whose prevaccination sera had been negative by all three tests. The lowest seroconversion was detected by NT (74.2%), seroconversions by ELISA and E-HIT were appreciably higher (82.4% and 86.8%, respectively). The seven children showing a seroconversion by E-HIT but not by ELISA had a 4 fold increase of anti-mumps ELISA IgG antibodies as well, but the rise of antibody titres was at a level falling in the range below the positivity criterion for ELISA. The statistically evaluated detection rate for antibodies was significantly higher (significance test "t") by ELISA as compared with neutralization test. However, antibody levels (geometric mean titres) were 8-10 times lower in postvaccination sera than in convalescent sera of 30 children with mumps in all three tests.     

Use of microplate cell culture and enzyme immunoassay in titration of serum neutralizing antibody against Hochi strain of serotype 4 human rotavirus

The tube neutralization test read by enzyme immunoassay developed by Wyatt et al. (1983) for serotype determination of human rotavirus was modified so as to use stationary cultures of MA104 cells in a microtiter plate instead of roller tube cultures. Sera obtained from different age groups were titrated for neutralizing antibody against serotype 4 human rotavirus Hochi strain by this test and the results were compared with those obtained by the plaque neutralization test. There was a good correlation between the titers obtained by the two tests and the age distribution pattern of serotype 4 neutralizing antibody was similar to those of serotype 1 and 3 antibodies previously reported.     

Quantitation of commercial equine tetanus antitoxin by competitive enzyme-linked immunosorbent assay

In the USA, the potency of commercially prepared equine tetanus antitoxin is determined by the method outlined in the Code of Federal Regulations, Title 9, Part 113.451. In the current test, commercial equine tetanus antitoxin is tested by a toxin neutralization test in guinea pigs. The in vivo test measures antitoxin content through effectiveness of protection of guinea pigs injected with diluted mixtures of antitoxin and a standard toxin. A competitive enzyme-linked immunosorbent assay, designed as an in vitro alternative to the in vivo test, measures antitoxin content based on a competitive reaction between standard or unknown serum and murine monoclonal antibody specific for tetanus toxin. The monoclonal antibody used in the assay delayed death in mouse passive protection studies and reacted with the C fragment of tetanus toxin. No cross-reaction was observed when the antibody was tested with the toxins of Clostridium chauvoei, C. novyi, C. perfringens, or C. sordellii. The in vitro test will measure the antitoxin content of serum samples containing 100-1500 units of antitoxin. Tetanus antitoxin titers obtained by the competitive enzyme-linked immunosorbent assay compared favorably with the toxin neutralization test conducted in guinea pigs. The in vitro assay serves as a feasible alternative to the in vivo test because it can be completed in less time, is reproducible, and eliminates the use of test animals.     

Neutralization of the human immunodeficiency virus type 1 primary isolate JR-FL by human monoclonal antibodies correlates with antibody binding to the oligomeric form of the envelope glycoprotein complex.

To test whether antibodies that are neutralizing or nonneutralizing for human immunodeficiency virus type 1 (HIV-1) primary isolates can be distinguished by their affinities for the oligomeric envelope glycoproteins, we selected HIV-1(JR-FL) as a model primary virus and a panel of 13 human monoclonal antibodies (MAbs) and evaluated three parameters: (i) half-maximal binding to recombinant monomeric envelope, gp120(JR-FL); (ii) half-maximal binding to oligomeric envelope of HIV-1(JR-FL) expressed on the surface of transfected 293 cells; and (iii) neutralization of HIV-1(JR-FL) in a peripheral blood mononuclear cell-based neutralization assay. Two conclusions can be drawn from these experiments. First, we confirm that antibody interactions with monomeric gp120 do not predict primary virus neutralization. Second, we show that neutralization correlates qualitatively with the relative affinity of an antibody for the oligomeric envelope glycoproteins, at least for HIV-1(JR-FL).     

Primary virus envelope cross-reactivity of the broadening neutralizing antibody response during early chronic human immunodeficiency virus type 1 infection

To test the hypothesis that changing neutralizing antibody responses against human immunodeficiency virus type 1 (HIV-1) during chronic infection were a response to emergence of neutralization escape mutants, we cloned expressed and characterized envelope clones from patients in the Multicenter AIDS Cohort Study (MACS). Pseudotyped HIV-1 envelope clones obtained from differing time points were assessed for sensitivity to neutralization by using sera from different times from the same and different patients. Clones from early and late time points during chronic infection had similar neutralization sensitivity, and neutralizing antibody responses cross-reacted with early, late, and heterologous envelopes. The potential for broadly effective HIV-1 immunization is supported.     

A dot-immunobinding assay on nitrocellulose with psoralen inactivated Herpesvirus simiae (B virus)

An enzyme-immunoassay performed with Herpesvirus simiae (B virus) and H. simplex antigens inactivated with a psoralen derivative and long-wavelength ultraviolet light irradiation is described. Although B virus is a known human pathogen requiring extreme care in its handling, the use of inactivated antigens in the test allows its performance without biosafety containment. The test utilizes nitrocellulose sheets dotted with antigen for the assay of antibody against B virus in nonhuman primate sera. Antigen-antibody complexes are detected visually as red dots by the use of enzyme-conjugated antiglobulin second antibody and a substrate that produces an insoluble product. The test is more rapid, sensitive and specific than the serum neutralization test it is intended to replace. Of 150 macaque monkey sera tested, 83 were negative by the enzyme and neutralization tests, 56 were positive by both tests and 11 were positive by enzyme-assay but negative by neutralization. Positive sera reacted with both simian and human viral antigens in the enzyme assay but with greater intensity against B virus. Absorption with H. simplex removes reactivity with this virus without reducing the B virus response.     

The expression of potency of neutralizing antibodies for interferons and other cytokines

The occurrence of antibody formation in patients administered biologically active human proteins as biotherapy for different diseases emphasizes the importance of establishing a common method of reporting neutralizing antibody levels for such cytokines. For quantitative neutralization bioassays, the preferred expression of the neutralizing potency of an antiserum is a titer, that is, the dilution of serum that reduces 10 Laboratory Units (LU)/ml of the cytokine to 1 Laboratory Unit/ml, the endpoint of most bioassays. This 10-to-1 LU/ml expression, which has been recommended by the World Health Organization for recording the results of interferon neutralization by the constant interferon method (with varying dilutions of serum) can also be used with the constant antibody method (with varying concentrations of interferon). For various reasons, interferon doses in International Units (IU)/ml should not be used for the neutralization test. Should the interferon concentration vary, intentionally or otherwise, from the intended dose of 10 LU/ml, a simple calculation allows expression of the neutralizing potency as the recommended reduction of 10-to-1LU/ml as follows: the titer to be reported is the reciprocal of the antibody dilution (achieving the endpoint), multiplied by the interferon concentration (measured in that day’s titration) minus one, divided by 9. This index of neutralization is the preferred method to represent the neutralizing potency of polyclonal and monoclonal antibodies and should make the results from different laboratories more readily interpretable and enable comparison.     

An immunofluorescence test for detection of serum antibody to rodent coronaviruses

An indirect immunofluorescence test, using cultured cells infected with two strains of mouse hepatitis virus, was developed for detection of antibody to rodent coronaviruses. The immunofluorescence test detected serum antibody to mouse hepatitis virus and rat sialodacryoadenitis virus earlier than the neutralization test. In the case of mouse hepatitis virus, the results of the immunofluorescence test closely paralleled those obtained with a commercially available enzyme-linked immunosorbent assay.