Effect of Gamma Irradiation on the Antibody Response Measured in Human Serum from Subjects Vaccinated with Recombinant Vesicular Stomatitis Virus-Zaire Ebola Virus Envelope Glycoprotein Vaccine.

rVSVΔG-ZEBOV-GP vaccine is a live recombinant (r) vesicular stomatitis virus (VSV), where the VSV G protein is replaced with the Zaire Ebola virus (ZEBOV) glycoprotein (GP). For vaccine immunogenicity testing, clinical trial sera collected during an active ZEBOV outbreak underwent gamma irradiation (GI) before testing in biosafety level 2 laboratories to inactivate possible wild-type ZEBOV. Before irradiating pivotal trial samples, two independent studies evaluated the impact of GI (50 kGy) on binding ZEBOV-GP (ELISA) antibodies against rVSVΔG-ZEBOV-GP, using sera from a North American phase 1 study. Gamma irradiation was associated with slightly higher antibody concentrations in pre-vaccination samples and slightly lower concentrations postvaccination. Results indicate that GI is a viable method for treating samples from regions where filoviruses are endemic, with minor effects on antibody titers. The impact of GI on immunogenicity analyses should be considered when interpreting data from irradiated specimens.

The effect of UVB irradiation on antibody responses during herpes simplex virus type 1 (HSV-1) infections of mice.

Ultraviolet B (UVB) exposure suppresses cell-mediated immunity and may alter the cytokine profile, reducing T helper 1 (Th1) cytokines and promoting Th2 cytokines. Th1 cytokines enhance the production of immunoglobulin (Ig) G2a, IgG2b and IgG3 antibodies, while Th2 cytokines enhance the production of IgG1 and IgE antibodies. The effect of suberythemal UVB irradiation on antibody isotypes following infection of C3H/HeN mice with herpes simplex virus (HSV) was investigated using two protocols. First, mice were irradiated prior to two subcutaneous infections with HSV. Second, mice were immunised with inactivated HSV before being irradiated and challenged epidermally with HSV, which led to an increase in the size of the clinical lesions compared with unirradiated animals. In both models, the HSV-specific IgG titre was not affected by the UVB exposure but, generally, the irradiated animals showed a small reduction in both Th1- and Th2-associated HSV antibody isotypes. IL-4 knockout (IL-4-/-) mice were used to investigate the role of IL-4 in UVB-induced isotype switching. Here IL-4-/- and IL-4+/+ strains were irradiated prior to primary and secondary epidermal infections with HSV, followed by measurement of antibody titres and lesion size. In both the mutant and parent mice, UV irradiation led to an increase in lesion severity. In IL-4+/+ mice, UV exposure did not affect the HSV titre of any of the individual isotypes tested but did suppress the total IgG to HSV This suppression may be due to UV-induced IL-4 release because, in the IL-4-/- mice, HSV IgG was elevated by the UVB irradiation. If UV modulates the immune response solely via the action of cytokines, then the downregulation of Th1 cytokines and upregulation of Th2 cytokines should be accompanied by antibody isotype switching from IgG2a and IgG3 towards IgG1 and IgE. This result was not obtained in the models tested, perhaps because HSV infection promotes such a complex array of innate and acquired immune responses that a clear effect on virus-specific isotype production may not be apparent.

The effect of microwave heating on vitamins B1 and E, and linoleic and linolenic acids, and immunoglobulins in human milk.

Breast milk was treated with (1) conventional heating (in water bath) vs microwave heating; (2) microwave heating at two power levels (30% and 100%); (3) increasing final temperatures; and (4) microwave thawing vs refrigerator thawing and examined for changes in specific immunoglobulins to a pool of E. coli and poliovirus type 1 antigens, vitamins E and B1, and the polyunsaturated fatty acids linoleic and linolenic acid. Immunoglobulin activities were stable until final milk temperatures of around 60-65 degrees C were reached, and total inactivation occurred at 77 degrees C. Heating even to high final temperatures did not change contents of vitamins and polyunsaturated fatty acids. No differences in immunoglobulins and nutrients were demonstrated between microwave heating and conventional heating, and between power levels or thawing methods. The study shows that microwave heating of human milk can be performed without significant losses of examined immunoglobulins and nutrients, provided that final temperatures are below 60 degrees C.

Effect of gamma irradiation on reactivity of rinderpest virus antigen with bovine immune serum in enzyme-linked immunosorbent assays and virus neutralization and indirect fluorescent-antibody tests.

Gamma irradiation effectively inactivated gradient-purified rinderpest virus. Irradiated antigen and sera remained functional in enzyme-linked immunosorbent assays, virus neutralization tests, and indirect fluorescent-antibody tests. Irradiation, however, led to a dose-dependent decrease in reactivity, particularly significant (P < 0.05) when both reagents were irradiated. To avoid false-positive reactions, only one reagent (serum or antigen) may be irradiated.

Inactivation of viruses during ultraviolet light treatment of human intravenous immunoglobulin and albumin.

A comparison of ultraviolet (UV) irradiation of two wavelength ranges UVB (280-320 nm) and UVC (lower than 280 nm) showed that UVC in particular could very effectively inactivate, in intravenous immunoglobulin (IVIG) and albumin preparations, non-enveloped and non-acid labile model viruses (i.e., Polio 2 and T4 phage) and dry heat-resistant viruses (vaccinia and T4 phage). This effective virucidal treatment (5 min, 5,000 J/m2 dose) was achieved before an unacceptable level of IVIG aggregates occurred. The use of UV irradiation to inactivate infectious agents could add safety and supplement current methods, e.g. solvent/detergent, low pH, which do not inactivate non-enveloped, non-acid labile or dry-heat-resistant viruses at present.

[The immunocorrective effect of laser reflexotherapy in experimental influenza infection]. / Immunokorrigiruiushchii éffekt lazernoi refleksoterapii pri éksperimental'noi grippoznoi infektsii.

The influence of two schemes of laser acupuncture on some cell-mediated and humoral immunity characteristics of mice, as well as on their nonspecific antiviral resistance, in acute experimental influenza infection has been studied. The use of both schemes has been found to considerably decrease the severity of infection, enhancing the activity of lymphocytes of infected mice in the graft versus host reaction, the O2-producing activity of alveolar macrophages and modulating the ratio of antihemagglutinins and nonspecific antiviral inhibitors in the blood serum.

Antibody against Epstein-Barr virus DNA polymerase activity in sera of patients with nasopharyngeal carcinoma.

A salt-dependent DNA polymerase activity was demonstrated in the culture of an EBV-producing, lymphoblastoid cell line (NPC-204 cells) treated with 5-iodo-2'-deoxyuridine (IUdR). There was a high frequency of levels of antibody to this enzyme in sera of patients with nasopharyngeal carcinoma (NPC). In contrast, sera from healthy subjects had little or no neutralizing activity. The high antibody level appeared as early as stage 1 of the disease in many NPC patients. The levels of the antibody increased with the progression of the disease and declined in treated patients. The results strongly suggest that tests measuring serum antibody against EBV DNA polymerase activity can be used for early diagnosis and prognosis of NPC.

Studies on the clonality of the response to an epitope of a protein antigen. Randomness of activation of epitope-recognizing clones and the development of clonal dominance.

Syngeneic mice immunized with tobacco mosaic virus protein (TMVP) can differ with respect to their ability to produce antibodies that bind a decapeptide epitope representing residues 103 to 112 of TMVP, and with respect to the fine specificity of the decapeptide binding antibodies as determined by their ability to bind several synthetic analogues of the decapeptide. To elucidate the mechanism responsible for the differences between the syngeneic animals in their ability to make anti-decapeptide antibodies, spleen cells from a large number of naive CSW mice were pooled, and aliquots were transferred (either including or excluding resident T cells) into naive recipients that were subsequently immunized with TMVP. Examination of the frequency and fine specificity of anti-decapeptide antibodies revealed that the recipients exhibited various clonalities of decapeptide binding antibody responses similar to those seen in a normal population of CSW mice. Moreover, the response of each individual mouse was of a restricted clonality despite the availability of a more extensive repertoire of decapeptide-recognizing clones. The results indicate that the selection of the clonality of the antibody response was not determined by the presence (or absence) of particular clones of B or T cells and that the mechanism responsible for generating differences between mice must have acted, subsequent to introduction of the Ag, by activation of a limited number of clones randomly selected by Ag and/or by Ag-driven mutation. The long term nature of the antibody response to the decapeptide epitope was also investigated. The response was shown to be "locked-in" for the life of the immunized individual. Thus, individuals that responded to TMVP but that did not produce antibodies to the decapeptide after the first set of immunizations with TMVP maintained their non-responsiveness to the decapeptide after the second set of immunizations with the protein. However, individuals that responded to an initial set of immunizations with TMVP by producing antibodies to the decapeptide epitope continue to produce antibodies to the decapeptide after a second set of immunizations with TMVP. The fine specificity of the decapeptide-binding antibodies also appeared to be "locked in" throughout the life of the immunized individual. The long term maintenance of the clonability of the antibody response does not appear to be influenced by Ag-specific T cells and is strictly a function of memory B cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Endogenous murine leukemia viruses: frequency of radiation-activation and novel pathogenic effects of viral isolates.

Female C57BL/6 and BALB/c mice were injected i.p. with 0.06 microCi/kg or 0.5 microCi/kg of the short-lived alpha-emitting radionuclide 224radium at 3-day intervals. Infectious N-ecotropic XC+, and xenotropic C-type retroviruses were activated in several tissues in both strains. In C57BL/6 mice the activation of ecotropic and xenotropic virus was dose-dependent as observed 4 weeks after the start of irradiation. In BALB/c mice a few animals showed activation of ecotropic virus after four weeks of irradiation. The expression of xenotropic virus was similar in irradiated mice and controls. Viral antigen, indicative for viraemia, was not detected in irradiated or control animals. Antiviral antibodies were found in both control and irradiated mice but higher titers were found in the irradiated mice. Bone tissue-derived N-tropic XC+ virus isolates were found to be non-oncogenic in newborn mice of the parental strain. In contrast, the same virus isolates induced a novel pattern of disease, such as osteopetrosis and osteomas together with malignant lymphomas in NMRI mice. The data indicate that the pattern of endogenous murine leukemia virus activation by internal alpha-irradiation is dependent on the dose rate, and on the genetics of the mouse strain.