No abstract

Rabbit antisera prepared against interferon produced in human fibroblast cell cultures stimulated with poly(I) -poly(C) neutralized the activity of interferon preparations produced in various human fibroblast cultures stimulated either with poly(I) poly(C) or with viruses. However, these antisera showed no detectable neutralizing activity against interferon produced in cultures of human leukocytes. On the other hand, most rabbit antisera against the human leukocyte interferon were active in neutralizing both homologous interferon and fibroblast interferons. A preparation of antiserum against leukocyte interferon, active against both leukocyte and fibroblast interferons, was shown by affinity chromatography to have two distinct antibody populations, one of which was specific for the fibroblast interferon. We conclude that the heterologous neutralizing activity of sera from rabbits immunized with leukocyte interferon is likely to be due to the presence of two antigenic species of interferon. The major antigenic species of leukocyte interferon preparations (designated "Le") is distinct from human fibroblast interferon. The minor species of leukocyte interferon ("F") is either identical with, or closely related to, interferon produced in human fibroblast cultures.

Mononuclear cells from the blood of healthy normal humans were kept in cultures under nonstimulating conditions for 16 [14C]thymidi'ne to 0.2 ml of cell supension in microtiter plates which were harvested and assayed for radioactivity 12-16 hr later, according to standard procedures. Cells were washed two or three times in medium containing 5% fetal calf serum And 15 mM Na azide and then were incubated with 1:25 diluted fluorescein isothiocyanate (FITC)-labeled specific rabbit anti-human [B2-m antiserum (Dakopatts, code F112, Dakopatts, Copenhagen) or with a 1:8 dilution of a nonlabeled broadly reacting anti-VJLA antiserum including the specificity Bw4. The serum "Buffo" from the International Serum Bank in Torino was kindly provided by J. Stocker (Basel). After a 45-min incubation, the cells were processed for quantitative immunofluorescence in the fluorescence-activated cell sorter (FACS II, Becton-Dickinson) or were washed three times and incubated with the second layer, which was a 1:50 dilution of FITC-conjugated goat IgG anti-human Fc antibodies (a kind gift of L. Forni, Basel), for a further 30 min.Immunoglobulin-bearing cells were labeled by using FITC-conjugated rabbit IgG anti-human IgM antibodies (Dakopatts, code.F1090) or swine anti-human Ig (polyvalent) from Dakopatts (F2190). Rabbits were immunized at 2-week intervals by two injections of human brain tissue (obtained from autopsies) suspended in complete Freund's adjuvant. After 1 month they received approximately 107 purified human peripheral T lymphocytes intravenously, and serum was harvested 2 weeks later. The antibodies reacted with close to 90% of the blood lymphocytes in a complement-dependent cytotoxicity test and were used unabsorbed in the present study. Cells to be labeled were incubated with a 1:10 dilution of the serum for 45 min at 4°C, washed, and subsequently stained with a 1:50 dilution of FITC-conjugated swine anti-rabbit Ig (Dakopatts,

During the last decade, various zinc salts have been used against the common cold syndrome, which is known to be initiated by respiratory viruses, particularly rhinoviruses. Using rhinovirus as the challenge virus, we investigated whether zinc salts (Zn) could potentiate the antiviral action of native human leukocyte interferon (HuIFN-alpha) and rHuIFN-gamma. We found that HuIFN-alpha was potentiated tenfold at rather low levels of IFN activity (0.6-0.8 U/ml), resulting in 100% protection. Zn alone gave only marginal protection, if any. In contrast to HuIFN-alpha, rHuIFN-gamma directly increased the cytopathic effect of rhinovirus at low levels (<2 U/ml) but protected the cells at higher IFN levels (5-20 U/ml). No potentiation was seen with Zn. HuIFN-beta protected against rhinovirus at the same doses as used with HuIFN-alpha, but in contrast to HuIFN-alpha, no potentiation was noted.

The influence of measles virus (MV) infection on gene expression by human peripheral blood mononuclear cells (PBMCs) was examined with cDNA microarrays. The mRNA levels of more than 3000 cellular genes were compared between uninfected PBMCs and cells infected with either the Edmonston MV strain or a wild-type MV isolate. The MV-induced upregulation of individual genes identified by microarray analyses was confirmed by RT-PCR. In the present study, a total of 17 genes was found to be upregulated by MV infection. The Edmonston strain grew better in the PBMC cultures than the wild-type MV, and the Edmonston strain was a stronger inducer of the upregulated host cell genes than the wild-type virus. The anti-apoptotic B cell lymphoma 3 (Bcl-3) protein and the transcription factor NF-κB p52 subunit were upregulated in infected PBMCs both at the mRNA and at the protein level. Several genes of the interferon system including that for interferon regulatory factor 7 were upregulated by MV. The genes for a number of chaperones, transcription factors and other proteins of the endoplasmic reticulum stress response were also upregulated. These included the gene for the pro-apoptotic and growth arrest-inducing CHOP/GADD153 protein. Thus, the present study demonstrated the activation by MV of cellular mechanisms and pathways that may play a role in the pathogenesis of measles.