Nobutoshi Maehara

Interferon production during the course of Mycoplasma pneumoniae infection

In patients infected with Mycoplasma pneumoniae the development of interferon (IFN) was studied in nasopharyngeal secretions and sera. The production of IFN-gamma by lymphocytes was also investigated in response to M. pneumoniae antigen and mumps virus antigen. IFN-alpha was detected in 25 (61.0%) of 41 nasopharyngeal secretion samples and in 25 (59.5%) of 42 serum samples within 6 days after the onset of illness. IFN-alpha was significantly higher in nasopharyngeal secretions than in sera and a significant correlation was observed between the two. In most of the patients lymphocytes produced a larger amount of IFN-gamma in the convalescent stage than in the acute stage, when lymphocytes were stimulated with M. pneumoniae antigen. In some patients, however, lymphocytes did not produce IFN-gamma during the course of illness. Such lymphocytes, negative for IFN-gamma production in response to M. pneumoniae, produced IFN-gamma after the depletion of macrophages, and readdition of macrophages suppressed the production of IFN-gamma by lymphocytes. When lymphocytes were stimulated with heterogeneous antigen (mumps virus), they produced no IFN or a small amount of IFN in the acute stage of M. pneumoniae infection, and IFN production increased in the convalescent stage. Different mechanisms seem to work for homogeneous and heterogeneous antigens in the suppression of IFN production in M. pneumoniae infection.

Detection of alpha-interferon in nasopharyngeal secretions and sera in children infected with respiratory syncytial virus.

We investigated the relationship between respiratory syncytial virus (RSV) antigen and interferon (IFN) in nasopharyngeal secretions (NPS) and sera obtained from 252 patients infected with RSV. A total of 146 (57.9%) of 252 patients had IFN in NPS with a mean titer of 28 units/ml and IFN was detected in 164 (71.6%) of 229 patients in the acute stage sera with a mean titer of 28 units/ml. IFN activities were neutralized with antiserum to IFN-alpha. RSV antigen in NPS decreased on Day 5 and later in parallel with the change of mean titer of IFN in NPS. IFN in NPS was detected in 40 to 60% of the samples with some fluctuation in the acute

Evaluation of Live Trivalent Vaccine of Measles AIK-C Strain, Mumps Hoshino Strain and Rubella Takahashi Strain, by Virus-Specific Interferon-γ Production and Antibody Response

A trivalent measles‐mumps‐rubella live virus vaccine, containing measles AIK‐C strain, mumps Hoshino strain, and rubella Takahashi strain, was evaluated in 229 children, aged 1 to 5 years. The vaccine induced a high seroconversion rate: 221 (98.7%) out of 224 subjects initially seronegative for measles virus, 167 (93.3%) out of 179 initially seronegative for mumps virus, and 212 (99.1%) out of 214 initially seronegative for rubella virus. It also induced a sufficient cellular immunity against each of the three viruses in over 90% of the subjects, as judged by virus‐specific interferon‐γ (IFN‐γ) production. Virus‐specific IFN‐γ production was observed 10 days after vaccination by stimulation with measles virus and rubella virus and 14 days after vaccination by stimulation with mumps virus. Mumps‐virus‐specific IFN‐γ production was observed in 7 out of 12 recipients without seroconversion for mumps virus. And measles‐virus‐specific IFN‐γ production was demonstrated in one out of three recipients without seroconversion for measles virus. A significant correlation was observed between the serum antibody and IFN‐γ production six weeks after vaccination for measles virus (r = 0.201, P<0.01) and for mumps virus (r‐0.174, P<0.05) but not for rubella virus (r= ‐0.045, P>0.05). The incidence of febrile reactions of ≧37.5 C was quite low, 14.4%, and that of ≧39 C occurred in only 1.3% of the recipients. These results suggested that the trivalent vaccine induced sufficient humoral and cellular immunity and yet resulted in no more untoward reaction than observed from the measles vaccine alone.

Enhanced Production of Virus-Inhibiting Factor (Interferon) in Human Diploid Cells by Ultraviolet Irradiation and Temperature Shift-Down after Stimulation with Newcastle Disease Virus

The production of the virus‐inhibiting factor or interferon (IF) was highest in cells incubated at 37 C after inoculation with Newcastle disease (ND) virus and decreased as the incubation temperature was lowered. Shift‐down of incubation temperature to 32 C or 34 C after incubation at 37 C for 4–7 hr enhanced IF production in cell cultures stimulated with ND virus, as compared with cultures incubated continuously at 37 C. Shift‐down to 32 C after incubation at 37 C for 6 hr. was optimal for this enhancement of IF yield. Enhanced IF production was also observed in cell cultures irradiated by ultraviolet light 4–7 hr after stimulation with ND virus.

[37] Induction of interferon by bacterial endotoxin

Publisher Summary Interferon (IF) induced by endotoxin (EII) appears more rapidly in the circulation than virus-induced interferon. EII, however, is not previously stored in the cells, but is synthesized in response to specific stimuli and after synthesis of specific RNA and protein. Continuous cell cultures have not been reported to produce EII. EII is produced by the animal body or by lymphoid cells and macrophages freshly harvested from the animal body. Lower temperatures are appropriate for cells to produce EII in a culture medium than are required for virus-stimulated IF production. The optimum temperature for the stimulation of peritoneal leukocytes with Newcastle disease virus to produce IF in vitro is 40°, but 22-26° is optimal to produce EII. There are various treatments that reduce EII production: injection of corticosteroids, is adrenalectomy, injection of olive oil emulsion, laparotomy, is and infusion of air into the peritoneal cavity. The kinds of treatment will have either no influence or an inhibitory effect on virus-induced IF production.

Suppressive Effect of Macrophages on Interferon-γ Production by Human Peripheral Lymphocytes Stimulated with Mycoplasma pneumoniae

Production of interferon (IFN)‐γ was investigated in human peripheral lymphocytes stimulated with Mycoplasma pneumoniae. Lymphocytes obtained from non‐immune individuals produced no IFN. IFN‐γ was produced by T cells obtained from immune individuals, and the helper/inducer T cells produced two‐ to sixfold higher titer of IFN‐γ than the suppressor/cytotoxic T cells. The addition of macrophages in T cell cultures suppressed the production of IFN‐γ; this differs from the previous result wherein the addition of macrophages enhanced the production of IFN‐γ, when stimulated with mumps virus or measles virus.