Effect of mouse genotype on interferon production. I. Lines congenic at theIf-1 locus

The level of circulating Interferon induced in mice by Newcastle disease virus is controlled by a single codominant locus,If-1, with two alleles,If-1 ^l for low andIf-1 ^h for high production. This locus is linked to the histocompatibility locusH-28. Of three C57BL/6By lines congenic for the BALB/cBy allele atH-28, two are carrying the BALB/cBy allele and one, the C57BL/6By allele atIf-1. Thus, mouse strains that are genetically very similar but different in their production of NDV-induced circulating Interferon now are available.A preliminary report of these studies was presented at the ASM meeting at Miami Beach in May 1973.     

Effect of mouse genotype on interferon production II. Distribution ofIf-1 alleles among inbred strains and transfer of phenotype by grafting bone marrow cells

TheIf-1 alleles of many inbred strains, some of common parentage with either BALB/c Gif or C57BL/Lac, were determined. Of the 23 inbred lines examined, all were eitherIf-1 ^h orIf-1 ^l , except the C57BR/cdJ strain, which gave intermediate results; the latter will have to be explored more thoroughly before the existence of a third allele can be established. Survey of the 23 lines showed no correlation betweenH-2 haplotypes andIf-1 alleles. The absence of linkage betweenH-2 andIf-1 was confirmed by typing (BALB/c×C57BL)F₁×C57BL backcross progeny for bothH-2 andIf-1. The fact that some high and some low producers were of sameH-2 type made it possible to study the production of interferon in radiation chimeras. Mice of a low-producer strain, C3H/Lac (If-1 ^l , were lethally irradiated and their hemopoietic function restored by grafting bone marrow from eitherIf-1 ^l orIf-1 ^h mice, all donors of the sameH-2 haplotype as that of the recipients (H-2 ^k . NDV-induced serum interferon production was measured 31 days after irradiation and restoration. The production of interferon in all mice restored with marrow fromIf-1 ^l donors was equal or lower than that of syngeneic chimeras (alsoIf-1 ^l ). In contrast, titers of interferon in all four groups restored withIf-1 ^h marrow were higher than those of control chimeras, three being higher than titers in unirradiatedIf-1 ^l controls. These data indicate that theIf-1 locus is expressed through cells derived from hemopoietic stem cells, possibly the interferon-producing cells themselves.     

Dipyridamole-induced interferon production in mouse peritoneal leukocytes

The in vitro explanted mouse peritoneal leukocytes were used for the optimization of the dipyridamole-induced interferon production. After 90-120 min incubation of cells with 30-100 microM dipyridamole, the production of interferon reached 6.4 X 10(4) IU/ml. It was demonstrated that the interferon production phase is preceded by the dipyridamole-dependent increase in cAMP concentration. The possibility of cAMP involvement in the mechanism of interferon production is being discussed.     

Effect of mycoplasma on interferon production and interferon assay in cell cultures

Armstrong, D. (The Children's Hospital of Philadelphia, Philadelphia, Pa.), and K. Paucker. Effect of mycoplasma on interferon production and interferon assay in cell cultures. J. Bacteriol. 92:97-101. 1966.-The influence of mycoplasma on the production and action of interferon was studied in cultures of both L and human embryonic kidney (HEK) cells. Mycoplasma hominis 1, the Negroni agent, and the F12 mycoplasma were used for infection of L cells, and M. hominis 1 and M. pneumoniae for inoculation of HEK cells. All strains were capable of multiplication in the culture systems employed. None produced detectable levels of interferon, and responsiveness of the cells to induction of interferon by virus remained unaltered. Infection with mycoplasma did not impair the sensitivity of the cells to the action of interferon, nor was the replication of vesicular stomatitis virus noticeably diminished.     

Effect of T-activin on the production of immune interferon

A study was made of the effect of T-activin on the biosynthesis of immune gamma-interferon. It was shown that in 27% of patients with chronic nonspecific pulmonary diseases, production of gamma-interferon by lymphocytes was substantially reduced during exacerbation of inflammatory process in the lungs. It was discovered that T-activin was not an interferon inductor but enhanced its synthesis in patients with a low capacity of producing immune interferon even at small doses of interferon inductor. The preparation does not produce any effect on this process in normal subjects and in patients showing the normal level of gamma-interferon. Thus T-activin can be used for stimulation of interferonogenesis.     

The immunosuppressive effect of type II mouse interferon preparations on antibody production.

Preparations containing Type II (immune induced) interferon suppressed the immune response to sheep erythrocytes (SRBC) both in vitro and in vivo. Type II interferon preparations were 250 times more active in immunosuppression than Type I (L cell) interferon preparations in parallel experiments. The antiviral and immunosuppressive activities shared several unique physical-chemical activities including pH 2 lability, 56 °C stability, and resistance to inactivation by anti-L-cell interferon antibody. Both activities were denatured by boiling at 100 °C for 2.5 min, but were not renatured by boiling for 1 min with 1% SDS, 1% β-mercaptoethanol and 5M urea. The bulk of both the immunosuppressive and antiviral activities were recovered from a 41–60% saturated ammonium sulfate precipitate of Type II interferon. Sephadex G-100 column chromatography of Type II interferon preparations yielded two major peaks of anti-viral activity of molecular weights of approximately 40,000 and 90,000, both of which together contained the total immunomodulating activity observed in the proteins of the Chromatographic effluent. The 90,000-dalton species was also detected by its anti-viral and immunosuppressive activity on polyacrylamide gel electrophoresis.     

Alterations of interferon production in a mouse model of thermal injury

The effect of thermal injury on the response of interferon (IFN) production in vivo and in vitro after stimulation with eight representative inducers was investigated in a mouse model. The response of mice to immune IFN (IFN-gamma) inducers, staphylococcal enterotoxin A, concanavalin A, and a specific antigen for BCG-sensitized lymphocytes (purified protein derivative) was impaired after a 30% total body surface area third-degree burn. Suppression of IFN-gamma production was observed at day 2 and persisted until day 7 after burn. Decreased IFN-gamma production correlated closely with the percentage of total body surface area burned. When virus type IFN (IFN-alpha/beta) inducers, Newcastle disease virus, polyriboinosinic-polyribocytidylic acid, 10-carboxymethyl-9-acridanone, and E. coli endotoxin, were administered to mice, no change in IFN response was observed after thermal injury. Similar results were obtained when spleen cells obtained from thermally injured mice were stimulated with IFN-gamma inducers in vitro. These studies suggest that although the capacity for IFN-alpha/beta production remains intact in thermally injured mice, IFN-gamma production may be selectively decreased in burned animals and in their spleen cells.     

Effect of levamisole on interferon production by PHA-stimulated human leukocyte cultures

Mononuclear leukocytes of 10 normal blood donors were cultured in vitro and treated with phytohemagglutinin (PHA-P) and/or levamisole. Interferon-like activity was investigated in the supernatant fluids of the cultures, using VSV as challenge virus. In most of the cases the PHA-stimulated interferon-like activity was slightly but significantly enhanced by levamisole. The antiviral activity produced in the supernatant fluids was characterized as interferon since it was trypsin sensitive, species specific and inhibited by specific antiserum. This interferon has the characteristic sensitivity to PH2 of immune interferon.     

Effect of preliminary treatment with homologous interferon (priming) on the production of human immune interferon

Pretreatment of the cultures of human peripheral blood leukocytes and splenocytes with the incubation medium of the mitogen-stimulated human lymphoid cells containing various concentrations of lymphokines (including 10 to 1280 units/ml of immune interferon) resulted in increased (by at least 4 times) production of interferon, induced by staphylococcal enterotoxin A, phytohemagglutinin and mitogen from Phytolacca americana (PWM), as well as in intensification of DNA synthesis in the producing cells. A more pronounced specific binding of the inductor labeled with radioactive iodine to the producing cells was also observed.     

Heterogeneity of mouse lymphocytes in interferon production upon influenza virus challenge in culture

Heterogeneity of mouse lymphocytes with respect to interferon production upon influenza virus challenge in culture was studied. Spleen cells produced much more interferon than thymocytes or mesenteric lymph node cells. Spleen cells mainly responsible for interferon production belonged to the hydrocortisone-sensitive population. When spleen lymphocytes were separated into seven fractions by centrifugation on a serum albumin density gradient, they were found to differ greatly in interferon producing capacity; a small fraction of intermediate density, representing a few percent or less of the total lymphocytes, produced markedly high levels of interferon.     

Induction of interferon production in mouse spleen cell cultures by corynebacterium parvum.

Spleen cells of CS7BL/6 mice produced considerable amounts of interferon (IF) in vitro when tested 5 to 20 days after injection of killed Corynebacterium parvum. Interferon was also produced when C. parvum was added in vitro to spleen cell cultures of previously untreated mice. High levels were detected after 1 day of culture with some increment during subsequent days. In a number of experiments IF was also produced in untreated control cultures but only after prolonged cultivation and not after 1 day. The highest levels of IF were usually obtained when spleen cells of C. parvum-treated mice were challenged with additional C. parvum in vitro. The IF induced by C. parvum shared certain physicochemical properties with a tested immune IF and was not neutralized by an antiserum raised against a type I IF. Spleen cells of nu/nu mice and spleen cells treated by anti-θ serum plus complement did not differ from their respective controls, indicating that production of IF did not require mature T lymphocytes. Removal of B lymphocytes by nylon wool columns abolished the capacity of spleen cells to produce IF. When spleen cells were freed of adherent cells by the use of plastic surfaces, they no longer produced IF. Peritoneal exudate macrophages (PEC), which by themselves did not produce IF, in small numbers reconstituted nonadherent spleen cells. Nylon column-treated spleen cells, however, could not be restored by PEC. It is concluded that IF upon challenge with C. parvum is produced by B lymphocytes and requires the help of macrophages.     

Effect of genotype on hormonal function formation of Leydig cells during mouse postnatal development

Changes in in vitro testosterone production by Leydig cells induced by chorionic gonadotropin, dibutyryl-cAMP, and pregnenolone have been studied during postnatal development of four inbred mouse strains BALB/c, PT, CBA/Lac, and A/He, with contrast hormonal activity of testes in sexually mature males. The interlinear differences significantly change with age of the males by all studied indices indicating genotype-dependent formation of hormonal activity of Leydig cells during postnatal development. Coordinated interlinear variability between all indices of Leydig cells reactivity has been established for each studied period of postnatal development. Hence, we have established coordinated interlinear genetic variability of hormonal function of Leydig cells, which was confirmed by considerable changes in it during postnatal development at puberty. Definitive genotypic differences in hormonal activity of Leydig cells appeared by late pubertal and early postpubertal development (day 60) and coincided with termination of morphological differentiation of Leydig cells and appearance of the differentiated cell population.