The use of T-activin for the prevention of congenital influenzal infection in mice and the correction of the immune deficiency

Viremia accompanying influenza infection and the possibility of transplacental passage of the virus into the fetus make it expedient to develop measures for the prophylaxis of intrauterine infection of the fetus in case of influenza during pregnancy. The work presents the optimum scheme of administration of T-activin for prophylactic purposes to pregnant mice with acute influenza infection. Besides, the use of T-activin for immunocorrection in case of established congenital influenza infection in mice is proposed.     

Interaction of T-activin with peritoneal macrophages

The action of T-activin on peritoneal macrophages of CBA mice after its introduction into the animals has been studied. In intact mice the phagocytic activity of macrophages and their resistance to the cytopathogenic action of Salmonella typhimurium live cells remains unchanged. The injection of corpuscular pertussis vaccine into mice leads to a decrease in the resistance of macrophages to the action of salmonellae. The simultaneous injection of T-activin into mice in doses of 0.1 and 1.0 microgram per animal abolishes the damaging action of the vaccine. The analysis of the in vitro action of T-activin on macrophages of intact mice revealed that the preliminary incubation of cells with the preparation sharply increases their resistance to the action of salmonellae, while its introduction simultaneously with bacteria or after them rapidly leads to the death of macrophages. The action of T-activin is supposed to be linked with triggering the biosynthetic processes mediating the resistance of macrophages to the cytopathogenic action of salmonellae.     

Effects of immunoactivity on Ascaris suum infection in mice]

The immune response to sheep red blood cell (sRBC) was monitored in the mice infected with Ascaris suum or Trichinella spiralis. The effects of the infection with T. spiralis or the injection with cyclophosphamide(CY) as an immunosuppression agent prior to challenge infection with the embryonated eggs of A. suum were monitored in mice by means of the level of infection with A. suum and cellular and humoral immune response to sRBC. Following the oral administration of 1,000 eggs of A. suum to mice, delayed-type hypersensitivity (DTH) and rosette-forming rate were gradually decreased and reached to the lowest levels at the 5th week and 6th week postinfection, respectively, and then returned to normal at the 10th week. The hemagglutinin(HA) and hemolysin(HE) titers were gradually elevated and reached to peak at the 3rd week postinfection, and then returned to normal level. The appearance ratios of the eosinophils and mast cells were in peak at the 4th week and the 2nd week postinfection, respectively. Meanwhile the harvest ratio of A. suum larvae from the liver and lungs was 21.97% at the 1st week postinfection. Following the oral administration of 300 T. spiralis infective larvae, DTH and rosette-forming rate were gradually decreased with the lapse of time and reached the lowest values in the 30th and 21st day of postinfection, and then slightly increased and transiently decreased in the 70th and 80th day of postinfection, respectively. HA and HE titers were the lowest in the 21st and 90th day, whereas the ratios of eosinophils and mast cells were the highest on the 40th and 14th day postinfection, respectively. Following the intraperitoneal injection of CY, the body weight, the spleen weight, DTH, rosette-forming ratio, HA and HE titers, the number of WBC and the ratio of the mast cell were predominantly decreased in the 5th day, and then returned to the same value of the 1st day postinjection. The ratio of eosinophils was gradually decreased following to advance of days. At the 1st, 5th and 10th days after intraperitoneal injection of CY of 400 mg/kg, a dose with 1,000 eggs of A. suum was administered orally to mice, and harvest rate of the larvae at the 7th day postadministration was 7.07% in the 1st day, 14.94% in the 5th day, 10.1% in the 10th day, 8.02% in control group. The effect of prior infection with infective larvae of T. spiralis upon immunological sequelae of a challenge infection of mice with embryonated eggs of A. suum in 30 or 70 days interval was checked.(ABSTRACT TRUNCATED AT 400 WORDS)     

Prostacyclin biosynthesis in activated, stimulated and normal mouse peritoneal cell populations.

Nonspecific resistance to infectious and neoplastic disease can be enhanced by administration of "immunomodulators". The levels of enhancement can be monitored by following in vitro function of cells of the lympho-reticuloendothelial system. To gain a better understanding of the physiological and biochemical nature of this enhancement, the metabolism of prostaglandin endoperoxide PGH2 was followed in mouse peritoneal cells (PCs). Homogenates of PCs from normal, unstimulated mice yielded primarily prostacyclin (PGI2) when incubated with PGH2. Homogenates of PCs from mice injected with the immunomodulators C. parvum, levamisole HCl, pyran copolymer, or thioglycollate yielded less PGI2. Reductions ranged from 73% for C. parvum to 32% for levamisole. A statistically significant inverse correlation existed between the level of macrophage "activation" and ability of cellular homogenates to produce prostacyclin. The results suggest that prostacyclin may be involved in modulation of nonspecific resistance.     

The influence of Mesocestoides corti on subsequent Angiostrongylus cantonensis infections in mice.

The influence of Mesocestoides corti on subsequent Angiostrongylus cantonensis infection in mice (C57BL/6 and BALB/c) was assessed. Both strains of mice infected with M. corti demonstrated a peak blood eosinophilia at around 3 weeks post-infection (p.i.). C57BL/6 and BALB/c mice primarily infected with M. corti were given A. cantonensis infection 18 days later, but pre-existing M. corti infection did not affect the recovery of intracranial worms of A. cantonensis at day 21 p.i. BALB/c mice with mixed parasite infections showed low morbidity and mortality as compared with mice singly infected with A. cantonensis and some mice demonstrated a pulmonary migration of intracranial worms. In C57BL/6 mice, intracranial worms were killed and thus all mice survived. C57BL/6 mice with mixed parasite infections failed to resist A. cantonensis reinfection. The blastogenic responses of spleen cells against A. cantonensis antigen were lower in BALB/c than in C57BL/6 mice and mixed parasite infections also resulted in less blastogenic responses against both concanavalin A and A. cantonensis antigen than monoinfection. The recovery of M. corti biomass was significantly higher in mice with mixed parasite infections than mice with monoinfection with M. corti. These data suggest a distinct difference in response to A. cantonensis infection between C57BL/6 and BALB/c mice, and the induction of immunosuppression in both mouse strains following M. corti infection. Blood eosinophilia provoked by M. corti infection is not directly associated with the killing of worms in subsequent A. cantonensis infection.     

Cross-reactions with Ascaris suum antigens of sera from mice infected with A. suum, Toxocara canis, and Angiostrongylus cantonensis

Ascaris suum larval excretory-secretory (AsES) antigen and larval (AsLA) as well as adult somatic antigen (AsAA) which were thought to be possibly helpful in the diagnosis of visceral larva migrans (VLM) due to A. suum infection were investigated in the present study. Serum taken from mice orally inoculated with approximately 250 embryonated eggs of A. suum or Toxocara canis, or 40 third-stage larvae of Angiostrongylus cantonensis were assessed by enzyme-linked immunosorbent assay (ELISA) using the AsES antigen, AsLA or AsAA at 1, 2, 3, 4, 6 and 8 weeks post infection (WPI). The titer of serum IgG from mice infected with A. suum increased from 1 WPI and a peak at 4 WPI was observed when it reached approximately three times the level of uninfected control mice. Thereafter, it decreased gradually but remained high as found from 6 to 8 WPI. No cross-reactions of heterologous serum IgG against AsES antigen was observed, whereas heterologous serum IgM exhibited significant cross-reactions to AsES antigen. Cross-reactivities to AsLA and AsAA by heterologous serum IgG as well as IgM antibodies were also observed in the trial. Altogether, the AsES antigen apparently seemed to be superior to the other two somatic antigens when used in the diagnosis of A. suum-induced VLM with serum IgG as tested by ELISA. Moreover, it was the first report to test the possibly antigenic cross-reactivity between A. suum and A. cantonensis.     

Effect of T-activin on peripheral immunity organs in intact and thymectomized mice

Morphometry of the spleen, axillary lymph nodes and cytological assay of the bone marrow and peripheral blood were performed in (CBA X C57BL)F1 mice 1, 5, 10 and 15 days after subcutaneous injection of 0.5 microgram T-activin to intact and thymectomized (when adult) mice 2 months after operation. It was demonstrated that in intact animals, injection of T-activin stimulated the whole system of immunogenesis. The time course of plasmatization and the response of the germinative centers differing from that seen during antigen administration suggests that T-activin is not immunogenous, acting as a stimulant of the previous immune responses. The permanent amount of the degenerating cells attests to the lack of the toxic drug effect.     

Hybridoma antibody immunoassays for the detection of parasitic infection: development of a model system using a larval cestode infection in mice

A prototype immunodiagnostic assay has been developed using chronic infection with the larval cestode, Mesocestoides corti, as a model system in mice. The assay is highly sensitive, it appears to be absolutely specific for M. corti infection, and is based on the inhibition of binding (by sera from infected mice) of a radiolabelled anti-M. corti hybridoma antibody to a crude M. corti antigen extract. The hybridoma antibody binds to living M. corti larvae and is an IgG1 protein. In large scale experiments no false positives were detected and the only M. corti-infected mice not detected by the assay were hypothymic nude (nu/nu) mice. Only limited success has been achieved in attempts to convert the assay to one not requiring parasite antigen and based on the inhibition of binding of radiolabelled anti-parasite hybridoma antibody and a large pool of anti-idiotype antiserum. Monoclonal antibodies derived from anti-parasite antibody-secreting hybridoma cell lines will be of particular use in the development of new, highly specific, immunodiagnostic reagents for the detection of parasite infection, exposure and disease.     

A comparative study of the susceptibility of inbred strains of mice to infection with Mesocestoides corti

White T. R., Thompson R. C. A. and Penhale W. J. 1982. A comparative study of the susceptibility of inbred strains of mice to infection with Mesocestoides corti. International Journal for Parasitology12: 29–33. The susceptibility of 6 strains of inbred mice to infection with Mesocestoides corti was studied following both intraperitoneal and oral inoculation of tetrathyridia. The greatest degree of resistance was seen in C57BL/6 mice and this resistance was independent of route of inoculation. The proliferation of the parasite in C57BL/6 mice was compared with a more susceptible strain (CBA/H) on 7, 14, 21, 35 and 60 days post-infection. Although both strains harboured significantly different parasite burdens during the initial period following infection, these differences were no longer apparent by day 60.     

猪蛔虫感染对小鼠肺部免疫病理反应的动态观察

目的：动态观察感染猪蛔虫后,小鼠肺组织的病理变化及肺泡灌洗液中相关细胞因子的变化,从而了解蛔虫感染对肺脏的侵害过程。方法：温箱孵育猪蛔虫受精卵至含蚴卵,用灌胃法感染小鼠,分别在感染后第0、7、14、45天处死小鼠,观察肺组织的病理改变,并通过ELISA方法检测肺泡灌洗液（bronchoalveolarlavagefluid,BALF）中IL-4、IFN-γ、IL-10和TGF-β1含量的动态变化。结果：感染14天组,肺组织的病理改变最为严重：大量炎症细胞浸润,嗜酸性粒细胞增多,严重者支气管狭窄,肺泡塌陷;感染45天组,小鼠肺组织病理变化比前者显著减轻。BALF中IL-4含量在感染7天、14天后分别为（169．20±34．61pg／m1）,（381．33±57．39pg／m1）,均明显高于未感染组（38．03±6．09pg／m1）;在感染45天后降低（98．49±25．33pg／m1）,但仍高于未感染组。IL-10水平在感染后降低;但感染45天组,IL-10水平却有所增高（179．78±21．33pg／m1）,并高于感染前。IFN-γ、TGF-β1,含量在感染后也有明显降低。结论：猪蛔虫感染初期,小鼠肺部损伤严重,小鼠BALF中促炎症细胞因子占主导地位;但在感染后期,BALF中促炎症细胞因子含量降低,炎症抑制因子IL-10有所增高,炎症缓和。     

Effect of T-activin on thymus involution in mice

The effect of T-activin on thymus involution in mice was studied. T-activin in a dose of 1.0 micrograms/mouse was injected into young male (CBA X C57BL)F1 mice weighing 24.0 +/- 2.0 g daily for 20 days. Morphometric analysis of the thymus was made 6 months after the treatment with T-activin was completed. It was found that T-activin induced the suppression of physiological involution of the thymus together with the enhancement of the processes of thymocyte transformation and proliferation.     

The IgE and IgG subclass responses of mice to four helminth parasites

To investigate whether the formation of IgE is linked in vivo to an IgG subclass, mice were infected with four helminth parasites, Nippostrongylus brasiliensis (Nbr), Mesocestoides corti, Taenia crassiceps and Trichinella spiralis, and the changes in the serum levels of the different Ig isotypes as well as the antibody response to M. corti and T. crassiceps antigen extracts were determined by radioimmunoassays. All four parasites induced a concomitant increase of the IgE and IgG1 serum levels and usually a decrease of the IgG2a level. They also induced an increase of the IgM level but had little effect on the IgG2b, IgG3, and IgA serum levels. The specific antibodies to an M. corti antigen extract were mainly of the IgG1 subclass, whereas it was of both IgG1 and IgG2a subclasses to T. crassiceps. Injections of dead M. corti induced an increase of all IgG subclasses and similar levels of IgG1 and IgG2a anti-parasite antibodies. Subcutaneous instead of intraperitoneal infection with T. crassiceps induced higher IgG2a than IgG1 levels and 10-fold lower IgE levels than the natural ip infection; however, despite the greater IgG2a polyclonal response, anti-parasite antibodies were predominantly of the IgG1 subclass. The data demonstrate that natural infection with four different helminth parasites induces a concomitant polyclonal IgG1 and IgE response. These in vivo observations corroborate the recent in vitro findings demonstrating that interleukin-4 induces lipopolysaccharide-activated murine B cells to secrete both IgG1 and IgE, suggesting that the regulation of these two isotypes is linked.     

Eosinophilia in Ascaris suum-reinfected mice

The secondary response of eosinophilia has been studied in mice infected with A. suum. In mice infected orally with 1000 A. suum eggs, larvae disappeared from the body within two weeks after infection. The number of peripheral blood eosinophils decreased to the pre-infection level within eight weeks. A typical secondary response of IgG antibody production to egg antigen was found after reinfection with 1000 eggs. The number of peripheral blood eosinophils increased more rapidly after reinfection than after the primary infection. However, the peak number of eosinophils after reinfection was similar to that after primary infection, and the long-lasting characteristics of eosinophilia after reinfection did not differ from those after primary infection. These results suggest that the secondary response of eosinophilia is characterized by a rapid increase in the number of eosinophils in A. suum-reinfected mice.     

Biochemical and functional analysis of extracellular stress proteins of Mesocestoides corti

Previous studies of the serum antibody response in mice to Mesocestoides corti infection indicated that molecules released by the parasite influenced the production of IgM and IgG1 to the exclusion of other isotypes. Two proteins isolated from M. corti culture supernatants were found to be homologous to the 70-kDa heat shock proteins (hsp70) and Escherichia coli GroEL families of stress proteins. The proliferative responses of splenic lymphocytes from infected mice were assessed to unfractionated M. corti supernatants as well as the 70- and 60-kDa stress protein homologs isolated from supernatants. Lymphocytes from infected mice respond to complete supernatant and both of the isolated p70 and p60 stress protein homologs. In addition, supernatant from M. corti cultures stimulates an in vitro antibody response restricted to IgM and IgG1; the same isotypes induced during infection. These results suggest that stress proteins play an integral part in the immune response to M. corti and the associated isotype restriction.     

Vaccination with recombinant Ascaris suum 24-kilodalton antigen induces a Th1/Th2-mixed type immune response and confers high levels of protection against challenged Ascaris suum lung-stage infection in BALB/c mice

Previous studies have shown that antigens from various life-cycle stages of Ascaris suum can induce host-protective immunity against challenge infections with infective eggs of A. suum. This study evaluated whether Escherichia coli-expressed recombinant 24-kDa antigen from A. suum (rAs24) was a suitable vaccine candidate for the control of Ascaris infections by examining its performance in a mouse model. Immunization of BALB/c mice in three consecutive doses with rAs24 in Freund's Complete Adjuvant (FCA) results in protection against challenge infections as manifested by a 58% reduction (P<0.001) in recovery and stunted development of A. suum lung-stage larvae at day 7 post-challenge. Sera obtained from immune protected mice had a significantly increased level of immunoglobulin G (IgG) (P<0.0001) but had no IgE response. Analysis of IgG-subclass profiles revealed that IgG1 (P<0.0001) showed the greatest increase followed by IgG2b (P<0.005), IgG2a (P<0.006) and IgG3 (P<0.04). Splenic T cells from rAs24-FCA immunized mice secreted significantly high levels of both Th1 cytokine gamma-interferon (P<0.005) and Th2 cytokine interleukin-10 (P<0.001) after stimulation with rAs24 in vitro. Interestingly, affinity purified anti-rAs24 IgG was shown to inhibit moulting of A. suum lung-stage L3 to L4 in vitro by 26%, indicating an in vivo function of the endogenous As24 in the moulting processes. An intense expression of endogenous As24 in the hypodermis and gut epithelium of A. suum lung-stage L3 by immunofluorescence supports a function for endogenous As24. These findings may contribute to the understanding of rAs24-induced Th1/Th2-mediated effector mechanisms required for the protection of A. suum lung-stage larval infection.     

Plasmodium berghei: eosinophilic depression of infection in mice

The effects of eosinophilia on the course of Plasmodium berghei infection in mice were studied. Eosinophilia was induced by intravenous injection of Ascaris suum body fluid into the mice. Results indicated that eosinophils may play a role in the suppression of murine malaria. A significant reduction in parasitemias and increased survival time in eosinophilic mice occurred compared to mice not treated with A. suum body fluid. Reduction of parasitemia was effectively achieved when the mice were challenged with P. berghei, only after the level of eosinophils reached at least 10% of total white cell counts in the circulation. These findings may offer an additional explanation for the suppression of malaria in individuals with severe ascariasis.     

Stimulation of leukocyte lysophospholipase activity by noninfectious agents

Mouse peritoneal leukocyte lysophospholipase (LPL) activity was studied to determine whether or not noninfectious agents cause increased enzyme activity and whether neutrophils have LPL activity. In the first study, mice infected with Ascaris suum, a known inducer of LPL activity, were given intraperitoneal injections of proteose peptone, thioglycolate, bovine albumin, paraffin, glycogen, or A. suum whole worm extract (WWE). Cell populations collected from mice injected with A. suum WWE, proteose peptone, thioglycolate, or bovine albumin contained increased numbers of neutrophils and eosinophils. These cell populations had increased LPL activity when treated, in vitro, with either A. suum WWE, zymosan-activated complement, or with the agent they were induced with. However, the LPL activity of the different cell populations did not respond to all treatments in the same way. In a second study, A. suum-infected or noninfected mice were given intraperitoneal injections of paraffin, thioglycolate, glycogen, or A. suum WWE. Enriched cell populations containing either lymphocytes or macrophages, from infected or noninfected mice, did not have increased LPL activity following in vitro stimulation with A. suum WWE, zymosan-activated complement, or with the agent they were induced with. Enriched neutrophil populations from infected or noninfected mice had increased LPL activity following in vitro treatment with A. suum WWE or zymosan-activated complement. Results demonstrate that the LPL activity of peritoneal leukocytes can be induced by noninfectious agents and that neutrophils have increased LPL activity following in vitro stimulation.     

Effects of T-activin on the morphology of the thymus gland in experimental injury of the lower limbs in mice (anti-stress effect of T-activin)

The effect of T-activin on thymic involution under the experimental trauma of femur was studied. T-activin in a dose of 1.0 micrograms/mouse was injected into young male (CBA X C57BL)F1 mice weighing 17.5-19.0 g before (I injection) or immediately after the fracture of the femur during 3 days. Morphometric analysis of the thymus was made 1, 5, 10 and 15 days after the trauma. It was found that T-activin suppressed the involution of the thymus, induced by the trauma, during the first 5 days and accelerate the process of its regeneration. It is suggested, that T-activin displays protective anti-stress effect on the mouse thymic involution.     

Cross-reactions of sera from Toxocara canis-infected mice with Toxascaris leonina and Ascaris suum antigens.

The ELISA method using larval excretory-secretory (E/S) products and homogenized Toxocara canis, Toxascaris leonina and Ascaris suum adult worm extract were used to determine possible cross-reactions in BALB/c and C57BL/10 mice, inoculated with embryonated eggs or adult worm extract of T. canis in single and multiple doses. When we used sera of mice infected with embryonated eggs of T. canis against different heterologous antigens, we observed no cross-reactions in BALB/c mice against A. suum E/S and adult worm extract antigens with a single dose. In multiple doses this was absent too against T. leonina adult worm extract in BALB/c mice, and in both strains against A. suum E/S and adult worm extract. In BALB/c mice inoculated with adult worm extract of T. canis we did not observe cross-reactions with A. suum E/S antigen with both inoculation doses. In the remainder of the experiments, we observed cross-reactions of different intensities.     

Cell proliferation in mouse tissues after thymectomy and the administration of T-activin

The epithelium of mouse cornea and lymph nodes was examined for DNA-synthetic and mitotic activity at different times after thymectomy and administration of T-activin, an active factor of the thymus. Thymectomy entails retardation of the rate of corneal epithelium regeneration, diminution in both tissues under study of the amplitude of oscillations in cell proliferation throughout the day. Administration to the animals of the immunoactive thymic factor T-activin makes the circadian rhythm of cell proliferation return to normal. It is assumed that T-activin raises the capacity of lymphocytes to interact with epithelial cells, which manifests itself in the enhancement of their mitotic activity.