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The kinetics of eosinophil growth and for survival stimulating factors (Eostimulating factors) released by spleen cells from A. cantonensis -infecled mice were assessed by in vitro marrow cultures. When spleen cells from C57BL/6 mice 8 to 20 days p.i. were cultured with young adult A. cantonensis worm antigen or Con A, almost equal amounts of Eo-stimulating factors were detected in the conditioned media obtained from both stimulations. No Eo-stimulating factor activity was detected in cultures from spleen cells without stimulation or from normal spleen cells with stimulation. Production of Eo-stimulating factors was inhibited by the pretreatment of the spleen cells with anti-Thy1.2 or anti-L3T4 antibodies plus complement but not with anti-Lyt2.2 antibody. In the presence of anti-mouse IL-5 monoclonal antibody, the activity of Eo-stimulating factors was inhibited by up to 99%. IL-5, therefore, appears to play a principal role in induction of eosinophilia in mice infected with A. cantonensis .

Male Mongolian gerbils, Meriones unguiculatus, vaccinated with 500 20-krad gamma-irradiated cercariae of Schistosoma mansoni did not exhibit resistance against a homologous challenge infection. Gerbils appear promising as alternative laboratory hosts for the study of schistosomiasis.

The effects of cell transfer on the defective natural defences of beige (bgj/bgj) mice against Strongyloides ratti were studied by assessing recovery of tissue-migrating larvae from head and lung. Transfer of peritoneal resident cells from normal bgj/+mice restored the defective natural defence of beige mice. The non-adherent population of normal peritoneal cells did not have the restorative capacity. Macrophages may be important to the natural defence against S. ratti.

Summary Eosinophil chemotactic activity associated with whole worm extracts of the young adult worms (YA) and 1st stage larvae (L1) of Angiostrongylus cantonensis was assessed using guinea-pig- and rat-eosinophils. Both whole worm extracts were potently chemotactic to guinea-pig-eosinophils whereas only the whole worm extract of L1 was chemotactic to rat-eosinophils. Gel filtration chromatography of YA-whole worm extract yielded an eosinophil chemotactic factor (ECF-YA) with an estimated molecular weight of 16900. ECF-YA was resistant to heating and pronase digestion but sensitive to periodate oxidation, suggesting that chemotactic activity was possibly associated with the sugar portion of the glycoprotein molecule. Guinea-pig- and rat-eosinophils were deactivated by previous incubation with homologous whole worm extracts but not with heterologous ones. When guinea-pig-eosinophils were treated with trypsin or pronase, their chemotaxis to ECF-YA was significantly inhibited, and pronase treatment was more effective. Both deactivated and trypsin-treated guinea-pig-eosinophils completely recovered their chemotaxis responses after in vitro culture for 12 and 24 h, respectively. When those eosinophils were cultured in vitro in the presence of puromycin or cycloheximide, however, their chemotaxis responses could not be recovered. These data clearly indicate that guinea-pig-eosinophils probably possess a kind of receptor (or ‘recognition unit’) capable of reacting to ECF-YA, and also that the receptor may be protein or glycoprotein molecules, and reproducible.

The kinetics of eosinophil growth and/or survival stimulating factor (Eo-stimulating factor) production in Angiostrongylus cantonensis-infected rats was assessed by in vitro marrow cultures. When lymphocytes, obtained from cervical, mediastinal or mesenteric lymph nodes of infected WKAH rats, were cultured with A. cantonensis antigens, Eo-stimulating factor activity was detected in the conditioned media obtained only from mediastinal lymph node cells at and after 35 days p.i. Eo-stimulating factor activity in the conditioned media was not detected before or at 20 days p.i. The kinetics of the factor was, therefore, almost identical to those of eosinophilia in bone marrow and peripheral blood. This Eo-stimulating factor activity was inhibited (maximum inhibition = 73%) by anti-mouse IL-5 monoclonal antibody in a dose-dependent fashion, indicating that the factor would be, at least in part, identical to IL-5. Similar Eo-stimulating factors were also detected in the conditioned media which were obtained by stimulating spleen cells from Wistar rats at 35–45 days p.i. with Con A. These data suggest that lymphocytes in the mediastinal lymph nodes, local lymph nodes near the adult worm habitat, could play an essential role in induction of eosinophilia in A. cantonensis-infected rats.

The survival, growth, and egg-laying capacity of young adult Angiostrongylus cantonensis, surgically transferred from intracranial sites into pulmonary arteries, were studied. A variety of experimental animals (rats, guinea pigs, mice, and mastomys) were chosen as donor animals and as recipient hosts (rats, guinea pigs, and rabbits). These species were specifically chosen to span the spectrum of host permissiveness relative to worm development in an attempt to understand the mechanisms which underlie species-dependent resistance. Recipient animals were monitored not only for the development of parasites per se but also for antibody production and histopathologic changes. The results indicated that these procedures were technically feasible, with good worm development following intra-rat transfers, as early as 15 days after initial exposure. Studies were performed to analyze the constraints of development both on initial, i.e., prelung and subsequent i.e., postlung development. When worms were obtained from permissive species such as rat or mastomys, transfer into rats resulted in good growth and development; however, worms which developed initially in exposed mice or guinea pigs developed less well in the rat. Conversely, worms which developed initially in permissive host such as the rat, when transferred into a variety of less permissive hosts such as the guinea pig and rabbit, apparently did not survive and caused significant morbidity and mortality within the nonpermissive host. Histopathologic evaluation revealed a strong eosinophilic perivascular and peribronchiolar infiltration as well as granulomatous reactions surrounding the worms in the lungs of recipient guinea pigs and rabbits, changes not observed in the lungs of permissive rat recipients. As reaginic antibody responses were also more prominent in nonpermissive than in permissive animals, it is possible that IgE responses may be more directly related to the phenomenon of morbidity and/or permissiveness than are other aspects of immune response. In support of this contention was the finding of nearly equivalent hemagglutinating antibody production between permissive rats and nonpermissive guinea pigs and rabbits.

Blood and bone marrow eosinophilia was assessed in nonpermissive (guinea pigs) and permissive (rats) hosts following the pulmonary arterial transfers of live or dead young adult worms of Angiostrongylus cantonensis. Guinea pigs showed a marked eosinophilic response to live worms but only a slight response to dead worms. Neither IgE nor haemagglutinating antibodies correlated with the induction of this eosinophilia. In contrast, the rat responded to neither form of the young adult worm. When the guinea pig and the rat were injected with whole worm extract (WWE) of the young adult worms either by an osmotic mini-pump connected to the jugular vein or by intermittent intravenous injections, the former animal showed blood eosinophilia but the latter failed to do so. Guinea pigs also developed blood eosinophilia after continuous exposure to the excretory and secretory products of the young adult worms, administered by the mini-pump. Eosinophil responses to WWE could be induced both in athymic CD-1 (ICR) nude mice and in its heterozygous litter mates, suggesting that T cell-independent mechanism(s) could be involved in the induction of blood eosinophilia in the nonpermissive, mouse host. These data clearly indicate that the eosinophilia-inducing factor(s) and the mechanism of eosinophilia are different in permissive and nonpermissive hosts.

Three strains (ACI, August and Wistar) of rats previously sensitized by oral infection with intact third-stage larvae of Angiostrongylus cantonensis developed significant protective immunity to challenge infections 6 weeks later. The degree of the immunity was highest in the August strain of rats, followed by Wistar and ACI rats. Protective immunity appears to affect both third-stage larvae and fourth- and/or fifth-stage worms. ACI rats showed poor antibody responses, especially in the IgE fraction. When 24-day-old young adult worms were transferred from the brain of donor rats into the peritoneal cavity of sensitized rodents, peritoneal eosinophils predominantly adhered to the worm surfaces in vivo.

Specific characteristics of Paragonimus westermani, P. ohirai , and P. miyazakii were sought in electrophoretic patterns of whole body proteins. From P. westermani , a minimum of 23 distinct protein bands was separated. Densitometric tracings gave at least 6 prominent peaks considered to be species specific. A minimum of 24 distinct bands was identified from P. ohirai . At least 7 of the bands were prominent and considered characteristic of P. ohirai . No significant difference was found in the electrophoretic patterns and the R F value of each band separated from P. ohirai worms obtained from rats and cats. A minimum of 23 distinct bands was identified from P. miyazakii . This species has at least 6 prominent bands, of which two (bands 7 and 11) were especially high in density. There was observed no significant difference between P. miyazakii worms originating from crabs collected at Iwakuni or at Kurodasho. The three species of lung flukes showed similar electrophoretic patterns in the gel regions near the origin and the front band. Two prominent bands identified from these gel regions were common to all of the above species. The major differences are found in the mid region of the gel. Each of the three lung flukes has a species-characteristic electrophoretic pattern containing several prominent protein fractions. These patterns are highly reproducible and definitive for all of the species.

“Autophagy” is a highly conserved pathway for degradation, by which wasted intracellular macromolecules are delivered to lysosomes, where they are degraded into biologically active monomers such as amino acids that are subsequently re-used to maintain cellular metabolic turnover and homeostasis. Recent genetic studies have shown that mice lacking an autophagy-related gene (Atg5 or Atg7) cannot survive longer than 12 h after birth because of nutrient shortage. Moreover, tissue-specific impairment of autophagy in central nervous system tissue causes massive loss of neurons, resulting in neurodegeneration, while impaired autophagy in liver tissue causes accumulation of wasted organelles, leading to hepatomegaly. Although autophagy generally prevents cell death, our recent study using conditional Atg7-deficient mice in CNS tissue has demonstrated the presence of autophagic neuron death in the hippocampus after neonatal hypoxic/ischemic brain injury. Thus, recent genetic studies have shown that autophagy is involved in various cellular functions. In this review, we introduce physiological and pathophysiological roles of autophagy.

Experimental transfer of the lung stage worms of Angiostrongylus cantonensis was performed between permissive hosts (rats) and between permissive (rat) and nonpermissive hosts (guinea pigs and rabbits). These worms from rats were rejected when implanted into nonpermissive hosts. Unexpectedly, similar worms did not survive well even in permissive hosts; the majority of recipient rats did not have first-stage larvae (L 1 ) in their stools and, even when positive for L 1 , the number of the larvae shed was few. These findings contrast with the successful pulmonary arterial transfer of younger, intracranial-stage worms. It was shown that differences in rat strain between donor and recipient had no significant effect on the subsequent worm survival in recipient hosts. The alteration of maintaining conditions of the intrapulmonary worms, prior to transfer, in terms of temperature, media, and maintaining period, also showed no profound effect on the subsequent worm survival. The kinetics of precipitating and reaginic antibody levels in rats implanted with the intrapulmonary worms were analogous to those in rats with intracranial-stage worms. The findings indicate that some qualitative differences may exist between the worms obtained from two different sites.

Angiostrongylus cantonensis-infected rats were examined for the presence of antigen sensitive lymphocytes, as assessed by the in vitro uptake of tritiated thymidine by cells of various lymphoid organs (cervical, mediastinal and mesenteric lymph nodes, spleen and periphereal blood), following stimulation by adult worm antigen. The lymphoid cell response of rats to A. cantonensis appeared to be local in nature in that significant responses were noted only in the cervical lymph node cells during the first 4 weeks of infection. The responses of spleen cells to phytohemagglutinin gradually declined as the infection progressed and this reduced responsiveness was statistically significant during the period of 5 to 10 weeks of infection. Homocytotropic antibody, demonstrated by 72-hour homologous passive cutaneous anaphylaxis, was detected throughout 2 to 17 weeks postinfection with a peak response at the 5th week of infection. The antibody was heat labile and sensitive to reduction by 2-mercaptoethanol and alkylation. Hemagglutinating antibody was first observed 5 weeks after infection and high titers occurred throughout 6 to 17 weeks postinfection.

8系統(ACI/N, Buffalo, Lewis, NIG III, Tokyo, Wistar-King-A, Wistar-King-S, Wistar/Mishima)の近交系ラットに広東住血線虫(Angiostrongylus cantonensis)を感染させ, 10週後に攻撃感染を行ない, 攻撃感染防御能, ならびにレアギン抗体と間接血球凝集(IHA)抗体の産生能を比較した. その結果, BuffaloとACI/Nでは他の系統より攻撃感染防御能が低く, これに対してTokyoとNIG IIIでは防御能の高いことがわかった. 残りの4系統も多かれ少かれ獲得免疫を産生したが, その程度は前述の4系統の中間的なものであった. 本虫の感染に対するレアギン抗体の産生パターンには系統間で著しい差異が認められた. すなわち, Tokyoはレアギン抗体のhigh responderであり, ACI/Nはlow responderであった. 一方, IHA抗体の産生パターンは系統間で酷似していた. しかし, TokyoやNIG IIIでは一般に他の系統よりIHA抗体価が高かった. ACI/NとNIG IIIについて肺の病変を比較したところ, ACI/Nでは肺の虫卵結節周囲に線維化がほとんど認められず, このことはNIC IIIとの著しい相違点であった. 以上の成績は, 広東住血線虫感染に対するラットの攻撃感染防御能やレアギン抗体産生能は遺伝的支配を受けていることを示唆するものと思われる.

Angiostrongylus cantonensis-infected rabbits and rats were monitered for the productions of reaginic and indirect hemagglutinating (IHA) antibodies. Rabbit reaginic antibody detected by 72 hour homologous passive cutaneous anaphylaxis (PCA) was first demonstrated in sera of rabbits infected with 230 infective larvae 9 weeks after primary infection and persisted at very low titers for considerable duration. When such rabbits were reinfected with 600-820 larvae on Day 36, the reaginic antibody occurred much earlier, i.e., as early as 6 weeks after primary infection. The secondary and tertiary infections markedly boosted the PCA titers which gradually declined thereafter. Rabbit reaginic antibody was heat resistant but other physico-chemical properties were analogous to human IgE. No substantial IHA antibody productions were observed in sera of the infected Tabbits. A peak reaginic antibody response in rats was observed 5 weeks after primary infection. However, the reaginic antibody production in rats was only transient and no anamnestic response was induced by reinfection. In rats, IHA antibody was first detected in sera as early as 6 weeks postinfection and persistently observed throughout 6 to 18 weeks postinfection. Reinfections significantly boosted the IHA titers in some rats but not in the others.

Guirxea pigs infected witlt Angiostrongylus cantonensis were examined forthe occttrrence of antigen sensitixe lymphocytes in variotns lymphoid organs (cervical, mediastinal and mesenteric l)mph nodes, and spleen), as assessed by in vitro incorpora-Lion of tritiated thymidine by lymphocytes following stimulation by adult or young adultworm antigens.Only splenic cells from infected guinea pigs showved significant blastogenic responses toboth adult and young adult worm antigens throtughout the course of infection. Thisresponse gradually increased as the infection progressed.Homocytotropic reaginic antibody was first detected 18 days postinfection and continu-ously demonstrated in some individuals throughout 18 to 47 days postinfection. However, the production of reaginic antibody was observed in only 50% (5/10) of the infectedanimals.No hemagglutinating antibody could be observed in the infected animals during thecourse of infection.

Time course of the production of reaginic antibody to ovalbumin (DA) wasassessed by 48-hr passive cutaneous anaphylaxis in 10 inbred rat strains (ACT, ALB, BUF, LE, LEW, NIG, Tokyo, WKA, WKS and W/Ms). The production of indirect hemagglu-tinating (IHA) antibodies was also examined. Immunization of the rat strqins with 0.1, 0.01 or 0.001 mg of DA resulted in a differentiation of the strains into high and low aswell as moderate responders in terms of the levels and duration of reaginic antibody pro-duction. Three strains, i.e., W/Ms, WKA and WKS, were high responders whose reaginproduction was persistent when immunized with 0.01 mg of DA. In contrast, ACT strainwas a low responder, producing less or no reaginic antibody following primary immuniza-tions. In NIG strains, a high titer reaginic antibody occurred shortly after immunizationbut did not persist. The data also suggested that ALB, BUF, LE and Tokyo strains wouldbe moderate responders. All rat strains examined produced the IHA antibodies followingimmunization with 0.1 or 0.01 mg of GA. The LEW, ACT and WKS rats, however, producedno IHA antibody after the primary immunization with 0.001 mg of DA and moreover, the latter two strains gave no IIIA antibody responses even when the secondary immuniza-tion was employed. Both ACT and LE strains could not switch over IgM to IgG antibodyproduction when immunized with 0.1 and 0.01 mg of DA, respectively. In the latter strain, no IgG antibody production could be induced even after the secondary immunization.These studies indicate that both high and low responders plus NIG strain would serveas a useful model for the evaluation of genetic factors involved in the production ofreaginic antibody.

Eosinophilia of the cerebrospinal fluid (CSF) in permissive (rats) and non-permissive (mice) hosts infected with Angiostrongylus cantonensis, and the possible mechanism of the eosinophilia were studied. In three strains of thymic mice (ICR, ddY and BALB/c), the infection provoked a marked CSF eosinophilia starting at around day 12, reaching a peak level at day 20 and maintaining significantly high levels until day 35. In contrast, in athymic nude mice of BALB/c strain the infection failed to evoke this eosinophilia, suggesting T-cell dependence of murine CSF eosinophilia. Humoral antibodies did not correlate with the induction of eosinophilia. A time-course study of worm recovery in the mouse brains indicated a gradual but consistent reduction in worm burden in accordance with the rapid rise in CSF eosinophil levels. Bone marrow eosinophilia occurred in mice at day 5, which preceded CSF eosinophilia. Jirds, a permissive but less susceptible host, developed a CSF eosinophilia with a peak level at day 17, but which declined rapidly following the peak. Permissive rat hosts developed significant peripheral and bone marrow eosinophilia at day 35 but their CSF eosinophilia was markedly less prominent than that of mice and jirds. These data clearly indicate that there are distinct differences in the mechanism of eosinophilia and eosinophilia-inducing factors between permissive and non-permissive hosts.

Lung infection with Angiostrongylus cantonensis was established in experimentally infected Indian softfurred rats (Millardia meltada) and Indian spiny mice (Mus platythrix). Pulmonary arterial migration occurred earlier (at day 20 after infection) in M. meltada than in Wistar rats. M. meltada and M. platythrix could serve as useful animal models for comparative studies of mechanisms determining host specificity of A. cantonensis.

BALB/c athymic nude and thymus-reconstituted nude mice and neonatally thymectomized BALB/c mice were infected with stage 3 larvae ofAngiostrongylus cantonensis and the worm burdens of the mice were determined at various times after infection. When the nude and thymectomized mice were exposed to the parasite, some worms were found to migrate from the brain to lungs but died there without reaching maturity. This pulmonary arterial migration of the worms in the nude mice did not occur following thymic reconstitution. These data suggest that the inability of murine intracranial worms to migrate to the lungs is at least in part due to thymus-dependent mechanisms, and also that the failure of worm maturation in mouse lungs might be due to thymus-independent immune mechanisms and/or nonimmunological mechanisms.

Summary Guinea-pigs infected with Angiostrongylus cantonensis developed pleocytosis and eosinophilia in the cerebrospinal fluid (CSF) at day 12 post-infection (p.i.). showing a peak response at day 20 p.i., followed by a gradual reduction. Ultrastructural observations on CSF eosinophils from infected mice and guinea-pigs revealed various signs of eosinophil degranulation after day 14 p.i., suggesting the exocytosis of lysosomal material. Morphometric analysis indicated that CSF eosinophils after day 22 p.i. contained fewer granules as well as smaller granules than those at days 14-20 p.i. These data suggest that CSF eosinophils release granule constituents into the outside of the cells and these secretion products could interact with the intracranial worms and are probably related to worm death. As degenerative atrophy or partial loss of Purkinje cells and the spongy vacuolation of the white matter were noted in the cerebellum of infected mice, it was suggested that CSF eosinophils could be a possible cause of neurological disorders in angiostrongyliasis cantonensis.

Morphologic characteristics and electrophoretic patterns of whole body proteins of a species of Paragonimus (Trematoda) found on Sado Island, Japan, were examined to aid in establishing its specific identity. The infection rate of the metacercariae in the crab, Potamon dehaani was 43%. Paragonimus sp. (Sado Island) will mature in both rats and cats, however, the worm recovery rate was higher in the single surviving cat (73%) than in the rats (3–47%). Worm maturation in these animals occurs in about 35 days after exposure. The adult worm of this species has “ ohirai-iloktsuenensis ” type cuticular spines and ovary but the eggs of this species are similar to those of P. ohirai . This species produced a minimum of 23 distinct protein bands of which seven were prominent. No significant differences were observed in electrophoretic patterns except in the mean R F values of three bands between Paragonimus sp. (Sado Island) obtained from rats and cats. This species is distinctly different from both P. westermani and P. miyazakii . However, the electrophoretic characteristics were essentially identical with P. ohirai . The R F value of each band separated from this species seems to be slightly smaller when compared with P. ohirai .

Background Rheumatoid arthritis (RA) is an inflammatory disease that leads to destruction of both articular cartilage and bone tissues. In rheumatic joints, synoviocytes and T-lymphocytes as well as bone cells produce the receptor activator of nuclear factor κ-B (RANK) ligand (RANKL), which binds to RANK on the surface of osteoclasts and their precursor cells to induce differentiation and activation of osteoclasts. Hence, inhibition of RANKL may be a promising approach to suppress osteolysis in RA. On the other hand, RANKL production by lymphocytes indicates the possibility that its inhibition would be effective to suppress inflammation in RA. In addition, it has been reported that cathepsin K, a predominant cysteine protease in osteoclasts, is involved in cartilage destruction in RA model mice. Here, we evaluated the effects of an anti-RANKL antibody on inflammation in footpads and degradation of articular cartilage in RA model mice. Results We induced arthritis in mice by injection of anti-type II collagen antibodies and lipopolysaccharide (LPS). Inhibition of RANKL by an anti-RANKL antibody (OYC1, Oriental Yeast, Tokyo, Japan) was confirmed by increased bone volume in the metaphysis of tibias. Swelling in either limb until day 14 was seen in 5 of 6 mice injected with anti-collagen antibodies and LPS without treatment with OYC1, while that was seen in 4 of 5 mice treated with OYC1. The average arthritis scores on day 14 in those groups were 2.17 and 3.00, respectively, indicating that OYC1 did not ameliorate inflammation in the limbs. Histological analyses indicated that OYC1 does not protect articular cartilage from destruction in mice with arthritis. Conclusions Our present study failed to show the effectiveness of an anti-RANKL antibody to ameliorate inflammation in the limbs or protect articular cartilage from degradation in a collagen antibody-induced arthritis mouse model. Electronic supplementary material The online version of this article (doi:10.1186/s12952-014-0018-0) contains supplementary material, which is available to authorized users.

佐渡肺吸虫のメタセル力リア1個をラットに感染させた場合(単数寄生)の虫体の発育や受精卵の産出状況(虫卵のミラシジウム形成)などを,複数個のメタセル力リアを感染させた場合(複数寄生)の成績と比較しながら検討した.単数寄生では,大部分の虫体が胸腔内遊離の状態で発見され,定型的虫嚢腫の形成は認められなかった.これらの虫体から産出された虫卵のミラシジウム形成率は0.76~2.57%であり,この値は複数寄生虫体のそれ(78~86%)と較べると著しく低いものであった.ミラシジウムの卿化までに要する虫卵の培養日数は単数寄生では23~25口であり,これは複数寄生の場合の16口と比較すると著しく長い.虫体を組織学的に検索したところ,単数寄生虫体でも複数寄生虫体の場合と同様に,精子形成や卵細胞形成は正常に行なわれていることがわかった.しかし,複数寄生虫体と異なり,単数寄生虫体では受精嚢や卵形成腔に全く精子が認められず,このためにミラシジウム形成率が低いものと推察された.