RESUMEN
ES-62 is a glycoprotein secreted by the filarial nematode Acanthocheilonema viteae that protects against ovalbumin (OVA)-induced airway hyper-responsiveness in mice by virtue of covalently attached anti-inflammatory phosphorylcholine (PC) residues. We have recently generated a library of small molecule analogues (SMAs) of ES-62 based around its active PC moiety as a starting point in novel drug development for asthma and identified two compounds - termed 11a and 12b - that mirror ES-62's protective effects. In this study, we have moved away from OVA, a model allergen, to test the SMAs against two clinically relevant allergens - house dust mite (HDM) and cockroach allergen (CR) extract. We show that both SMAs offer some protection against development of lung allergic responses to CR, in particular reducing eosinophil infiltration, whereas only SMA 12b is effective in protecting against eosinophil-dependent HDM-induced allergy. These data therefore suggest that helminth molecule-induced protection against model allergens may not necessarily translate to clinically relevant allergens. Nevertheless, in this study, we have managed to demonstrate that it is possible to produce synthetic drug-like molecules based on a parasitic worm product that show therapeutic potential with respect to asthma resulting from known triggers in humans.
Asunto(s)
Acanthocheilonema/química , Alérgenos/inmunología , Proteínas del Helminto/inmunología , Factores Inmunológicos/inmunología , Hipersensibilidad Respiratoria/prevención & control , Acanthocheilonema/inmunología , Animales , Cucarachas/química , Cucarachas/inmunología , Femenino , Proteínas del Helminto/administración & dosificación , Proteínas del Helminto/genética , Humanos , Factores Inmunológicos/administración & dosificación , Factores Inmunológicos/genética , Pulmón/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Pyroglyphidae/química , Pyroglyphidae/inmunología , Hipersensibilidad Respiratoria/inmunologíaRESUMEN
Prolonged existence of helminth parasites in their mammalian hosts has led to the establishment of a very particular immunological microenvironment that supports the fitness of both the pathogen and the host. The modern way of living in developed societies has interrupted this tight relationship by almost completely removing helminths from the human population. It is believed that, as a consequence of this process, a rapid increase in the incidence of asthma and other inflammatory disorders has occurred. Data derived from experimental models clearly show that worms and their products can ameliorate asthma-like disease in mice. This review will concentrate on the effects of helminth-driven regulatory mechanisms on the function of eosinophils and neutrophils in experimental asthma. Eosinophils and neutrophils are major effector cells driving pathology in the lung, therefore learning how to control their exacerbated activation in asthma might aid in creating much needed novel therapeutics to combat this common inflammatory disorder.
Asunto(s)
Asma/inmunología , Aptitud Genética/inmunología , Helmintos/inmunología , Interacciones Huésped-Parásitos/inmunología , Animales , Asma/parasitología , Asma/patología , Modelos Animales de Enfermedad , Eosinófilos/inmunología , Eosinófilos/parasitología , Helmintos/crecimiento & desarrollo , Humanos , Pulmón/inmunología , Pulmón/parasitología , Pulmón/patología , Ratones , Neutrófilos/inmunología , Neutrófilos/parasitologíaRESUMEN
There is growing evidence that helminth infections might suppress allergic responses by mechanisms potentially involving regulatory T lymphocytes, cytokines, helminth molecules and polyclonal IgE. Heligmosomoides polygyrus infection in mice is associated with reduced local and systemic immune responses, thus providing an excellent model to study the mechanisms of immune regulation. In this research, we examined the way that nematode infection modulates the influx of eosinophils into the airways of asthmatic mice. We observed a reduction in the total number and percentage of lung eosinophils that coincided with decreased levels of eotaxin in bronchoalveolar lavage fluid (BALF), lower expression of the CCR3 receptor on eosinophils and impaired chemotaxis of these cells toward eotaxin. We conclude that allergen-induced immune response was down-regulated as production of Th1 (IFN-gamma)-, Th2 (IL-4, IL-5)- and Treg (IL-10)-related cytokines as well as IL-6 and TNF-alpha was diminished upon nematode infection. We postulate that attenuation of allergic inflammation during H. polygyrus infection is a consequence of the dichotomy of the immune response in the face of concurrent antigenic challenge.
Asunto(s)
Quimiocinas CC/inmunología , Eosinófilos/inmunología , Nematospiroides dubius/inmunología , Neumonía/inmunología , Receptores de Quimiocina/inmunología , Infecciones por Strongylida/inmunología , Animales , Líquido del Lavado Bronquioalveolar/inmunología , Quimiocina CCL11 , Quimiotaxis de Leucocito , Citocinas/inmunología , Regulación hacia Abajo , Integrina alfa4beta1/inmunología , Pulmón/citología , Pulmón/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Receptores CCR3RESUMEN
We evaluated levels of apoptosis and the immune response ex vivo in BALB/c mice infected with Heligmosomoides polygyrus. Cell proliferation, apoptosis and cytokine production were measured in mesenteric lymph nodes (MLN) without exposure to H. polygyrus antigens in culture. The inhibited apoptosis and cytokine production reported might reflect a state of cell hyporesponsiveness in the prepatent phase of infection. These changes were accompanied by changes in the percentage of CD4+ cells in MLN and popliteal lymph nodes (PLN). The prolonged reduction in apoptosis coexisted with induced cell proliferation, elevated TNF-alpha, IL-12p70, IFN-gamma, IL-6, IL-10 and TGF-beta synthesis, but lowered IL-4 and IL-2 levels. In the chronic phase of infection an increasing production of IFN-gamma, monocyte chemotactic protein-1 (MCP-1), IL-10 and TGF-beta with decreasing concentrations of other cytokines resulted in restored apoptosis. The cytokine response in serum showed moderate production of TNF-alpha, temporary involvement of IL-12p70, induction of IFN-gamma and IL-10 synthesis, as well as growing IL-6 and MCP-1 production. It is suggested that a synchronized synthesis of distinct cytokines is accompanied by different levels of inhibited apoptosis during the prepatent and chronic phases of H. polygyrus infection in BALB/c mice. We suggest that immunosuppression provoked by the nematode is not the outcome of parasite-induced apoptosis, but rather results from a hyporesponsiveness experienced by cells during H. polygyrus infection.
Asunto(s)
Apoptosis/inmunología , Linfocitos T CD4-Positivos/inmunología , Nematospiroides dubius/inmunología , Infecciones por Strongylida/inmunología , Animales , Recuento de Linfocito CD4 , Procesos de Crecimiento Celular/inmunología , Citocinas/sangre , Citocinas/inmunología , Ganglios Linfáticos/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Infecciones por Strongylida/parasitología , Infecciones por Strongylida/patologíaRESUMEN
Primary infection with Heligmosomoides polygyrus in some strains of mice is chronic although fast responder mouse strains eliminate the parasite in a short period of time. The reason for the differences is unknown. In this study apoptosis, proliferation, IL-2 and IL-6 production of mesenteric lymph node (MLN) and spleen cells in vitro from fast (FVB) and slow (C57Bl/6) responder mice were compared during H. polygyrus infection. FVB cells showed decreased apoptosis, more proliferation and more cytokine production than cells from C57Bl/6 mice during infection. At the beginning of infection in C57Bl/6 mice the apoptosis of CD4(+) but not CD8(+) cells significantly increased in MLN and spleen cell cultures. Apoptosis, when the first immune signal is given by infective larvae, might play an important role in the modulation of the response in slow responder mice.
Asunto(s)
Apoptosis/inmunología , Ganglios Linfáticos/citología , Nematospiroides dubius/inmunología , Bazo/citología , Infecciones por Strongylida/inmunología , Análisis de Varianza , Animales , Proliferación Celular , Células Cultivadas , Interleucina-2/biosíntesis , Interleucina-6/biosíntesis , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/parasitología , Activación de Linfocitos , Masculino , Mesenterio , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Bazo/inmunología , Bazo/parasitología , Infecciones por Strongylida/patologíaRESUMEN
Parasitic nematodes are constantly exposed to the immune effector mechanisms of their hosts. One strategy of the worms to cope with these defence reactions is the secretion of modulatory proteins that down-regulate cell-mediated immune responses. We analysed the proliferation of mesenteric lymph node cells of mice infected with Heligmosomoides polygyrus and showed that cellular proliferation was strongly suppressed in the chronic phase of infection. To identify proteins of H. polygyrus that are involved in parasite-induced immunomodulation, worm extract and culture supernatant of adult H. polygyrus were fractionated by gel chromatography and activity of each fraction was determined. One of the fractions (fraction 9) of worm extract as well as worm secretory products inhibited the antigen-specific cellular proliferation by about 40%. This reduced cellular reactivity coincided with a down-regulation of inducible nitric oxide production of mouse macrophages by 57%. Furthermore, fraction 9 contained antigens that were recognized by IgE antibodies of H. polygyrus-infected mice and induced degranulation of an IgE-sensitized basophil cell line. Single proteins of fraction 9 were analysed by mass spectrometry. These data suggest that antigens that are recognised by IgE antibodies might play an important role in immunomodulation exerted by nematode infections.
Asunto(s)
Proteínas del Helminto/inmunología , Factores Inmunológicos/inmunología , Nematospiroides dubius/inmunología , Infecciones por Strongylida/inmunología , Secuencia de Aminoácidos , Animales , Procesos de Crecimiento Celular/inmunología , Proteínas del Helminto/química , Proteínas del Helminto/aislamiento & purificación , Inmunoglobulina E/inmunología , Factores Inmunológicos/química , Factores Inmunológicos/aislamiento & purificación , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Macrófagos Peritoneales/inmunología , Espectrometría de Masas/métodos , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Datos de Secuencia Molecular , Nematospiroides dubius/química , Óxido Nítrico/biosíntesis , Óxido Nítrico/inmunología , Ratas , Bazo/citología , Bazo/inmunología , Infecciones por Strongylida/parasitologíaRESUMEN
Hyporesponsiveness induced by Heligmosomoides polygyrus was quantified and the relationship between TGF-beta and inflammation was identified in BALB/c mice. The immune response and pathological changes modified by neutralization of TGF-beta were characterized in vivo. Nine and twelve days following infection, BALB/c mice were injected intraperitoneally with anti-TGF-beta (1,2,3) antibodies, isotype control antibodies or isosmotic solution. We assessed both Th1 and Th2 related cytokines production ex vivo and in vitro, IgA, the number of CD4+ cells, and eosinophils in the lamina propria and the villus : crypt ratio in the small intestine 6 weeks after infection. The pattern of cytokine production differed in the intestine, peritoneal fluid and serum. In mice infected with H. polygyrus the concentrations of IL-5, IL-12, TNF-alpha and IL-10 were raised in the intestine, but in serum the level of cytokines was diminished below the value observed in uninfected mice. The neutralization of TGF-beta converted the pattern of immune response induced by H. polygyrus. The elevation of cytokines in serum coincided with the reduction of cytokine concentration in the intestine or peritoneum. Neutralization of TGF-beta restored infiltration of eosinophils into the lamina propria of the intestine despite the low level of IL-5. We conclude that H. polygyrus infection suppresses the immune response through pathways involving TGF-beta production or activity and that the Th2 related immune response was not affected by neutralization.
Asunto(s)
Parasitosis Intestinales/inmunología , Nematospiroides dubius/inmunología , Infecciones por Strongylida/inmunología , Factor de Crecimiento Transformador beta/inmunología , Animales , Eosinófilos/inmunología , Inmunoglobulina A/inmunología , Interleucina-13/inmunología , Interleucina-13/metabolismo , Interleucina-4/metabolismo , Interleucina-5/inmunología , Interleucina-5/metabolismo , Parasitosis Intestinales/parasitología , Parasitosis Intestinales/patología , Mucosa Intestinal/inmunología , Mucosa Intestinal/parasitología , Mucosa Intestinal/patología , Ganglios Linfáticos/citología , Masculino , Ratones , Ratones Endogámicos BALB C , Infecciones por Strongylida/parasitología , Infecciones por Strongylida/patologíaRESUMEN
The influence of Heligmosomoides polygyrus on infection with Trichinella spiralis was studied in BALB/c mice. Mice coinfected with T. spiralis and previously given H. polygyrus harboured both nematode species till day 34. The number of T. spiralis muscle larvae was greater in mice coinfected with H. polygyrus/T. spiralis or T. spiralis/H. polygyrus than after infection with T. spiralis alone. Infection with H. polygyrus did not enhance eosinophil and IL-5 levels induced by T. spiralis. Additionally, the production of IgG1 specific to L1 T. spiralis was inhibited by co-infection. Changes in the levels of IFN-gamma and IgG2a implicated a disturbance in Th2 cell activation during protective response and resulted in the greater number of T. spiralis muscle larvae in coinfected mice.