Site of expression of immunity to Naegleria fowled in immunized mice

Yh, Thong; Rf, Carter; Fèrrante, Antonio; Rowan-Kelly, B

doi:10.1111/j.1365-3024.1983.tb00724.x

Cited by 28 publications

(23 citation statements)

References 12 publications

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“…Several reports (Ferrante and Mocatta 1984;Ferrante 1989) have shown that neutrophils fail to kill the ameba in vitro unless they are exposed to inflammatory cytokines (TNF-a). In addition, in vivo studies have proposed that activation of neutrophils is important in the defense against infection by N. fowleri in mice (Thong et al 1983;Ferrante et al 1988Ferrante et al , 1989. Moreover, neutrophils do not seem to have amebicidal activity in spite of the close association of large numbers of neutrophils with amebas.…”

Section: Discussionmentioning

confidence: 96%

Immunohistochemical characterization of the initial stages of Naegleria fowleri meningoencephalitis in mice

et al. 2004

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The initial stages of Naegleria fowleri meningoencephalitis in mice were immunohistochemically characterized following the first 8 h post-intranasal inoculation. The events found after 8 h were: (1) amebas in contact with the mucous layer of the olfactory epithelium, (2) numerous parasites eliminated by extensive shedding of the mucous layer, and (3) many organisms reaching the nasal epithelium. In contrast to other works, we observed that after 24 h, amebas invaded the epithelium, without evidence of the disruption of the nasal mucosa. In addition some trophozoites invading through the respiratory epithelium were observed, suggesting an additional invasion route. The inflammatory response detected was scarce until 30 h post-inoculation. After 96 h, the inflammatory response was severe in the olfactory bulb and brain, and the tissue damage great. Consequently, an inflammatory reaction may enhance tissue damage but apparently does not destroy amebas which seem to proliferate in the olfactory bulb.

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Section: Discussionmentioning

confidence: 96%

Immunohistochemical characterization of the initial stages of Naegleria fowleri meningoencephalitis in mice

et al. 2004

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“…This fact has discouraged the development of a vaccine strategy directed at stimulating humoral immunity against this parasite. However, Thong et al, (28), based on their antibody transference results, showing partial protection to Naegleria infection, suggested that this strategy may provide a lead to the development of immunotherapy for this virulent disease, for which satisfactory chemotherapy is presently unavailable.…”

Section: Discussionmentioning

confidence: 99%

Protection against Naegleria fowleri infection in mice immunized with Cry1Ac plus amoebic lysates is dependent on the STAT6 Th2 response

Carrasco-Yépez

Rojas-Hernández

Rodríguez-Monroy

et al. 2010

Parasite Immunology

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We previously reported that intranasal administration of Cry1Ac protoxin alone or in combination with amoebic lysates increases protection against Naegleria fowleri meningoencephalitis in mice. Those results suggested that both antibody responses and innate immune mechanisms may be participating in the protective effects observed. The present study was aimed to investigate whether the STAT6-induced Th2 immune response is essential for the resistance to N. fowleri infection, conferred by immunization with amoebic lysates plus Cry1Ac. STAT6-deficient (STAT6-/-) and wild-type (STAT6+/+) BALB/c mice were immunized by the intranasal route with a combination of N. fowleri lysates plus Cry1Ac, and subsequently challenged with lethal doses of N. fowleri trophozoites. STAT6+/+ mice displayed 100% protection, while no protection was observed in STAT6-/- mice. Significantly higher titres of Th2-associated IgG1 as well as interleukin-4 (IL-4) were found in STAT6+/+ mice, whereas in STAT6-/- mice significantly more IL-12 and IFN-gamma as well as significantly higher titres of Th1-associated IgG2a were detected. Thus, whereas protected STAT6+/+-immunized mice elicited a Th-2 type inclined immune response that produced predominantly humoral immunity, unprotected STAT6-/- mice exhibited a polarized Th1 type cellular response. These findings suggest that the STAT6-signalling pathway is critical for defence against N. fowleri infection.

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“…It has been proposed that one of the main defence mechanisms of the nasal mucosa against N. fowleri in mice is the phagocytosis of trophozoites by polymorphonuclear cells (32). Although the Fcα/RI and Fcα/µR receptors for the Fc fraction of the IgA have not been described for murine neutrophils (28), the fact that of neutrophils adhere to amoebas covered with IgA suggests that these polymorphonuclears may interact with the IgA on the surface of trophozoites through other yet undefined receptors for the Fc fraction of IgA or for the secretory component (33).…”

Section: Discussionmentioning

confidence: 99%

Intranasal immunization with Naegleria fowleri lysates and Cry1Ac induces metaplasia in the olfactory epithelium and increases IgA secretion

Jarillo-Luna

Moreno‐Fierros

Campos-Rodrı́guez

et al. 2007

Parasite Immunology

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According to previous reports, intranasal administration of the Cry1Ac protein alone or with amoebic lysates increases protection against Naegleria fowleri meningoencephalitis in mice, apparently by eliciting IgA responses in the nasal mucosa. In the current study, we performed an immunohistochemical analysis of IgA in the nasal mucosa of mice immunized intranasally with Cry1Ac, and amoebic lysates or a combination of both. The animals were sacrificed 24 h after the last immunization or after an intranasal lethal challenge with N. fowleri. Our results indicate that all of the intranasal immunizations provoked an increase in areas with metaplasia in the olfactory epithelium, allowing for secretion of IgA. As a result, IgA antibodies were found interacting with trophozoites in the nasal lumen, and there was a marked increase of IgA in the metaplasic epithelium. On the other hand in nonimmunized mice trophozoites were observed invading the nasal mucosa, which was not the case for immunized mice. Our results suggest that intranasal immunization provokes cellular changes in the olfactory epithelium, leading to greater protection against N. fowleri that is probably caused by an increased secretion of IgA. The increased IgA response induced in the nasal mucosa by immunization probably impedes both amoebic adhesion and subsequent invasion of the parasite to the nasal epithelium.

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Site of expression of immunity to Naegleria fowled in immunized mice

Cited by 28 publications

References 12 publications

Immunohistochemical characterization of the initial stages of Naegleria fowleri meningoencephalitis in mice

Immunohistochemical characterization of the initial stages of Naegleria fowleri meningoencephalitis in mice

Protection against Naegleria fowleri infection in mice immunized with Cry1Ac plus amoebic lysates is dependent on the STAT6 Th2 response

Intranasal immunization with Naegleria fowleri lysates and Cry1Ac induces metaplasia in the olfactory epithelium and increases IgA secretion

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