Limits...
Lutzomyia longipalpis saliva or salivary protein LJM19 protects against Leishmania braziliensis and the saliva of its vector, Lutzomyia intermedia.

Tavares NM, Silva RA, Costa DJ, Pitombo MA, Fukutani KF, Miranda JC, Valenzuela JG, Barral A, de Oliveira CI, Barral-Netto M, Brodskyn C - PLoS Negl Trop Dis (2011)

Bottom Line: Animals immunized with Lu. longipalpis saliva exhibited smaller lesion sizes as well as reduced disease burdens both at lesion site and in the draining lymph nodes.These alterations were associated with a significant decrease in the expression levels of IL-10 and TGF-β.These findings point out an important role of immune response against saliva components, suggesting the possibility to develop a vaccine using a single component of Lu. longipalpis saliva to generate protection against different species of Leishmania, even those transmitted by a different vector.

View Article: PubMed Central - PubMed

Affiliation: Centro de Pesquisa Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.

ABSTRACT

Background: Leishmania transmission occurs in the presence of insect saliva. Immunity to Phlebotomus papatasi or Lutzomyia longipalpis saliva or salivary components confers protection against an infection by Leishmania in the presence of the homologous saliva. However, immunization with Lutzomyia intermedia saliva did not protect mice against Leishmania braziliensis plus Lu. intermedia saliva. In the present study, we have studied whether the immunization with Lu. longipalpis saliva or a DNA plasmid coding for LJM19 salivary protein would be protective against L. braziliensis infection in the presence of Lu. intermedia saliva, the natural vector for L. braziliensis.

Methodology/principal findings: Immunization with Lu. longipalpis saliva or with LJM19 DNA plasmid induced a Delayed-Type Hypersensitivity (DTH) response against Lu. longipalpis as well as against a Lu. intermedia saliva challenge. Immunized and unimmunized control hamsters were then intradermally infected in the ears with L. braziliensis in the presence of Lu. longipalpis or Lu. intermedia saliva. Animals immunized with Lu. longipalpis saliva exhibited smaller lesion sizes as well as reduced disease burdens both at lesion site and in the draining lymph nodes. These alterations were associated with a significant decrease in the expression levels of IL-10 and TGF-β. Animals immunized with LJM19 DNA plasmid presented similar findings in protection and immune response and additionally increased IFN-γ expression.

Conclusions/significance: Immunization with Lu. longipalpis saliva or with a DNA plasmid coding LJM19 salivary protein induced protection in hamsters challenged with L. braziliensis plus Lu. intermedia saliva. These findings point out an important role of immune response against saliva components, suggesting the possibility to develop a vaccine using a single component of Lu. longipalpis saliva to generate protection against different species of Leishmania, even those transmitted by a different vector.

Show MeSH

Related in: MedlinePlus

Cellular response against sand fly saliva in hamsters.Hamsters were immunized three times with Lu. longipalpis SGS (A–B; 9 hamsters per group total), LJM19 DNA plasmid (C–D; 5 hamsters per group total) or were inoculated with saline (E–F; 8 hamsters per group total) in the right ear. After the last immunization, hamsters were challenged in the left ear dermis with Lu. longipalpis or with Lu. intermedia SGS. The cellular infiltration was observed by light microscopy stained using H&E at 100x (A–F) and the left corner inserts at 1000x with arrows indicating mononuclear cells (A–D). Experiments were repeated three times and the photographs are representative from each group.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3104964&req=5

pntd-0001169-g001: Cellular response against sand fly saliva in hamsters.Hamsters were immunized three times with Lu. longipalpis SGS (A–B; 9 hamsters per group total), LJM19 DNA plasmid (C–D; 5 hamsters per group total) or were inoculated with saline (E–F; 8 hamsters per group total) in the right ear. After the last immunization, hamsters were challenged in the left ear dermis with Lu. longipalpis or with Lu. intermedia SGS. The cellular infiltration was observed by light microscopy stained using H&E at 100x (A–F) and the left corner inserts at 1000x with arrows indicating mononuclear cells (A–D). Experiments were repeated three times and the photographs are representative from each group.

Mentions: DTH response against salivary proteins can be a marker or correlate of protection against a challenge of parasite plus saliva [8], [9]. To evaluate the induction of DTH reaction by immunization with Lu. longipalpis SGS or by LJM19 DNA plasmid, immunized hamsters were challenged in the contralateral ear using either Lu. longipalpis or Lu. intermedia SGS. Immunization and challenge with Lu. longipalpis SGS induced an intense mononuclear cell infiltrate and edema, whereas the challenge with Lu. intermedia SGS elicited a smaller recruitment of mononuclear cells and edema (Fig. 1A). Hamsters immunized with LJM19 DNA plasmid and challenged with Lu. longipalpis or Lu. intermedia SGS also resulted in a DTH response, but with less recruitment of mononuclear cells and more pronounced edema. Control hamsters injected with saline and challenged with SGS exhibited no edema and scarce inflammatory cells (Fig. 1E,F). The observed inflammatory response in all immunized groups consisted predominantly of mononuclear cells (inserts in Fig. 1A–D), characteristic of a typical DTH response.


Lutzomyia longipalpis saliva or salivary protein LJM19 protects against Leishmania braziliensis and the saliva of its vector, Lutzomyia intermedia.

Tavares NM, Silva RA, Costa DJ, Pitombo MA, Fukutani KF, Miranda JC, Valenzuela JG, Barral A, de Oliveira CI, Barral-Netto M, Brodskyn C - PLoS Negl Trop Dis (2011)

Cellular response against sand fly saliva in hamsters.Hamsters were immunized three times with Lu. longipalpis SGS (A–B; 9 hamsters per group total), LJM19 DNA plasmid (C–D; 5 hamsters per group total) or were inoculated with saline (E–F; 8 hamsters per group total) in the right ear. After the last immunization, hamsters were challenged in the left ear dermis with Lu. longipalpis or with Lu. intermedia SGS. The cellular infiltration was observed by light microscopy stained using H&E at 100x (A–F) and the left corner inserts at 1000x with arrows indicating mononuclear cells (A–D). Experiments were repeated three times and the photographs are representative from each group.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3104964&req=5

pntd-0001169-g001: Cellular response against sand fly saliva in hamsters.Hamsters were immunized three times with Lu. longipalpis SGS (A–B; 9 hamsters per group total), LJM19 DNA plasmid (C–D; 5 hamsters per group total) or were inoculated with saline (E–F; 8 hamsters per group total) in the right ear. After the last immunization, hamsters were challenged in the left ear dermis with Lu. longipalpis or with Lu. intermedia SGS. The cellular infiltration was observed by light microscopy stained using H&E at 100x (A–F) and the left corner inserts at 1000x with arrows indicating mononuclear cells (A–D). Experiments were repeated three times and the photographs are representative from each group.
Mentions: DTH response against salivary proteins can be a marker or correlate of protection against a challenge of parasite plus saliva [8], [9]. To evaluate the induction of DTH reaction by immunization with Lu. longipalpis SGS or by LJM19 DNA plasmid, immunized hamsters were challenged in the contralateral ear using either Lu. longipalpis or Lu. intermedia SGS. Immunization and challenge with Lu. longipalpis SGS induced an intense mononuclear cell infiltrate and edema, whereas the challenge with Lu. intermedia SGS elicited a smaller recruitment of mononuclear cells and edema (Fig. 1A). Hamsters immunized with LJM19 DNA plasmid and challenged with Lu. longipalpis or Lu. intermedia SGS also resulted in a DTH response, but with less recruitment of mononuclear cells and more pronounced edema. Control hamsters injected with saline and challenged with SGS exhibited no edema and scarce inflammatory cells (Fig. 1E,F). The observed inflammatory response in all immunized groups consisted predominantly of mononuclear cells (inserts in Fig. 1A–D), characteristic of a typical DTH response.

Bottom Line: Animals immunized with Lu. longipalpis saliva exhibited smaller lesion sizes as well as reduced disease burdens both at lesion site and in the draining lymph nodes.These alterations were associated with a significant decrease in the expression levels of IL-10 and TGF-β.These findings point out an important role of immune response against saliva components, suggesting the possibility to develop a vaccine using a single component of Lu. longipalpis saliva to generate protection against different species of Leishmania, even those transmitted by a different vector.

View Article: PubMed Central - PubMed

Affiliation: Centro de Pesquisa Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.

ABSTRACT

Background: Leishmania transmission occurs in the presence of insect saliva. Immunity to Phlebotomus papatasi or Lutzomyia longipalpis saliva or salivary components confers protection against an infection by Leishmania in the presence of the homologous saliva. However, immunization with Lutzomyia intermedia saliva did not protect mice against Leishmania braziliensis plus Lu. intermedia saliva. In the present study, we have studied whether the immunization with Lu. longipalpis saliva or a DNA plasmid coding for LJM19 salivary protein would be protective against L. braziliensis infection in the presence of Lu. intermedia saliva, the natural vector for L. braziliensis.

Methodology/principal findings: Immunization with Lu. longipalpis saliva or with LJM19 DNA plasmid induced a Delayed-Type Hypersensitivity (DTH) response against Lu. longipalpis as well as against a Lu. intermedia saliva challenge. Immunized and unimmunized control hamsters were then intradermally infected in the ears with L. braziliensis in the presence of Lu. longipalpis or Lu. intermedia saliva. Animals immunized with Lu. longipalpis saliva exhibited smaller lesion sizes as well as reduced disease burdens both at lesion site and in the draining lymph nodes. These alterations were associated with a significant decrease in the expression levels of IL-10 and TGF-β. Animals immunized with LJM19 DNA plasmid presented similar findings in protection and immune response and additionally increased IFN-γ expression.

Conclusions/significance: Immunization with Lu. longipalpis saliva or with a DNA plasmid coding LJM19 salivary protein induced protection in hamsters challenged with L. braziliensis plus Lu. intermedia saliva. These findings point out an important role of immune response against saliva components, suggesting the possibility to develop a vaccine using a single component of Lu. longipalpis saliva to generate protection against different species of Leishmania, even those transmitted by a different vector.

Show MeSH
Related in: MedlinePlus