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Trypanosoma rangeli: a new perspective for studying the modulation of immune reactions of Rhodnius prolixus.

Garcia ES, Castro DP, Figueiredo MB, Genta FA, Azambuja P - Parasit Vectors (2009)

Bottom Line: Insects are exposed to a wide range of microorganisms (bacteria, fungi, parasites and viruses) and have interconnected powerful immune reactions.Although insects lack an acquired immune system they have well-developed innate immune defences that allow a general and rapid response to infectious agents.Over the last few decades we have observed a dramatic increase in the knowledge of insect innate immunity, which relies on both humoral and cellular responses.However, innate reactions to natural insect pathogens and insect-transmitted pathogens, such as parasites, still remain poorly understood.In this review, we briefly introduce the general immune system of insects and highlight our current knowledge of these reactions focusing on the interactions of Trypanosoma rangeli with Rhodnius prolixus, an important model for innate immunity investigation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Avenida Brasil 4365, Rio de Janeiro, 21045-900, RJ, Brazil. egarcia@fiocruz.br.

ABSTRACT
Insects are exposed to a wide range of microorganisms (bacteria, fungi, parasites and viruses) and have interconnected powerful immune reactions. Although insects lack an acquired immune system they have well-developed innate immune defences that allow a general and rapid response to infectious agents.Over the last few decades we have observed a dramatic increase in the knowledge of insect innate immunity, which relies on both humoral and cellular responses. However, innate reactions to natural insect pathogens and insect-transmitted pathogens, such as parasites, still remain poorly understood.In this review, we briefly introduce the general immune system of insects and highlight our current knowledge of these reactions focusing on the interactions of Trypanosoma rangeli with Rhodnius prolixus, an important model for innate immunity investigation.

No MeSH data available.


Related in: MedlinePlus

Toll, IMD and JAK-STAT pathways. Insect tissues recognize pathogen-associated molecular patterns (PAMPs) by transmembrane receptors (DOME, Toll and PGRPs) in plasmatic membrane (PM) that activate the three pathways. The JAK-STAT pathway is activated by the receptor DOME (domeless) that transduces the signal to JAK and the cytosolic STAT. The Toll pathway starts with activation of the receptor Toll that signals to the cleavage of Dorsal-related immunity factor (DIF) complex releasing DIF. The IMD pathway through peptidoglycan recognition proteins (PGRPs) activates IMD (immune deficiency) that regulates the proteolytic cleavage and activation of Relish. The transcription factors (STAT, DIF and Relish) translocate to the nucleus through the nuclear membrine activating the expression of its transcriptional targets resulting in the production of antimicrobial peptides and other immune responses.
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Figure 1: Toll, IMD and JAK-STAT pathways. Insect tissues recognize pathogen-associated molecular patterns (PAMPs) by transmembrane receptors (DOME, Toll and PGRPs) in plasmatic membrane (PM) that activate the three pathways. The JAK-STAT pathway is activated by the receptor DOME (domeless) that transduces the signal to JAK and the cytosolic STAT. The Toll pathway starts with activation of the receptor Toll that signals to the cleavage of Dorsal-related immunity factor (DIF) complex releasing DIF. The IMD pathway through peptidoglycan recognition proteins (PGRPs) activates IMD (immune deficiency) that regulates the proteolytic cleavage and activation of Relish. The transcription factors (STAT, DIF and Relish) translocate to the nucleus through the nuclear membrine activating the expression of its transcriptional targets resulting in the production of antimicrobial peptides and other immune responses.

Mentions: Investigation in Drosophila demonstrated that production of AMPs is related to two distinct pathways: Toll and IMD pathways [3]. Recent studies suggested that these two pathways respond respectively to Gram-positive or Gram-negative bacteria and fungal infections in insects [5,12]. A third pathway involved in immune reactions, especially in mammals, is the JAK/STAT (Janus kinase/Signal transducer and activator of transcription) [13]. The JAK/STAT signaling pathway takes place mainly in the fat body of insects. The production of AMPs is a common result of JAK/STAT, Toll and Imd pathway activity [14] (Figure 1).


Trypanosoma rangeli: a new perspective for studying the modulation of immune reactions of Rhodnius prolixus.

Garcia ES, Castro DP, Figueiredo MB, Genta FA, Azambuja P - Parasit Vectors (2009)

Toll, IMD and JAK-STAT pathways. Insect tissues recognize pathogen-associated molecular patterns (PAMPs) by transmembrane receptors (DOME, Toll and PGRPs) in plasmatic membrane (PM) that activate the three pathways. The JAK-STAT pathway is activated by the receptor DOME (domeless) that transduces the signal to JAK and the cytosolic STAT. The Toll pathway starts with activation of the receptor Toll that signals to the cleavage of Dorsal-related immunity factor (DIF) complex releasing DIF. The IMD pathway through peptidoglycan recognition proteins (PGRPs) activates IMD (immune deficiency) that regulates the proteolytic cleavage and activation of Relish. The transcription factors (STAT, DIF and Relish) translocate to the nucleus through the nuclear membrine activating the expression of its transcriptional targets resulting in the production of antimicrobial peptides and other immune responses.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2719633&req=5

Figure 1: Toll, IMD and JAK-STAT pathways. Insect tissues recognize pathogen-associated molecular patterns (PAMPs) by transmembrane receptors (DOME, Toll and PGRPs) in plasmatic membrane (PM) that activate the three pathways. The JAK-STAT pathway is activated by the receptor DOME (domeless) that transduces the signal to JAK and the cytosolic STAT. The Toll pathway starts with activation of the receptor Toll that signals to the cleavage of Dorsal-related immunity factor (DIF) complex releasing DIF. The IMD pathway through peptidoglycan recognition proteins (PGRPs) activates IMD (immune deficiency) that regulates the proteolytic cleavage and activation of Relish. The transcription factors (STAT, DIF and Relish) translocate to the nucleus through the nuclear membrine activating the expression of its transcriptional targets resulting in the production of antimicrobial peptides and other immune responses.
Mentions: Investigation in Drosophila demonstrated that production of AMPs is related to two distinct pathways: Toll and IMD pathways [3]. Recent studies suggested that these two pathways respond respectively to Gram-positive or Gram-negative bacteria and fungal infections in insects [5,12]. A third pathway involved in immune reactions, especially in mammals, is the JAK/STAT (Janus kinase/Signal transducer and activator of transcription) [13]. The JAK/STAT signaling pathway takes place mainly in the fat body of insects. The production of AMPs is a common result of JAK/STAT, Toll and Imd pathway activity [14] (Figure 1).

Bottom Line: Insects are exposed to a wide range of microorganisms (bacteria, fungi, parasites and viruses) and have interconnected powerful immune reactions.Although insects lack an acquired immune system they have well-developed innate immune defences that allow a general and rapid response to infectious agents.Over the last few decades we have observed a dramatic increase in the knowledge of insect innate immunity, which relies on both humoral and cellular responses.However, innate reactions to natural insect pathogens and insect-transmitted pathogens, such as parasites, still remain poorly understood.In this review, we briefly introduce the general immune system of insects and highlight our current knowledge of these reactions focusing on the interactions of Trypanosoma rangeli with Rhodnius prolixus, an important model for innate immunity investigation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Avenida Brasil 4365, Rio de Janeiro, 21045-900, RJ, Brazil. egarcia@fiocruz.br.

ABSTRACT
Insects are exposed to a wide range of microorganisms (bacteria, fungi, parasites and viruses) and have interconnected powerful immune reactions. Although insects lack an acquired immune system they have well-developed innate immune defences that allow a general and rapid response to infectious agents.Over the last few decades we have observed a dramatic increase in the knowledge of insect innate immunity, which relies on both humoral and cellular responses. However, innate reactions to natural insect pathogens and insect-transmitted pathogens, such as parasites, still remain poorly understood.In this review, we briefly introduce the general immune system of insects and highlight our current knowledge of these reactions focusing on the interactions of Trypanosoma rangeli with Rhodnius prolixus, an important model for innate immunity investigation.

No MeSH data available.


Related in: MedlinePlus