Potential of KM+ lectin in immunization against Leishmania amazonensis infection
Introduction
Leishmania parasites are intracellular protozoa that cause a variety of disease that can range from a self-healing cutaneous lesion to a visceral disseminated disease. Cutaneous leishmaniasis is the most common form that can be caused by L. amazonensis and L. braziliensis in South America, including Brazil [1]. In experimental cutaneous leishmaniasis, it has been clear that host protection depends on the expansion of Th1 CD4+T cells and suppression of Th2 CD4+T cells [2], [3], [4], [5], [6]. Lymphocytes committed to a Th1 profile are classically known to secrete mainly IFN-γ, a major macrophage activator factor, in response to IL-12 stimulation. Although, the role of Th1 cells is clear, the mechanisms governing the expansion of Th1 and Th2 cells in vivo are currently unexplained. During these early events, the role of antigen presenting cells (APC) is critical to direct the response to a specific phenotype. Among this cells, dendritic cells (DC) are known as professional APC because of their natural potential to process and present antigens. The early production of some cytokines during this initial step is important to define a Th1 or Th2 response.
Many molecules have been tested in order to drive a protective Th1 response. Lectins are proteins with the capacity to bind specifically to carbohydrates [7]. They have been isolated from many different sources including higher plant seeds, animal tissues and algae. Plant lectins have been described for their immunostimulatory potential to cell proliferation and lymphokine production. Lectin from Canavalia brasiliensis (ConBr) is able to induce IFN-γ production by human lymphocytes [8]. ConBr and the lectin from Pisum arvense (PAA) were able to directly stimulate murine macrophages and lymphocytes both in vitro and in vivo to produce NO. In addition, animals treated with this lectins were able to maintain NO production ex vivo [9]. NO is the major molecule that mediates Leishmania killing and its production is induced by IFN-γ [10]. A lectin from Artocarpus integrifolia (KM+) induced IL-12p40 production by macrophages, which then stimulates IFN-γ production by lymphocytes. Moreover, immunization of BALB/c mice with KM+ lectin and SLA antigen from Leishmania major resulted in protection against further challenge [11].
In the present report we explore the immunostimulatory potential of three plant lectins, Canavalia brasiliensis (ConBr), Pisum arvense (PAA) or Artocarpus integrifolia (KM+) in the immunization against Leishmania. Our results indicate that only mice immunized with KM+ lectin were able to control Leishmania infection probably due to the capacity of KM+ to act on the initial innate response by modifying inflammatory and dendritic cell responses.
Section snippets
Lectins
Lectin from Canavalia ensiformis (ConA) was obtained from Sigma (Sigma/St. Louis, EUA). Lectins from Canavalia brasiliensis (ConBr) and Pisum arvense (PAA) and Artocarpus integrifolia lectin (KM+) were obtained according to methods previously described [12], [13], [14]. The concentrations of the lectins were determined based on previous work [8], [9], [11].
All lectins preparations used were free of bacterial endotoxin.
Mice, parasites and preparation of SLA antigen
Inbred BALB/c of both sexes, 8–12 weeks of age were obtained from the central
Immunization of BALB/c mice with ConBr, PAA or KM+ lectins
BALB/c mice were immunized with SLA (10 μg/ml) in combination or not with ConBr, PAA or KM+ and challenged 15 days after the last booster with Leishmania amazonensis (BA125). The immunization with ConBr or PAA lectins alone or in combination with SLA did not result in lesion size reduction (Fig. 1A and B), while immunization with KM+ lectin alone resulted in significant lesion size reduction (p = 0.0049) when compared to the non-immunized control (Fig. 1C). Since lesion size not always correlates
Discussion
The search for immunostimulatory molecules and adjuvants in order to enhance or to direct an appropriate immune response against target immunogens has been a major and recurrent issue for vaccine development. In leishmaniasis, protection requires proper cellular immune response with the presence of specific CD4+ T cells and IFN-γ production and initial IL-12 production are elements required for protection. In fact, IL-12 used as an adjuvant to SLA conferred protection to mice against L. major
Acknowledgements
Teixeira CR, Cavassani KA, Teixeira MJ and Gomes RBB are recipients of CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) or CNPq (Brazilian National Research Council) scholarships. Roque-Barreira MC, Cavada BS, Silva JS, Barral A and Barral-Netto M are senior investigators of CNPq.
References (29)
- et al.
In vivo protective effect of the lectin from Canavalia brasiliensis on Balb/c mice infected by Leishmania amazonensis
Acta Tropica
(1996) - et al.
Lectin-induced nitric oxide production
Cell Immunol
(1999) Limiting dilution assays for the determination of immunocompetent cell frequencies. III. Validity tests for the single-hit Poisson model
J Immunol Meth
(1984)- et al.
An advanced culture method for generating large quantities of highly pure dendritic cells from mouse bone marrow
J Immunol Meth
(1999) - et al.
Leishmaniasis of the New World: current concepts and implications for future research
Clin Microbiol Rev
(1993) - et al.
Patterns of cytokine secretion in murine leishmaniasis: correlation with disease progression or resolution
Infect Immun
(1990) - et al.
IL-4 Induces a Th2 response in Leishmania major infected mice
J Immunol
(1992) - et al.
Reciprocal expression of interferon gamma or IL4 during the resolution or progression of murine leishmaniasis. Evidence for expansion of distinct helper T cell subsets
J Exp Med
(1989) - et al.
Production of interferon gamma, interleukin 2, interleukin 4, and interleukin 10 by CD4+ lymphocytes in vivo during healing and progression of murine leishmaniasis
Proc Natl Acad Sci USA
(1991) - et al.
Regulation of immunity to parasites by T cells and T cell-derived cytokines
Ann Rev Immunol
(1992)
The role of lectins in plant defense
Histochem J
Activated macrophages destroy intracellular Leishmania major amastigotes by an l-arginine-dependent killing mechanism
J Immunol
KM (+), a lectin from Artocarpus integrifolia, induces IL-12 p40 production by macrophages and switches from type 2 to type 1 cell-mediated immunity against Leishmania major antigens, resulting in Balb/c mice resistance to infection
Glycobiology
Lectin from Canavalia brasiliensis (Mart.) isolation, characterization and behavior during germination
Biol Planta
Cited by (53)
Jackfruit and its beneficial effects in boosting digestion and immune-enhancing properties
2021, Nutrition and Functional Foods in Boosting Digestion, Metabolism and Immune HealthCrystal structure of Pisum arvense seed lectin (PAL) and characterization of its interaction with carbohydrates by molecular docking and dynamics
2017, Archives of Biochemistry and BiophysicsYeast expressed ArtinM shares structure, carbohydrate recognition, and biological effects with native ArtinM
2016, International Journal of Biological MacromoleculesCitation Excerpt :Because of its pleiotropic action, ArtinM is an interesting immunomodulatory agent. Systemic administration of ArtinM to mice induces Th1 immunity that confers protection against various intracellular pathogens [10,12–15]. Topical administration of ArtinM promotes regeneration of injured corneal epithelium and oral mucosa in rabbits and rats, respectively [16,17].