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Updated: Aug 8, 2026
Immuno-fluorescence Assay of Leptospiral Surface-exposed Proteins
Published on: July 1, 2011
Peripheral blood mononuclear cell activation induced by Leptospira interrogans glycolipoprotein
Decio Diament1, Milena Karina Colo Brunialti, Eliete Calo Romero
1Escola Paulista de Medicina, Federal University of São Paulo, Instituto de Infectologia Emilio Ribas, São Paulo, Brazil.
Insights
Leptospira interrogans glycolipoprotein (GLP) activates immune cells, increasing inflammatory markers and cell surface activation. This suggests GLP plays a key role in leptospirosis pathogenesis.
Area of Science:
- Immunology
- Microbiology
- Pathogenesis
Background:
- Leptospira interrogans glycolipoprotein (GLP) is linked to leptospirosis pathology.
- Understanding GLP's role in cellular activation is crucial for disease insight.
Purpose of the Study:
- To assess GLP's capacity to induce immune cell activation.
- To evaluate cytokine production and surface marker expression following GLP stimulation.
Main Methods:
- Peripheral blood mononuclear cells (PBMCs) from healthy donors were stimulated with GLP.
- Cytokine levels were measured using ELISA.
- Cellular activation markers (CD69, HLA-DR) and LPS binding were analyzed via flow cytometry.
Main Results:
- GLP significantly increased TNF-alpha and IL-10 levels in a dose-dependent manner.
- CD69 expression rose on T lymphocytes and monocytes; HLA-DR increased on monocytes.
- Nonpathogenic Leptospira biflexa GLPp did not induce these activation markers.
Conclusions:
- GLP induces significant cellular activation, characterized by cytokine release and surface marker upregulation.
- GLP's activation pathways differ from LPS binding.
- GLP is likely a major contributor to leptospirosis pathogenesis.
Abstract:
Leptospira interrogans glycolipoprotein (GLP) has been implicated in pathological and functional derangement seen in leptospirosis. The goal of this study was to evaluate GLP's ability to induce cellular activation, as assessed by cytokine production and expression of surface activation markers. GLP extracted from either pathogenic L. interrogans serovar Copenhageni or nonpathogenic Leptospira biflexa serovar Patoc (GLPp) was used to stimulate peripheral blood mononuclear cell cultures from healthy donors. Supernatant cytokine levels were measured by enzyme-linked immunosorbent assay. Expression of CD69 and HLA-DR on lymphocytes and monocytes, as well as lipopolysaccharide (LPS) binding, were measured by flow cytometry. At 6 h of incubation, GLP induced a significant rise in tumor necrosis factor alpha levels, which dropped progressively until 72 h of incubation. Interleukin-10 peak levels were obtained at between 24 and 48 h, with sustained levels until 72 h of incubation. The response magnitude was proportional to the GLP dose. CD69 expression on T lymphocytes and monocytes increased significantly, as did HLA-DR expression on monocytes. GLPp induced no CD69 or HLA-DR expression. GLP did not block biotinylated LPS binding to monocytes, suggesting that different pathways are used to induce cell activation. In conclusion, GLP induces cellular activation and may play a major role in the pathogenesis of leptospirosis.
