Culture-attenuated pathogenic Leptospira lose the ability to survive to Complement-mediated-killing due to lower expression of Factor H binding proteins

Publication date: Available online 25 March 2019Source: Microbes and InfectionAuthor(s): Azaf Moreno-Torres, Irving R. Malvido-Jiménez, Alejandro de la Peña-Moctezuma, Luz O. Castillo Sánchez, Tatiana R. Fraga, Angela S. Barbosa, Lourdes Isaac, Alfredo Sahagún-RuizAbstractSeveral pathogens including Gram-negative bacteria hijack complement regulators to escape host’s innate response. Pathogenic Leptospira species bind Factor H, C4b binding protein and vitronectin from the complement system. We evaluated the ability of low passage (LP) and culture-attenuated (CA) pathogenic strains of Leptospira, to bind Factor H. We used LOCaS46 (L. interrogans sv Canicola), LOVe30 (L. interrogans sv Icterohaemorrhagiae) and MOCA45 (L. santarosai sv Tarassovi), and ten high passage strains of Leptospira [used in the microscopic agglutination test (MAT)]. Afterwards, we assessed their survival in normal human serum (NHS). Interestingly, the ability in binding Factor H was higher for LOCaS46 and LOVe30 LP strains, than for the respective CA strains suggesting that the ability of evading the alternative complement pathway is lost after culture attenuation. Accordingly, the level of mRNA expression of the Factor H binding proteins, LigA, LigB and Lsa23 was higher in these LP strains than in the corresponding CA strains. Unexpectedly, no difference in Factor H binding and surviving was observed between LP and CA MOCA45 strains. The high passage MAT-reference strains showed variation in Facto...
Source: Microbes and Infection - Category: Infectious Diseases Source Type: research