Effects of Temperature on Gene Expression Patterns in Leptospira interrogans Serovar Lai as Assessed by Whole-Genome Microarrays

Abstract

Leptospirosis is an important zoonosis of worldwide distribution. Humans become infected via exposure to pathogenic Leptospira spp. from infected animals or contaminated water or soil. The availability of genome sequences for Leptospira interrogans, serovars Lai and Copenhageni, has opened up opportunities to examine global transcription profiles using microarray technology. Temperature is a key environmental factor known to affect leptospiral protein expression. Leptospira spp. can grow in artificial media at a range of temperatures reflecting conditions found in the environment and the mammalian host. Therefore, transcriptional changes were compared between cultures grown at 20°C, 30°C, 37°C, and 39°C to represent ambient temperatures in the environment, growth under laboratory conditions, and temperatures in healthy and febrile hosts. Data from direct pairwise comparisons of the four temperatures were consolidated to examine transcriptional changes at two generalized biological conditions representing mammalian physiological temperatures (37°C and 39°C) versus environmental temperatures (20°C and 30°C). Additionally, cultures grown at 30°C then shifted overnight to 37°C were compared with those grown long-term at 30°C and 37°C to identify genes potentially expressed in the early stages of infection. Comparison of data sets from physiological versus environmental experiments with upshift experiments provided novel insights into possible transcriptional changes at different stages of infection. Changes included differential expression of chemotaxis and motility genes, signal transduction systems, and genes encoding proteins involved in alteration of the outer membrane. These findings indicate that temperature is an important factor regulating expression of proteins that facilitate invasion and establishment of disease.

Insights into Leptospirosis, a Neglected Disease

“…The lipopolysaccharides (LPS), located within the outer membrane are highly antigenic and their structural variations give rise to the large diversity of the serovars and serotypes seen among the leptospiral species. Haake and his group [Haake et al, 1993;Haake et al, 2000;Haake et al, 1998;Matsunaga, 2002, 2005;Haake et al, 1999;Haake et al, 2004;Haake et al, 1991;Lo et al, 2006] contributed significantly to the identification and isolation of the leptospiral membrane proteins. They used different isolation techniques and classified the outer membrane proteins into transmembrane, lipoprotein and peripheral membrane proteins.…”

High-coverage proteome analysis reveals the first insight of protein modification systems in the pathogenic spirochete Leptospira interrogans

“…These short CDSs are usually beyond the detection power of available gene prediction methods and many methods usually ignore such short CDSs. In a later revised annotation for the serovar Lai by Adler and his colleagues, almost all of these short CDSs were excluded and 3 614 CDSs were eventually annotated [8].…”

“…The genome sequences of the pathogenic L. interrogans serovar Lai and serovar Copenhageni, the pathogenic L. borgpetersenii serovar Hardjo and the saprophytic L. biflexa serovar Patoc have been reported [3][4][5][6]. The accomplishment of these sequencing projects greatly facilitated the studies of Leptospira physiology and pathology at the genomic [4][5][6], transcriptomic [7,8] and proteomic levels [9][10][11][12][13][14]. However, there are discrepancies in the annotations for the same genome sequences by different institutions or by using diverse prediction methodologies, which hinders further studies [8].…”

“…The accomplishment of these sequencing projects greatly facilitated the studies of Leptospira physiology and pathology at the genomic [4][5][6], transcriptomic [7,8] and proteomic levels [9][10][11][12][13][14]. However, there are discrepancies in the annotations for the same genome sequences by different institutions or by using diverse prediction methodologies, which hinders further studies [8]. Recently, mass spectrometry-based approaches have been employed to support the annotations of prokaryotic and eukaryotic genomes, and to more accurately determine the existence and boundaries of genes [15][16][17].…”

Avaliação e caracterização de candidatos vacinais voltados para o controle da leptospirose.

“…santarosaisv Shermani (89) Chou et al, 2012 associada ao (HAAKE et al, 1991;MATSUNAGA et al, 2003). Além da virulência, outros fatores como temperatura e osmolaridade, também podem estar envolvidos com a regulação da expressão, como observado com outros genes de leptospiras (LO et al, 2006;MATSUNAGA et al, 2007). A Figura 7 D mostra a amplificação do RNA ribossômico 16S, no qual foi usado como controle da integridade das amostras.…”