ABSTRACT
Theiler's murine encephalomyelitis virus-induced demyelination (TMEVD) and experimental allergic encephalomyelitis (EAE) are the principal animal models of multiple sclerosis (MS). Previously, we provided evidence that Tmevd2 and Eae3 may represent either a shared susceptibility locus or members of a gene complex controlling susceptibility to central nervous system inflammatory demyelinating disease. To explore the genetic relationship between Tmevd2 and Eae3, we generated a D2.C-Tmevd2 interval-specific congenic (ISC) line and three overlapping interval-specific recombinant congenic (ISRC) lines in which the Tmevd2-resistant allele from BALB/cByJ was introgressed onto the TMEVD-susceptible DBA/2J background. These mice, all H2(d), were studied for susceptibility to EAE elicited by immunization with proteolipid protein peptide 180-199. Compared with DBA/2J mice, D2.C-Tmevd2 mice developed a significantly less severe clinical disease course and EAE pathology in the spinal cord, confirming the existence of Eae3 and its linkage to Tmevd2 in this strain combination. Compared with DBA/2J and D2.C-Tmevd2, all three ISRC lines exhibited clinical disease courses of intermediate severity. Neither differences in ex vivo antigen-specific cytokine nor proliferative responses uniquely cosegregated with differences in disease severity. These results indicate that multiple quantitative trait loci (QTLs) within the Tmevd2/Eae3 interval influence EAE severity, one of which includes a homology region for a QTL found in MS by admixture mapping.
Subject(s)
Animals, Genetically Modified/genetics , Demyelinating Diseases/genetics , Demyelinating Diseases/virology , Encephalomyelitis, Autoimmune, Experimental/genetics , Genetic Predisposition to Disease/genetics , Quantitative Trait Loci/genetics , Animals , Animals, Genetically Modified/immunology , Animals, Genetically Modified/virology , Cardiovirus Infections/genetics , Chromosomes, Mammalian/genetics , Demyelinating Diseases/immunology , Disease Models, Animal , Disease Susceptibility , Encephalomyelitis, Autoimmune, Experimental/immunology , Female , Genetic Markers , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Inbred DBA , Myelin Proteolipid Protein/immunology , Peptide Fragments/immunology , TheilovirusABSTRACT
IL-2, a T-cell growth and differentiation factor, plays an important role in immune homeostasis. Previously, we identified IL2 as a candidate for Aod2, a quantitative trait locus (QTL) controlling susceptibility to autoimmune ovarian dysgenesis (AOD) induced by day 3 neonatal thymectomy. Here, we report the identification of single-nucleotide polymorphisms (SNPs) in a region upstream of the minimal IL2 promoter (-2.8 kb to -300 bp), which distinguish AOD-susceptible A/J and AOD-resistant C57BL/6J (B6/J) mice. Six of the SNPs (-1010 C --> T, -962 C --> T, -926/-925 Delta Delta --> AC, -921 T --> C, -914 T --> C and -674 G --> A) contribute to the enhanced transcriptional activity of the extended B6/J promoter relative to A/J. Importantly, the -1010 SNP resides within a canonical AP-1-binding motif with the C --> T transition at this site abrogating AP-1 binding. Moreover, these SNPs segregate with differential production of IL-2 by CD4(+) T cells as well as susceptibility alleles at Idd3 and Eae3, QTL controlling insulin-dependent diabetes mellitus and experimental allergic encephalomyelitis. These are the first SNPs identified within the extended murine IL2 promoter that control differential IL-2 transcription in CD4(+) T cells, and, as such, they are not only candidates for Aod2, but are also candidates for a shared autoimmune disease-susceptibility locus underlying Idd3 and Eae3.
Subject(s)
Autoimmune Diseases/genetics , Gene Expression Regulation/immunology , Genetic Predisposition to Disease/genetics , Interleukin-2/genetics , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/immunology , Animals , Autoimmune Diseases/immunology , Autoimmune Diseases/metabolism , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Diabetes Mellitus, Type 1/genetics , Encephalomyelitis, Autoimmune, Experimental/genetics , Female , Genetic Markers/immunology , Interleukin-2/biosynthesis , Mice , Mice, Inbred A , Mice, Inbred C57BL , Mice, Inbred NOD , Ovarian Diseases/genetics , Quantitative Trait Loci/immunology , Species SpecificityABSTRACT
PURPOSE: To study the differences between pathogenic and saprophytic leptospires. METHOD: A total of 275 samples were collected from different sources out of which 107 were subjected to PCR and bacteriological culturing. Two sets of primers were used for detection of leptospiral DNA and differentiation of pathogenic and saprophytic leptospires. Differentiation was also carried out by conventional methods. RESULTS: Twenty seven samples were found positive by PCR ut of which 26 were pathogenic and one was saprophytic. Culturing in EMJH medium yielded four isolates, of which isolates from sera were found to be pathogenic and isolate from water was found to be saprophytic. CONCLUSION: From the present study, it was concluded that PCR is simple, specific and rapid method for detection as well as differentiation of leptospires when compared to conventional methods.
