However, after infection or treatment with H. polygyrus AgS, F9 or F17, the percentage of apoptotic cells decreased. The percentage of apoptotic CD8+ cells remained
unchanged. Taken together, during infection and after cell activation by TCR and CD28 receptors, H. polygyrus antigens reduced both the proliferation and apoptosis of CD4+cells. Seventeen fractions were separated from the somatic homogenate of the H. polygyrus complete antigen with molecular range from 11 to 130 kDa and differences in activity between fractions were observed in cell culture. In naïve mice, the percentage of apoptotic cells decreased after stimulation of MLN cells with AgS (from 51% to 34.9%) and with antigenic fractions (Figure 4a). Infection Deforolimus in vivo with H. polygyrus also significantly reduced the percentage of apoptotic cells. Spontaneous apoptosis in RPMI medium decreased from 51% Target Selective Inhibitor Library research buy in uninfected mice to 22,8% after infection and only 6.3% of CD4+ cells were in apoptosis after stimulation with F9. The percentage of apoptotic cells was reduced in all examined populations
of T cells; CD4+CD25−, CD4+CD25hi, CD3+CD8+ in MLN (Figure 4b). Cells isolated on day 12 post infection responded distinctly to complete antigen (AgS) and to each antigen fraction. Treatment of cells with fraction F9, F13 and F17 deeply reduced apoptosis. In contrast, when fractions F6 and F19 were added, the percentage of apoptotic cells increased (data not shown). The lowest level of apoptosis was observed in CD3+CD4+ population. Only 5% of cells underwent apoptosis after treatment with fraction F9. Apoptosis of CD4+CD25hi and CD3+CD8+ cells was higher, 30% and 18% respectively, but was still lower in infected than in control mice (Figure 4b). Fraction F9 contrary to F17, was the most potent to reduce the percentage of apoptotic cells of infected mice. Overall, H. polygyrus somatic antigen and its fractions inhibited apoptosis Gemcitabine nmr both in naïve and infected mice. To examine apoptosis signalling pathways, apoptosis of MLN cells was induced by dexamethasone (DEX), a synthetic corticosteroid and by rTNF-α,
and the percentage of apoptotic cells was evaluated both in uninfected and infected mice. All examined cell populations were sensitive to DEX which induced apoptosis (Figure 5). In naïve mice, 60% of CD4+ cells were apoptotic and only AgS inhibited cell death; fractions F9 and F17 even increased the percentage of apoptotic cells. Response of CD4+CD25hi cells was also significant and after treatment with DEX more than 80% of cells underwent apoptosis. After infection with H. polygyrus apoptosis of these cells was reduced by 40% and even by 60% after restimulation with the nematode antigens. CD3+CD8+ cells were less sensitive to DEX and approximately 60% of cells were apoptotic. Apoptosis of these cells was inhibited both in control and infected mice after exposition to H. polygyrus antigens.
“Genetic factors do not seem to account fully for Alzheimer disease (AD) pathogenesis. There is evidence for the contribution of environmental factors, whose effect may be mediated by epigenetic mechanisms. Epigenetics involves the regulation of gene expression independently of DNA sequence and these epigenetic changes are influenced by age and environmental factors, with DNA methylation being one of the best characterised epigenetic mechanisms. The human genome is predominantly Adriamycin nmr methylated on
CpG motifs, which results in gene silencing; however methylation within the body of the gene may mark active transcription. There is evidence suggesting an involvement of environmental factors in the pathogenesis of Alzheimer’s disease (AD), which prompted our study examining DNA methylation in this disorder. Using immunohistochemistry with 5-methylcytosine/5-hydroxymethylcytosine antibodies we studied, in comparison with age matched controls, DNA methylation in sporadic and familial AD cases in the entorhinal
cortex that exhibits substantial pathology and the cerebellum, which is relatively spared. Neuronal nuclear labelling with 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) was evident in all cases studied. We did not detect any significant change in the levels of nuclear staining in the AD samples compared to neurologically normal controls. In the entorhinal cortex we also examined global DNA methylation and hydroxymethylation using an enzyme-linked immunosorbent assay (ELISA). No significant differences were found between AD and control cases in global levels of 5mC and 5hmC MI-503 in the entorhinal cortex using immunohistochemistry and enzyme-linked immunosorbent
“Y. S. Davidson, A. C. Robinson, Q. Hu, M. Mishra, A. Baborie, E. Jaros, R. H. Perry, N. J. Cairns, A. Richardson, A. Gerhard, D. Neary, J. S. Snowden, E. H. Bigio and D. M. A. Mann (2013) Neuropathology and Applied Neurobiology39, 157–165 Nuclear carrier and RNA-binding proteins in frontotemporal lobar degeneration associated with fused in sarcoma (FUS) pathological changes Aims: We aimed to investigate the role Ribonuclease T1 of the nuclear carrier and binding proteins, transportin 1 (TRN1) and transportin 2 (TRN2), TATA-binding protein-associated factor 15 (TAF15) and Ewing’s sarcoma protein (EWS) in inclusion body formation in cases of frontotemporal lobar degeneration (FTLD) associated with fused in sarcoma protein (FTLD-FUS). Methods: Eight cases of FTLD-FUS (five cases of atypical FTLD-U, two of neuronal intermediate filament inclusion body disease and one of basophilic inclusion body disease) were immunostained for FUS, TRN1, TRN2, TAF15 and EWS. Ten cases of FTLD associated with TDP-43 inclusions served as reference cases. Results: The inclusion bodies in FTLD-FUS contained TRN1 and TAF15 and, to a lesser extent, EWS, but not TRN2. The patterns of immunostaining for TRN1 and TAF15 were very similar to that of FUS.
67 Thus, taking into account other factors that contribute to elevated BNP in patients receiving dialysis, BNP is a measure of left ventricular stress. The other use for measurement of BNP in patients undergoing dialysis is to evaluate volume status. Volume assessment techniques
that have been studied include bioimpedance,68–71 inferior vena cava diameter,72 left atrial volume index53 and changes in weight with haemodialysis.73 selleck products However, associations with BNP in these studies are not consistent. Although chronic volume overload contributes to increased left ventricular wall stress, which in turn results in elevated levels of BNP, measurement of BNP for the purpose of adjusting dry weight with dialysis cannot currently be recommended because current studies are limited by the lack of an acceptable gold standard measure of volume overload against which to compare this approach. Troponin testing was requested for dialysis patients in the emergency department for a variety of symptoms including chest pain, dyspnoea, abdominal pain and others.74 Regardless of the symptoms, an elevated
cTnI Pritelivir mw predicted major cardiac events. In patients undergoing dialysis who presented with symptoms of an acute coronary syndrome, a rise in cTnT of 0.11 µg/L approximately 7 h after the first level had a sensitivity of 36% and a specificity of 97% for predicting an in-hospital adverse cardiac event.75 Of 49 patients undergoing haemodialysis who had a baseline cTnT measured, five presented (-)-p-Bromotetramisole Oxalate with a diagnosis of non-ST elevation myocardial infarction (non-STEMI), one with an STEMI and one with unstable angina pectoris some time after being enrolled in the study.76 All had elevated cTnT on their baseline sample. Patients with a non-STEMI had a 2- to 50-fold increase in cTnT from baseline and the patient with an STEMI a 250-fold increase in cTnT from baseline. It is not clear from these studies whether the troponin level was used to make the diagnosis of the cardiac event. Cardiac
troponin I has also been studied in patients receiving dialysis who presented with acute coronary syndromes but the outcome in these studies was a >70% stenosis of at least one vessel at angiography. In a study of African American patients, 95% of patients with elevated cTnI had a >70% stenosis of at least one vessel at angiography77 and the overall sensitivity was 73% and specificity 83% for this outcome. A case–control study of patients with a non-STEMI plus coronary artery disease at diagnostic coronary angiography demonstrated poorer sensitivity and specificity for detecting a coronary lesion >70% in the cases undergoing haemodialysis compared with the controls with normal kidney function.
Methods for immunoblotting and immunostaining of endogenous LC3 have been described (76). Bafilomycin A1 (an inhibitor of V-ATPase) is also used to inhibit autophagy and to estimate the autophagic flux of LC3-II. As V-ATPase contributes
to the acidification of other organelles, including the Golgi and endosomes, bafilomycin A1 may show multiple off-target effects (92, 93). p62 has ubiquitin-binding and LC3-binding domains, and binds to ubiquitylated protein Alisertib clinical trial aggregates to degrade them selectively via autophagy (94–96). When autophagy is impaired, p62 increases in cells and tissues (94, 97). At the same time, ubiquitin-positive aggregates accumulate. Ubiquitin-positive and p62-positive aggregates MK-2206 purchase are observed in brains in some neurodegenerative diseases and in other autophagy-defective tissues. Therefore, accumulation of p62 and
ubiquitin-positive proteins suggests the possibility of impairment of autophagy. Atg4B is a cysteine protease which is essential for conversion of proLC3 to LC3-I and for delipidation of LC3-II (Figs 1 and 2) (98). A mutant Atg4BC74A, in which the active site Cys74 is changed to Ala, produces defects in conversion and delipidation (Fig. 2, Atg4BC74A) (99, 100). Because overexpression of the mutant Atg4BC74A results in inhibition of LC3 lipidation, that is, in autophagy, the mutant is employed as a dominant negative mutant. Autophagy is a bulk process of degradation of cytoplasmic components, including organelles. The pathophysiological functions of autophagy are becoming clear; however, our understanding of autophagy machinery, and methods for monitoring autophagy, are somewhat less than perfect. Methocarbamol We have reviewed both the “core” Atg complexes essential for autophagosome formation, and assays
of autophagy. Mammalian cells have mammalian-specific Atg proteins and more complicated mechanisms than yeast, probably because mammalian cells utilize autophagic machinery for tissue- and cell-specific functions as well as for self defense mechanisms against intracellular and extracellular stresses. In addition to so called “autophagy” as a non-selective function, the presence of selective autophagy has been reported; mitophagy is a type of autophagy specific for degradation of mitochondria, reticulophagy for the endoplasmic reticulum, ribophagy for ribosomes, piecemeal autophagy for the nucleus, and xenophagy for pathogens. Selective autophagy-specific genes are now being isolated and characterized. For future clinical applications based on autophagy, it will be necessary to screen for compounds which inhibit or activate autophagy.
Recently, the inhibition of Th17 differentiation by invariant NKT cells was reported using the 2D2 autoimmune encephalitis model 26. However, the mechanism through which the NKT cells regulated Th17 differentiation remains unclear. In this study, we further investigated the direct regulatory role of CD1d-dependent invariant Panobinostat molecular weight NKT cells on CD4+ Th differentiation using an in vitro co-culture system and an in vivo model of organ-specific autoimmune disease. Invariant NKT cells inhibited Th1 differentiation in
an IL-4-dependent manner and suppressed Th17 differentiation predominantly through a contact-dependent manner in co-culture experiments. More severe uveitis and an increased number of IL-17-producing
CD4+ T cells were observed in invariant NKT cell-deficient (CD1d−/− or Jα18−/−) mice compared with WT mice, and the transfer of NKT cells from WT, IL-4−/−, IL-10−/−, or IFN-γ−/− mice into CD1d−/− mice significantly reversed the disease phenotype. Therefore, invariant NKT cells suppressed the progression of uveitis through the cytokine-independent inhibition of Th17 differentiation. Although the potential regulatory functions of NKT cells in organ-specific autoimmune diseases have been described 18, 19, definitive evidence supporting the direct effect of NKT cells on pathogenic effector cells is lacking. We analyzed populations of NKT cells by staining with anti-TCR antibody and CD1d:α-galactosylceramide
(α-GalCer) dimer. Although hepatic mononuclear cells (HMNC) from WT C57BL/6 (B6) contained about 20% αβTCR+CD1d:α-GalCer+ cells, only 0.12 Kinase Inhibitor Library and 0.2% of HMNC were αβTCR+CD1d:α -GalCer+ cells from CD1d−/− and Ja18−/− mice, respectively 3-oxoacyl-(acyl-carrier-protein) reductase (Supporting Information Fig. 1). To evaluate the impact of NKT cells on the regulation of CD4+ T-cell differentiation, we used in vitro co-culture experiments in which lymph node cells from NK1.1+-depleted OT-II OVA-specific TCR transgenic mice were stimulated with OVA peptide for 3 days in the presence of FACS-purified NK1.1+αβTCR+ T cells (>98% purity) isolated from HMNC from WT B6, CD1d−/−, or Jα18−/− mice. α-GalCer-stimulated NKT cells from WT, but not CD1d−/− or Jα18−/− mice, dramatically reduced the differentiation of OT-II CD4+ T cells into Th17 cells by more than 80% in the presence of Th17-promoting cytokines (10 ng/mL IL-6 and 5 ng/mL TGF-β) (Fig. 1A). Activated WT NKT cells also decreased the proportion of IFN-γ-producing CD4+ T cells by 60% (Fig. 1B). Th1 and Th17 differentiation was not inhibited with NKT cells when they were not stimulated with α-GalCer (Supporting Information Fig. 2). Cellular proliferation and cytokine production were simultaneously evaluated using CFSE-labeled OT-II CD4+ T cells. CD4+ T-cell proliferation was only minimally affected by the presence of α-GalCer-activated NKT cells under either differentiation condition (Fig.
As no large-scale study has yet been undertaken, we investigated human brain and astrocytomas for SPARC expression and associations with tumour grade, proliferation, vascular
density and patient survival. Methods: A spectrum of 188 WHO grade I–IV astrocytic tumours and 24 autopsy cases were studied by immunohistochemistry for SPARC, MIB-1 proliferation index and CD31-positive vessels. SPARC protein expression was confirmed by quantitative real-time polymerase chain reaction and Western blot in 13 cases. Results: In normal brain, SPARC is expressed in cortical marginal glia, cerebellar Bergmann glia and focally in white matter but is absent in neurones or vessels. High Palbociclib SPARC expression levels
in the cytoplasm of astrocytic tumour cells decreased with the grade of malignancy but showed an increase with grade of malignancy in tumour vessels. SPARC negatively correlated with tumour proliferation but not with vascular density. While cytoplasmic SPARC staining was not associated with survival, vascular SPARC showed a significant association in the group of grade II–IV tumours (P = 0.02) and also in grade II astrocytomas alone (P = 0.01) with vascular SPARC associated Kinase Inhibitor Library with worse prognosis. Conclusions: SPARC is highly expressed in astrocytomas and decreases with tumour progression. We confirm an association of increased SPARC expression and decreased proliferation. While there is no association between the level of SPARC in the tumour cells Sodium butyrate and patient survival, increased tumour vascular SPARC expression is associated with decreased patient survival. “
“Parkinson’s disease is now recognized as a major form of α-synucleinopathy involving both the central and peripheral
nervous systems. However, no research has focused on the posterior pituitary lobe (PPL), despite the fact that this organ also plays an important role in systemic homeostasis. In the present study, we aimed to distinguish phosphorylated α-synuclein (pαSyn)-positive deposits in the PPL, as is observed in Lewy body- and non-Lewy body-related disorders. PαSyn deposits were immunohistochemically analyzed using formalin-fixed, paraffin-embedded PPL specimens obtained from 60 autopsy cases. Among the cases with Lewy body-related disorders, PPL pαSyn deposits were observed in almost all cases of Parkinson’s disease (22/23), and in one case of dementia with Lewy bodies (1/1). On the other hand, only 3/36 cases of non-Lewy body-related disorders had pαSyn immunoreactivity in the PPL.
2A and 2B). When lymphatic vessels were not enhanced
by microscopic ICG lymphography, lymphatic vessels were dissected as a conventional method without intraoperative ICG lymphography guidance.[3, 4] Lymphatic vessels were anastomosed to appropriate venules in an end-to-end fashion using 11-0 or 12-0 nylon sutures.[3, 4, 12-14] Patency of the anastomosis can be confirmed by lymph fluid washout into the venule (Fig. 2C and 2D; See Video, Supporting Information Digital Content 1, which shows intraoperative microscopic ICG lymphography-guided LVA). A week after the LVA surgery, patients resumed the same compression therapy as preoperatively performed to make lymphatic pressure higher than venous pressure. Intraoperative findings and treatment efficacy were compared between LVA with and without selleck chemicals intraoperative microscopic ICG lymphography. Edematous volume was evaluated preoperatively and 6 months after the operations using LEL index. A summation of squares of circumferences C1, C2, C3, C4, and C5 (cm) divided by BMI is defined as the LEL index. C1 denotes circumference at 10 cm above the superior border of the patella, C2 circumference at the superior border of the patella, C3 circumference at 10 cm below the superior border of the patella, C4 circumference at the lateral malleolus, and C5 circumference
at the dorsum Inhibitor Library in vivo of the foot. Student’s t-test and Mann Whitney U test were used for statistical analysis. A statistical significance was defined as P-value < 0.05. Forty LVAs were performed on 12 lymphedematous limbs by one surgeon (T.Y.): 24 LVAs with intraoperative microscopic ICG lymphography-guidance on 7 limbs, and 16 LVAs without the guidance on 5 limbs (Tables 1 and 2). Lymphatic vessels were enhanced by intraoperative Silibinin microscopic ICG lymphography in 11 of 12 skin incision sites. In 1 of 12 skin incision, lymphatic vessels could not be enhanced even after additional ICG
injection. The nonenhanced site was shown diffuse pattern on preoperative ICG lymphography. All anastomoses, regardless of ICG-enhancement of lymphatic vessels, showed good anastomosis patency after completion of anastomoses. Time required for detection and dissection of lymphatic vessels in cases with intraoperative microscopic ICG lymphography-guidance was significantly shorter than that in cases without the guidance (2.3 ± 1.7 min vs. 6.5 ± 4.0 min, P = 0.010). Postoperative LEL index decreased significantly compared with preoperative LEL index (254.9 ± 35.8 vs. 238.0 ± 32.5, P < 0.001). There was no statistically significant difference in LEL index reduction between cases with and without intraoperative microscopic ICG lymphography guidance (18.3 ± 5.5 vs. 15.0 ± 5.5, P = 0.337). A representative case is shown in Figure 3. Secondary lymphedema is caused by obstruction and subsequent congestion of lymph flows.
5% bovine serum albumin; ELISA buffer) and incubated. Bound IgG antibodies were detected by adding 50 μL/well of peroxidase-conjugated anti-mouse IgG (1:2000 in ELISA buffer) and incubated at 37°C for 1 hr. The color reaction was developed by adding 100 μL/well of o-phenylenediamine dihydrochloride (Sigma, St Louis, MO, USA) in the presence of 0.07% H2O2 for 30 min at room
temperature, and the absorbance at 450–620 nm was measured. The MDV3100 nmr results for each serum sample were reported as the positive–negative difference (P–N), that is, the difference of the optical density (OD) with the positive antigen to the OD with the negative antigen; NusA -Tag protein was expressed from E. coli. Rabbit anti-TBE virus E protein IgG (23) was coated onto 96-well microplates (50 μL/well, 5 μg/mL in carbonate buffer). After overnight incubation at 4°C, the plates were washed five times with PBST. A blocking solution was applied (200 μL/well) and the plates were incubated at 37°C for 1 hr. The plates were washed before adding the SP antigen (50 μL/well, 1:150 dilution in ELISA buffer) and incubated at 37°C for 1 hr. After washing with PBST, the serum samples were added in duplicate (50 μL/well, 1:100 dilution in ELISA buffer)
and incubated at 37°C for 1 hr. Bound IgG antibodies were detected by adding 50 μL/well of ALP-conjugated anti-mouse IgG (1:5000 in ELISA buffer) and incubating at 37°C for 1 hr. The color reaction was developed by adding 100 μL/well of p-nitrophenyl phosphate and
incubating at 37°C for 60 min, and the absorbance D-malate dehydrogenase at 405–620 nm was measured. The results for each serum sample were reported as the P–N, that GSK3235025 is, the difference of the OD with the positive antigen to the OD with the negative antigen, which was prepared from the supernatant of non-transfected 293T cells. The OD values of each ELISA were compared with the results of the neutralization test. The sensitivity and the specificity of the ELISA were calculated corresponding to each cut-off value. The sensitivity was the ratio of the number of positive sera for ELISA and the neutralization test to the number of positive sera for the neutralization test. The specificity was the ratio of the number of negative sera for ELISA and the neutralization test to the number of negative sera for the neutralization test. The cut-off value that showed the minimum difference between the sensitivity and the specificity was used as the cut-off value of each ELISA. To prepare the recombinant antigen, we first attempted to express the whole E proteins of the TBE virus in E. coli, but the proteins were expressed as insoluble proteins and could not be applied to the ELISA (data not shown). Next, domain III of the E protein of the Oshima 5–10 strain was expressed as a fused protein with NusA -Tag protein (EdIII). To confirm and characterize the EdIII antigen, expressed proteins were analyzed by SDS-PAGE and Western blot (Fig. 1).
These data strongly indicate that the eight peptides induce HLA-DR restricted responses. It should be noticed that the presence of IVA12 does not affect HLA class I restricted responses and the presence of anti-DR antibody does not affect HLA-DP restricted responses.28 A recently selleck chemicals llc developed assay for peptide binding to recombinant HLA-DR molecules was employed.32 Fourteen recombinant HLA-DR subtypes, representing
33% of all HLA-DR subtypes expressed by the PPD+ donors (Table 2), were assayed for binding of the eight antigenic peptides. However, only three of the eight M. tuberculosis peptides showed binding to HLA-DR subtypes (DRB1*0806, 1*1201, 1*1202), but none of these HLA-DR molecules was expressed by the two donors (no. 19 and 32) who showed reactivity for the three peptides (data not included). To obtain direct evidence of the phenotype of M. tuberculosis-peptide-reactive
cells, anti-M. tuberculosis reactivity was tested in PBMC depleted of CD4+ T cells before peptide exposure in expansion cultures. As shown in Fig. 2, CD4+ T-cell depletion resulted in a total loss of peptide reactivity in all but one (anti-TB Dabrafenib molecular weight 60 peptide reactivity) of the CD4+ T-cell-depleted PBMC fractions. To further validate that the ELISPOT responses were in fact a CD4+ T-cell response and not a mixture of CD4+ and CD8+ T-cell responses, we used a flow cytometry-based intracellular cytokine secretion assay. Two donors were analysed in this
assay, Donor 32 stimulated with TB2, TB88 and TB92, and donor 28 stimulated with TB60. After 10 days in vitro restimulation the cells were analysed by intracellular cytokine secretion. For all combinations a low but clear CD4+ T-cell response could be measured, with peptide TB2 and TB92 peptide recognized by donor 32 showing the highest frequency of CD4+-specific T cells (> 1%) (Fig. 3). In all cases no measurable peptide-specific CD8+ T-cell responses could be detected. For the peptide responses in donor 32 this correlates with the finding that the specific ELISPOT response was absent after CD4+ depletion (Fig. 2). The peptide T60 response in donor 28 could only be partially removed by CD4+ depletion (about 30% resides) but only a peptide-specific Glycogen branching enzyme CD4+ T-cell response and no CD8+ T-cell response could be detected by intracellular cytokine secretion. The aim of the present study was to identify CD8+ T-cell epitopes derived from M. tuberculosis using immuno-bioinformatics. We have previously used such an approach to successfully identify T-cell epitopes derived from smallpox virus and influenza A virus.26,27 However, in our previous study 39 and a more recent observation,28 it was shown that HLA-I binding 9mer peptides were able to induce CD4+ T-cell-dependent responses that apparently are restricted by the HLA-II molecules.
burgdorferi (Fikrig et al., 1991). Therefore, a major emphasis in B. burgdorferi research has been selleck chemicals to develop a new vaccine that could be used as a safe and effective second-generation preventative against Lyme disease. As B. burgdorferi is an extracellular pathogen, and humoral immunity has been shown to be protective
against this organism, vaccine studies have revolved around identifying borrelial antigens that are (1) surface exposed, (2) conserved among different strains and genospecies of Borrelia spirochetes, and (3) produced during tick transmission and mammalian infection. Any outer surface protein that fulfills these three basic requirements is considered an excellent candidate for vaccine studies. As the surface of B. burgdorferi is the interface between the host and pathogen during infection, outer membrane proteins (OMPs) also have been implicated as important virulence factors. As a first step in identifying borrelial proteins that are surface exposed, many laboratories performed microarray analyses
to examine the global response of gene expression in B. burgdorferi after exposure to either temperature shift or cultivation within a mammalian host environment (Revel et al., 2002; Brooks et al., 2003; Ojaimi et al., 2003; Tokarz et al., 2004). The underlying assumption in these studies, which has been supported by empirical data, is that genes upregulated by temperature will correspond to genes upregulated during tick feeding and transmission to the mammalian host, while genes upregulated during cultivation Selleck Everolimus Carnitine dehydrogenase in a mammalian host correspond to genes upregulated during mammalian infection. Using these two different environmental stimuli, numerous
genes that are upregulated during tick feeding and/or mammalian infection were identified. Among the genes observed to be upregulated by temperature- and/or mammalian-specific signals, over 50 have been shown to encode known or putative leader peptides, indicating that they may encode outer surface proteins (Revel et al., 2002; Brooks et al., 2003; Ojaimi et al., 2003; Tokarz et al., 2004). Further, many of the genes identified were observed to encode hypothetical OMPs that had not previously been characterized. Therefore, a major goal in the Lyme disease field in recent years has been to further characterize surface-exposed proteins by (1) determining their cellular location throughout the enzootic cycle of B. burgdorferi, (2) examining their overall conservation among different strains and genospecies of B. burgdorferi, and (3) assessing their ability to protect mice and nonhuman primates from experimental Lyme disease. The combined studies have led to the identification of several candidate vaccine molecules and to the identification of many virulence determinants. The enzootic life cycle of B. burgdorferi is complex and typically involves horizontal transmission between ticks of the genus Ixodes and wild rodents (Lane et al., 1991).