Leishmania RNA virus ile enfekte Leishmania major eksozomlarının karakterizasyonu ve L. Major enfeksyonunda sitosolik DNA algılama ile alakalı yolakların etkisinin değerlendirilmesi

Leishmaniasis is a neglected infectious disease caused by Leishmaniaparasite. The disease represents a significant health problem, necessitating urgent development of effective treatment strategies. New World Leishmaniaspecies harboringLeishmania RNA virus (LRV) causesevere,metastatic disease. In this thesis, we compared LRV2-1 deficient and proficient Old World L. majorstrains in terms of their exosomal content and infectivity. PCR and mass spectrometry based analysis revealed that virus infectedLeishmaniaexosomes containedat least 64%of the viralRNA but not the viral proteins. LRV2-1positive and negative L.majorstrains had similar infectivity in macrophages, the positive strain exhibited delayed infection in a cutaneous leishmaniasis model in mice.Next,we aimedto investigatethe role ofcGAS-STING DNA sensing pathwayinLeishmania infection. Infection rates inSTING and TBK-1 knockout cell lines were significantly lower than wild type THP-1 cells and this difference wasrelated to decreased phagocytic capacities of the knockout lines. Effect of the TBK1 inhibitor amlexanox was investigated in in vitroand in vivoinfection models. The drug blocked parasite phagocytosis in macrophages and delayed footpad swellingin parasite infected mice, suggesting that amlexanox could be of interest asa candidate drug in cutaneous leishmaniasis treatment. We alsoaimed to determine the virole of ISG15 in L. majorinfectionand autophagy by mutating the ISG15 using a LentiCRISPRv2 system.Our findings revealed apro-parasitic role ofISG15 inearlystages of Leishmaniainfection. Furthermore, we found that autophagy was enhanced in ISG15 KO cells,suggestinga regulatory role forISG15 in autophagy. Collectively,our findings might benefit future work related to Leishmaniaimmunity in defining new targets and developing effective treatment strategies.Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Biology

FtsZ’nin fazla üretimi yoluyla L-form E. coli’de mini hücre oluşumunun indüksiyonu üzerine bir çalışma.

L-form organisms (or L-phase, L-variants) are cell wall-deficient (CWD) bacteria consisting of protoplasts and spheroplasts that have the ability to grow and divide. The mutant strain LW1655F+ (also known as L-form E. coli) was originally derived from the parental E. coli K-12 parental strain and is known to be deficient in cell wall, periplasmic space, flagella, fimbriae and outer membrane. Minicells are small cell-like structures that do not have genomic DNA and are produced during the logarithmic phase of growth during which division event does not occur. Minicell production in E. coli K-12 parental strain can be induced by introducing a mutation at the minB locus of the bacterial genome. Moreover, previous studies have shown that overproducing FtsZ to two to seven folds led to minicell production in rod-shaped E. coli K-12. The present study originally intended to investigate whether spherical; cell-wall deficient L-form E. coli is also capable of producing minicells upon overproduction of FtsZ. To achieve this, two types of model organisms were used: a) L-form E. coli, b) L-form E. coli overproducing 2.25-fold more FtsZ as constructed in the present study. Electron microscopy analyses of the organism demonstrated that L-form E. coli cells spontaneously produced vesicle-like structures. Such spontaneous vesicle production was previously reported for other L-form bacteria such as Listeria monocytogenes, yet the current study is the first to demonstrate this event in L-form E. coli. Furthermore, flow cytometric analyses revealed that overproduction of FtsZ in L-form E. coli significantly increased the number of vesicles released into the growth medium when compared to L-form E. coli. Although minicell formation by both L-form E. coli and its FtsZ overproducing derivative could not be verified and remained ambiguous, the present study demonstrated two new findings: (i) L-form E. coli spontaneously produces vesicle-like structures without any modification, and (ii) FtsZ overproduction in such cells leads to a significantly increased vesicle secretion.M.S. - Master of Scienc

BORDETELLA PERTUSSİS BAKTERİSİNE AİT SERİN PROTEAZ PROTEİNİNİN E. COLİ BAKTERİSİNE KLONLANMASI, OVER-EKSPRESYONU VE İMMUNOJENİK ÖZELLİĞİNİN ARAŞTIRILMASI

BORDETELLA PERTUSSİS BAKTERİSİNE AİT SERİN PROTEAZ PROTEİNİNİN E. COLİ BAKTERİSİNE KLONLANMASI, OVER-EKSPRESYONU VE İMMUNOJENİK ÖZELLİĞİNİN ARAŞTIRILMAS

FEN BİLİMLERİ ENSTİTÜSÜ/LİSANSÜSTÜ TEZ PROJESİ

L-FORM E.COLİ NİN BÖLÜNME MEKANIZMAS

FEN BİLİMLERİ ENSTİTÜSÜ/LİSANSÜSTÜ TEZ PROJESİ

DİVİSİON MECHANİSM OF L-FORM E.COL

Cognitive assessment and cytokine profile of multiple sclerosis patients presenting with only optic neuritis and myelitis

ntroduction:Clinical disease activity in multiple sclerosis (MS) may manifest as predominant involvement of spinal cord and optic nerve (MS-SCON). In early stages, a major problem in the diagnosis of MS-SCON is distinction of patients presenting as MS-SCON throughout the disease course from those initially presenting as MS-SCON and developing supratentorial attacks later on. Therefore, identification of biomarkers for diagnosis of MS-SCON may be helpful in a clinical setting.Objectives:To characterize the neuropsychological features of MS-SCON patients and to find a serum-based biomarker to distinguish the MS-SCON subtype.Methods:Fourteen patients with MS-SCON, 20 conventional MS (CMS) patients without myelitis and optic neuritis attacks and 21 healthy individuals were recruited. Serum levels of a panel of cytokines and chemokines that were previously associated with spinal cord involvement in MS were measured by multiplex assay or ELISA. A panel of neuropsychological tests (selective reminding test, spatial recall test, paced auditory serial addition test, symbol digit modalities test, controlled oral word association test), Beck depression inventory, 9-hole peg and timed 25-foot walk tests were employed to all participants.Results:CMS and MS-SCON patients showed similar clinical and disability features. Both CMS and MS-SCON patients displayed reduced IL-8 and CXCL2 and increased TNF-α levels than healthy controls, while IL-10 and CXCL5 levels were identical among all groups. MS-SCON patients had significantly lower TNF-α levels than CMS patients. While both CMS and MS-SCON patients showed worse cognitive, mood status and motor function scores than healthy controls, there were no significant differences among test performances of CMS and MS-SCON patients.Conclusions:CMS and MS-SCON present with similar clinical, neuropsychological and immunological features. Serum TNF-α levels may serve to distinguish MS-SCON and CMS. Cognitive networks of the central nervous system may be damaged during the disease course of MS, despite the absence of clinical attacks characterized by cerebral or cerebellar symptoms

Microarray analysis indicates altered expression levels of B cell genes in benign multiple sclerosis

Objective:To identify immunological mechanisms associated with disease progression in multiple sclerosis (MS).Background:Benign MS (B-MS) is characterized with preserved motor, sensory and visual functions despite prolonged disease duration. Molecular mechanisms underlying B-MS are poorly understood.Design/Methods:Peripheral blood mononuclear cells (PBMC) obtained from 6 B-MS patients (EDSS<3.0 at disease duration > 10 years), 5 age/gender-matched non-benign MS (NB-MS) patients (EDSS≥3.0 at disease duration > 10 years) and 5 healthy controls were investigated with gene expression microarray analysis using Sureprint G3 Human Gene Expression V3 microarray system and a total of 26083 Entrez genes were evaluated. ANOVA test was used to identify genes, expression levels of which were specifically altered in B-MS patients. Gene set enrichment analysis was performed using the DAVID algorithm to analyze the biological functions of the filtered phenotypic differential genes and the results were annotated in the GEGG and GO databases. Validation of microarray study was done by real time PCR.Results:The most significantly altered expression levels belonged to factors involved in B cell proliferation (BANK1, BLNK, EBI3, BLK) and lymphocyte trafficking (CCL16, CCL19). Real time PCR studies conducted with PBMS of 30 each B-MS patients, NB-MS patients and healthy controls showed significantly reduced expression levels of BLNK, CCL16 and CCL19 genes and increased levels of BANK1, EBI3 and BLK in B-MS patients.Conclusions:B-MS patients appear to upregulate B cell development inhibitors (BANK1, EBI3, BLK) and suppress B cell development promoter BLNK and lymphocyte trafficking chemokines CCL16 and CCL19. Thus our results suggest that altered B cell functions are involved in progression of disability in MS

A Case with Bilateral Periventricular Nodular Heterotopia Diagnosed as Depression

Periventricular nodular heterotopia is a form of neuronal migration abnormality. Periventricular nodular heterotopia can easily be recognized by cranial magnetic resonance imaging. The most common clinical appearance is epileptic seizures. In some cases, symptoms are accompanied with psychiatric complaints. In this article, we report a 33-year-old female with complaints of left-sided paresthesia induced by emotional stress. She had been followed at an outpatient psychiatry clinic for about 10 years with the diagnosis of somatization disorder. Her electroencephalography recordings -awake as well as during sleep- were found to be normal. The cranial magnetic resonance imaging showed bilateral periventricular nodular heterotopia. Her seizures were controlled with carbamazepine treatment. Partial epileptic seizures might also be observed, even though the cerebral heterotopic lesions are bilateral. When a history is obtained from a patient with somatoform complaints, it should be kept in mind that these symptoms might be seizures, and the patient should be questioned accordingl