<p>The current research is directed towards dissection of host genetic factors involved in host immune response and the malaria disease outcome. A possible association between FcγRIIa polymorphism and anti-malarial antibody (A.M.A) responses were investigated in Sudanese patients in relation to clinical outcome of falciparum malaria. The frequency of the R/R131 genotype was significantly higher in patients with severe malaria as compared with mild malaria. A.M.A IgG3 was shown to be associated with reduced risk of clinical malaria in individuals carrying the H/H131 genotype. Low levels of IgG2 reactive with the Pf332-C231 antigen were associated with lower risk of severe malaria in individuals carrying the H131 allele. </p><p>Fulani and Masaleit, two sympatric ethnic groups in Sudan, are characterized by marked differences in susceptibility to falciparum malaria. We investigated whether the two populations differ in the frequency of GM/KM allotypes. The distribution of GM/KM phenotypes differed significantly among the two groups, with Gm 6 being significantly lower among the Fulani, and the combined frequency of Km 1,3 and Gm 1,17 5,6,13,14 phenotypes was found to be higher among Masaleit.</p><p> In interethnic study we investigated whether the two groups differ in the frequency of FcγRIIa and HbAS genotypes. The frequency of the H/H131, R/R13 and HbAS genotypes differed significantly among the two groups. Moreover, the Fulani showed higher levels of A.M.A IgG2 and lower IgG1 and IgG3 when compared to their sympatric non-Fulani neighbours.</p><p>A tri-allelic SNP (C/T/A) in the CRP gene was investigated for possible ethnic associations. The A allele, which is associated with higher basal CRP levels, was found to be less frequent in the Fulani compared with non-Fulani ethnic groups both in Sudan and Mali. </p><p>In conclusion, our results suggest possible associations between FcγRIIa, CRP genotypes, GM/KM allotypes, and anti-malarial antibody responses and the clinical outcome of falciparum malaria.</p>

<p>IIn the first study, we investigated the functional implications of prolonged TLR signalling on IFN-γ mediated killing of mycobacteria by murine macrophages <i>in vitro</i>. TLR2, but not TLR4 ligation interfered with IFN-γ mediated killing of mycobacteria in macrophages. In terms of mechanisms, neither TNF nor nitric oxide (NO) production was significantly affected, and the refractoriness induced could be reversed with increasing amounts of IFN-γ In the second study, we aimed to identify immunological markers of diagnostic importance in both the respiratory tract and serum during pulmonary mycobacterial infection in mice. We found that increased levels of immunological markers in the respiratory tract, but not serum, correlated better with active mycobacterial infection in the lungs, suggesting that the immune response in the respiratory tract is more reflective of the infection status and pathology than the systemic response. Finally, we investigated the level and nature of immune responses to pulmonary mycobacterial infection in BALB/c and C57BL/6 mice, two mouse strains known to exhibit different susceptibilities to infection with several intracellular pathogens, including mycobacteria. We showed that increased susceptibility of BALB/c mice to early mycobacterial infection was associated with reduced Th1 immune responses, and increased sTNFR secretion in the lung. Moreover, BALB/c mice recruited fewer monocytes/macrophages to the lung, and although IFN-γ stimulation of infected bone marrow derived macrophages in both mouse strains resulted in induction of antimycobacterial activity, BALB/c mice had a reduced capacity to kill ingested bacteria. The work presented in this thesis provide further insight into the mechanisms involved in the host-pathogen interaction; from persistence, to the immunological processes induced by the pathogen, to susceptibility of the host to infection.</p>

<p><p>Handhygien är en grundläggande princip som förebygger, kontrollerar och reducerar vårdrelaterade infektioner och är ensam den mest effektiva metoden för att bryta en smittspridning. Syfte: att belysa vårdpersonalens följsamhet till de basala rutinerna gällande handhygien. Metod: Författarna gjorde en litteratursökning och granskning av vetenskapliga artiklar inom området. Resultat: Vårdpersonalens följsamhet till handhygienrutinerna visade sig ligga mellan 16,5%-70% och var större efter än före patientvård. Det fanns faktorer som gynnade och minskade följsamheten. Diskussion: Författarna fann stöd i sin teori om att vårdpersonalen skyddar sig i första hand själv och utför därför handhygienen i större grad än efter patientkontakt. Då det visade sig att kunskap leder till ökad följsamhet ansåg författarna att en årlig genomgång av handhygienrutinerna är lika viktigt som att repetera hjärt- och lungräddning.</p></p>

<p>Both Multiple Sclerosis (MS) and Guillan-Barré syndrome (GBS) are neurological inflammatory demyelinating autoimmune diseases, with a probable antibody contribution. Complement proteins in both MS and GBS does play a role in inflammation and demyelination at pathogenesis, according to earlier scientific evidence. The aim of this examination project work was to investigate systemic and intrathecal complement activation in MS and GBS, to gain further knowledge that might be useful for development of future therapeutics targeting immune responses during those diseases. An additional aim was to develop a new ELISA method for detection of complement iC3.</p><p>By using sandwich ELISA, complement proteins C1q, C4, C3, fH and C3a were measured in plasma and cerebrospinal fluid (CSF) from persons within 4 different diagnostic groups; MS, other neurological diseases (OND), GBS and controls (C). An ELISA method to detect iC3 (hydrolysed C3) was also developed, including usage of SDS-PAGE. Results based on raw data and statistical analysis show significantly elevated levels of C3a (C3a/C3) in MS and decreased C3 in plasma. In CSF low levels of C4 and C3a/C3 in MS were detected, though correlation of C3a and C1q was positive. GBS reveal high levels of all complement proteins analysed in CSF except for C3, and a positive correlation of C3a and C1q as well as C3a and fH was found.</p><p>These results indicate that MS patients have systemic complement activation; however the activation pathway is not determined. Complement activation in MS may also occur intrathecally, with correlation analysis indicating a possible activation via the classical pathway. MS patients suffering from a more acute relapsing-remitting (RR) MS have a more prominent systemic complement activation compared to MS patients responding to beta-interferon treatment. Systemic increased C3a/C3 ratio may be a possible biomarker to distinguish more acute RR MS in an earlier step of MS pathogenesis and should be further investigated. GBS patients have an intrathecal complement activation that seems to occur via the classical pathway.</p>

<p>Campylobacter jejuni is the main cause of bacterial diarrhoeal illness in developed countries, with ~7000 cases being reported each year in Sweden. C. jejuni has received growing attention since it’s recognition as a human pathogen in the 1970s, but its epidemiology is complex and much still remains unknown. There are several potential reservoirs for C. jejuni, including environmental sources as water and soil, wild and domesticated animals, particularly poultry, but also other livestock and pets. In this study 348 Swedish C. jejuni isolates from the year 2000 from humans (n = 164) and broilers (n = 184) were characterized with multilocus sequence typing (MLST) with the aim of comparing the population structures and diversity of C. jejuni between isolates from the two hosts. MLST is a method for characterization of bacterial isolates that indexes the variation in DNA sequence of multiple protein encoding housekeeping genes. A secondary aim in this study was to compare populations of C. jejuni from 11 subgroups of isolates based on location of the sampling. The overlap between the populations was analyzed numerically based on genotypes detected and with analysis of phylogeny, gene flow and molecular variation. It was shown that the population structure of C. jejuni isolates from broilers and humans show a high degree of similarity, supporting broilers as an important source of human infection. However, even though the population structure of human and broiler C. jejuni were almost genetically indistinguishable other sources of C. jejuni infections in humans cannot be ruled out since the same genotypes can be found in other sources as well. Analysis of the 11 subgroups suggested that there may be a difference in populations infecting humans in different Swedish regions, and between populations of C. jejuni in broilers from different slaughterhouses. But this could be a result of chance since most of the subgroups were small. Future studies to improve the understanding of C. jejuni epidemiology, for which MLST has proven itself as a valid method, is important to develop control strategies to prevent infection with this common cause of diarrhoeal illness.</p>

<p>In the demyelinating autoimmune disease multiple sclerosis (MS) there is a great need for validated prognostic biomarkers that can give information about both prognosis and disease course. So far only clinical parameters have been shown to predict future outcome. CXCL13 is a potent B cell chemoattractant that has been suggested to be a potential biomarker candidate. The aim of this study was to investigate the usefulness of CXCL13 as a prognostic biomarker for MS.</p><p>Clinical, paraclinical, laboratory and MRI data about a large group of MS patients and controls were collected. CXCL13 levels in cerebrospinal fluid (CSF) samples from these patients were determined by standard enzymelinked immunosorbent assay (ELISA).</p><p>In general CXCL13 were increased in CSF in MS, especially in relapsing-remitting MS during relapses, i.e. with ongoing inflammations in the central nervous system. CXCL13 is a good candidate prognostic marker for MS, since newly diagnosed MS with high CXCL13 levels showed worsened disease course within five years. Most importantly, MS conversion occurred in higher rate in possible MS patients with high concentrations of CXCL13 in CSF, and in a shorter time point. This observation may support an early treatment decision in these patients.</p><p>In conclusion, this study provides support for an association between CXCL13 levels in the CSF and later development of disease severity in MS.</p>

<p>The third domain of life, Archaea is one of the three main evolutionary lineages together with the Bacteria and the Eukarya domains. The archaea are, despite their prokaryotic cell organisation, more closely related to eukaryotes than to bacteria in terms of the informational pathways (DNA replication, transcription and translation). Organisms from the archaeal hyperthermophilic genus <i>Sulfolobus</i> thrives in a hot (80°C), acidic (pH 2-4) and sulphur-rich environment.</p><p>In my thesis, I have used a variety of different approaches to study the <i>Sulfolobus</i> cell cycle. After dilution of a stationary phase cell culture with fresh medium, synchronous cell cycle progression was obtained. From the synchronised cell culture experiment we could conclude that the major cell cycle events (nucleoid segregation, cell division and chromosome replication) were tightly coupled to each other and to cellular mass increase. </p><p>Inhibitors of the elongation stage of chromosome replication, and of cell division, as well as drugs arresting the cell cycle in the post-replicative phase, were found in an in vivo screening of a range of antibiotics. The cell cycle was found to be regulated such that the previous cell cycle step had to be successfully accomplished before the next could initiate, except for DNA replication which could occur without an intervening cell division event.</p><p>The replication pattern of <i>Sulfolobus solfataricus</i> was analysed using a marker frequency assay. From the results, we were able to determine that a single origin is utilized in vivo, that the replication directionality is bidirectional, and also an approximate location of the replication origin within the genome.</p><p>Intracellular virus production in vivo of SIRV2 (<i>Sulfolobus islandicus</i> rod-shaped virus2) in <i>Sulfolobus islandicus</i> was also analysed. The effects on the host cell were determined, including loss of cell viability, inhibited initiation of replication at virus infection and DNA degradation and loss of cell integrity at the time of virus release. Also, for the first time intracellular virus DNA was visualized with flow cytometry.</p>

<p>A new European labeling directive (2003/89/EC) states that certain foods and products derived thereof must always be declared. Among the tree nuts specified is Macadamia nut (Macadamia spp.). During the last few years, cases of IgE-allergic reactions, even severe anaphylaxes, have been reported. Reliable methods for the detection of this nut are needed.</p><p>Protein from Macadamia nuts was isolated. Polyacrylamide gel electrophoresis in SDS revealed two main protein bands of about 20 and 50kDa. These protein bands were cut and extracted from the gel and rabbits were immunized with each protein.</p><p>Immunoblotting showed dominant reactivity with the respective antigens. The antisera were further tested for specificity in immunodiffusion and in rocket immunoelectrophoresis.</p><p>In addition, a specific DNA-method was developed, based on Real-Time PCR using Macadamia vicilin as target sequence. Two different primer pairs were tested. Specificity was tested against potentially related nuts. Optimisation of primer and probe concentrations was performed. The limit of detection was 2-4 pg DNA, corresponding to a macadamia nut concentration of 50 to 100 μg per g. In a background of soybean DNA, down to 0,01 % macadamia DNA could be detected.</p>

<p>T lymphocytes can be rendered specific against a wide range of antigens by the genetic transfer of a chimeric receptor, a fusion between the antigen-binding domain of an antibody and the signalling domain of a T cell receptor. The use of such chimeric T lymphocytes has shown promising results for cancer therapy. Previous experiments in our laboratory have shown low rates of gene transfer using retroviral vectors. In this study, investigations have been done to increase the number of genetically modified cells. Different enhancers such as PLL and polybrene have previously been used in combination with retroviral transduction. The optimal retroviral protocol in this study showed to be the use of retrovectors produced with twice the normal concentration of the plasmids encoding env and gag-pol rather than the use of the enhancers. A 6-day pre stimulation of T lymphocytes prior transduction together with a centrifugation step increased the rate of modified cells even further. Alternative approaches of gene transfer were also investigated, including plasmid transfection and adenoviral transduction. While transfection protocols yielded low numbers of modified cells, adenoviral vectors showed the highest rate of gene transfer.</p> / <p>Cancer är den sjukdom som idag, efter hjärt-kärl-sjukdomar, kräver flest dödsfall i i-länder. Som en alternativ behandlingsmetod mot cancer pågår just nu forskning om genetiskt förbättrade immunceller, s.k. chimära T lymfocyter, skulle kunna användas för att döda tumörceller. De chimära cellerna är utrustade med en konstgjord receptor som är en fusion av en antikropp och en signalkedja. Det gör att cellerna kan riktas mot ett brett urval av cancertyper. Att få cellerna att ta upp generna som behövs för den konstgjorda receptorn har visats sig vara problematiskt. Den här studien har därför som mål att förbättra cellernas förmåga att ta upp gener. För detta har vi använt oss av retrovirus- och adenovirus-system tillsammans med försök att få cellerna att spontant ta upp generna, sk. plasmid-transfektion. Studien har visat att de båda virussystemen ger högst antal modifierade celler. Olika substanser som tidigare har visat sig förhöja graden av gentillförsel har testats, men vår studie har visat att tillverkningen av virusvektorerna har större påverkan på resultaten än någon av de olika hjälpmedlen.</p>

<p>The amyloidoses are biochemically heterogeneous diseases with patholophysiologic deposits of various proteins. Amyloid deposits can occur either localized to one organ or tissue or as part of a systemic disease with deposits in many different tissue. The clinical course, prognosis and therapy are different for each type of amyloidosis and therefore a type specific diagnosis is demanded as early as possible. We describe a method for typing of the most common systemic amyloidoses based on Western blot analysis combined with specific</p><p>in- house antibodies, using subcutaneous fat biopsies. We found that the method is reliable and easy to perform and the tissue sample needed is obtained by minor surgery.</p><p>In the aortic intima amyloid deposits are often associated with atherosclerosis plaques. In our study we also investigated the prevalence of intimal amyloid from 10 patients age 58-94, amyloid deposits were present in 50% of the cases.</p> / <p>Amyloidos är ett sjukdomstillstånd där proteiner som normalt är lösliga i kroppen felveckas och formar långa olösliga fibriller som ansamlas i vävnader och organ såsom t.ex. hjärta, hjärna och lever. Det finns cirka 25 proteiner som kan ge upphov till amyloidos. Man kan skilja på två huvudgrupper av amyloidos, systemisk och lokaliserad. Vid lokal amyloidos kan inlagringar förekomma i specifika vävnader vid framför allt vissa åldersberoende sjukdomar som t.ex. Alzheimers sjukdom. Vid systemisk amyloidos förekommer inlagringar i praktiskt taget alla vävnader. Symtomatologin vid systemisk amyloidos är variabel och sjukdomsbilden kan vara svårtolkad men tidig och specifik diagnostik ger möjlighet till riktad terapi mot den bakomliggande sjukdomen. Syftet med denna studie var att utvärdera en Western blot metod som använts för typning av vanligaste formerna av systemisk amyloidos. De slutsatser som nåtts är att denna metod är snabbt, pålitligt och enkel att utföra. Diagnos erhölls med finnålsbiopsi av bukfettvävnad som är enkel, snabb och billig metod med liten risk för patienternas hälsa. Vi lyckades också med hjälp av immunhistokemisk infärgning titta på prevalens av amyloid i aortas intima.</p>