Neurofilaments are the main cytoskeletal constituents in neuronal cells. They are belived to be important for maintaining the structural integrity and calibre of axons and dendrites thereby influencing the conduction velocity of nerve impulses.The neurofilament chains are divided into three groups according to their molecular size, neurofilament light (NF-L), neurofilament medium (NF-M) and neurofilament heavy (NF-H). The neurofilaments are obligate heteropolymers in vivo in which NF-L forms the backbone to which the heavier chains copolymerize to form the 10 nm neurofilament fibre. Different degenerative processes in the brain raise significant interest owing to the increasing mean age in the western world. Such diseases include amyotrophic lateral sclerosis, vascular dementia, frontal lobe dementia, progressive supra-nuclear paralysis, multiple system atrophy, low pressure hydrocephalus, and multiple sclerosis (MS). We have been able to generate six highly specific monoclonal antibodies for NF-L, and four independent epitopes were elucidated using Biacore and V8 protease degradation. Antibody 2:1 and 47:3 were selected components in a two-site ELISA assay for detection of NF-L in body fluids owing to their outstanding abililty to bind the antigen. The assay has a least detectable dose of 60 ng/l and a standard range of 60 to 64 000 ng/l. The assay was validated on its ability to detect changes of NF-L levels in CSF in patients with different neurological diseases. These were cerebral infarction, amyotrophic lateral sclerosis, relapsing remitting MS, extrapyramidal symptoms, and late onset Alzheimer’s disease. All the patient groups displayed significantly elevated NF-L levels as compared to the controls. We also tested the assay’s ability to monitor the amount of axonal breakdown in an animal model of MS. The NF-L levels were found to be elevated in rodents with chronic experimental autoimmune encephalomyelitis, giving a possible tool for monitoring new treatment strategies for axonal protection in MS. When studying a large population based MS material, we found axonal breakdown to be present early in the disease course and the breakdown was observed both in active relapse and clinically stable disease, indicative of ongoing neurodegeneration. NF-L levels were correlated to progression index, that is, high NF-L levels detected early in disease predict a fast progression of the disease. The amount of glial fibrillary acidic protein, a cytoskeletal protein found in astrocytes, was also quantified and was shown to be a good marker for the more progressive MS subtypes, that is, primary progressive and secondary progressive disease, indicating formation of astrocytic scars and activation of astrocytes. The test dealt with in this thesis has the potential to identify the slow chronic degenerative diseases with progressive disappearance of nerve cells and their large myelinated axons. There is a significant need clinically to be able to quantify such types of cell degeneration in relation to the progressive disappearance of nerve functions and to relate these different conditions to treatment regimens, disease progress, and prognosis.

No description available.

<p>Macrophages are an important key effector cell in the immune system which can practically be found in every tissue. Macrophages have for a long time been considered a population of cells only responsible for pro-inflammatory responses and anti-microbial activities. But over the past decade, many have come to realize the amazing plasticity of macrophages in response to different stimulations. The anti-microbial and pro-inflammatory macrophage is known as classically activated macrophages but newly discovered phenotypes have been revealed named wound-healing macrophages and regulatory macrophages. Through systematic screening we have identified an inducible macrophage activation state which has both wound-healing and regulatory capabilities activated by the novel cytokine combination IL-4/IL-10 with or without TGF-β.</p>

Biomaterials are commonly used in the medical clinic today; however, artificial materials can activate the cascade systems in the blood (complement-, coagulation-, contact- and fibrinolytic systems) as well as the platelets to various degrees. When an artificial surface comes in contact with blood, plasma proteins will be adsorbed to the surface within seconds. The composition of the layer of proteins differs between materials and is crucial for the hemocompatibility of the material. This thesis includes five projects. In Paper I the anticoagulants heparin and the thrombin inhibitor hirudin were evaluated in a whole blood model. Hirudin was found to be superior to low dose heparin since it did not affect the activation of the complement system nor the leukocytes. The most interesting observation was that expression of TF was seen on surface-attached monocytes in hirudin- treated blood but not heparin blood. In Paper II peptides from the streptococcal M-protein, which has affinity for the human complement inhibitor C4BP, were attached to a polymeric surface. When being exposed to blood the endogenous complement regulator was enriched at the surface of the material, via the M-peptides. With this new approach we created a self-regulatory surface, showing significant lowered material-induced complement activation. In Paper III apyrase, an enzyme which hydrolyzes nucleoside ATP and ADP, was immobilized on a polymer surface. Lower platelet activation and platelet-induced coagulation activation was seen for the apyrase-coated surface compared to control surfaces after exposure to whole human blood, due to the enzymes capability to degrade ADP released from activated platelets. In Paper IV and V we synthesized an array of polymeric materials which were characterized regarding physical-chemical properties, adsorption of plasma proteins, and hemocompatibility. The polymers showed widely heterogeneous protein adsorption. Furthermore, when the polymers were exposed to whole blood, two of the materials showed superior hemocompatibility (monitored as complement- and coagulation activation), compared to the reference poly(vinyl chloride).

<p>Malaria antigen-induced polarization of T cells into effectors Th1 and/or Th2 cells and their subsequent release of cytokines is known to affect antibody production. This thesis includes studies on early innate responses to the parasite, with a focus on γδT cells, and acquired specific responses in African sympatric ethnic tribes. In the last part of this thesis, a method for enrichment for the asexual blood stages of <i>P. falciparum </i>and their use in <i>in vitro</i> T-cell studies is presented.</p><p>To investigate mechanisms involved in parasite growth inhibition by γδT cells, an <i>in vitro</i> system was set up using blood stage parasites co-cultured with differently treated γδT cells. The results showed that Vγ9/δ2⁺ γδT cells inhibited the in vitro growth of <i>P. falciparum</i> parasites whereas CD4⁺and CD8⁺ T cells did not. This inhibition was positively correlated with the expression of cytolytic molecules in the cell lines tested. Anti-granulysin antibodies reversed γδT cell-mediated inhibition, suggesting a role for granulysin in the parasite growth inhibition. Thus, our data suggest that Vγ9/δ2⁺ γδT cells inhibit the parasite growth by a granulysin-exocytosis dependent cytotoxic pathway that needs perforin.</p><p>To study the humoral responses and their relation to Th1/Th2 cytokine profiles, antibody levels, numbers of cytokine-producing cells and spleen rates were measured in two sympatric tribes living in Mali, the Fulani and the Dogon. Our results revealed significantly elevated malaria-specific IgG and IgE antibody levels and spleen rates in the Fulani compared to the Dogon. The Fulani exhibited elevated numbers of both IL-4 and IFN-γ-producing cells, a typical profile seen of CD1-restricted NKT cells. This together with the higher spleen rates and elevated anti-malarial antibodies suggests a role of CD1-restricted cells in the different responses seen between these tribes.</p><p>To investigate whether such responses were specifically confined to malaria or a reflection of a generally activated immune system, total levels of IgG and of IgM as well as IgG antibodies to non-malarial antigens were examined in the Fulani in Burkina Faso and Mali. The results showed that the Fulani consistently mounted stronger malaria-specific IgG, IgG1, IgG3 and IgM responses. Total IgM levels were significantly higher in the Fulani than the non-Fulani, whereas total IgG did not differ between the two tribes. While IgG levels to some non-malarial antigens were significantly higher in the Fulani, no such differences were seen in the responses to several other non-malarial antigens suggesting that the Fulani are not generally hyper-reactive and that other specific factors are of importance for their higher malaria resistance.</p><p>Finally, a new method to enrich for early and late asexual blood stages of <i>P. falciparum</i> parasite from a single parasite culture was developed, using a 3-step centrifugation procedure. Such enriched parasite fractions beside other malaria-parasite antigen preparations were used in an in vitro system to analyse T-cell responses in malaria-exposed and non-exposed donors. Such analysis revealed significant proliferative cell response and CD4⁺ T cell expansion to whole-cell parasite antigens, but not to acellular parasite fractions, in the malaria-exposed as compared to the non-exposed ones. Our data suggest that natural infection preferentially leads to formation of memory cells against certain antigen expressed in live parasites.</p><p>Malaria antigen-induced polarization of T cells into effectors Th1 and/or Th2 cells and their subsequent release of cytokines is known to affect antibody production. This thesis includes studies on early innate responses to the parasite, with a focus on γδT cells, and acquired specific responses in African sympatric ethnic tribes. In the last part of this thesis, a method for enrichment for the asexual blood stages of P. falciparum and their use in in vitro T-cell studies is presented.</p><p>To investigate mechanisms involved in parasite growth inhibition by γδT cells, an in vitro system was set up using blood stage parasites co-cultured with differently treated γδT cells. The results showed that Vγ9/δ2⁺ γδT cells inhibited the in vitro growth of P. falciparum parasites whereas CD4⁺and CD8⁺T cells did not. This inhibition was positively correlated with the expression of cytolytic molecules in the cell lines tested. Anti-granulysin antibodies reversed γδT cell-mediated inhibition, suggesting a role for granulysin in the parasite growth inhibition. Thus, our data suggest that Vγ9/δ2⁺ γδT cells inhibit the parasite growth by a granulysin-exocytosis dependent cytotoxic pathway that needs perforin.</p><p>To study the humoral responses and their relation to Th1/Th2 cytokine profiles, antibody levels, numbers of cytokine-producing cells and spleen rates were measured in two sympatric tribes living in Mali, the Fulani and the Dogon. Our results revealed significantly elevated malaria-specific IgG and IgE antibody levels and spleen rates in the Fulani compared to the Dogon. The Fulani exhibited elevated numbers of both IL-4 and IFN-γ-producing cells, a typical profile seen of CD1-restricted NKT cells. This together with the higher spleen rates and elevated anti-malarial antibodies suggests a role of CD1-restricted cells in the different responses seen between these tribes.</p><p>To investigate whether such responses were specifically confined to malaria or a reflection of a generally activated immune system, total levels of IgG and of IgM as well as IgG antibodies to non-malarial antigens were examined in the Fulani in Burkina Faso and Mali. The results showed that the Fulani consistently mounted stronger malaria-specific IgG, IgG1, IgG3 and IgM responses. Total IgM levels were significantly higher in the Fulani than the non-Fulani, whereas total IgG did not differ between the two tribes. While IgG levels to some non-malarial antigens were significantly higher in the Fulani, no such differences were seen in the responses to several other non-malarial antigens suggesting that the Fulani are not generally hyper-reactive and that other specific factors are of importance for their higher malaria resistance.</p><p>Finally, a new method to enrich for early and late asexual blood stages of <i>P. falciparum</i> parasite from a single parasite culture was developed, using a 3-step centrifugation procedure. Such enriched parasite fractions beside other malaria-parasite antigen preparations were used in an in vitro system to analyse T-cell responses in malaria-exposed and non-exposed donors. Such analysis revealed significant proliferative cell response and CD4⁺ T cell expansion to whole-cell parasite antigens, but not to acellular parasite fractions, in the malaria-exposed as compared to the non-exposed ones. Our data suggest that natural infection preferentially leads to formation of memory cells against certain antigen expressed in live parasites.</p><p>Malaria antigen-induced polarization of T cells into effectors Th1 and/or Th2 cells and their subsequent release of cytokines is known to affect antibody production. This thesis includes studies on early innate responses to the parasite, with a focus on γδT cells, and acquired specific responses in African sympatric ethnic tribes. In the last part of this thesis, a method for enrichment for the asexual blood stages of <i>P. falciparum</i> and their use in <i>in vitro</i> T-cell studies is presented.</p><p>To investigate mechanisms involved in parasite growth inhibition by γδT cells, an <i>in vitro</i> system was set up using blood stage parasites co-cultured with differently treated γδT cells. The results showed that Vγ9/δ2⁺ γδT cells inhibited the in vitro growth of<i> P. falciparum</i> parasites whereas CD4⁺ and CD8⁺ T cells did not. This inhibition was positively correlated with the expression of cytolytic molecules in the cell lines tested. Anti-granulysin antibodies reversed γδT cell-mediated inhibition, suggesting a role for granulysin in the parasite growth inhibition. Thus, our data suggest that Vγ9/δ2⁺ γδT cells inhibit the parasite growth by a granulysin-exocytosis dependent cytotoxic pathway that needs perforin.</p><p>To study the humoral responses and their relation to Th1/Th2 cytokine profiles, antibody levels, numbers of cytokine-producing cells and spleen rates were measured in two sympatric tribes living in Mali, the Fulani and the Dogon. Our results revealed significantly elevated malaria-specific IgG and IgE antibody levels and spleen rates in the Fulani compared to the Dogon. The Fulani exhibited elevated numbers of both IL-4 and IFN-γ-producing cells, a typical profile seen of CD1-restricted NKT cells. This together with the higher spleen rates and elevated anti-malarial antibodies suggests a role of CD1-restricted cells in the different responses seen between these tribes.</p><p>To investigate whether such responses were specifically confined to malaria or a reflection of a generally activated immune system, total levels of IgG and of IgM as well as IgG antibodies to non-malarial antigens were examined in the Fulani in Burkina Faso and Mali. The results showed that the Fulani consistently mounted stronger malaria-specific IgG, IgG1, IgG3 and IgM responses. Total IgM levels were significantly higher in the Fulani than the non-Fulani, whereas total IgG did not differ between the two tribes. While IgG levels to some non-malarial antigens were significantly higher in the Fulani, no such differences were seen in the responses to several other non-malarial antigens suggesting that the Fulani are not generally hyper-reactive and that other specific factors are of importance for their higher malaria resistance.</p><p>Finally, a new method to enrich for early and late asexual blood stages of <i>P. falciparum</i> parasite from a single parasite culture was developed, using a 3-step centrifugation procedure. Such enriched parasite fractions beside other malaria-parasite antigen preparations were used in an <i>in vitro</i> system to analyse T-cell responses in malaria-exposed and non-exposed donors. Such analysis revealed significant proliferative cell response and CD4⁺ T cell expansion to whole-cell parasite antigens, but not to acellular parasite fractions, in the malaria-exposed as compared to the non-exposed ones. Our data suggest that natural infection preferentially leads to formation of memory cells against certain antigen expressed in live parasites.</p>

<p>The interaction between nutritional status and malaria disease is complex and often controversial. Nutritional deficiencies (macro- or micro-nutrient) are thought to lead to malnutrition with subsequent susceptibility to malaria infection. On the other hand severe malaria or repeated malaria infections lead to malnutrition. While the cause and effect are difficult to attribute, micronutrient deficiencies such as iron deficiency and malaria infection often co-exist and show complex interactions leading to mutually reinforced detrimental clinical effects.</p><p>That iron deficiency has adverse effects on human health is widely recognized. Iron plays a crucial role in processes of growth and cell division and in the transport of oxygen throughout the body. It is also important for the proliferation of cells of the immune system as well as for microorganisms including the malaria parasite. Iron deficiency results in a decrease in hemoglobin concentrations and subsequent anemia. However, the etiology of anemia is multi-factorial and may be affected, in addition, by several factors including malaria and host factors, especially hemoglobinopathies such as alpha-thalassemia and sickle cell trait. These hemoglobinopathies are also common in malaria endemic areas.</p><p>In this thesis, we have investigated the relationship between nutritional status, immunity, hemoglobinopathies and <i>falciparum</i> malaria in a cohort of children less than 8 years old living on the coast of Kenya. We have found that malaria was associated with malnutrition in an age-dependent fashion. Malaria was associated with subsequent underweight or stunting in children under the age of 2 years, but this effect was not there in older children. Also, we observed that iron deficiency was associated with protection of children against clinical malaria. Children who were iron deficient had a lower incidence of malaria episodes as compared to those who were iron replete.</p><p>While studies on the effects of single micronutrient deficiencies on components of the immune system are difficult to design and interpret, there is ample evidence that micronutrient deficiencies, in general, affect all components of immunity. In line with this, we found that nutritional iron status was associated with certain malaria-specific immunoglobulins and interleukin-4 mRNA levels. Iron deficient children had lower levels of malaria-specific IgG2 and IgG4 but higher expression levels of IL-4 mRNA as compared to the iron replete children. Finally, we observed a tendency towards a higher prevalence of iron deficiency in children carrying either alpha-thalassemia or sickle cell trait.</p>

<p>The lungs and upper airways are mucosal surfaces that are common site for infection with an enormous variety of inhaled pathogens. Therefore, induction of immune responses in the respiratory tract is crucial for protection against respiratory diseases.</p><p>One of the pathogens infecting the host via the respiratory tract is <i>Mycobacterium Tuberculosis</i>. The reported efficacy of the currently used Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis is highly variable, ranging from 50% against pulmonary tuberculosis to 80% against disseminated tuberculosis. Recently, the current route of vaccination (intradermal) has been considered as a possible factor influencing the protective capacity of the BCG vaccine. In this regard, intradermal route most likely induces protective systemic responses while it fails to induce optimal responses in the lungs. Therefore, our working hypothesis is that vaccination should be directed towards the respiratory mucosal immunity in order to improve the degree of host protection in the lungs.</p><p>In this thesis we studied the effect of the route of immunization as well as of different mucosal adjuvants on the induction of mucosal immune responses against the mycobacterial surface antigen PstS-1. We found that, the intranasal (i.n.) route of immunization was a more favorable route inducing strong local immune responses, than intraperitoneal (i.p.) route. Indeed, i.n. route immunization, unlike the i.p. route, elicited strong IgA responses in the lungs accompanied by a major influx of CD4⁺ T cells and a significant local production of IFN-gamma.</p><p>IgA, being the predominant Ig isotype at mucosal tissues, is considered a major effector molecule involved in defense mechanisms against viral and bacterial pathogens at these sites. Therefore, we investigated the possible role of IgA in the protection of the respiratory mucosa against mycobacterial infections, using mice deficient in IgA and in the polymeric Ig receptor. We show that, deficient mice are more susceptible to mycobacterial infections than wild type mice, thereby demonstrating a role for IgA in protection against mycobacteria. Importantly, our studies revealed a reduced production of protective factors, such as INF-gamma and TNF-alpha in the lungs of deficient mice that was associated with the higher susceptibility seen in these mice compared to wild-type mice. We also conducted challenge experiments against another respiratory pathogen, <i>Chlamydia pneumoniae</i>, using IgA deficient mice. Likewise to mycobacteria, our data support a role for IgA in the protection of the respiratory tract against <i>C. pneumoniae</i> infection.</p><p>Finally, we investigated the possible mechanisms explaining the reduced pro-inflammatory responses in IgA deficient mice. Our data indicated that IgA deficient mice present a defective response to stimulation with LPS or 19kDa which appears to be both, essentially due to suboptimal stimulation of macrophages and restricted to the lungs.</p>

<p>New efficient vaccines against infectious diseases are in demand. Some important factors impeding the vaccine development are the poor immunogenicity and the MHC restriction of the immune responses to a number of antigens. The use of novel vaccine adjuvants or carrier proteins, which are known to enhance the immunogenicity of the subunit antigens and provide T-cell help, can circumvent these problems. The potential of heat shock proteins (HSPs) to function as adjuvants when fused to or co-delivered with protein antigens, make them attractive vaccine candidates. In this thesis we have evaluated the potency of heat shock protein 70 (HSP70) as a possible vaccine adjuvant and studied the mechanisms behind the adjuvanticity.</p><p>The first article aims to evaluate the carrier effect of glutathione-S-transferase (GST) on a malarial antigen EB200 that induces a MHC restricted response in mice. Immunization of CBA and C57BL/6 mice, high and low responders to EB200, respectively, with the GST-EB200 fusion protein elicited EB200 specific antibody responses in both strains of mice, which indicated that MHC restriction was broken in C57BL/6 mice. However, the antibody affinity and the magnitude of the response were lower in the C57BL/6 mice compared with that in CBA. To improve the response, the efficacy of various adjuvants like alum, HSP70 from <i>Trypanosoma cruzi</i>, and the adjuvant combination (HSP70 and cholera toxin) was evaluated. The results indicated that cholera toxin and HSP70 act synergistically and improve the immunogenicity of EB200 antigen by increasing the affinity and magnitude of the response.</p><p>HSP belongs to a family of conserved molecules and the maximum homology lies on the N-terminal region of the protein, therefore there is a risk that use of a complete molecule would give rise to autoimmunity. Thus, in our second study we first evaluated the adjuvant effect of the less conserved portion of HSP70 derived from <i>Plasmodium falciparum</i> (Pf70C). We found that the Pf70C exhibited similar adjuvant properties as the whole molecule. We further analyzed the adjuvant potential of Pf70C against EB200 formulated as a chimeric DNA vaccine construct. These constructs alone failed to generate substantial levels of EB200 specific antibodies in mice. However, the DNA immunization efficiently primed the immune system. This was evident as the subsequent boosting with the corresponding recombinant fusion proteins Pf70C-EB200 elicited strong EB200 specific Th-1 antibody responses. In contrast, no such priming effect was observed for <i>ex vivo</i> IFN-γ production, however stimulation with the Pf70C-EB200 fusion protein induced an enhanced secretion of IFN-γ <i>in vitro</i>.</p><p>During the infection process, the synthesis of bacterial HSP is up-regulated, which is known to sensitize T cells in the infected host. Since a high degree of homology exists within the phylogenetic families of HSPs, we postulated that exposure of mice to microorganisms could prime the immune system for evolutionary diverse HSPs and for any antigen coupled to them. We tested this hypothesis by priming mice with different microorganisms such as BCG, <i>Mycobacterium vaccae</i> or <i>Chlamydia pneumoniae</i> and boosted with a recombinant fusion protein Pf70C-EB200 or with a panel of HSPs. We found that BCG and <i>M. vaccae</i> but not <i>C. pneumoniae</i> could provide priming of the immune system to induce secondary IgG responses to Pf70C as well as to other HSPs tested. The priming effect was also observed when the EB200 antigen was coupled to Pf70C. Analysis of the IgG1 and IgG2a profiles and IFN-g production induced against the HSPs revealed a mixture of Th1/Th2 type of responses. We also observed that HSP70 specific sera cross-reacted some extent with certain autoreactive antigens. However, no deposits were observed in the kidneys of HSP treated animals.</p><p>Finally, we investigated the role of TLR2 and TLR4 on HSP70-mediated adjuvanticity. We found that HSPs displayed different degrees of adjuvanticity regarding both the strength and the profile of the induced immune response. Also, they possessed different requirements for signaling through TLRs. While HSP70 from <i>T. cruzi</i> induced antigen-specific humoral responses in wild type as well as in both the TLR2 and TLR4 knockout mice, the response was diminished in the TLR4 knockout mice when both the whole and C-terminal fragment of HSP70 from <i>Mycobacterium tuberculosis</i> was used. However, the C-terminal fragment of <i>P. falciparum</i> HSP70 elicited responses only in wild type mice but not in TLR2 or TLR4 knockout mice indicating that the adjuvant function differ for phylogenetically related HSPs. Taken together our data suggest that HSPs can be promising candidates in future vaccines.</p>

<p>The humoral immune response is dependent on the formation of antibodies. Antibodies are produced by terminally differentiated B cells, plasma cells. Plasma cells are generated either directly from antigen challenged B cells, memory cells or from cells that have undergone the germinal center (GC) reaction. The GC is the main site for class switch, somatic hypermutation and generation of memory cells.</p><p>Different factors, both internal and external, shape the outcome of the immune response. In this thesis, we have studied a few factors that influence the maturation of the humoral response. We have studied how age affects the response, and we show that responses against thymus dependent antigens (TD) are more affected than responses to thymus independent (TI) antigens, in concordance with the view that the T cell compartment is more affected by age than the B cell compartment. Furthermore, we demonstrate that priming early in life have a big influence on the immune response in the aged individual. Priming with a TI form of the carbohydrate dextran B512 (Dx) induces a reduction of IgG levels in later TD responses against Dx. We have evaluated possible mechanisms for this reduction. The reduction does not seem to be caused by clonal exhaustion or antibody mediated mechanisms. We also showed that the reduced TD response after TI priming can be induced against another molecule than Dx. With the hypothesis that TI antigens induce a plasma cell biased maturation of the responding B cells, we examined the presence of Blimp-1, a master regulator of plasma cell differentiation, in GCs induced by TD and TI antigen. Blimp-1 was found earlier in GCs induced by TI antigen and the staining intensity in these GCs was stronger than in TD antigen induced GCs, indicating that plasma cells might be continuously recruited from these GCs.</p><p>B cells undergoing the GC reaction are thought to be under a strict selection pressure that removes cells with low affinity for the antigen and also cells that have acquired self-reactivity. We investigated the effect of apoptotic deficiencies on the accumulation of somatic mutations in GC B cells. In mice lacking the death receptor Fas, <i>lpr</i> mice, the frequency of mutations was increased but the pattern of the mutations did not differ from wild type mice. In contrast, mice over-expressing the anti-apoptotic protein Bcl-2, had a lowered frequency of mutations and the mutations introduced had other characteristics.</p>

<p>The tolerance towards the semi-allogenic foetus is obtained through both systemic and local changes in the maternal immune response. Locally, in the decidua, the cell composition differs from that found in the blood; natural killer (NK) cells and macrophages being the major cell types. Decidual macrophages (dMØ), which are alternatively activated, and trophoblasts, placental cells of foetal origin, are believed to participate in the foetal tolerance at the foetal-maternal interface. To test the recruitment ability of macrophages and trophoblasts, and to test if these cells are responsible for the special cell composition in the decidua, a migration assay was established. In this migration assay peripheral blood mononuclear cells (PBMC) were allowed to migrate through Matrigel-coated transwell inserts into lower wells containing a recruiting stimulus. After testing several conditions, a protocol was established for further use. The results showed that <em>in vitro</em> alternatively activated macrophages, which display many of the surface markers as dMØ, hold a recruiting ability and recruit monocytes. Further there was an indication that trophoblasts also hold a recruiting ability. Neither cell types were shown to recruit NK cells. In conclusion, this study presents a suitable protocol for assessing chemotactic factors and different cell type’s ability to recruit cells from blood. Although the experiments need to be repeated and extended and the recruitment ability of dMØ needs to be evaluated in detail before a final conclusion can be drawn, the preliminary data indicated that macrophages and trophoblasts can recruit monocytes.</p>