66 research outputs found
Blue light induces major changes in the gene expression profile of the cyanobacterium <i>Synechocystis</i> sp. PCC 6803
A flexible MHC class I multimer loading system for large-scale detection of antigen-specific T cells
Tumorimmunolog
Immunochemical approaches to monitor and modulate the adaptive immune system
The two branches of our highly advanced immune system work closely together to detect and eliminate pathological threats. The first line of defense is provided by the innate immune system via detection of pathogenic or tumor cell fragments. Adaptive immune cells, on the other hand, recognize pathogens or malignant cells more specifically by scanning peptides, small protein fragments, presented by MHC molecules on other cells in our body. Specialized white blood cells (cytotoxic or killer T cells) can distinguish self- from non-self-peptides and directly eliminate cells that display signs of infection or mutation.The work described in this dissertation highlights how adaptive immunity can be used to our advantage, either from a therapeutic or diagnostic perspective. Immunotherapies that induce or promote anti-tumor or anti-viral responses have proven efficacious against infection and cancer. One strategy described is the development of chemically-modified epitopes as peptide vaccines, but small-molecule chemical drugs are also playing an increasing role in the field of cancer immunotherapy.In addition, monitoring of immune status and response to treatment, as well as mapping of epitopes, can aid diagnosis and design of treatment plans. The second part describes a novel method and application to visualize and monitor cytotoxic T cells.</table
The bluest blues: Exploring the low photosynthetic efficiency of cyanobacteria in blue light
Cyanobacteria (blue-green algae) play a key role in aquatic ecosystems, the global carbon cycle, and the accumulation of oxygenation in the Earth’s atmosphere. These microorganisms are of great interest in the pursuit of a sustainable, biobased economy. However, in contrast to green algae and plants, cyanobacteria grow much slower in blue light than in other light colors. The work described in this thesis aims to elucidate the underlying mechanisms of this intriguing phenomenon. Therefore, the model cyanobacterium Synechocystis was studied extensively. The performed experiments have lead to the hypothesis that the light-harvesting antennae of cyanobacteria are unable to distribute blue light between the two photosystems, while the different antenna composition of green algae allows them to balance blue light between the photosystems. This hypothesis was confirmed in several experiments, including a comparison with a mutant lacking light-harvesting antennae and analyses of gene expression in different light colors. The competition model that was developed in this research, and competition experiments between cyanobacteria and green algae, showed that the color-dependence of photosynthetic efficiency strongly influences the ecological distribution of phytoplankton and competition with other species. The research described in this thesis guides the selection of suitable light colors to culture cyanobacteria in a variety of biotechnological applications. Furthermore, the findings complement knowledge of the evolution of phytoplankton species and their photosynthetic pigments. Finally, the results lead to improved prediction of how human-induced changes in underwater light color will affect the species composition of natural phytoplankton at the base of the food web
Immunochemical approaches to monitor and modulate the adaptive immune system
The two branches of our highly advanced immune system work closely together to detect and eliminate pathological threats. The first line of defense is provided by the innate immune system via detection of pathogenic or tumor cell fragments. Adaptive immune cells, on the other hand, recognize pathogens or malignant cells more specifically by scanning peptides, small protein fragments, presented by MHC molecules on other cells in our body. Specialized white blood cells (cytotoxic or killer T cells) can distinguish self- from non-self-peptides and directly eliminate cells that display signs of infection or mutation.The work described in this dissertation highlights how adaptive immunity can be used to our advantage, either from a therapeutic or diagnostic perspective. Immunotherapies that induce or promote anti-tumor or anti-viral responses have proven efficacious against infection and cancer. One strategy described is the development of chemically-modified epitopes as peptide vaccines, but small-molecule chemical drugs are also playing an increasing role in the field of cancer immunotherapy.In addition, monitoring of immune status and response to treatment, as well as mapping of epitopes, can aid diagnosis and design of treatment plans. The second part describes a novel method and application to visualize and monitor cytotoxic T cells.</table
Immunochemical approaches to monitor and modulate the adaptive immune system
The two branches of our highly advanced immune system work closely together to detect and eliminate pathological threats. The first line of defense is provided by the innate immune system via detection of pathogenic or tumor cell fragments. Adaptive immune cells, on the other hand, recognize pathogens or malignant cells more specifically by scanning peptides, small protein fragments, presented by MHC molecules on other cells in our body. Specialized white blood cells (cytotoxic or killer T cells) can distinguish self- from non-self-peptides and directly eliminate cells that display signs of infection or mutation.The work described in this dissertation highlights how adaptive immunity can be used to our advantage, either from a therapeutic or diagnostic perspective. Immunotherapies that induce or promote anti-tumor or anti-viral responses have proven efficacious against infection and cancer. One strategy described is the development of chemically-modified epitopes as peptide vaccines, but small-molecule chemical drugs are also playing an increasing role in the field of cancer immunotherapy.In addition, monitoring of immune status and response to treatment, as well as mapping of epitopes, can aid diagnosis and design of treatment plans. The second part describes a novel method and application to visualize and monitor cytotoxic T cells.LUMC / Geneeskund
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