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- Liu, Lisa
(författare)
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Dynamic shaping of human NK cell receptor repertoires : implications for NK cell-based immunotherapy
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Natural killer (NK) cells are innate lymphocytes with a potent intrinsic capacity to kill tumor cells, which makes them attractive candidates for cell-based cancer immunotherapy. Advances during the past decade have revealed that NK cells display a high degree of functional plasticity, suggesting that some subsets may be more effective in targeting cancer cells. In this thesis I have investigated the dynamic shaping of human NK cell repertoires with a focus on the biology and tumor killing potential of “adaptive” NK cells developing in response to human cytomegalovirus infection (HCMV). In the first part of this thesis we performed an in depth analysis of the NK cell killer immunoglobulin-like receptor (KIR) repertoire in a cohort of 204 healthy individuals. We found a subset of NK cells that displayed evidence of clonal-like expansion in HCMV seropositive individuals (referred to as adaptive or memory NK cells). These cells displayed a highly differentiated phenotype and distinct functional properties, characterized by a strong potential to perform antibody-dependent cellular cytotoxicity (ADCC). Furthermore, these NK cells had a preferential expression of self-specific KIRs. It is well established that the expression of KIR is genetically hardwired. In line with this, we found a linear correlation between KIR copy number variation (CNV) and the frequency of KIR expression. Although CNV had no effect on education at the single cell level, it influenced the overall size of the educated NK cell pool. However, KIR CNV had no effect on the frequency or magnitude of adaptive NK cell responses in HCMV seropositive individuals. A series of studies have linked the activating receptor NKG2C to the expansions observed in association to HCMV infection. To investigate whether other pathways could be involved in driving adaptive NK cell responses we analyzed NK cell repertoires in donors carrying a homozygous deletion of the NKG2C gene. We found that these individuals were fully capable of mounting adaptive NK cell responses and that CD2 co-stimulation of CD16 signaling play a crucial role in NK cell-mediated ADCC by adaptive NK cells, suggesting that CD2 and CD16 could compensate for the loss of NKG2C in the presence of HCMV antibodies. Furthermore, this indicated that, like the T cell activation model, NK cells also require multiple steps to become fully activated, where CD2 co-stimulation represents “signal-2”. Based on the insights into the regulation of adaptive NK cells, we established a platform for selective expansion of this highly cytotoxic NK cell subset. We found that in vitro expanded, and functionally reprogrammed, adaptive NK cells showed potent and specific killing of primary acute lymphoid leukemia (ALL) blasts, suggesting that this strategy may be effective in the context of cell-based cancer immunotherapy.
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- Liu, Yuanhua, 1971, et al.
(författare)
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Considering the importance of user profiles in interface design
- 2009
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Ingår i: User Interfaces. ; , s. 23-
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- User profile is a popular term widely employed during product design processes by industrial companies. Such a profile is normally intended to represent real users of a product. The ultimate purpose of a user profile is actually to help designers to recognize or learn about the real user by presenting them with a description of a real user’s attributes, for instance; the user’s gender, age, educational level, attitude, technical needs and skill level. The aim of this chapter is to provide information on the current knowledge and research about user profile issues, as well as to emphasize the importance of considering these issues in interface design. In this chapter, we mainly focus on how users’ difference in expertise affects their performance or activity in various interaction contexts. Considering the complex interaction situations in practice, novice and expert users’ interactions with medical user interfaces of different technical complexity will be analyzed as examples: one focuses on novice and expert users’ difference when interacting with simple medical interfaces, and the other focuses on differences when interacting with complex medical interfaces. Four issues will be analyzed and discussed: (1) how novice and expert users differ in terms of performance during the interaction; (2) how novice and expert users differ in the perspective of cognitive mental models during the interaction; (3) how novice and expert users should be defined in practice; and (4) what are the main differences between novice and expert users’ implications for interface design. Besides describing the effect of users’ expertise difference during the interface design process, we will also pinpoint some potential problems for the research on interface design, as well as some future challenges that academic researchers and industrial engineers should face in practice.
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