A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / The multifaceted phenotype of the B‐lymphocyte has a remarkably effective role in peptide derived pathogen clearance and the prevention of re‐infection. This mechanism of host tolerant defense can be attributed to the actions of particular cellular subsets that arise from Blymphocytes: memory cells and high‐affinity antibody secreting plasma cells. Notably B cell propagation does not commence without the help of follicular helper T cells (TFH), a specialized subset of CD4+ cells. TFH cells are involved in the maturation and differentiation of Blymphocytes after antigen stimulation with a thymus‐dependent peptide. With this specific stimulus the formation of germinal centers (GCs) within B‐cell follicles of secondary lymphoid organs is induced and it is within these centers that TFH cells are able to interact with B cells to facilitate immunoglobulin affinity maturation, somatic hypermutation, and isotype class switching. Importantly, these respective processes play a fundamental role in manufacturing high‐affinity antibodies for effective pathogen clearance. Conversely, by means not well understood, the occurrence of spontaneous GC formation and the mass production of high affinity autoreactive antibodies have been shown to occur simultaneously with the development of autoimmune diseases. By the same token this incident is of particular interest and could play a role in the destruction of pancreatic insulin secreting β cells consequently driving the pathogenesis of type I diabetes. Our objective is to identify a possible correlation between the evolution of type I diabetes and the proliferatory behavior of B‐lymphocytes and TFH cells within developing GCs of non‐obese diabetic (NOD) mouse models.

Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Proefschrift--Amsterdam. / "Stellingen" (3 p.) inserted. "Litteratuur-opgave": p. [177]-187.

During a T-dependent immune response, activated B cells enter structures called germinal centers (GC) in the follicles of secondary lymphoid organs. GC B cells proliferate and undergo diversification of their Ig through somatic hypermutation and class-switch recombination. These Ig diversifications require the activity of the enzyme activation-induced deaminase (AID). Clonal selection within GCs selects GC B cells with the highest affinities for antigen to mature into plasma cells and memory B cells. GCs are underpinned by stromal cells called follicular dendritic cells (FDC). FDC functions include secretion of B cell chemokines and the retention of Ag complexes that allow GC B cells to test the affinity of their Ig. FDCs require constitutive signaling through lymphotoxin beta receptor (LTβR) from lymphotoxin alpha-beta (LTαβ) on the surface of B cells to maintain their functions. In these studies, I investigated the properties of GCs using two primary experimental models. First, I employed genetic and pharmacological ablation of LTβR signaling to investigate the expression of AID and the function of GCs in the absence of FDCs. I determined that FDCs are not required for GC formation or the expression of AID in lymph nodes, but that FDCs are crucial for affinity maturation. Second, I examined the competition between AID-/- and WT B cells in the GCs of mixed BM chimeras to investigate the role of affinity maturation during clonal selection. I found that AID increases GC B cell apoptosis, likely by inducing DNA damage, and that this is important in regulating GC size. I also found that AID-/- B cells accumulate at the centrocyte stage of the GC reaction and that this is due to a partial block in plasma cell maturation.

During a T-dependent immune response, activated B cells enter structures called germinal centers (GC) in the follicles of secondary lymphoid organs. GC B cells proliferate and undergo diversification of their Ig through somatic hypermutation and class-switch recombination. These Ig diversifications require the activity of the enzyme activation-induced deaminase (AID). Clonal selection within GCs selects GC B cells with the highest affinities for antigen to mature into plasma cells and memory B cells. GCs are underpinned by stromal cells called follicular dendritic cells (FDC). FDC functions include secretion of B cell chemokines and the retention of Ag complexes that allow GC B cells to test the affinity of their Ig. FDCs require constitutive signaling through lymphotoxin beta receptor (LTβR) from lymphotoxin alpha-beta (LTαβ) on the surface of B cells to maintain their functions. In these studies, I investigated the properties of GCs using two primary experimental models. First, I employed genetic and pharmacological ablation of LTβR signaling to investigate the expression of AID and the function of GCs in the absence of FDCs. I determined that FDCs are not required for GC formation or the expression of AID in lymph nodes, but that FDCs are crucial for affinity maturation. Second, I examined the competition between AID-/- and WT B cells in the GCs of mixed BM chimeras to investigate the role of affinity maturation during clonal selection. I found that AID increases GC B cell apoptosis, likely by inducing DNA damage, and that this is important in regulating GC size. I also found that AID-/- B cells accumulate at the centrocyte stage of the GC reaction and that this is due to a partial block in plasma cell maturation.

Proefschrift--Amsterdam. / "Stellingen" (3 p.) inserted. "Litteratuur-opgave": p. [177]-187.

In view of the fact that very little of the total body of Zola scholarship concerning Germinal can be classed as "new" criticism and that until recent years, most studies of the novel have stressed the historical, biographical and sociological issues which are central to the plot, this analysis will attempt to analyze in terms of the vertical perspective the thematic and structural patterns which form the basis of Germinal. Indeed Zola insists in his letters that we read Germinal as a symbolic structure and not just as the mere reproduction of facts or reality in that he claims facts function as a springboard from which his creative imagination takes a leap towards the higher, more complex level of symbolic meaning. Thus, if Zola is creating a work of art, as he insists he is, and if art by definition is the product of the creative imagination, it is then essential to read Germinal as such and , thus to employ one's own imagination in order to examine the complex structure the artist has produced. Clearly, to restrict one's vision of the novel to the surface events and issues is to pass over the more subtle and exciting aspects of the novel which remain hidden in the intricacy of its symbolic structure. Zola's use of symbolism becomes apparent by analyzing the vertical perspective revealed in the thematic and structural patterns around which the plot is woven and hence which are central to the novel as a unified, total work of art. As a definition of vertical perspective, I am using Northrop Frye's concept that in all great works of literature, the artist presents two totally opposite visions of human existence: one inferior and one superior to our own which together form the demonic and divine poles respectively and which thus correspond to the vertical poles of Heaven and Hell in religion. In Germinal, the analysis of thematic patterns will focus on the general theme of sexual relations which is presented in terms of the demonic and divine perspective. The least complex sexual relationships are those which represent the divine pole; for example, the Grégoire and the Maheu marriages. The negative or demonic sexual relationships are divided into three sub-themes: the theme of adultery, the theme of castration and the theme of the virgin which is central to the 'Gothic tradition in literature. The structural patterns center on what Frye calls the moral and anagogic levels of meaning. The first pattern involves the intricate link Frye makes between the four narrative forms of comedy, tragedy, romance and irony, the four seasons which he associates with the forms and the one year time span of Germinal. Together, these three factors chronicle Etienne's progression towards moral maturity. Secondly, the anagogic structure presents in symbolic terms a vision of man's destiny as he struggles to maintain an existence between the demonic and divine poles of his society which correspond to the Heaven and Hell of traditional Christian doctrine. Moreover, on the anagogic level, Germinal embodies the Christian archetypes of the Creation, the Battle of Armageddon and the Apocalypse in terms of the social rebel lion which Zola portrays. / Arts, Faculty of / French, Hispanic, and Italian Studies, Department of / Graduate

According to classical Greek mythology, Eros was one of the first beings to arise out of Chaos and represented the concepts of harmony and union necessary in creating the world and its creatures. The primary fear that Zola addresses (and exploits) in Germinal is the fear of anarchy and of social chaos. This is accomplished thanks to a relentless textual insistency on eroticism. This emphasis on human sexuality, along with Zola's ground-breaking treatment of the working class, represents the breaking of the two greatest literary taboos in nineteenth century French literature: the vivid depiction of bodily urges and the minute examination of the proletariat. Our thesis is that the revolutionary impact and the incontestable literary longevity of Germinal stem largely from Zola's successful shattering of these timorous traditions--the logical extension of reigning bourgeois morals--via his persistent depictions of the corporeal and the erotic. This essay, therefore, is an attempt to analyze, to describe, and to reconcile the diverse and contradictory elements which comprise the erotic subtext in Zola's most famous novel, that is to provide an erotic reading of Germinal. / Arts, Faculty of / French, Hispanic, and Italian Studies, Department of / Graduate

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Herpesviruses are ubiquitous in both humans and animals and can cause life-threatening disease. The discovery of murine gammaherpesvirus 68 (MHV-68), which has many similarities in genome and pathogenesis as the human pathogens Epstein-Barr virus and Kaposi’s sarcoma-associated herpesvirus, provides a model for further investigation of the pathogenesis of gammaherpesviruses. The M4 gene was found to be at the left end region of MHV-68 genome. The presence of the M4 protein is required during the early establishment of MHV-68 latency. However, the function of M4 protein remains unclear. The aim of this project was to investigate the function of the M4 protein in vitro and during infection. By using an ELISA, the recombinant M4 protein was shown to bind several Cxc-chemokines and stop the interaction between Cxcl4 and GAGs. The role of M4 protein during MHV-68 lytic infection and in the early establishment of latency was studied by comparing the pathogenesis of virus which does not express M4 (M4stop) and wild type virus (WT). Compared to WT infection, this study found that M4stop was decreased in the lungs at day 8 post infection (p.i.). At the same time point, the viral loads were higher in M4stop infected spleens, which was accompanied by increased expression of the CD4+ T cell activation marker PD-1 and the macrophage activation marker CD69. However, at day 14 p.i., the M4stop infected spleens had lower viral loads, and the expression of CD69 was decreased on CD4+, CD8+ T cells, B cells and macrophages. Furthermore, gene expression PCR arrays were used to investigate how cellular activation and inflammation were transcriptionally regulated. It has been found that the transcription of several genes, which are involved in germinal centre development, was lower in the spleens of WT infected mice at day 12 and 14 p.i. compared to day 10 p.i. of WT infection, as well as day 12 and 14 p.i. of M4stop infection. In addition, the percentage of germinal centre B cells was found to be higher in spleens infected with M4stop at day 10 p.i.. However, there was no difference in percentages of TFH and plasma cells in the spleens. Finally, in order to understand the role of IFN-γ in control of infection in M4stop infected mice, IFN-γR-/- mice were infected with M4stop and WT. Although there were differences in pathogenesis between WT and M4Stop virus infected IFN-γR-/- mice, there was no clear evidence that M4 function is involved in inhibiting IFN-γ pathways. In this study, we found M4 can disturb the interaction of chemokine and GAGs and might delay virus trafficking to the spleen, which could lead to a reduction of cellular activation. M4 may also impair the development of germinal centres at the beginning of latent infection in the spleens.