This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

No description available.

Natural killer (NK) cell deficiency (NKD) occurs when an individual’s major clinical immunodeficiency derives from abnormal NK cells and is associated with several genetic etiologies. Three categories of β actin-related diseases with over 60 ACTB variants have previously been identified, none with a distinct NK cell phenotype. An individual with mild developmental delay, macrothrombocytopenia, susceptibility to infections, molluscum, and EBV-associated lymphoma had functional NK cell deficiency for over a decade. A de novo ACTB variant encoding G342D β actin was identified and was consistent with the individual’s developmental and platelet phenotype. This novel variant also was found to have a direct impact in NK cells, as its expression in YTS (YTS-NKD) cells caused increased cell spreading in lytic immune synapses created on activating surfaces. YTS-NKD cells were able to degranulate and perform cytotoxicity, but demonstrated defective serial killing owing to prolonged conjugation to the killed target cell and thus were effectively unable to terminate lytic synapses. G342D β actin results in a novel mechanism of functional NKD via increased synaptic spreading and defective lytic synapse termination with resulting impaired serial killing leading to overall reductions in NK cell cytotoxicity.

Abelson murine leukemia virus (A-MuLV)-induced transformation was investigated to determine whether cells not sensitive to TNF-α could be made sensitive to the cytolytic action of TNF-α when infected with this retrovirus. Mouse embryonic fibroblast cell line CL.7 was found to be relatively insensitive to TNF-α. Upon transformation with A-MuLV, these cells gave rise to a clone (3R.1) which was found to be insensitive to TNF-α and another clone (6R.1) which had an increased sensitivity to TNF-α. The differential cytotoxicity was observed when cells were treated with TNF-α, for 18 hr, at 0 to 100 units/ml, at 37°C. The mechanism of this differential cytotoxicity was further investigated. Thus, TNF-R levels on the cell surface were found to be not correlated with the differential TNF-α response. The A-MuLV transformation suppressed the epidermal growth factor-receptor (EGF-R) in 3R.1 clone and induced its levels significantly in the 6R.1 clone (p<0.05). Cell surface EGF-receptor (EGF-R) levels in CL.7 and 3R.1 clones were lower than the 6R.1 clone (p<0.05). Although the EGF-R levels in all the clones were induced with TNF-α, the expression of EGF-R correlated with the susceptibility to TNF-α. The role of antioxidants, such as α-tocopherol and β-carotene, (known anti-cancer agents) in modulating TNF-α-induced EGF-R expression was investigated. In both the untransformed and the transformed clones, f-carotene suppressed the constitutive and the TNF-α induced EGF-R levels whereas α-tocopherol was found to have an enhancing effects. Studies with metabolic inhibitors on TNF-R and EGF-R expression indicate that inhibitors of the arachidonic acid cascade and modulators of protein kinase-C (PK-C), could influence the binding and internalization of TNF-α and thereby controlling the physiologic future of the cells. The A-MuLV specific V-abl protein, p120, tyrosine phosphorylation was determined by a radio-labelled anti-phosphotyrosine antibody in an antigen capture assay. TNF-α had little effect on p120 phosphotyrosine levels of TNF-α insensitive CL.7 and 3R.1 clones. The, TNF-α sensitive, 6R.1 clone, however, was found to induce its p120 specific phosphotyrosine upon exposure to TNF-α for 8 hr. Thus, TNF-α modulated the tyrosine phosphorylation of p120 only in the TNF-α-sensitive cell line. The mitochondrial toxicity of TNF-α was determined by monitoring the rate of quenching of a cationic spin probe CAT 16. Mitochondrial preparation from CL.7 and 3R.1 clones had higher ability to quench CAT 16 signal with TNF-α incubation time than mitochondria from the 6R.1 cells. This indicates that the differential TNF-α cytotoxicity manifested in A-MuLV transformed clones may, in part, be due to the differential mitochondrial toxicity of this cytokine. The hypothesis that TNF-α cytotoxicity was mediated via an oxidative process was tested on the TNF-α sensitive L929 cells. Using a flow cytometric detection system it was determined that TNF-α produced intracellular hydrogen peroxide in these cells which was sensitive to concentration and incubation time of TNF-α. Superoxide radicals were also generated during TNF-α action on L929 cells, as determined by the use of the spin trap PBN in conjunction with EPR spectroscopic techniques. The PBN-OOH spin adduct spectrum peaked at 9 hr of TNF-α incubation and was inhibitable upto 30 % with 10 µM of desferral-Mn complex (a known SOD mimic). These data indicate that superoxide and hydrogen peroxide are common events in TNF-α dependent cell killing process. The differential TNF-α cytotoxicity was found to depend on differences in the antioxidant status of the target clones. Thus, it was found that Cu/Zn-SOD, Mn-SOD, GSH-Peroxidase and GSH-Reductase enzymes were all induced significantly in the CL.7 clone (p<0.05) upon incubation with 100 units/ml of TNF-α for 18 hrs. TNF-α had little effect on the antioxidant enzymes of both 3R.1 and 6R.1 cells. However, the constitutive levels of most antioxidant enzymes were found to be higher in 3R.1 cells than in the 6R.1 cells. Therefore, the susceptibility of 6R.1 to TNF-α may, in part, be due to a low level of antioxidant enzymes present in this clone. In conclusion we found that the differential cytotoxicity of TNF-a may, in part, due to: (1) differential EGF-R expression, (2) differential mitochondrial cytotoxicity, and (3) differential ability to modulate the tyrosine phosphorylation in untransformed and A-MuLV transformed cells and (4) differential antioxidant status of these cells to handle oxidative stress imposed by TNF-α. / Ph. D.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 283-321).

Alopecia areata (AA) is a chronic inflammatory disease of hair follicles manifesting as patchy areas of hair loss on the scalp and body. Development of AA is associated with pen- and intra-follicular inflammation of anagen stage hair follicles, primarily by CD4+ and CD8+ cells. We hypothesized that if cell-mediated cytotoxicy against hair follicles is to be a component of the hair loss disease mechanism, increased expression of genes and products typical of cytotoxic cells, as well as increased apoptosis activity within affected hair follicles, would be expected to occur in the lesional skin compared to the normal skin. Furthermore, we studied gene expression levels of multiple cytokines and characteristic chemokines, using the C3FI/HeJ mouse model of AA. mRNA expression levels of granzyme A, granzyme B, perform Fas, Fas ligand, TNF-cL, TNF-aRl and R2, TRAIL, TRAILR, TRAMP, Thi-, Th2-, and Th17-associated cytokines, as well as multiple chemokines were compared between the skin, draining lymph nodes, thymus and spleens of normal and AA-affected mice using quantitative reverse transcriptase PCR. FasL, granzyme A, granzyme B, pro- and anti-inflammatory cytokines were all highly up-regulated in the skin of AA-affected mice. Immunohistochemical studies of the skin revealed that, although greater numbers of granzyme B and FasL expressing cells were present in AA affected skin, the cells were morphologically diffusely distributed and not exclusively located within the focal pen- and intrafollicular infiltrate. The majority of these cells were further characterized as mast cells, which were also found in substantially greater numbers in the skin of mice with AA compared to their normal haired controls. Almost no perform expressing cells were identified in AA affected mouse skin and TUNEL staining suggested relatively limited apoptosis activity in hair follicle keratinocytes. In conclusion, while granzymes and FasL may play important roles in disease development, the profiles and patterns of expression are not consistent with direct cell-mediated cytotoxic action against the follicular epithelium in chronic mouse AA. Potentially, hair growth inhibiting cytokines may play a more dominant role in AA development than previously thought. Furthermore, mast cells, with their increased presence around hair follicles in the AA affected mouse skin and their ability to express granzyme B and FasL, are suggested as potential key players in the pathogenesis of AA.

published_or_final_version / Obstetrics and Gynaecology / Master / Master of Philosophy

Alopecia areata (AA) is a chronic inflammatory disease of hair follicles manifesting as patchy areas of hair loss on the scalp and body. Development of AA is associated with pen- and intra-follicular inflammation of anagen stage hair follicles, primarily by CD4+ and CD8+ cells. We hypothesized that if cell-mediated cytotoxicy against hair follicles is to be a component of the hair loss disease mechanism, increased expression of genes and products typical of cytotoxic cells, as well as increased apoptosis activity within affected hair follicles, would be expected to occur in the lesional skin compared to the normal skin. Furthermore, we studied gene expression levels of multiple cytokines and characteristic chemokines, using the C3FI/HeJ mouse model of AA. mRNA expression levels of granzyme A, granzyme B, perform Fas, Fas ligand, TNF-cL, TNF-aRl and R2, TRAIL, TRAILR, TRAMP, Thi-, Th2-, and Th17-associated cytokines, as well as multiple chemokines were compared between the skin, draining lymph nodes, thymus and spleens of normal and AA-affected mice using quantitative reverse transcriptase PCR. FasL, granzyme A, granzyme B, pro- and anti-inflammatory cytokines were all highly up-regulated in the skin of AA-affected mice. Immunohistochemical studies of the skin revealed that, although greater numbers of granzyme B and FasL expressing cells were present in AA affected skin, the cells were morphologically diffusely distributed and not exclusively located within the focal pen- and intrafollicular infiltrate. The majority of these cells were further characterized as mast cells, which were also found in substantially greater numbers in the skin of mice with AA compared to their normal haired controls. Almost no perform expressing cells were identified in AA affected mouse skin and TUNEL staining suggested relatively limited apoptosis activity in hair follicle keratinocytes. In conclusion, while granzymes and FasL may play important roles in disease development, the profiles and patterns of expression are not consistent with direct cell-mediated cytotoxic action against the follicular epithelium in chronic mouse AA. Potentially, hair growth inhibiting cytokines may play a more dominant role in AA development than previously thought. Furthermore, mast cells, with their increased presence around hair follicles in the AA affected mouse skin and their ability to express granzyme B and FasL, are suggested as potential key players in the pathogenesis of AA.

Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Immunology, Department of Medical Microbiology and Immunology. Title from pdf file main screen (viewed on September 3, 2009). Includes bibliographical references.

Thesis (doctoral)--University of Lund, 1996. / Added t.p. with thesis statement added.