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Papers by Gunnvor Oijordsbakken

Research paper thumbnail of Ro52- and Ro60-specific B cell pattern in the salivary glands of patients with primary Sjögren's syndrome

Clinical & Experimental Immunology, 2013

Primary Sjögren's syndrome (pSS) is characterized by the presence of autoantibodies against the r... more Primary Sjögren's syndrome (pSS) is characterized by the presence of autoantibodies against the ribonucleoprotein (RNP) particles Ro/SSA and La/SSB, and mononuclear cell infiltration of exocrine tissues, especially salivary and lachrymal glands. Low numbers of autoantigen-specific memory B cells and elevated levels of plasma cells have been detected previously in the peripheral blood (PB) of pSS patients compared to controls. As both Ro52 and Ro60-specific cells have been detected in the salivary glands (SG) of pSS patients, we aimed to characterize the SSA-specific B cell pattern in SG biopsies. A series of double immunohistochemical stainings were performed on paraffin-embedded tissue from 10 well-characterized pSS patients for each Ro52 and Ro60 along with CD19, CD5, CD20 or CD27, respectively. Ro52 and Ro60-specific cells detected in SG tissue were found to be CD19 + B cells located outside the CD19 + /CD20 + B cell zones (BCZ) and also interstitially. These SSA-specific cells were also quantified. No SSA-specific cells were CD5 + , indicating that they do not belong to the B-1 B cell subset. Furthermore, no SSA-specific cells were observed within the CD20 + BCZ. Hence, no SSA-specific memory B cells were detected in these individuals. Contrary to this, SSA-specific cells were found to be CD19 + /CD27 ++ , demonstrating that they are differentiating short or long-lived plasma cells. Taken together, our findings suggest that these lower levels of SSA-specific memory B cells in PB and absence of SSA-specific memory B cells in SG of pSS patients could result from activation of these cells into plasma cells at the site of inflammation.

Research paper thumbnail of Altered CD40 and E-cadherin expression - putative role in oral lichen planus

Journal of Oral Pathology & Medicine, 2007

BACKGROUND: Oral lichen planus (OLP) is characterized among other features by apoptosis of basal ... more BACKGROUND: Oral lichen planus (OLP) is characterized among other features by apoptosis of basal keratinocytes. To identify potential regulatory mechanisms associated with basal cell apoptosis in OLP, we investigated the expression of CD40, CD40 ligand (CD40L), CD44 and epithelial (E)-cadherin. METHODS: Biopsies from 22 patients with OLP were investigated by immunohistochemistry for detection of CD40, CD40L, E-cadherin, CD44, Laminin-5 and Collagen IV, double-labelling for CD40 and CD3, and in situ mRNA hybridization for CD40 and CD40L. RESULTS: In actively diseased areas of OLP lesions, basal keratinocytes did not express CD40 and were focally E-cadherin-negative, in contrast to non-diseased areas and normal oral mucosa. Demonstration of intraepithelial T cells expressing CD40 and CD40L, indicates a potential role in inflammatory cell responses involved in the disease process of OLP. CONCLUSION: T cells may orchestrate inflammatory cell responses in OLP via CD40-CD40L interactions. As basal keratinocytes downregulate CD40, they may escape CD40-CD40L-induced apoptosis in OLP. On the other hand, loss of E-cadherin expression may contribute to epithelial basal cell destruction and T-cell migration into the epithelial compartment in OLP. J Oral Pathol Med (2007) 36: 153-60 J Oral Pathol Med (2007) 36: 153-60 ª Blackwell Munksgaard 2007 AE All rights reserved www.blackwellmunksgaard.com/jopm CD40 and E-cadherin in oral lichen planus Neppelberg et al. 154 J Oral Pathol Med CD40 and E-cadherin in oral lichen planus Neppelberg et al. 156 J Oral Pathol Med

Research paper thumbnail of Levels of plasmacytoid dendritic cells and type-2 myeloid dendritic cells are reduced in peripheral blood of patients with primary Sjogren's syndrome

Research paper thumbnail of Salivary glands of primary Sjogren's syndrome patients express factors vital for plasma cell survival

Arthritis Research & Therapy, 2011

The presence of circulating Ro/SSA and La/SSB autoantibodies has become an important marker in th... more The presence of circulating Ro/SSA and La/SSB autoantibodies has become an important marker in the classification criteria for primary Sjögren's syndrome (pSS). Plasma cells producing these autoantibodies are mainly high affinity plasma cells originating from germinal centre reactions. When exposed to the right microenvironment these autoimmune plasma cells become long-lived and resistant to immunosuppressive treatment. Since autoimmune plasma cells have been detected in the salivary glands of SS patients, we wanted to investigate if the glandular microenvironment is suitable for plasma cell survival and if glandular residing plasma cells are the long-lived plasma cell subset.

Research paper thumbnail of Ro52- and Ro60-specific B cell pattern in the salivary glands of patients with primary Sjögren's syndrome

Clinical & Experimental Immunology, 2013

Primary Sjögren's syndrome (pSS) is characterized by the presence of autoantibodies against the r... more Primary Sjögren's syndrome (pSS) is characterized by the presence of autoantibodies against the ribonucleoprotein (RNP) particles Ro/SSA and La/SSB, and mononuclear cell infiltration of exocrine tissues, especially salivary and lachrymal glands. Low numbers of autoantigen-specific memory B cells and elevated levels of plasma cells have been detected previously in the peripheral blood (PB) of pSS patients compared to controls. As both Ro52 and Ro60-specific cells have been detected in the salivary glands (SG) of pSS patients, we aimed to characterize the SSA-specific B cell pattern in SG biopsies. A series of double immunohistochemical stainings were performed on paraffin-embedded tissue from 10 well-characterized pSS patients for each Ro52 and Ro60 along with CD19, CD5, CD20 or CD27, respectively. Ro52 and Ro60-specific cells detected in SG tissue were found to be CD19 + B cells located outside the CD19 + /CD20 + B cell zones (BCZ) and also interstitially. These SSA-specific cells were also quantified. No SSA-specific cells were CD5 + , indicating that they do not belong to the B-1 B cell subset. Furthermore, no SSA-specific cells were observed within the CD20 + BCZ. Hence, no SSA-specific memory B cells were detected in these individuals. Contrary to this, SSA-specific cells were found to be CD19 + /CD27 ++ , demonstrating that they are differentiating short or long-lived plasma cells. Taken together, our findings suggest that these lower levels of SSA-specific memory B cells in PB and absence of SSA-specific memory B cells in SG of pSS patients could result from activation of these cells into plasma cells at the site of inflammation.

Research paper thumbnail of Altered CD40 and E-cadherin expression - putative role in oral lichen planus

Journal of Oral Pathology & Medicine, 2007

BACKGROUND: Oral lichen planus (OLP) is characterized among other features by apoptosis of basal ... more BACKGROUND: Oral lichen planus (OLP) is characterized among other features by apoptosis of basal keratinocytes. To identify potential regulatory mechanisms associated with basal cell apoptosis in OLP, we investigated the expression of CD40, CD40 ligand (CD40L), CD44 and epithelial (E)-cadherin. METHODS: Biopsies from 22 patients with OLP were investigated by immunohistochemistry for detection of CD40, CD40L, E-cadherin, CD44, Laminin-5 and Collagen IV, double-labelling for CD40 and CD3, and in situ mRNA hybridization for CD40 and CD40L. RESULTS: In actively diseased areas of OLP lesions, basal keratinocytes did not express CD40 and were focally E-cadherin-negative, in contrast to non-diseased areas and normal oral mucosa. Demonstration of intraepithelial T cells expressing CD40 and CD40L, indicates a potential role in inflammatory cell responses involved in the disease process of OLP. CONCLUSION: T cells may orchestrate inflammatory cell responses in OLP via CD40-CD40L interactions. As basal keratinocytes downregulate CD40, they may escape CD40-CD40L-induced apoptosis in OLP. On the other hand, loss of E-cadherin expression may contribute to epithelial basal cell destruction and T-cell migration into the epithelial compartment in OLP. J Oral Pathol Med (2007) 36: 153-60 J Oral Pathol Med (2007) 36: 153-60 ª Blackwell Munksgaard 2007 AE All rights reserved www.blackwellmunksgaard.com/jopm CD40 and E-cadherin in oral lichen planus Neppelberg et al. 154 J Oral Pathol Med CD40 and E-cadherin in oral lichen planus Neppelberg et al. 156 J Oral Pathol Med

Research paper thumbnail of Levels of plasmacytoid dendritic cells and type-2 myeloid dendritic cells are reduced in peripheral blood of patients with primary Sjogren's syndrome

Research paper thumbnail of Salivary glands of primary Sjogren's syndrome patients express factors vital for plasma cell survival

Arthritis Research & Therapy, 2011

The presence of circulating Ro/SSA and La/SSB autoantibodies has become an important marker in th... more The presence of circulating Ro/SSA and La/SSB autoantibodies has become an important marker in the classification criteria for primary Sjögren's syndrome (pSS). Plasma cells producing these autoantibodies are mainly high affinity plasma cells originating from germinal centre reactions. When exposed to the right microenvironment these autoimmune plasma cells become long-lived and resistant to immunosuppressive treatment. Since autoimmune plasma cells have been detected in the salivary glands of SS patients, we wanted to investigate if the glandular microenvironment is suitable for plasma cell survival and if glandular residing plasma cells are the long-lived plasma cell subset.