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| Author(s): |
Lizandre Keren Ramos da Silveira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD) |
| Defense date: | 2023-06-07 |
| Examining board members: |
Walcy Paganelli Rosolia Teodoro;
Ricardo Fuller;
Maria Notomi Sato;
Pedro Leme Silva
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| Advisor: | Walcy Paganelli Rosolia Teodoro |
| Abstract | |
Recently, many authors have suggested that tissue and vascular damage resulting from pathological inflammatory processes can expose collagen V, a fibrillar protein located within collagen fibrils. Thus, due to its antigenic properties, collagen V can become a neoantigen when exposed to the immune system, generating autoimmunity in several diseases. Previous studies by our group have shown that rats with joint inflammation induced by methylated bovine serum albumin (mBSA) and complete Freund\'s adjuvant, have anti-collagen V antibodies. Furthermore, prophylactic oral administration with collagen V, positively interfered in the modulation of the process inflammation and synovial remodeling in rats with joint inflammation; however, the effect of collagen V as an immunotherapy is not yet known. In the present study, we evaluated the effect of immunotherapy with collagen V after the establishment of joint synovitis in a model of arthritis in rats. For this, twenty-five male Lewis rats, three months old, with an average weight of 360g were divided into three groups: induced arthritis (IA, n=10), arthritis treated with collagen V (IA-Col V, n=10) and control with collagen V (CT-Col V, n=5). Arthritis was induced by intra-articular (ai) injection of mBSA and complete Freund\'s adjuvant in the right knee, with intra-articular mBSA boosters on the 7th and 14th days. On the 15th day, after the induction period, the IA-Col V group received oral administration of 300 l of a 1.6 g/l collagen V solution, three times a week. In the CT-Col V group, 20 l of saline solution (ai) was injected, and the animals received the same treatment protocol as in the IA-Col V group. The groups were euthanized 30 days after the first injection. Joint diameter, inflammation by PET/CT with [18F]FDG, expression of CD3+, CD4+, CD8+, CD20+, FoxP3+, Caspase 3+ and IL-10+ and collagen types I, III and V, in addition to search for anti-collagen II and V antibodies in serum. Our results showed an increase in joint diameter at 7 and 14 days in the IA and IA-Col V groups and a decrease at 30 days. Still, no significant difference was detected in cellular metabolic activity between the IA-Col V and IA groups after 30 days. Morphologically, we identified thickening of the synovial membrane, presence of intense inflammatory infiltrate in the synovial tissue of the IA group; on the contrary, we identified a slight decrease in inflammatory cells associated with collagen deposition in the IA-Col V group. In the IA and IA-Col V groups, we identified an increase in T lymphocytes (CD3+, CD4+, CD8+), B lymphocytes (CD20+) and macrophages (CD68+) in the synovial tissue of the right knee with arthritis induction, compared to the left knee. We highlight the intense infiltration of lymphocytes doubly labeled for FoxP3+ and IL-10+, and also of CD3+ lymphocytes with caspase 3+ in the synovial tissue of the IA-Col V group, when compared to the synovial tissue of the IA group. Additionally, the synovial tissue of the IA-Col V group showed a decrease in collagen V expression in regions with intense positivity for IL-10, when compared to the IA group. In the IA-Col V group, we also identified a significant increase in collagen I and a decrease in collagen V, which was not observed for collagen III. Regarding the frequency of antibodies in the serum, we found anti-collagen II in 50% and 46.6% of the animals, respectively in the IA and IA-Col V groups, and anti-collagen V in 50% and 58.3% of the animals, respectively in IA and IA-Col V. Knowing that the oral administration of collagen V, 15 days after the induction of arthritis in rats, induced an increase in FoxP3+ lymphocytes with intense production of IL-10+, combined with an increase in collagen I and a decrease in collagen V, we can conclude that collagen V has an immunotherapeutic effect on arthritis in rats. Furthermore, we suggest that anti-collagen V antibodies could be used as a biomarker of the evolution of the joint inflammatory process in this disease (AU) | |
| FAPESP's process: | 19/24178-0 - Effect of type V collagen supplementation on inflammatory process and experimental extracellular arthritis matrix remodeling |
| Grantee: | Lizandre Keren Ramos da Silveira |
| Support Opportunities: | Scholarships in Brazil - Master |