Assessment of T CD8+ lymphocytes proliferation by dendritic cells challenged with pro-oxidants.

Author(s)

Gilberto Moreira Piassa Filho

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2010-09-23

Examining board members

Marilene Demasi; Jose Alexandre Marzagao Barbuto; Joao Gustavo Pessini Amarante Mendes

• Advisor: Marilene Demasi

Abstract

To be presented in dendritic cells MHC I, antigens are processed by immunoproteasome. The aim of the study was to examine the effect of pro-oxidants in dendritic cell-induced T CD8+ lymphocyte proliferation with focus on ubiquitin-proteasome system. The co-culture of DC incubated with Xanthine/Xanthine Oxidase system and T CD8+ isolated from mice immunized with DNA-HSP65 promoted T CD8+ proliferation. XaXO incubation was more efficient in promoting DC maturation compared to LPS. In addition, XaXO incubation decreased IP catalytic activity in relation to LPS, suggesting that increased T CD8+ proliferation is not directly related to IP activity. XaXO incubation did not alter the expression of 20S catalytic subunit, 19S regulatory unit or <font face=\"Symbol\">&#9465i subunit. XaXO incubation increased 11S regulatory unit content as well as that of ubiquitinated proteins. We suggest that the DC incubation with XaXO increased 11S content favoring its coupling to 20S in detriment of 19S. This would increase ubiquitinated protein levels and direct more peptide fragments for antigen presentation. (AU)

• FAPESP's process: 06/05498-3 - Redox modulation of the immunoproteasome in dendritic cells under oxidative challenge: implications upon generation of peptides for antigenic presentation by MHC I
• Grantee: Gilberto Moreira Piassa Filho
• Support Opportunities: Scholarships in Brazil - Master