Expression Profiles of Molecules Involved in Antigen Presentation in Gangliosides-stimulated Primary Astrocytes from Rat brain

Astrocytes can function as antigen-presenting cells (APC) by expressing class II major histocompatibility complex (MHC) antigens and co-stimulatory molecules upon activation. In vitro, astrocytes are activated by lipopolysaccharides (LPS), and interferon-gamma (IFN-gamma). We previously reported that gangliosides, membrane components of brain cells, especially neurons, can activate brain glial cells in vitro, thus could play roles in brain physiology and pathology. In this study, I tested whether gangliosides could induce the expression of immune molecules related to antigen presentation, using cultured rat brain glial cells, astrocytes and microglia. I treated cells with 50 ug/ml gangliosides mixture (Gmix) for 6 h to 3 d, and assayed the mRNA expression of class II transactivator (CIITA) and class II major histocompatibility (MHCII) molecules, using RT-PCR and real-time PCR. Gangliosides induce CIITA mRNA expression, followed by MHC II in astrocytes, but not in microglia. Critical for the development of mature APC capability is surface expression of class II MHC molecules and co-stimulatory molecules expression. Cell surface molecules of central importance to costimulation are CD40, ICAM-1, CD80 (B7-1) and CD86 (B7-2). In astrocytes, mRNA expressions of the above molecules were constitutive and that of CD86 was further induced by treatment of Gmix. Those expression patterns are the same in IFN-gamma-treated cells. Next, I tested the surface expression of MHC II by FACS and immunocytochemistry analysis. Gmix treatment failed to induce it in both FACS and immunocytochemistry analysis, in contrast to IFN-gamma treatment. This imply that Gmix could induce the mRNA expressions of CIITA and MHCII, but they could not induce surface expression of MHCII. To clarify the mechanisms, I assayed the molecules involved in it, including invariant chain (Ii) and the non-classical class II molecule RT1-DMs. Treatment of Gmix could not induce the mRNA expression of Ii, while IFN-gamma could. Still further studies are needed, I presumably suggest that Gmix are defective in fully presenting antigens due to a lack of expressing Ii molecules.

Author dc:creator

• 윤, 희정

Contributors dc:contributor

• 주, 일로
• 대학원 의학과
• 200324281

• Ganglioside
• Astrocyte
• antigen-presentig cell
• MHCII
• CIITA
• co-stimulatory molecules
• Gmix
• Ii

Language dc:language

en

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000000285
000000000285

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/2287