MHC class II deficiency has proven to be an excellent model to study transcription regulation of MHC genes and T cell development. Cell lines established from MHC class II deficient patients have been of great value for the identification of proteins necessary for MHC expression and their study has resulted in the identification of a common regulatory pathway for MHC class II and class I genes....

CD70 is a TNF-related transmembrane molecule expressed by mature dendritic cells (DCs), which present antigens to T cells via major histocompatibility complex (MHC) molecules. In DCs, CD70 localizes with MHC class II molecules in late endosomal vesicles, known as MHC class II compartments (MIICs). MIICs are transported to the immune synapse when a DC contacts an antigen-specific CD4(+) T cell. ...

Major histocompatibility complex class II molecules (MHC-II), which present exogenous antigens to CD4+ T-lymphocytes, play an essential role in the initiation of the antigen-specific immune response. MHC-II is expressed in antigen presenting cells (APCs) including B cells, monocytes, macrophages and dendritic cells (DCs). MHCII is constitutively expressed on resting/immature APCs at a relativel...

Tumor cells that constitutively express MHC class I molecules and are genetically modified to express MHC class II (MHC II) and costimulatory molecules are immunogenic and have therapeutic efficacy against established primary and metastatic cancers in syngeneic mice and activate tumor-specific human CD4+ T lymphocytes. Previous studies have indicated that these MHC II vaccines enhance immunity ...

Dendritic cells (DCs) initiate adaptive immune responses by activating T cells via cognate interactions between MHC-peptide complexes and T cell receptors. In immature DCs, MHC class II is predominantly stored in late endocytic compartments, where it has a short half-life because of degradation. In contrast, mature DCs recruit MHC class II to the plasma membrane. We here demonstrate that in imm...

During maturation of MHC II molecules, newly synthesized and assembled complexes of MHC II alphabeta dimers with invariant chain (Ii) are targeted to endosomes, where Ii is proteolyzed, leaving remnant class II-associated Ii peptides (CLIP) in the MHC II peptide binding groove. CLIP must be released, usually with assistance from the endosomal MHC II peptide exchange factor, HLA-DM, before MHC I...

Hodgkin's disease is a common malignancy of the lymphoid system. Although the scarce Hodgkin and Reed-Sternberg (HRS) tumor cells in involved tissue synthesize major histocompatibility complex (MHC) class II and costimulatory molecules such as CD40 or CD86, it is unclear whether these tumor cells are operational antigen-presenting cells (APC). We developed an immunofluorescence-based assay to d...

Major histocompatibility complex (MHC) class II molecules (MHC-II) function by binding antigenic peptides and displaying these peptides on the surface of antigen presenting cells (APCs) for recognition by peptide-MHC-II (pMHC-II)-specific CD4 T cells. It is known that cell surface MHC-II can internalize, exchange antigenic peptides in endosomes, and rapidly recycle back to the plasma membrane; ...

Ag presentation by MHC class II (MHC II) molecules to CD4(+) T cells plays a key role in the regulation of the adaptive immune response. Loading of antigenic peptides onto MHC II is catalyzed by HLA-DM (DM), a nonclassical MHC II molecule. The mechanism of DM-facilitated peptide loading is an outstanding problem in the field of Ag presentation. In this study, we systemically explored possible k...

Anthrax Lethal Toxin consists of Protective Antigen (PA) and Lethal Factor (LF), and current vaccination strategies focus on eliciting antibodies to PA. In human vaccination, the response to PA can vary greatly, and the response is often directed toward non-neutralizing epitopes. Variable vaccine responses have been shown to be due in part to genetic differences in individuals, with both MHC cl...