Publications by authors named "Rebecca C Keim"

Conventional APCs that express MHC class II (MHCII) and co-stimulatory molecules include dendritic cells (DCs) and macrophages. Beyond these conventional APCs, immune stimulatory cells have been more recently shown to extend to a class of atypical APCs, composed of mast cells, basophils, and eosinophils. Here, we describe a unique type of APC, Gr1 CD11b cells with a granularity and size characteristic of myeloid cells and with the ability to present Ag for crosspresentation.

View Article and Find Full Text PDF

Breast cancer patients who initially respond to cancer therapies often succumb to distant recurrence of the disease. It is not clear why people with the same type of breast cancer respond to treatments differently; some escape from dormancy and relapse earlier than others. In addition, some tumor clones respond to immunotherapy while others do not.

View Article and Find Full Text PDF

Sperm associated antigen 6 (SPAG6), a component of the central apparatus of the "9 + 2" axoneme, plays a central role in ciliary and flagellar motility; but, its contribution to adaptive immunity and immune system development is completely unknown. While immune cells lack a cilium, the immunological synapse is a surrogate cilium as it utilizes the same machinery as ciliogenesis including the nucleation of microtubules at the centrosome. This prompted our hypothesis that SPAG6 critically regulates the formation and function of immunological synapses.

View Article and Find Full Text PDF

Two major barriers to cancer immunotherapy include tumor-induced immune suppression mediated by myeloid-derived suppressor cells and poor immunogenicity of the tumor-expressing self-antigens. To overcome these barriers, we reprogrammed tumor-immune cell cross-talk by combined use of decitabine and adoptive immunotherapy, containing tumor-sensitized T cells and CD25(+) NKT cells. Decitabine functioned to induce the expression of highly immunogenic cancer testis antigens in the tumor, while also reducing the frequency of myeloid-derived suppressor cells and the presence of CD25(+) NKT cells rendered T cells, resistant to remaining myeloid-derived suppressor cells.

View Article and Find Full Text PDF

Two major barriers in the immunotherapy of breast cancer include tumor-induced immune suppression and the establishment of long-lasting immune responses against the tumor. Recently, we demonstrated in an animal model of breast carcinoma that expanding and reprogramming tumor-sensitized lymphocytes, ex vivo, yielded T memory (Tm) cells as well as activated CD25+ NKT cells and NK cells. The presence of activated CD25+ NKT and NK cells rendered reprogrammed T cells resistant to MDSC-mediated suppression, and adoptive cellular therapy (ACT) of reprogrammed lymphocytes protected the host from tumor development and relapse.

View Article and Find Full Text PDF