Negative selection by endogenous antigen and superantigen occurs at multiple thymic sites

Negative selection by endogenous antigen and superantigen occurs at multiple thymic sites.

The site of negative selection in the thymus has been inferred from a range of different experiments. Analysis of thymic deletion of V beta 5+, V beta 11+ or V beta 17a+ cells in H-2E transgenic mice led to the theory that negative selection occurs predominantly in the medulla (specifically, through presentation by medullary dendritic cells). Other experiments investigated whether transgenic TC...

Negative Selection by IgM Superantigen

Negative selection of T cells occurs throughout thymic development.

Thymic positive and negative selections govern the development of a self-MHC-reactive, yet self-tolerant, T cell repertoire. Whether these processes occur independently or sequentially remains controversial. To investigate these issues, we have employed tetrameric peptide-MHC complexes to fluorescently label and monitor polyclonal populations of thymocytes that are specific for moth cytochrome ...

In vitro negative selection of viral superantigen-reactive thymocytes by thymic dendritic cells.

Intrathymic expression of endogenous mouse mammary tumor virus (MMTV)-encoded superantigens (SAg) induces the clonal deletion of T cells bearing SAg-reactive T-cell receptor (TCR) Vbeta elements. However, the identity of the thymic antigen-presenting cells (APC) involved in the induction of SAg tolerance remains to be defined. We have analyzed the potential of dendritic cells (DC) to mediate th...

Normal T Cell Selection Occurs in CD205-Deficient Thymic Microenvironments

The thymus imparts a developmental imprint upon T cells, screening beneficial and self-tolerant T cell receptor (TCR) specificities. Cortical thymic epithelial cells (CTEC) present self-peptide self-MHC complexes to thymocytes, positively selecting those with functional TCRs. Importantly, CTEC generate diverse self-peptides through highly specific peptide processing. The array of peptides utili...