Thymocytes bearing autoreactive TCR are eliminated from the organism by a process termed negative selection. The molecular basis of this deletion has been recently shown to be a consequence of TCR-triggered activation of a caspase by certain peptide-MHC ligands in the immature CD4+CD8+ double-positive (DP) thymocyte subpopulation. Of note, the numerically minor TCRhigh DP thymocyte subpopulatio...

The distribution of the viral glycoprotein, gp 69/71, was studied on the cell surfaces of virus-producing and nonproducing cells. gp 69/71 was distributed evenly on cell membranes and on viral membranes of cells producing murine leukemia virus. gp 69/71 was distributed uniformly on cell membranes of thymocytes from NZB and strain 129 mice but was not detected on cell membranes of BALB/c thymocy...

Cadherins mediate homotypic adhesion between lineage-related cells in epithelia and other tissues. One cadherin, E-cadherin, is also responsible for adhesion of murine epidermal Langerhans cells to keratinocytes in vitro, and may play a role in the localization of Langerhans cells in epidermis. The thymus is another tissue in which important adhesive interactions between bone marrow-derived cel...

In mice that express a transgene for the 2C T cell antigen-receptor (TCR) and lack a recombinase-activating gene (2C(+)RAG(-/-) mice) most of the peripheral T cells are CD8(+), a few are CD4(+), and a significant fraction are CD4(-)CD8(-) [double negative (DN)]. The DN 2C cells, like DN T cells that are abundant in various other alphabeta TCR-transgenic mice, appear to be derived directly from ...

Prior studies have shown that thymocytes, unlike peripheral T cells, do not proliferate in response to mitogenic combinations of anti-CD2 mAbs. The present study demonstrated that stimulation by a mitogenic anti-CD2 combination (9-1 plus 9.6) with anti-CD28 induced vigorous thymocyte proliferation in the absence of exogenous IL-2. This thymocyte proliferation was IL-2 dependent as shown by the ...

In sepsis, apoptosis occurs in many different organs. The mediators responsible for induction of apoptosis are not clearly known, although there are some suggestions that C5a and the C5a receptor (C5aR) might be directly linked to apoptosis. In the cecal ligation/puncture (CLP) model of sepsis in rats, apoptosis occurs early in a variety of organs, especially in the thymus. We demonstrate that ...

Recent studies have revealed that 10-20% of CD4+8 or CD4-8thymocyte populations contain NKI.1 + T cell receptor (TCR)-cff~ + cells. This subpopulation shows characteristics that are different from NKI.1CD4 § or NKI.1CD8 + T calls and seems to have developed in a manner different from NKI.1T cells. Although extensive studies have been performed on the NKI.1 + TCR-od~8 + thymocytes, the physiolog...

The thymus gland is a central lymphoid organ in which developing T cell precursors, known as thymocytes, undergo differentiation into distinct type of mature cells, ultimately migrating to the periphery where they exert specialized effector functions and orchestrate immune responses against tumor pathogens self-antigens. mechanisms supporting intrathymic are pleiotropically regulated by thymic ...

The golli products of the myelin basic protein gene have been shown to be expressed in mouse thymus and brain. The full repertoire of thymic cell types expressing golli products has not yet been determined, although immunoreactivity has been found in some macrophages. We have analyzed the cellular expression of golli mRNAs and proteins in the thymus. The results showed that MTS5(+) cortical/MTS...

The SCID-hu Thy/Liv mouse and human fetal thymic organ culture (HF-TOC) models have been used to explore the pathophysiologic mechanisms of HIV-1 infection in the thymus. We report here that HIV-1 infection of the SCID-hu Thy/Liv mouse leads to the induction of MHC class I (MHCI) expression on CD4+CD8+ (DP) thymocytes, which normally express low levels of MHCI. Induction of MHCI on DP thymocyte...