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Tao Wen

Publications and source records attributed to Tao Wen.

5 recordsLinked to original sources
PubMed2003

Costimulation of human CD28- T cells by 4-1BB ligand.

The T cell surface protein CD28 provides a critical costimulatory signal for T cell activation. With age, humans accumulate increasing numbers of CD28- T cells, and this loss of CD28 expression is exacerbated certain disease states, such as HIV infection, autoimmune conditions or cancer. It is unclear whether CD28- T cells represent terminally differentiated effector cells or whether they remain sensitive to costimulation by CD28-independent pathways. Here, we demonstrate that 4-1 BB ligand can costimulate human CD28- T cells, resulting in cell division, inflammatory cytokine production, increased perforin levels, enhancement of cytolytic effector function, as well as the up-regulation of the anti-apoptotic protein Bcl-X(L). Thus, human CD28- T cells can respond to costimulatory signals and as such become attractive targets for therapeutic intervention, particularly in chronic infectious and inflammatory diseases where large numbers of these cells accumulate.

4-1BB Ligand↗
PubMed2002

4-1BB ligand-mediated costimulation of human T cells induces CD4 and CD8 T cell expansion, cytokine production, and the development of cytolytic effector function.

4-1BB (CD137) is a costimulatory member of the TNFR family expressed on activated T cells. Its ligand, 4-1BBL, is expressed on activated APC. In the mouse, CD8 T cells are preferentially activated by agonistic anti-murine 4-1BB Abs. However, murine 4-1BBL can stimulate both CD4 and CD8 T cells. To date, there are only limited data on the effects of 4-1BBL on human T cell responses. To further understand the role of 4-1BBL in human T cell responses, we compared human CD4 and CD8 T cell responses to transfected human 4-1BBL plus TCR-mediated stimulation. Both human CD4 and CD8 T cells responded to 4-1BBL. The presence of 4-1BBL on the APC led to increased expansion, cytokine production, and the development of cytolytic effector function by human T cells. In unfractionated T cell cultures, CD4 and CD8 T cells could expand to a similar extent in response to signals through the TCR and 4-1BB, as measured by CFSE labeling and by quantitating T cell numbers in the cultures. In contrast to the results with total T cells, isolated CD8 T cells produced less IL-2 and expanded to a lesser extent than isolated CD4 T cells responding to 4-1BBL. Thus, 4-1BBL is most effective when both CD4 and CD8 T cells are included in the cultures. CD28 and 4-1BB were found to synergize in the induction of IL-2 by human T cells, and CTLA-Ig partially blocked 4-1BBL-dependent IL-2 production. However, a portion of the 4-1BBL-mediated effects were independent of CD28-B7 interaction.

4-1BB Ligand↗
PubMed2002

Generalized emissivity inverse problem.

Inverse problems have recently drawn considerable attention from the physics community due to of potential widespread applications [K. Chadan and P. C. Sabatier, Inverse Problems in Quantum Scattering Theory, 2nd ed. (Springer Verlag, Berlin, 1989)]. An inverse emissivity problem that determines the emissivity g(nu) from measurements of only the total radiated power J(T) has recently been studied [Tao Wen, DengMing Ming, Xianxi Dai, Jixin Dai, and William E. Evenson, Phys. Rev. E 63, 045601(R) (2001)]. In this paper, a new type of generalized emissivity and transmissivity inverse (GETI) problem is proposed. The present problem differs from our previous work on inverse problems by allowing the unknown (emissivity) function g(nu) to be temperature dependent as well as frequency dependent. Based on published experimental information, we have developed an exact solution formula for this GETI problem. A universal function set suggested for numerical calculation is shown to be robust, making this inversion method practical and convenient for realistic calculations.

Journal Article↗