T lymphocyte activation by staphylococcal enterotoxins: Role of class II molecules and T cell surface structures

We describe a murine cDNA, designated Early T lymphocyte activation 1 (ETA-1) which is abundantly expressed after activation of T cells. Eta-1 encodes a highly acidic secreted product having structural features of proteins that bind to cellular adhesion receptors. The Eta-1 gene maps to a locus on murine chromosome 5 termed Ric that confers resistance to infection by Rickettsia tsutsugamushi (RT), an obligate intracellular bacterium that is the etiological agent for human scrub typhus. With one exception, inbred mouse strains that expressed the Eta-1a allele were resistant to RT infection (RicR), and inbred strains expressing the Eta-1b allele were susceptible (RicS). These findings suggest that Eta-1 is the gene inferred from previous studies of the Ric locus (5). Genetic resistance to RT infection is associated with a strong Eta-1 response in vivo and inhibition of early bacterial replication. Eta-1 gene expression appears to be part of a surprisingly rapid T cell-dependent response to bacterial infection that may precede classical forms of T cell-dependent immunity.

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Induced Expression of Class II Transplantation Antigens in the Cartilage-Pannus Junction in RA: Chronic Synovitis as a Model System for Aberrant T-Lymphocyte Activation

Rheumatology ◽

10.1093/rheumatology/xxvii.suppl_2.141 ◽

1988 ◽

Vol XXVII (suppl 2) ◽

pp. 141-149 ◽

Cited By ~ 7

Author(s):

L. Klareskog ◽

O. Johnell

Keyword(s):

T Lymphocyte ◽

Lymphocyte Activation ◽

Class Ii ◽

Model System ◽

Induced Expression ◽

T Lymphocyte Activation ◽

Chronic Synovitis ◽

Transplantation Antigens

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Systemic and Mucosal T-Lymphocyte Activation Induced by Recombinant Adenovirus Vaccines in Rhesus Monkeys

Journal of Virology ◽

10.1128/jvi.01170-09 ◽

2009 ◽

Vol 83 (20) ◽

pp. 10596-10604 ◽

Cited By ~ 13

Author(s):

Yue Sun ◽

Robert T. Bailer ◽

Srinivas S. Rao ◽

John R. Mascola ◽

Gary J. Nabel ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

T Lymphocyte ◽

Rhesus Monkeys ◽

Recombinant Adenovirus ◽

Lymphocyte Activation ◽

T Cell Responses ◽

Cell Responses ◽

T Lymphocyte Activation

ABSTRACT The administration of vectors designed to elicited cell-mediated immune responses may have other consequences that are clinically significant. To explore this possibility, we evaluated T-cell activation during the first 2 months after recombinant adenovirus serotype 5 (rAd5) prime or boost immunizations in rhesus monkeys. We also evaluated the kinetics of T-lymphocyte activation in both the systemic and the mucosal compartments after rAd5 administration in monkeys with preexisting immunity to Ad5. The rAd5 immunization induced lower-frequency Gag epitope-specific CD8+ T cells in the colonic mucosa than in the peripheral blood. There was evidence of an expansion of the simian immunodeficiency virus Gag-specific CD8+ T-cell responses, but not the Ad5 hexon-specific T-cell responses, following a homologous rAd5 boost. A striking but transient T-lymphocyte activation in both the systemic and the mucosal compartments of rhesus monkeys was observed after rAd5 immunization. These findings indicate that the administration of a vaccine vector such as Ad5 can induce a global activation of T cells.

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Shikonin Suppresses Human T Lymphocyte Activation through Inhibition of IKKβActivity and JNK Phosphorylation

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/379536 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 5

Author(s):

Ting Li ◽

Fenggen Yan ◽

Rui Wang ◽

Hua Zhou ◽

Liang Liu

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

T Lymphocyte ◽

Cell Activation ◽

Nuclear Translocation ◽

Lymphocyte Activation ◽

Immunosuppressive Agent ◽

Buffy Coat ◽

T Lymphocyte Activation

The key role of T cells has been elaborated in mediating immune responses and pathogenesis of human inflammatory and autoimmune conditions. In the current study the effect of shikonin, a compound isolated from a medicinal plant, on inhibition of T-cell activation was firstly examined by using primary human T lymphocytes isolated from buffy coat. Results showed that shikonin dose dependently suppressed T-cell proliferation, IL-2 and IFN-γsecretion, CD69 and CD25 expression, as well as cell cycle arrest activated by costimulation of PMA/ionomycin or OKT-3/CD28 monoclonal antibodies. Moreover, these inhibitory responses mediated by shikonin were found to be associated with suppression of the NF-κB signaling pathway via inhibition of the IKKα/βphosphorylation, IκB-αphosphorylation and degradation, and NF-κB nuclear translocation by directly decreasing IKKβactivity. Moreover, shikonin suppressed JNK phosphorylation in the MAPKs pathway of T cells. In this connection, we conclude that shikonin could suppress T lymphocyte activation through suppressing IKKβactivity and JNK signaling, which suggests that shikonin is valuable for further investigation as a potential immunosuppressive agent.

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