Antigen-specific activation thresholds of CD8⁺ T cells are independent of IFN-I-mediated partial lymphocyte activation

Simple item page
dc.contributor.authorWijesundara, D.
dc.contributor.authorKumar, S.
dc.contributor.authorAlsharifi, M.
dc.contributor.authorMullbacher, A.
dc.contributor.authorRegner, M.
dc.date.issued2010
dc.description.abstractType-I IFN (IFN-I) are highly pleiotropic cytokines known to modulate immune responses and play an early central role in mediating antiviral defenses. We have shown that IFN-I mediate transient up-regulation of a distinct subset of lymphocyte surface activation markers on both B and T cells in vivo independent of cognate antigen: a state referred to as ‘partial lymphocyte activation’. Here we investigated in vitro the possibility that partial lymphocyte activation may serve to lower the antigen-specific activation thresholds for T cells. We found that the kinetics of Ca2+ flux in T cells responding to TCR cross-linking was not enhanced in partially activated T cells. Furthermore, following TCR stimulation with anti-cluster of differentiation (CD) 3ε, a lower proportion of partially activated than naive T cells proliferated. In contrast, the proliferation of partially activated and naive ovalbumin peptide (OVAp, SIINFEKL) specific CD8+ T cells (OT-I CD8+ T cells) was similar when stimulated with OVAp. Surprisingly, using an enzyme-linked immunospot (ELISPOT) assay for IFN-γ secretion, we found that a higher number of partially activated OT-I CD8+ T cells expressed effector functions than did naive OT-I CD8+ T cells. This is most readily explained by an increased survival of activated antigen-specific CD8+ T cells from a pool of partially activated T cells than naive T cells. Overall, when examining the effects of early (Ca2+ flux), intermediate (proliferation) or late events (IFN-γ secretion) of T-cell activation, we found that partial activation promotes the survival but does not alter the antigen-specific activation thresholds of CD8+ T cells.
dc.description.statementofresponsibilityDanushka K. Wijesundara, Sheetal Kumar, Mohammed Alsharifi, Arno Müllbacher and Matthias Regner
dc.identifier.citationInternational Immunology, 2010; 22(9):757-767
dc.identifier.doi10.1093/intimm/dxq064
dc.identifier.issn0953-8178
dc.identifier.issn1460-2377
dc.identifier.orcidWijesundara, D. [0000-0002-0740-8362]
dc.identifier.urihttp://hdl.handle.net/2440/63227
dc.language.isoen
dc.publisherOxford Univ Press
dc.rights© The Japanese Society for Immunology. 2010. All rights reserved.
dc.source.urihttps://doi.org/10.1093/intimm/dxq064
dc.subjectCa2⁺
dc.subjectIFN
dc.subjectIFN-γ
dc.subjectr-IFN-β
dc.subjectproliferation
dc.titleAntigen-specific activation thresholds of CD8⁺ T cells are independent of IFN-I-mediated partial lymphocyte activation
dc.title.alternativeAntigen-specific activation thresholds of CD8(+) T cells are independent of IFN-I-mediated partial lymphocyte activation
dc.typeJournal article
pubs.publication-statusPublished

Files

Collections

Microbiology and Immunology publications