TY  - JOUR
A1  - Langenhorst, Daniela
A1  - Haack, Stephanie
A1  - Göb, Selina
A1  - Uri, Anna
A1  - Lühder, Fred
A1  - Vanhove, Bernhard
A1  - Hünig, Thomas
A1  - Beyersdorf, Niklas
T1  - CD28 costimulation of T helper 1 cells enhances cytokine release in vivo
JF  - Frontiers in Immunology
N2  - Compared to naive T cells, differentiated T cells are thought to be less dependent on CD28 costimulation for full activation. To revisit the role of CD28 costimulation in mouse T cell recall responses, we adoptively transferred in vitro generated OT-II T helper (Th) 1 cells into C57BL/6 mice (Thy1.2\(^{+}\)) and then either blocked CD28–ligand interactions with Fab fragments of the anti-CD28 monoclonal antibody (mAb) E18 or deleted CD28 expression using inducible CD28 knock-out OT-II mice as T cell donors. After injection of ovalbumin protein in adjuvant into the recipient mice we observed that systemic interferon (IFN)γ release strongly depended on CD28 costimulation of the Th1 cells, while secondary clonal expansion was not reduced in the absence of CD28 costimulation. For human memory CD4\(^{+}\) T cell responses we also noted that cytokine release was reduced upon inhibition of CD28 costimulation. Together, our data highlight the so far underestimated role of CD28 costimulation for the reactivation of fully differentiated CD4\(^{+}\) T cells.
KW  - CD4\(^{+}\) T helper cells
KW  - T helper 1 cells
KW  - antigenic recall
KW  - CD28 costimulation
KW  - cytokine secretion
KW  - mouse
KW  - human
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176726
VL  - 9
IS  - 1060
ER  - 
TY  - JOUR
A1  - Bergfeld, Arne
A1  - Dasari, Prasad
A1  - Werner, Sandra
A1  - Hughes, Timothy R.
A1  - Song, Wen-Chao
A1  - Hortschansky, Peter
A1  - Brakhage, Axel A.
A1  - Hünig, Thomas
A1  - Zipfel, Peter F.
A1  - Beyersdorf, Niklas
T1  - Direct binding of the pH-regulated Protein 1 (Pra1) from Candida albicans inhibits cytokine secretion by mouse CD4\(^{+}\) T cells
JF  - Frontiers in Microbiology
N2  - Opportunistic infections with the saprophytic yeast Candida albicans are a major cause of morbidity in immunocompromised patients. While the interaction of cells and molecules of innate immunity with C. albicans has been studied to great depth, comparatively little is known about the modulation of adaptive immunity by C. albicans. In particular, direct interaction of proteins secreted by C. albicans with CD4\(^{+}\) T cells has not been studied in detail. In a first screening approach, we identified the pH-regulated antigen 1 (Pra1) as a molecule capable of directly binding to mouse CD4\(^{+}\) T cells in vitro. Binding of Pra1 to the T cell surface was enhanced by extracellular Zn\(^{2+}\) ions which Pra1 is known to scavenge from the host in order to supply the fungus with Zn\(^{2+}\). In vitro stimulation assays using highly purified mouse CD4\(^{+}\) T cells showed that Pra1 increased proliferation of CD4\(^{+}\) T cells in the presence of plate-bound anti-CD3 monoclonal antibody. In contrast, secretion of effector cytokines such as IFNγ and TNF by CD4\(^{+}\) T cells upon anti-CD3/ anti-CD28 mAb as well as cognate antigen stimulation was reduced in the presence of Pra1. By secreting Pra1 C. albicans, thus, directly modulates and partially controls CD4\(^{+}\) T cell responses as shown in our in vitro assays.
KW  - Candida albicans
KW  - pH-regulated antigen 1 (Pra1)
KW  - CD4\(^{+}\) T cells
KW  - immune evasion
KW  - cytokine secretion
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158274
VL  - 8
IS  - 844
ER  -