European Journal of Immunology, Feb, 2015, Vol.45(2), p.418(10)
To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1002/eji.201445060/abstract Byline: , , Vitaly I. Pozdeev, Haifeng C. Xu, Prashant Shinde, Colin Reardon, Zhenyue Hao, Marc Beyer, Andreas Bergthaler, Dieter Haussinger, Dieter Haussinger, Dieter Haussinger, Philipp A. Lang Keywords: Chronic infection; Humoral immunity; LCMV; STAT3; T follicular helper cells STAT3 is a critical transcription factor activated downstream of cytokine signaling and is integral for the function of multiple immune cell types. Human mutations in STAT3 cause primary immunodeficiency resulting in impaired control of a variety of infections, including reactivation of latent viruses. In this study, we investigate how T-cell functions of STAT3 contribute to responses to viral infection by inducing chronic lymphocytic choriomeningitis virus (LCMV) infection in mice lacking STAT3 specifically in T cells. Although mice with conditional disruption of STAT3 in T cells were able to mount early responses to viral infection similar to control animals, including expansion of effector T cells, we found generation of T-follicular helper (Tfh) cells to be impaired. As a result, STAT3 T cell deficient mice produced attenuated germinal center reactions, and did not accumulate bone marrow virus specific IgG-secreting cells, resulting in failure to maintain levels of virus-specific IgG or mount neutralizing responses to LCMV in the serum. These effects were associated with reduced control of viral replication and prolonged infection. Our results demonstrate the importance of STAT3 in T cells for the generation of functional long-term humoral immunity to viral infections. Article Note: These authors contributed equally to this work as first authors. These authors contributed equally to this work as senior authors. Supporting information: Additional Supporting Information may be found in the online version of this article As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. CAPTION(S): Figure 1. Thymic T-cell populations and survival are similar between naive control and T-cell STAT3 deficient mice. (A) Survival of naive uninfected Lck-Cre- Stat3fl/fl vs. Lck-Cre+ Stat3fl/fl mice was monitored over time (mean [+ or -] SEM; n = 155-175 mice/group). (B) CD4+, CD8+, CD4+CD8+, and CD4-CD8- T-cells were measured in naive thymus samples from Lck-Cre- Stat3fl/fl vs. Lck-Cre+ Stat3fl/fl mice (mean [+ or -] SEM; n = 5-6 mice, data pooled from two independent experiments). (C) CD44 and CD25 expression were analyzed on double negative (CD4-CD8-) T cells in naive thymus from Lck-Cre- Stat3fl/fl vs. Lck-Cre+ Stat3fl/fl (mean [+ or -] SEM; n = 5-6 mice). Data shown in (C and D) are pooled from two independent experiments. Statistical significance between groups was determined by Student's t-test or Kaplan-Meier log rank test for survival data. Figure 2. Representative flow cytometry gating strategy. (A) Pregaiting strategy used to identify T cells, including tetramer positive or IFN-[gamma] positive T cells as shown in Figure 1. (B) Pregating strategy used to identify B cells as shown in Figure 2. Figure 3. B-Cell proliferation is unaffected by the absence of STAT3 in T cells. Percentage of cells in each division cycle for positively selected (B220+), CFSE labeled Lck-Cre- Stat3fl/fl vs. Lck-Cre+ Stat3fl/fl B cells, stimulated with (A) 1 I1/4g/mL LPS or (B) 2 I1/4g/mL CD40-L and 10 ng/mL Il-4 for 72 h as measured by flow cytometry (mean [+ or -] SEM; n = 4-6 mice). Data is pooled from two independent experiments. Statistical significance between groups was determined by Student's t-test.
Virus Diseases -- Health Aspects ; Virus Diseases -- Analysis ; T Cells -- Health Aspects ; T Cells -- Analysis