Staphylococcal Enterotoxin B (SEB) Induces Memory CD4 T Cell Anergy in vivo and Impairs Recall Immunity to Unrelated Antigens
|David K Janik1 and William T Lee1,2*|
|1The Department of Biomedical Sciences, School of Public Health, The University at Albany, USA|
|2The Laboratory of Immunology, The Wadsworth Center, New York State Department of Health, USA|
|Corresponding Author :||William T Lee
The Wadsworth Center
New York State Department of Health
Albany, New York 12201-2002, USA
E-mail: [email protected]
|Received: April 30, 2015 Accepted: July 17, 2015 Published: July 24, 2015|
|Citation: Janik DK, Lee WT (2015) Staphylococcal Enterotoxin B (SEB) Induces Memory CD4 T Cell Anergy in vivo and Impairs Recall Immunity to Unrelated Antigens. J Clin Cell Immunol 6:346. doi:10.4172/2155-9899.1000346|
|Copyright: © 2015 Jaik DK, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
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Introduction: Naïve and memory T cells can utilize unique regulatory pathways to promote protection but prevent self-reactivity. A bacterial superantigen SEB exploits unique TCR proximal signaling processes in memory CD4 T cells to induce clonal anergy. The aim of this study was to determine if SEB could antagonize memory CD4 T cells in vivo and whether there would be consequences on recall immune responses. We evaluated Ab responses to a T-dependent antigen as a measurement of memory T cell helper function.
Method: BALB/c mice were primed with TNP-RGG to elicit memory B cells and also immunized with an ovalbumin peptide to elicit memory helper T cells. Another group of TNP-RGG immunized mice were used as adoptive transfer recipients of exogenous DO11.10 memory T cells. Mice were challenged with TNP-OVA with or without prior administration of SEB. B cells secreting IgM or IgG TNP-specific Ab were enumerated by ELISPOT as indicators of primary versus secondary humoral immunity.
Results: Comparing the SEB and non-SEB-treated groups, the SEB-treated group failed to produce TNP-specific IgG in response to challenge with TNP-OVA, even if they were previously immunized with OVA. All groups produced IgM, indicating that the primary Ab responses and naïve helper T cells were not impacted by SEB. SEB had no negative impact when DO11.10 × Fyn-/- memory T cells were used as donor cells.
Conclusion: The present study indicated that SEB selectively targeted memory CD4 T cells in vivo and prevented helper function. Consequently, recall humoral immunity was lost. The data are most consistent with in vivo T cell anergy as opposed to indirect suppression as elimination of Fyn kinase restored helper function. These data suggest that bacterial superantigens can impair post-vaccination memory cell responses to unrelated antigens via their ability to target Vb families and antagonize memory cell activation.