|MAGGIOLI, M - Iowa State University|
|VORDERMEIER, H - Veterinary Laboratories Agency (VLA)|
|WHELAN, A - Veterinary Laboratories Agency (VLA)|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/5/2014
Publication Date: 12/8/2014
Citation: Maggioli, M.F., Palmer, M.V., Vordermeier, H.M., Whelan, A.O., Waters, W.R. 2014. Polyfunctional cytokine responses by central memory CD4+T cells in response to bovine tuberculosis [abstract]. Conference of Research Workers in Animal Disease. Abstract No. 45.
Technical Abstract: CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. Mycobacterium bovis infection of cattle elicits ex vivo polyfunctional T cell responses. Long-term (i.e., 14 days) cultured IFN-gamma responses by peripheral blood mononuclear cells are used as a correlate of T cell central memory (Tcm) responses in both humans and cattle. The objective of the present study was to assess polyfunctional T cell responses by Tcm in cattle (n = 6) in response to aerosol M. bovis infection. For long-term culture, PBMCs collected from infected cattle were stimulated with M. bovis purified protein derivative (PPDb), rESAT-6:CFP-10 (E:C) and peptide cocktails of Tb10.4 and Ag85A for 13 days with periodic addition of fresh media and rIL-2. After stimulation, the expression of CD4, CD45RO, CCR7, IL-2, IFN-gamma, TNF-alpha and cell viability were analyzed by flow cytometry. Long-term T cells responding to E:C consisted of 11% effectors (CD4+ CD45RO- CCR7-), 22% effector memory (CD4+ CD45RO+ CCR7-), and 76% central memory (CD4+ CD45RO+ CCR7+) phenotypes. In regard to the cytokine profile, 53% of cells producing cytokines expressed both IFN-gamma and TNF-alpha, 42% expressed all three cytokines, 13% expressed both TNF-alpha and IL-2, and 7% expressed IL-2 and IFN-gamma. Cells producing only IFN-gamma, IL-2, or TNF-alpha represented, 9%, 5% and 1%, respectively. These findings demonstrate that 14-day cultured cells (primarily Tcm cells) exhibit polyfunctional responses consisting mainly of cells co-producing IFN-gamma and TNF-alpha or IL-2, IFN-gamma and TNF-alpha.