Depletion of Human NK and CD8 Cells prior to In Vitro H1N1 Flu Vaccine Stimulation Increases the Number of Gamma Interferon-Secreting Cells Compared to the Initial Undepleted Population in an ELISPOT Assay

Abstract

In order to study the respective roles of CD4, CD8, and CD56 (NK) cells in gamma interferon (IFN-␥) production after in vitro stimulation with flu vaccine in a healthy adult human population, we depleted these cellular subtypes before stimulation with antigen (inactivated split vaccine, A/Texas H1N1, or A/Sydney H3N2). We observed that while CD4 cells were required for IFN-␥ secretion in both conditions in vitro, CD56 (NK) cells and, to a lesser extent, CD8 cells had a negative effect on such synthesis upon H1N1 stimulation, as judged by an increased number of spots compared to the initial undepleted population. This regulation of IFN-␥ secretion was associated with an increase in ICAM-1 expression, in particular on T and B cells. This study points out the importance of evaluating in vitro immune responses on a whole-cell population in addition to isolated subtypes if one needs to address potential cellular interactions occurring in vivo in some situations (H1N1 stimulation in the present case). Such cross-regulations occur even in vitro during the antigenic stimulation step.

The role of CD8+ cells in the establishment and maintenance of a Trichuris muris infection

“…Despite not changing the overall susceptible response to the parasite, with IL-4, IL-9, IL-13, IL-12, parasite-specific IgG1, IgG2a and caecal mastocytosis all remaining unaltered by depleting CD8 cells, we did observe an altered IL-5 and IFN-γ response to parasite Ag. The elevated IFN-γ production by Ag re-stimulated MLN cells from anti-CD8 treated animals supports the CD4 + IFN-γ + FACS data discussed above, again perhaps suggesting a regulative role for CD8 cells in CD4 IFN-γ production, as suggested in other studies (41,42). The fivefold increase in IL-5 production within treated AKR mice is perhaps the more surprising result, as these data suggest that CD8 + T cells are also regulating the IL-5 response to the parasite.…”

“…Either way it is possible that the increase in IFN‐γ from CD4 cells was maintaining the observed susceptible phenotype. Indeed, other studies previously have noted such an effect (41), for example in vivo depletion of CD8 + T cells in a model of murine mycoplasma respiratory disease caused an exacerbation of CD4 + Th1 associated lung pathology (42).…”

Role of Baicalin in Anti-Influenza Virus A as a Potent Inducer of IFN-Gamma

“…Final values were obtained after subtraction of the control values (without stimulation). The mean value for negative controls according to the different experiments was a maximum of 1 spot/well, corresponding to 10 spots/million cells [ 18 ].…”

Cell-mediated immune responses to influenza vaccination in healthy volunteers and allogeneic stem cell transplant recipients

“…[5][6][7][8][9][10] Although antibodies play critical roles in protection, activation of T-lymphocytes, in particular, the CD4 þ helper subpopulation is essential for supporting virusspecific effector cell functions. 11 Few studies have addressed the possibility to investigate cell-mediated immune response as a marker of vaccine responsiveness. 12 The aim of the present study was, therefore, to develop an enzyme-linked immunospot (ELISPOT) technique for measuring influenza-specific T-cell response for use in future prospective studies aiming to improve existent vaccination schemes in immunosuppressed recipients.…”