RESUMO
In this approach, pre-stained cells from extrasanguinous fluids (ESFs) are stimulated in the presence of blood from the same individual. Thus, blood-derived antigen-presenting cells enable stimulation of both ESF- and blood T cells. Pre-staining allows distinction of T cells from ESF and blood, and simultaneous analysis of antigen-specific T cells in both compartments.
Assuntos
Células Apresentadoras de Antígenos/imunologia , Antígenos/imunologia , Herpesvirus Humano 3/imunologia , Imunoensaio/métodos , Meningite Viral/diagnóstico , Linfócitos T/imunologia , Adulto , Líquido Cefalorraquidiano/citologia , Humanos , Meningite Viral/imunologia , Meningite Viral/virologia , Mycobacterium tuberculosis/imunologia , Neurite (Inflamação)/imunologia , Neurite (Inflamação)/virologia , Recidiva , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/imunologiaRESUMO
Preformed cellular alloreactivity can exist prior to transplantation and may contribute to rejection. Here, we used a rapid flow-cytometric whole-blood assay to characterize the extent of alloreactive T cells among 1491 stimulatory reactions from 61 renal transplant candidates and 75 controls. The role of preformed donor-specific alloreactive T cells in cellular rejection was prospectively analyzed in 21 renal transplant recipients. Alloreactive CD8+ T cells were more frequent than respective CD4+ T cells, and these levels were stable over time. CD8+ T cells were effector-memory T cells largely negative for expression of CD27, CD62L, and CCR7, and were susceptible to steroid and calcineurin inhibitor inhibition. Alloreactivity was more frequent in samples with higher number of HLA mismatches. Moreover, the percentage of individuals with alloreactive T cells was higher in transplant candidates than in controls. Among transplant candidates, 5/61 exhibited alloreactive CD8+ T cells against most stimulators, 23/61 toward a limited number of stimulators, and 33/61 did not show any alloreactivity. Among 21 renal transplant recipients followed prospectively, one had donor-specific preformed T-cell alloreactivity. She was the only patient who developed cellular rejection posttransplantation. In conclusion, donor-specific alloreactive T cells may be rapidly quantified from whole blood, and may predict cellular rejection after transplantation.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Rejeição de Enxerto , Transplante de Rim , Adulto , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Inibidores de Calcineurina/farmacologia , Feminino , Citometria de Fluxo , Antígenos HLA/imunologia , Humanos , Memória Imunológica , Selectina L/genética , Selectina L/imunologia , Masculino , Pessoa de Meia-Idade , Receptores CCR7/deficiência , Receptores CCR7/genética , Receptores CCR7/imunologia , Doadores de Tecidos , Transplante Homólogo , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/deficiência , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologiaRESUMO
Specific T cell immunity in patients with active tuberculosis is associated with a decrease in multifunctionality. However, it is unknown whether cytokine profiles differ in patients with primary infection and those with prior contact. We therefore used intravesical immunotherapy with attenuated live Bacille Calmette-Guérin (BCG) in patients with urothelial carcinoma as a model to characterise the induction of systemic immunity towards purified protein derivate (PPD) and to study whether cytokine profiles differ depending on pre-existing immunity. Eighteen patients with non-muscle invasive bladder cancer were recruited during the BCG-induction course. Fifty-four healthy individuals served as controls. Interferon (IFN)-γ and interleukin (IL)-2 producing PPD-specific CD4 T cells were analysed longitudinally before each instillation using a rapid flow-cytometric whole blood immunoassay. Baseline levels of IFN-γ producing PPD-specific T cells were comparable to controls. T cells showed a 5-fold increase to 0.23% by week 2/3, and further increased 8-fold by week 4/5 (to 0.42%, p=0.0007). Systemic immunity was induced in all patients, although the increase was less pronounced in patients with pre-existing immunity. As in active TB, cytokine profiling during therapy revealed a lower percentage of multifunctional IFN-γ/IL-2 double-positive T cells compared to controls (60.2% vs. 71.9%, p=0.0003). Of note, when comparing patients with and without pre-existing immunity, cytokine profiles in patients with primary immunity were shifted towards IL-2 single producing T cells (p=0.02), whereas those in patients with pre-existing immunity were shifted towards IFN-γ single-positivity (p=0.01). In conclusion, systemic T cell responses were induced after BCG-therapy, and their kinetics and cytokine profile depended on pre-existing immunity. Decreased functionality is a typical feature of specific immunity in both patients with active tuberculosis and BCG-therapy. Among patients with active infection, a shift towards IL-2 or IFN-γ single-positive cells may allow distinction between patients with primary infection and cases with boosted immunity after prior contact, respectively.
