Zuzana Mikulková

Numerical defects in CD8+CD28- T-suppressor lymphocyte population in patients with type 1 diabetes mellitus and multiple sclerosis.

Type 1 diabetes mellitus (T1D) and multiple sclerosis (MS) are organ-specific autoimmune diseases leading to an attack of auto-aggressive lymphocytes against the pancreatic beta-cells and central nervous system, respectively. Using four-colour flow cytometry, T-lymphocyte populations having an important function in autoimmune processes were analyzed. T-regulatory cells (Treg) CD4(+)CD25(+)CD127(low), T-suppressor cells (Ts) CD8(+)CD28(-), activated helper CD4(+)CD25(+)CD127(+) and cytotoxic CD8(+)CD25(+) T-cells and also naive CD4(+)CD45RA(+) and memory T-cells CD4(+)CD45RO(+) were compared in the group of patients with T1D (n=30), MS (n=31) and in the group of healthy controls (n=29). Significant differences in Ts cells, activated helper and cytotoxic cells and also memory T-cells were recognized in the group of T1D patients compared to healthy controls. Ts population was significantly lowered in MS patients as well. However, no significant differences were noticed in Treg population. The observed data demonstrate significant differences among patients with T1D and MS in comparison to healthy individuals.

Immunoregulatory T cells in multiple sclerosis and the effect of interferon beta and glatiramer acetate treatment on T cell subpopulations.

INTRODUCTION Multiple sclerosis (MS) is a chronic disease characterized by demyelination and chronic inflammation of the central nervous system (CNS). Many of the immune cells including T and B cells seem to be involved in disease pathogenesis by inducing or controlling the immune responses in the nervous system of MS patients. The objective of this study was to evaluate the differences in subpopulations of T cells between MS patients and healthy controls and the effects of interferon beta (INF-beta) and glatiramer acetate (GA) treatment on T cell subpopulations. MATERIAL AND METHODS We have investigated the frequency of subpopulations of T cells using flow cytometry in 84 relapsing-remitting MS patients; forty-five patients started treatment with INF-beta and eighteen patients with GA, twenty-one patients were not treated. We collected blood samples at the beginning and after 6 and 12 months. RESULTS We observed a significant decrease in CD4(+)CD25(+) Treg cells (p=0.03) and a significant increase in T helper cells (p=0.002) and central memory T cells (p=0.03) in MS patients compared to healthy controls. After INF-beta therapy, we demonstrated a significant increase in naive T cells (p=0.008), a decline in central memory T cells (p=0.01). After GA therapy, we observed a significant increase in naive T cells (p=0.04), a decrease in central memory T cells (p=0.03) and an increase in T-suppressor cells (p=0.008). CONCLUSION In conclusion, we demonstrated the imbalance of T-cell subpopulations in MS patients and the potential benefit of DMD (disease modifying drugs) treatment on its restoration.

Imbalance in T-cell and cytokine profiles in patients with relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is characterized by autoimmune attack leading to demyelination of the white matter in the central nervous system with devastating clinical consequences. Several immune-mediated destruction mechanisms were previously proposed including different T-cell subsets but complex view on immune system function in patients with MS is missing. In the present study, T-lymphocyte populations and pro-inflammatory as well as suppressive cytokine profiles were evaluated in detail in previously untreated patients with relapsing-remitting MS (RRMS). CD4(+) and CD8(+) naïve, central memory (Tcm), effector memory (Tem), terminal effector memory (Ttem), CD4(+) regulatory T-cells (Treg) and CD8(+) T-suppressor cells (Ts) were analysed using flow cytometry, and levels of ten plasma cytokines were determined using fluorescent bead-based immunoassay. We evaluated two groups of RRMS with minor (n=33) and major (n=25) clinical impairment and compared them with healthy controls (n=40) in order to detect any correlation between severity of MS clinical symptoms and immune disturbances. Significant differences were noted in CD4(+)CD45RA(+)CCR7(+) naïve T-cells, CD4(+)CD45RO(+)CCR7(-) and CD8(+)CD45RO(+)CCR7(-) Tem cells, while no differences were recognized in Tcm, Ttem, Treg and Ts cells in RRMS patients. Nine out of ten studied cytokines were disturbed in plasma samples of patients with RRMS. In conclusion, we demonstrate complex immune dysbalances in untreated MS patients.

In vitro activation of CMV-specific human CD8 + T cells by adenylate cyclase toxoids delivering pp65 epitopes

Human CMV infects between 50–85% of healthy individuals and can cause live-threatening infections in immunocompromised patients. Therefore, peptide vaccination is being developed as a promising immunotherapeutic approach for treatment of patients at risk of CMV disease. The enzymatically inactive toxoid of Bordetella adenylate cyclase (CyaA-AC−) was shown to be an efficient tool for delivery of peptide epitopes and stimulation of Ag-specific T-cell immune responses. We investigated here the capacity of two CyaA-AC− constructs to deliver epitopes derived from the CMV phosphoprotein pp65 for activation of human T cells in vitro. Expansion of γ-IFN-secreting CMV-specific CD8+ T cells, as well as increase of total IFN-γ and TNF-α production by PBMCs from CMV-seropositive donors were observed after in vitro stimulation with CyaA-AC− constructs carrying CMV epitopes, whereas limited activation of immune response occurred with free peptides. The activation of immune response was confirmed by expansion of CMV-specific T-cell clones and anti-CMV cytotoxic effect of stimulated PBMCs. These data open the way to clinical evaluation of CyaA-AC− constructs as tools for detection and expansion of CMV-specific T-cell immune responses for diagnostic and immunotherapeutic applications against CMV-associated diseases.