Investigating the role of Natural Killer T-cells in Gram negative infections of patients with type 2 diabetes mellitus.

BACKGROUND: Invariant Natural Killer T (iNKT) cells belong to innate immunity and combine T-cell receptor specificity with Natural Killer surface markers. They can produce cytokines immediately after stimulation and direct immunity to either Th1 or Th2 cytokine production. iNKT cells participate in a variety of immune responses, such as microbial infections, autoimmunity, and cancer. Type 2 Diabetes Mellitus (T2DM) has been associated with activated innate immunity and certain cytokine profile during microbial infections. This study aimed to evaluate whether iNKT cells have a role in the immune response of T2DM patients during infections with gram-negative bacteria. METHOD: The T2DM group consisted of patients (n =11) who had a diagnosis of T2DM for at least six months and febrile illness for three days, while the control group consisted of patients (n =11) who had not T2DM, but were febrile for three days. All patients were infected by gram-negative bacteria. Physical examination was performed, and peripheral blood was drawn on days three and six of febrile illness. Flow cytometry was utilized for iNKT cell identification with monoclonal antibodies Phycoerythrin (PE) - Cyanin (CY) 5 anti-Human CD3, Fluorescein isothiocyanate (FITC) anti-Human CD4, PE anti-human invariant NKT T-Cell Receptor. For intracellular staining, we used Alexa Fluor anti-Human interferon-γ (IFN-γ) and Allophycocyanin (APC) anti-human interleukin-4 (IL-4). The variables processed were: CD3+IL-4+iNKT+ , CD4+IL-4+iNKT+, CD3+IFNγ+iNKT+, CD4+IFNγ+iΝΚΤ+, CD3+iNKT+, CD4+iNKT+ ,CD3+IL4+, CD4+IL-4+, CD3+IFNγ+, CD4+IFNγ+ on days three and six of febrile illness (CD3+, CD4+: T lymphocyte surface markers, iNKT+: invariant Natural Killer T- Cell Receptor, IL4+: interleukin 4, IFNγ+: interferon γ). RESULTS: Comparisons between T2DM patients and controls revealed no statistically significant difference in any of the study's variable. Regarding within T2DM patients comparisons CD4+IL4+iNKT+, CD3+IL4+iNKT+, CD4+IFN+iNKT+, CD3+IFN+iNKT+, and CD3+iNKT+  decreased, whereas CD3+IL4+ was increased at day six compared to day three. Within control group CD4+IL4+iNKT+, CD3+IL4+iNKT+, and CD3+iNKT+ were decreased, whereas CD4+IFN+, CD3+IFN+ were increased at day six compared to day three. CONCLUSION: The absence of statistical difference between T2DM patients and controls implies that the role of iNKT cells is virtually the same in both groups of patients during the course of gram-negative infections and that there is no numerical variance of this cell population between the two groups. Despite the small sample size, we notice that all iNKT parameters (both IL4/IFNγ) are suppressed in the T2DM group during the later phase, but only those concerning IL4+iNKT+ in the control group, suggesting that IFNγ production remains elevated in the controls. A compensatory anti-inflammatory type-response could provide an explanation for the prevalence of IL4 production during the later phase of infection in T2DM and the sustained production of IFNγ in controls. Hippokratia 2015; 19 (3): 231-234.

Genetic polymorphism study of regulatory B cell molecules and cellular immunity function in an adult patient with Common Variable Immunodeficiency.

A 43 year old female patient presented for recurrent bacterial lower respiratory infections. A research for immunodeficiency status revealed total hypogammaglobulinemia, reduced IgG1, IgG2, IgG3 subclass levels, and low number of B lymphocytes (CD19+). Common Variable Immunodeficiency (CVID) 11.2 category was diagnosed according to recent criteria of primary immunodeficiencies (PID). Further immunological study consisting of genetic polymorphism of genes relating to differentiation, activation and function of B cells (ICOS, BAFF receptor BCMA and TACI) was performed, which did not reveal any related mutations. T cell parameters and Th1/Th2 cytokine network did not show any disturbances. It is postulated that probable endstage B cell differentiation defects should be investigated. The patient receives IVIGs replacement thereafter and the rate and severity of infections have significantly improved.

Impact of prematurity, stress and sepsis on the neutrophil respiratory burst activity of neonates.

The aim of this study was to evaluate the impact of prematurity, sepsis and stress on the neutrophil respiratory burst activity (NRBA) of neonates. For this purpose 122 healthy neonates (89 term and 33 preterm), 33 preterm stressed neonates, 59 septic neonates (12 term and 47 preterm) and 26 healthy adults were studied. The NRBA was assessed after in vitro stimulation by PMA using a whole blood flow cytometric microassay with dihydrorhodamine 123 (DHR 123). It was found that the percentage of responding neutrophils in term neonates was comparable to that found in adults (medians 83.5 and 89.8%, respectively), whereas it was significantly lower in the healthy preterm neonates (median 70.6%, p < 0.05). The NRBA was further depressed in the stressed (median = 63%) and septic neonates, both term and preterm (medians 60.5 and 54.3%, respectively). No correlation with the levels of G-CSF, TNF-alpha and IL-1 beta, which were found to be higher in the stressed and septic neonates, was observed. These findings indicate that prematurity, sepsis and stress significantly depress the respiratory burst activity of neonatal neutrophils.