Possible role of highly activated mucosal NK cells against viral respiratory infections in children undergoing haematopoietic stem cell transplantation

Abstract

Infection is the leading cause of non-relapse-related mortality after allogeneic haematopoietic stem cell transplantation (HSCT). Altered functions of immune cells in nasal secretions may influence post HSCT susceptibility to viral respiratory infections. In this prospective study, we determined T and NK cell numbers together with NK activation status in nasopharyngeal aspirates (NPA) in HSCT recipients and healthy controls using multiparametric flow cytometry. We also determined by polymerase chain reaction (PCR) the presence of 16 respiratory viruses. Samples were collected pre-HSCT, at day 0, +10, +20 and +30 after HSCT. Peripheral blood (PB) was also analyzed to determine T and NK cell numbers. A total of 27 pediatric HSCT recipients were enrolled and 16 of them had at least one viral detection (60%). Rhinovirus was the most frequent pathogen (84% of positive NPAs). NPAs of patients contained fewer T and NK cells compared to healthy controls (p = 0.0132 and p = 0.120, respectively). Viral PCR + patients showed higher NK cell number in their NPAs. The activating receptors repertoire expressed by NK cells was also higher in NPA samples, especially NKp44 and NKp46. Our study supports NK cells relevance for the immune defense against respiratory viruses in HSCT recipients.

Infecciones respiratorias virales en episodios de fiebre en niños con trasplante de precursores hematopoyéticos

“…Un estudio reciente demostró, por una parte, una disminución en número de linfocitos T y células natural killer (NK) en la mucosa respiratoria de los pacientes que han recibido TPH, en comparación a controles sanos. Por otra parte, evidenciaron una mayor activación de las células NK presentes en la mucosa, importantes en la producción de citoquinas, incluyendo IFN-γ el que es fundamental en la respuesta inmune antiviral 21 . Ahora bien, al evaluar los episodios en forma individual se pudo apreciar un aumento de expresión de interleuquina-8 (IL-8), proteína inducible por IFN-γ (IP10) y el oncogén regulado por crecimiento (GRO, por sus siglas del inglés growth-regulated oncogene) en los pacientes con IRV y en el paciente con IRV asociada a sinusitis bacteriana.…”

Characteristics, Classification, and Application of Stem Cells Derived from Human Teeth

“…Due to the uncertainty of the timeliness of cell transplantation in vivo, the injection method is one of the factors that affect the therapeutic effect, including systemic injection and local injection [ 123 ]. Injection in the lesion area is one of the common ways to improve the effectiveness of cell transplantation, but it is not suitable for systemic diseases and chronic diseases [ 124 , 125 ].…”

A phase I/II dose-escalation multi-center study to evaluate the safety of infusion of natural killer cells or memory T cells as adoptive therapy in coronavirus pneumonia and/or lymphopenia: RELEASE study protocol

“…Recent and previous data have shown that infusions of donor memory T-lymphocytes (CD45RA − T cells) are safe and constitute a simple measure to prevent infections in the setting of allogeneic hematopoietic stem cell transplantation (HSCT) [ 26 , 29 ]. The infusion of a population of immune cells that have been in contact with COVID-19 and with immunological memory would create a quicker and more robust secondary immune response [ 26 , 27 , 30 , 31 ].…”