Epstein-Barr Virus Co-infection in Children Boosts Cytomegalovirus-induced Differentiation of Natural Killer Cells

• During childhood, infections with cytomegalovirus (CMV) and Epstein-Barr virus (EBV) can occur in close temporal proximity. Active as well as latent CMV infection is associated with enlarged subsets of differentiated NK- and cytotoxic T cells. How EBV infection may influence CMV-driven immune differentiation is not known. Here we found that EBV co-infection selectively influenced the NK-cell compartment of CMV-seropositive (CMV+) children. Co-infected children had significantly higher proportions of peripheral-blood NKG2C+ NK cells than CMV+EBV– children. Ex vivo NK-cell degranulation after target cell stimulation and plasma IL-15 levels were significantly higher in CMV+ children. EBV co-infection related with the highest levels of plasma IL-15 and IL-12p70. Remarkably, in vitro EBV infection of peripheral blood mononuclear cells (PBMC) from EBV–CMV+ children increased NKG2C+ NK-cell proportions. A similar tendency was seen in co-cultures of PBMC with EBV+ lymphoblastoid B-cell lines (LCL) and IL-15. Following K562 challenge, NKG2C+ NK cells excelled in regards to degranulation and production of IFN-g, regardless of previous co-culture with LCL. Taken together, our data suggest that herpesvirus interplay during childhood could contribute to an in vivo environment supporting differentiation and maintenance of distinct NK-cell populations. This viral imprint may affect subsequent immune responses through altered distributions of effector cells.

Ämnesord

NATURVETENSKAP  -- Biologi -- Immunologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Immunology (hsv//eng)

Nyckelord

CMV

EBV

co-infection

NK cell

NKG2C

immunologi

Immunology

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vet (ämneskategori)

ovr (ämneskategori)