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. 2010 Mar;84(5):2374-83.
doi: 10.1128/JVI.01807-09. Epub 2009 Dec 16.

A systemic neutrophil response precedes robust CD8(+) T-cell activation during natural respiratory syncytial virus infection in infants

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A systemic neutrophil response precedes robust CD8(+) T-cell activation during natural respiratory syncytial virus infection in infants

Michaël V Lukens et al. J Virol. 2010 Mar.

Abstract

Severe primary respiratory syncytial virus (RSV) infections are characterized by bronchiolitis accompanied by wheezing. Controversy exists as to whether infants suffer from virus-induced lung pathology or from excessive immune responses. Furthermore, detailed knowledge about the development of primary T-cell responses to viral infections in infants is lacking. We studied the dynamics of innate neutrophil and adaptive T-cell responses in peripheral blood in relation to the viral load and parameters of disease in infants admitted to the intensive care unit with severe RSV infection. Analysis of primary T-cell responses showed substantial CD8(+) T-cell activation, which peaked during convalescence. A strong neutrophil response, characterized by mobilization of bone marrow-derived neutrophil precursors, preceded the peak in T-cell activation. The kinetics of this neutrophil response followed the peak of clinical symptoms and the viral load with a 2- to 3-day delay. From the sequence of events, we conclude that CD8(+) T-cell responses, initiated during primary RSV infections, are unlikely to contribute to disease when it is most severe. The mobilization of precursor neutrophils might reflect the strong neutrophil influx into the airways, which is a characteristic feature during RSV infections and might be an integral pathogenic process in the disease.

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Figures

FIG. 1.
FIG. 1.
Kinetics of the parameters of mechanical ventilation. Day 0 denotes the first reported symptomatic day. Shown is the disease severity of RSV patients, based on the ventilation index (VI) (A) or the oxygenation index (OI) (B) determined during the stay at the ICU. Each line and symbol (open or closed) represents the VI (A) or OI (B) in time in a single patient.
FIG. 2.
FIG. 2.
Decrease in the viral load. The RSV load was determined by PCR in NPA (A) or TA (B) during the stay in the ICU and plotted as log10 viral particles/ml. Each line (and symbol) represents the decreasing viral load over time in a single patient. The lower limit of detection of the PCR was 2.9 log10 viral particles/ml RSV.
FIG. 3.
FIG. 3.
Identification of blood neutrophils. (A) Whole blood of a healthy control was stained with anti-CD16 and anti-CD49d. Granulocytes were identified based on FSC/SSC patterns and CD16 staining (left), and neutrophils were identified based on low expression of CD49d, while eosinophils had high expression of CD49d (right). (B) Expression pattern of CD16 on granulocytes from a healthy control (left) or an RSV patient (right). (C) (Left) Gating strategies (FACS plot) for sorting of eosinophils and neutrophils of an RSV patient; (right) cytospin with May-Günwald Giemsa staining of sorted eosinophils, neutrophil precursors, and mature neutrophils.
FIG. 4.
FIG. 4.
Influx of neutrophil precursors into peripheral blood. (A) Whole blood of an RSV patient was stained with anti-CD16, and the percentage of precursor neutrophils within the granulocyte gate was enumerated on the indicated days after the onset of symptoms. (B) Kinetics of neutrophil precursor (CD16int expression) recruitment into the blood, where day 0 denotes the first reported symptomatic day. Each line and symbol (open or closed) represents the dynamic influx of precursor neutrophils in peripheral blood over time in one individual RSV patient.
FIG. 5.
FIG. 5.
Identification of activated CD8+ T cells in blood. (A) Whole blood of a healthy control infant (top) and a 12-week-old RSV patient (bottom) drawn on day 11 after the onset of symptoms was surface stained with anti-CD3, -CD8, -CD45RO, -CD127, -CCR5, or -CCR7 or stained intracellularly with anti-GzmB, -perforin, and -Ki-67. CD8+ T cells were identified based on FSC/SSC lymphocyte gating and then on the expression of CD3+ CD8+. (B and C) Example of developing CD8+ T-cell response over time in a second (2-week-old) RSV patient. Whole blood was drawn at admission and every other day until discharge. The blood was surface stained with anti-CD3, -CD8, -CCR5, or -CCR7 (B) or stained with anti-CD3 or -CD8 and intracellularly with anti-GzmB and -perforin (C). The percentages of activated CD8+ T cells are given in the respective quadrants. The experiments shown are representative examples of 13 individual RSV patients and 7 healthy controls. In all patients and controls, similar patterns of activation markers and chemokine receptor expression were observed; however, the levels of activation differed between patients. (D) Summary of the kinetics of CD8+ T-cell activation measured in whole blood of 13 patients during the stay at the ICU based on the expression patterns of CCR5 and CCR7 on CD3+ CD8+ lymphocytes. Due to technical reasons, we could measure T-cell activation in only 13 out of the 17 patients. Each line and symbol (open or closed) represents the CD8+ T-cell kinetics in the blood of one individual RSV patient.
FIG. 6.
FIG. 6.
Dynamics of disease parameters during primary RSV infection in infants. (A and B) Kinetics of normalized and grouped data of disease severity (A) and viral load (B) in TA during the stay at the ICU. (C and D) Normalized values of precursor neutrophil percentages (C) and activated CCR5+ CCR7 CD8+ T-cell recruitment into peripheral blood (D). The error bars represent the SEM. (E) Combined dynamics of viral load, neutrophil precursor recruitment, and CD8+ T-cell activation.

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References

    1. Adkins, B., C. Leclerc, and S. Marshall-Clarke. 2004. Neonatal adaptive immunity comes of age. Nat. Rev. Immunol. 4:553. - PubMed
    1. Barrios, C., P. Brawand, M. Berney, C. Brandt, P. H. Lambert, and C. A. Siegrist. 1996. Neonatal and early life immune responses to various forms of vaccine antigens qualitatively differ from adult responses: predominance of a Th2-biased pattern which persists after adult boosting. Eur. J. Immunol. 26:1489. - PubMed
    1. Blom, D., M. Ermers, L. Bont, W. M. Van Aalderen, and J. B. van Woensel. 2007. Inhaled corticosteroids during acute bronchiolitis in the prevention of post-bronchiolitic wheezing. Cochrane. Database. Syst. Rev. CD004881. - PubMed
    1. Bont, L., C. J. Heijnen, A. Kavelaars, W. M. Van Aalderen, F. Brus, J. T. Draaisma, S. M. Geelen, H. J. van Vught, and J. L. Kimpen. 1999. Peripheral blood cytokine responses and disease severity in respiratory syncytial virus bronchiolitis. Eur. Respir. J. 14:144. - PubMed
    1. Bont, L., A. Kavelaars, C. J. Heijnen, A. J. van Vught, and J. L. Kimpen. 2000. Monocyte interleukin-12 production is inversely related to duration of respiratory failure in respiratory syncytial virus bronchiolitis. J. Infect. Dis. 181:1772. - PubMed

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