Exercise effects on mucosal immunity

Abstract

SummaryThe present review examines the effects of exercise on mucosal immunity in recreational and elite athletes and the role of mucosal immunity in respiratory illness. Habitual exercise at an intense level can cause suppression of mucosal immune parameters, while moderate exercise may have positive effects. Saliva is the most commonly used secretion for measurement of secretory antibodies in the assessment of mucosal immune status. Salivary IgA and IgM concentrations decline immediately after a bout of intense exercise, but usually recover within 24 h. Training at an intense level over many years can result in a chronic suppression of salivary immunoglobulin levels. The degree of immune suppression and the recovery rates after exercise are associated with the intensity of exercise and the duration or volume of the training. Low levels of salivary IgM and IgA, particularly the IgA1 subclass, are associated with an increased risk of respiratory illness in athletes. Monitoring mucosal immune parameters during critical periods of training provides an assessment of the upper respiratory tract illness risk status of an individual athlete. The mechanisms underlying the mucosal immune suppression are unknown.

Salivary antimicrobial peptides (LL-37 and alpha-defensins HNP1–3), antimicrobial and IgA responses to prolonged exercise

“…This is not surprising given that IgA is the predominant immunoglobulin in saliva (Gleeson and Pyne 2000) and the relationship between this aspect of mucosal immunity and the incidence of upper respiratory illness (URI) symptoms that is often reported in the literature (Fahlman and Engels 2005;Gleeson et al 1999;Gleeson 2000;Mackinnon and Jenkins 1993;Neville et al 2008). However, there are many other factors present in mucosal secretions (including saliva), which also serve to protect mucosal surfaces and contribute to innate host defence, such as the antimicrobial peptides and proteins (AMPs) (Allgrove et al 2008;Singh et al 2000;West et al 2006).…”

Living high–training low altitude training: effects on mucosal immunity

“…Heavy training over several weeks can depress the mucosal immune system in the resting situation. Indeed, decreased sIgA concentrations have been reported during periods of intense training (Tomasi et al 1982;Gleeson et al 1999;Gleeson and Pyne 2000;Tiollier et al 2005). Although the physiological mechanisms underlying the decline in sIgA are still unclear, it is likely that both neural and endocrine factors influence the immune response to exercise (Fleshner 2000;Pedersen and Steensberg 2002).…”

Intense training: mucosal immunity and incidence of respiratory infections

“…Resistance to respiratory infections is provided by the mucosal immune system, with the major immunoglobulin being secretory immunoglobulin A. Secretory IgA thus acts as a first line of defense against colonization of infectious agents on mucosal surfaces by neutralization and elimination of viral pathogens (Gleeson and Pyne 2000). It has been suggested that low levels of salivary IgA (sIgA) reduce the resistance to infection as indicated by the finding of a precise relationship between IgA concentrations and the risk of infection (Pyne and Gleeson 1998;Gleeson et al 1999).…”

“…Indeed, decreased sIgA concentrations have been reported either after intense exercise (Mackinnon et al 1993;Nieman et al 2002;Novas et al 2003) or during periods of intense training (Tomasi et al 1982;Gleeson et al 1999;Gleeson and Pyne 2000). Psychological stress has also been related to decreased sIgA concentrations (Deinzer et al 2000).…”