An aged mouse model for RSV infection and diminished CD8(+) CTL responses

Area of Science:

• Immunology
• Virology
• Gerontology

Background:

• Respiratory syncytial virus (RSV) causes significant illness and death in the elderly, similar to influenza.
• Existing animal models do not adequately represent how aging affects RSV disease and immunity.

Purpose of the Study:

• To describe a new animal model for studying the impact of aging on respiratory syncytial virus (RSV) disease and immunity.
• To investigate age-related differences in immune responses to RSV infection in mice.

Main Methods:

• Aged (22-24 months) and young (2-4 months) BALB/c mice were infected with RSV A2.
• Viral load was assessed using culture and RT-PCR.
• Immune responses, including CD8(+) cytotoxic T-lymphocyte (CTL) activity and cytokine production (IFN-gamma, IL-4), were measured in splenic lymphocytes.

Main Results:

• RSV was detected in both old and young mice, with slightly higher titers in old mice.
• Aged mice exhibited significantly lower RSV-specific CD8(+) CTL responses and reduced IFN-gamma production compared to young mice.
• Elevated IL-4 production was observed in older mice.

Conclusions:

• Aged mice demonstrate diminished RSV-specific CD8(+) CTL and IFN-gamma responses, suggesting a potential mechanism for increased RSV morbidity and mortality in the elderly.
• The described aged BALB/c mouse model offers a platform for further research into the role of CD8(+) CTLs and cytokines in RSV pathogenesis during aging.