Persistent human bocavirus 1 infection and tonsillar immune responses

Area of Science:

• Immunology
• Virology
• Respiratory Medicine

Background:

• Persistent human bocavirus 1 (HBoV1) infection is common in chronic tonsillar disease.
• The specific immune reactions associated with HBoV1 infection remain unclear.
• This study investigates T-cell cytokine, transcription factor, and interferon expression in HBoV1-positive versus negative tonsils.

Purpose of the Study:

• To compare in vivo immune responses in human tonsils between HBoV1-positive and -negative patients.
• To elucidate the role of HBoV1 in modulating local immune reactions within tonsillar tissue.
• To identify specific immune pathways affected by persistent HBoV1 infection.

Main Methods:

• Analysis of tonsil tissue, nasopharyngeal aspirate, and serum from 143 tonsillectomy patients.
• Detection of HBoV1 and other respiratory viruses using polymerase chain reaction (PCR).
• Quantitative reverse-transcription PCR (RT-PCR) to analyze the expression of 14 cytokines and transcription factors.

Main Results:

• HBoV1 was detected in 17% of patients' tonsils and nasopharyngeal aspirates.
• HBoV1 infection was associated with suppressed RORC2 and FOXP3 transcription factors (p < 0.05).
• Intratonsillar HBoV1 DNA loads correlated negatively with IFN-λ cytokines and IL-13.

Conclusions:

• HBoV1-positive tonsillectomy patients exhibit decreased T-helper 17 and T-regulatory immune responses.
• These findings suggest HBoV1 acts as a suppressive immune modulator in the local lymphoid tissue.
• Persistent HBoV1 infection may contribute to the pathogenesis of chronic tonsillar disease through immune suppression.