Abstract
CD4 T cells are important for development of long-term immunity to bacterial infections. Here we describe construction of a group A streptococcus (GAS) strain that expresses the model ovalbumin epitope (OVA) on its surface, and the use of this strain in adoptive transfer experiments to study CD4 T cell response to bacterial infection in nasal-associated lymphoid tissue (NALT), which was previously shown W be a specific target for GAS colonization. The OVA+ GAS, but not the wild-type strain was shown to activate CD4 T cells in an antigen-specific manner both in vitro and in vivo. After intranasal infection of mice with this strain, OVA-specific CD4 T cells were first activated in NALT, which is functionally equivalent to human tonsils, rather than in the cervical lymph nodes. During localized infection, OVA+ GAS induced rapid and prolonged activation of CD4 T cells at higher magnitudes in the NALT than in draining lymph nodes and spleen, where CD4 T cells underwent little or no activation. In contrast, systemic infection induced significantly higher activation of CD4 T cells in both lymph nodes and spleens, compared to when the infection was localized in NALT. Further investigation of cellular immune responses in NALT during GAS infection using adoptive T cell transfer, combined with the model antigen on the pathogen may ultimately shed light on mechanisms for failure of children to develop protective immune responses following streptococcal tonsillitis.
Original language | English (US) |
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Pages (from-to) | 2843-2853 |
Number of pages | 11 |
Journal | European Journal of Immunology |
Volume | 34 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2004 |
Externally published | Yes |
Keywords
- CD4 T cells
- GAS
- NALT
- Rodents
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology