Differential modulation of B7-1 and B7-2 isoform expression on human monocytes by cytokines which influence the development of T helper cell phenotype

Differential modulation of B7-1 and B7-2 isoform expression on human monocytes by cytokines which influence the development of T helper cell phenotype. NVP-TAE 226 after antigen stimulation were analyzed by reverse transcription-PCR, protein array analysis, and an immunoassay, along with an antibody production analysis. The roles, interactions, and cellular sources of the main cytokines identified were evaluated further. Pneumococcal CCS induced production of CbpA- and Ply-specific antibodies in association with several chemokines and cytokines, including gamma interferon (IFN-) and interleukin-10 (IL-10) in MNC. The antibody production correlated well with the concentrations of these two cytokines. Addition of recombinant NVP-TAE 226 IFN- or IL-10 enhanced antibody production, and monoclonal antibodies to these two cytokines and T-cell depletion significantly reduced antibody production. Intracellular cytokine staining showed that T cells are a major source of IFN- and IL-10. Recombinant Ply and, to a lesser extent, recombinant CbpA induced significant production of IFN- and IL-10 in MNC. T-cell-derived IFN- and IL-10 may be key regulators of production of mucosal antibody to pneumococcal protein antigens in the nasopharynx and may play an important role in local protection against pneumococcal infection in children. is NVP-TAE 226 an encapsulated bacterium that is associated with significant global morbidity and mortality (37). Due to the high cost and limited coverage of capsular polysaccharide-based vaccines, several candidate protein antigens are currently being studied, including choline-binding protein A (CbpA), and pneumolysin (Ply). CbpA, also called pneumococcal surface protein C (PspC) or secretory immunoglobulin A (IgA) binding protein (SpsA) (8, 14, 33), is exposed on the pneumococcal surface and can act as an adhesin (33, 39); recently, the solution structure of the adhesion domains (R1 and R2) of CbpA has been studied, which has provided insight into the mechanism by which this protein binds polymeric immunoglobulin receptor, through which pneumococci adhere and invade human cells (25, 39). Ply is produced by virtually all clinical isolates of pneumococci. Immunization with a genetically detoxified Ply derivative has been shown to protect mice against multiple serotypes of pneumococci (1). Recent studies have demonstrated the advantage of intranasal mucosal immunization for elicitation of pneumococcal polysaccharide-specific memory NVP-TAE 226 responses early in the life of mice (4). Nasopharyngeal tonsils (adenoids) are mucosa-associated lymphoid tissue and are thought to be functionally related to the nasopharynx-associated lymphoid tissues (NALT) of rodents (22). As adenoids are in direct contact with local mucosal pathogens, such as the pneumococcus, adenoidal immune cells may play an important role in local immunity. We have shown previously that cells secreting antibodies to pneumococcal protein antigens are present in adenoidal mononuclear cells (MNC) isolated from children undergoing adenoidectomies (42) and that children colonized with pneumococcus tend to have lower levels of serum and salivary antibodies to CbpA and Ply than culture-negative children have, suggesting that the existing levels of systemic and local mucosal antibodies to these antigens in vivo may protect against carriage (41). In in vitro cell cultures, adenoidal B cells stimulated with pneumococcal antigens produce significant antibodies to protein antigens, including CbpA and Ply, especially in children who are colonized with pneumococcus (41). Our results have also shown that the levels of both immunoglobulin J chain-expressing and nonexpressing IgG immunocytes are increased after antigen stimulation, which suggests that adenoids can be induction sites for both mucosal and systemic antibody production (6, 41). It is generally thought that B-cell responses to protein antigens are T cell dependent and modulated by cytokines. This study was designed to determine which cytokines are induced by pneumococcal antigens and which cytokine(s) is crucial in the regulation of production of local antibodies to pneumococcal protein antigens in nasopharngeal tonsils in children. We show here that production of antibodies to CbpA and Ply by adenoidal cells is closely correlated with the production of cytokines, especially gamma interferon (IFN-) and interleukin-10 (IL-10). The results suggest that these cytokines are key independent regulators Rabbit polyclonal to ADORA3 of mucosal anti-pneumococcal protein antibody production in the nasopharynx and are likely to be important in local protection against pneumococci in children. MATERIALS AND METHODS Subjects and samples. Adenoids were obtained from children who were 2 to 12 years old (median age, 5 years), were undergoing adenoidectomies for adenoidal hypertrophy, and were otherwise healthy at Bristol Royal Hospital for Children, Bristol, United Kingdom. Patients who were immunized against pneumococcus previously, who had received antibiotics within 2 weeks of the operation or steroids, or who had an immunodeficiency or serious infection were excluded. The study was approved by the South Bristol local research ethics committee (approval number E5142), and written informed consent was obtained in all cases. Pneumococcal culture supernatants. The pneumococcal strains used in this study included a standard encapsulated type 2 strain (strain D39), isogenic CbpA? and Ply? mutant strains,.