Accessory cell defect in unresponsiveness of neonates and aged to polysaccharide vaccines

• Published in: Vaccine Vol. 19; no. 4; pp. 557 - 565
• Main Authors: Bondada, Subbarao, Wu, Hsin-Jung, Robertson, Darrell A, Chelvarajan, Ralph L
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15-10-2000; Elsevier
• Subjects: Aged; Antigen-Presenting Cells - immunology; Antigens, Bacterial - administration & dosage; Antigens, T-Independent - administration & dosage; B cells; B-Lymphocytes - immunology; Bacteriology; Biological and medical sciences; Cytokines; Cytokines - pharmacology; Epidemiology. Vaccinations; Fundamental and applied biological sciences. Psychology; General aspects; Humans; Humoral response; IL-1; Immune Tolerance; Infant, Newborn; Infectious diseases; Lymphocyte Activation; Medical sciences; Microbiology; Pneumococcal vaccine; Polysaccharides, Bacterial - administration & dosage; Polysaccharides, Bacterial - immunology; Spleen - immunology; Splenectomy; Thymus independent antigens; TNP-Ficoll; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Splenectomy; Humoral response; Cytokines; TNP-Ficoll; IL-1; Thymus independent antigens; B cells; Pneumococcal vaccine; Human; Dendritic cell; Immunostimulation; Cytokine; Activation; B-Lymphocyte; Vaccine; Review; Streptococcus pneumoniae; Streptococcaceae; Newborn; Immunogenicity; Bacteria; Micrococcales; Defectivity; Polysaccharide; Humoral immunity; Macrophage
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(00)00161-4

T independent antigens elicit antibody responses in the absence of carrier specific T helper cells but require signals from accessory cells (macrophages and dendritic cells) or specific cytokines. They are further subdivided into TI-1 and TI-2 categories based on the ability of TI-1 but not TI-2 antigens to elicit immune responses from neonates. Most bacterial polysaccharides including the pneumococcal polysaccharide vaccines belong to the TI-2 class. It is hypothesized that defects in accessory cell function play a critical role in the failure of neonates to respond to such TI-2 antigens. Immune responses to these TI-2 stimuli are also reduced in the aged, also due to a quantitative deficiency in accessory cells. Agents that can stimulate accessory cell function may provide an alternative strategy to improve the immunogenicity of the polysaccharide vaccines in the neonates and the aged.