Immune Antibody Levels Research Articles

Myeloid 12/15-LOX regulates B cell numbers and innate immune antibody levels in vivo

Background. The myeloid enzyme 12/15-lipoxygenase (LOX), which generates bioactive oxidized lipids, has been implicated in numerous inflammatory diseases, with several studies demonstrating an improvement in pathology in mice lacking the enzyme. However, the ability of 12/15-LOX to directly regulate B cell function has not been studied. Methods. The influence of 12/15-LOX on B cell phenotype and function, and IgM generation, was compared using wildtype (WT) and 12/15-LOX ( Alox15 -/-) deficient mice. The proliferative and functional capacity of splenic CD19 + B cells was measured in vitro in response to various toll-like receptor agonists. Results. WT and Alox15 -/- displayed comparable responses. However in vivo, splenic B cell numbers were significantly elevated in Alox15 -/- mice with a corresponding elevation in titres of total IgM in lung, gut and serum, and lower serum IgM directed against the 12/15-LOX product, 12-hydroxyeicosatetraenoic acid-phosphatidylethanolamine (HETE-PE). Discussion. Myeloid 12/15-LOX can regulate B cell numbers and innate immune antibody levels in vivo, potentially contributing to its ability to regulate inflammatory disease. Furthermore, the alterations seen in 12/15-LOX deficiency likely result from changes in the equilibrium of the immune system that develop from birth. Further studies in disease models are warranted to elucidate the contribution of 12/15-LOX mediated alterations in B cell numbers and innate immune antibody generation to driving inflammation in vivo.

Myeloid 12/15-LOX regulates B cell numbers and innate immune antibody levels in vivo.

Background. The myeloid enzyme 12/15-lipoxygenase (LOX), which generates bioactive oxidized lipids, has been implicated in numerous inflammatory diseases, with several studies demonstrating an improvement in pathology in mice lacking the enzyme. However, the ability of 12/15-LOX to directly regulate B cell function has not been studied. Methods. The influence of 12/15-LOX on B cell phenotype and function, and IgM generation, was compared using wildtype (WT) and 12/15-LOX (Alox15-/-) deficient mice. The proliferative and functional capacity of splenic CD19+ B cells was measured in vitro in response to various toll-like receptor agonists. Results. WT and Alox15-/- displayed comparable responses. However in vivo, splenic B cell numbers were significantly elevated in Alox15-/- mice with a corresponding elevation in titres of total IgM in lung, gut and serum, and lower serum IgM directed against the 12/15-LOX product, 12-hydroxyeicosatetraenoic acid-phosphatidylethanolamine (HETE-PE). Discussion. Myeloid 12/15-LOX can regulate B cell numbers and innate immune antibody levels in vivo, potentially contributing to its ability to regulate inflammatory disease. Furthermore, the alterations seen in 12/15-LOX deficiency likely result from changes in the equilibrium of the immune system that develop from birth. Further studies in disease models are warranted to elucidate the contribution of 12/15-LOX mediated alterations in B cell numbers and innate immune antibody generation to driving inflammation in vivo.

Pertussis antibody levels in infants immunized with an acellular pertussis component vaccine, measured using whole-cell pertussis ELISA.

A commercially available whole-cell pertussis IgG ELISA was used to test the response of 137 2-month-old infants to immunization with a trivalent acellular pertussis vaccine. The pre-immunization geometric mean (GM) IgG index was 6.96 (95% confidence interval (CI) 5.88-8.04) and the postimmunization GM index was 13.16 (95% CI 12. 20-14.11), P < 0.001. Eighty percent of subjects (110/137) had a significant 1.5-fold increase of pertussis IgG index (97/137, 71%) or a postimmunization IgG index > 10 (93/137, 68%). In single antigen ELISA, 83% showed at least a fourfold increase in pertussis toxin-specific IgG (PT-IgG) and 91% showed an increase in IgG specific for filamentous haemagglutinin (FHA-IgG). Four percent had high pre- immunization antibody levels (index > 20), likely to reflect recent maternal exposure to pertussis. This correlated with a smaller increase in pertussis IgG index. A decline in pertussis IgG index postimmunization occurred in 17/24 infants (71%) whose pre-immunization IgG index was > 10. This postimmunization pertussis IgG index was not significantly different to that of infants with a low pre-immunization index. A similar trend was noted with PT-IgG and FHA-IgG results. The whole-cell ELISA can detect a response to acellular pertussis vaccination in most infants if both antibody index and degree of seroconversion are calculated and at least one criterion is satisfied.

Appearance of new strains associated with group B meningococcal disease and their use for rapid vaccine development.

There has been a decrease in the prevalence of disease in the United States due to meningococcal serotypes 2a and 2b containing class 2 proteins with a concomitant increase in nonserotypable strains containing class 3 major outer membrane proteins. A new disease associated strain was identified using monoclonal antibodies as B:4:P1.15. Serotype 4 strains have been heretofore isolated almost only from carriers. This B:4:P1.15 strain predominated among group B disease isolates in Cuba from the late 1970s to the present and among Miami, Florida isolates recovered in 1981 and 1982. To determine whether protein vaccines for new strains or serotypes could be prepared using our present methods, a combined vaccine was prepared from a group B strain (B:8:P1.15) recovered during a recent outbreak in Virginia, and a serotype 2b strain, plus group C polysaccharide. The vaccine was prepared with aluminum hydroxide, or with trehalose dimycolate plus monophosphoryl lipid A, or without adjuvant. Four weeks after immunization antibody levels were much higher in mice that received vaccine containing adjuvant.

Immunization of immunosuppressed patients with pneumococcal polysaccharide vaccine.

The antibody response after immunization with capsular polysaccharides of Streptococcus pneumoniae of patients with Hodgkin's disease or with carcinoma of the head and neck was studied. Patients with Hodgkin's disease who were immunized prior to the institution of immunosuppressive therapy were capable of responding to each of the pneumococcal polysaccharides evaluated. The level of antibody achieved by the patients is lower than that of normal control subjects. Nevertheless, absolute values were in the range that would be expected to result in protection. The duration of antibody response was not evaluated. Patients with carcinoma of the head and neck did not demonstrate a significant increase in antibody levels after vaccination, which was done at the time of radiation therapy. Two years after immunization antibody levels were lower with recovery at three years. However, these changes were not statistically significant. Decreased levels of antibody to pneumococcal polysaccharide types not present in the vaccine were observed. Studies of patients with carcinoma of the heat and neck demonstrated that radiation therapy has a profound immunosuppressive effect on antibody levels. More selective immunosuppressive therapy and/or an increase in the immunogenicity of the polysaccharides in the vaccine are required for protection of patients with malignancy.