Past studies have shown that freshly isolated human B cells from peripheral blood and tonsils do not express IL-6 receptors (IL-6R); however, mitogen or antigen activation of these B cells induces IL-6R and responsiveness to IL-6. In this study, we have shown that a high proportion of B cells enzymatically dissociated from human appendix, a gut-associated lymphoreticular tissue (GALT), expresses the IL-6R, and that recombinant human IL-6 induces significant increases in the number of Ig-producing cells. The recombinant human IL-6-induced increase in Ig-producing 1991. 88:248-252.)

Conjugates of an uronic acid-containing capsular polysaccharide (CP), pneumococcous type 12F (Pn12F) bound to diphtheria toxoid (DT), were studied for safety and immunogenicity in adult volunteers. In mice, these conjugates, prepared with the same lot of DT and Pnl2F-40234-006, a homogenous CP of high molecular weight, or Pnl2-812408, a polydisperse CP with lower-molecular-weight material, were more immunogenic than the Pnl2F alone and had T-cell dependent properties (Infect. Immun. 56:2292Immun. 56: -2298Immun. 56: , 1988. Adult volunteers, randomized into three groups, were injected either with one of these two conjugates or with Pnu-Imune, the 23 valent pneumococcus vaccine containing 25 ,ug of Pn12F as one of its components.Volunteers were injected two times, 4 weeks apart, with the Pnl2F-DT conjugates and once with the Pnu-Imune. Side reactions following injection of the conjugates or Pnu-Imune were mild and short-lived. At 4 weeks and at 7 months after the first injection, higher levels of Pnl2F antibodies were found in the volunteers injected with the conjugates than in the Pnu-Imune group (P < 0.001). The conjugate prepared with the higher-molecular-weight Pnl2F elicited higher levels of antibodies than the conjugate prepared with a lower-molecular-weight Pn12F preparation (P = 0.05). Both conjugates elicited about a 13-fold rise in DT antibodies.

No abstract

Production of antibodies to collagen type I was analyzed by means of an enzyme-linked immunospot (ELISPOT) assay in patients with chronic adult periodontitis (AP) before and after periodontal hygiene treatment. Anti-collagen type I antibody-secreting cells were found among mononuclear cells enzymatically eluted from inflamed gingiva in 9 of 15 patients with untreated AP and in 4 of 14 hygiene-treated patients with a varied isotype distribution. A notably high prevalence of IgG and IgM isotypes was observed for the anti-collagen antibodies in untreated patients. With wide variation, chronic AP was characterized by a high frequency of spontaneous IgG and low numbers of IgA and IgM-producing cells. Periodontal hygiene treatment significantly reduced the number of IgA and IgM-secreting cells. Although AP is not an autoimmune disease in the accepted sense, our results indicate that local autoimmune reactions to collagen type I are common in untreated AP, implying an interplay between periodontal infection and autoimmunity.

SUMMARYHuman IgA occurs in multiple molecular forms (polymeric and monomcric) and iwo subclasses which show ditferential distribution between the niucosai and circulatory comparimenis of the immune system. However, the molecular form and subclass of specific IgA antibodies are influenced, especially during an immune response, by Ihe type of antigen and duration of the response as well as by the route ofexposure. These considerations quesUon previously held notions thai polymeric IgA and an increased representation of the lgA2 subclass among circulating antibodies or antibodysecreting cells signify their mucosal origin. Although the functional properties of different molecular forms and subclasses of IgA antibodies are incompletely understood, it appears that there is physiological benefit in the diversity of the IgA immune system.