Prevalence of Epstein-Barr virus type 1 in patients with chronic periodontitis by nested-PCR.

The present study evaluated the subgingival presence of Epstein-Barr virus type 1 (EBV-1) in patients with chronic periodontitis with nested-PCR. Subgingival plaque samples from 61 patients with chronic periodontitis with Probing Depth (PD) > or = 6 and 40 healthy controls were collected by sterile curette. DNA was extracted. A nested Polymerase Chain Reaction (PCR) method determined presence of EBV-1. The study included 61 patients (34 women, 27 men; 24-69 years of age; mean 43) and 40 periodontally health controls (22 Women, 18 men, 21-69 years in age; mean 41.35%). EBV type 1 was detected in 37 samples (60.7%) and 1 samples (2.5%) of chronic periodontitis patients and healthy subjects, respectively. This study demonstrated that EBV-1 infection is associated with the activity of chronic periodontitis.

Induction of IL-2 and IFN-gamma in BALB/c mice immunised with subunit influenza A vaccine in combination with whole cell or acellular DTP vaccine.

Splenocytes from mice immunised with two doses of subunit influenza A/Beijing/353/89 vaccine mixed with whole cell DTP (wDTP), acellular DTP (aDTP) or PBS were collected 7 and 10 days after the second immunisation, and re-stimulated with subunit influenza vaccine or live virus in vitro. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were assayed in supernates from these cultures by an ELISA procedure. Splenocytes from mice given subunit influenza vaccine in wDTP produced greater than two-fold and greater than five-fold responses of IL-2 and IFN-gamma, respectively, compared with splenocytes from mice immunised with subunit vaccine alone. In contrast, the response of splenocytes from mice immunised with subunit vaccine in saline or aDTP was similar, significantly less than for vaccine in wDTP (p < 0.01) and only slightly greater than for controls (p < 0.05). The production of IL-2 and IFN-gamma by these spleen cells was not significantly different on days 7 and 10 post-immunisation. Previous reports have shown that wDTP and aDTP enhance the serum antibody response of mice to influenza vaccine, but wDTP enhanced the response 100-fold greater than aDTP, and induced greater IgG2a and IgG2b subclass antibody responses; this last result indicates a cell-mediated immune response to vaccine. The present studies confirm these earlier findings; furthermore, as the IL-2 and IFN-gamma responses of splenocytes are associated with Th-1 subset T-lymphocyte response, the findings indicate a cytotoxic T-cell response to immunisation. The results indicate that influenza vaccine combined with wDTP induced a cell-mediated response in mice, which could confer a more solid immunity to challenge virus infection.

Immune response and protection against influenza A infection in mice immunised with subunit influenza A vaccine in combination with whole cell or acellular DTP vaccine.

Following the demonstration of the strong adjuvant effect of whole-cell DTP vaccine (wDTP) on the immune responses to influenza subunit vaccine, studies were undertaken to identify the component of wDTP responsible for the adjuvant effect, and to determine if acellular DTP (aDTP) vaccine was as effective since it is less reactogenic and likely to replace wDTP for primary or secondary immunisation. In addition, wDTP and aDTP were directly compared in a dose-response study. Experiments in mice indicated that the adjuvant effect of wDTP resided in the LPS component of B. pertussis, since purified LPS enhanced the IgG antibody response, the IgG subclass response and protection to the same level as wDTP. An adjuvant effect was detected using aDTP, but was statistically less pronounced than wDTP by a factor of some 100-fold. These results suggest that immunisation against influenza in infants and young children can be achieved combining small amounts of influenza antigen with wDTP or LPS, and to a lesser extent by combining vaccine with aDTP. However, these results were obtained in mice and should be confirmed in man since species vary considerably in response to adjuvant.

Immune response of mice to immunization with subunit influenza A vaccine in DTP vaccine.

Experiments were carried out to examine the initial feasibility of immunizing infants and children with inactivated influenza virus vaccine combined with diphtheria-tetanus-pertussis (DTP) vaccine. Groups of mice were immunized with saline vaccine or vaccine mixed with DTP: three doses of vaccine were given 3 weeks apart, and the antibody response and resistance to challenge infection were tested 3 weeks after the 1st and 3rd immunizations. The results showed that the antibody response and immunity to challenge virus infection were significantly greater for mice given vaccine in DTP than for mice given saline vaccine alone. Comparison of the response to graded doses of vaccine in saline or DTP indicated that vaccine in DTP was > 250-fold more effective in inducing serum antibody and protection than saline vaccine alone. The enhancing activity of DTP was significant for the alum component alone; however, most of the adjuvant effect was from the antigen components of the DTP vaccine. The results suggest that immunization against influenza in infants and young children could be achieved by combining small amounts of influenza antigen with DTP vaccines; however, the present results have been obtained in mice, and, since the responses to vaccines and adjuvants vary from species to species, the present results cannot be used to indicate similar results in human volunteers. The results indicate the potential value of an immunization procedure which should be tested in volunteers and which could provide a simple strategy for the immunization of at-risk infants and children against influenza.