[Influence of the different detoxifying agents on toxic characteristics of Haemophilus influenzae lypooligosaccharides].

AIM: To study toxicity of lypooligosaccharides (LOS) of non-typable Haemophilus influenzae (NTHi) strain and products of their detoxication obtained using different reagents. MATERIALS AND METHODS: LPS was obtained from the NTHi strain grown on solid brain-heart infusion nutrient medium using previously described method of isolation and purification of LOS. Obtained LPS was treated in same conditions by one of the 3 detoxifying agents: anhydrous hydrazine (AH), alkali (NaOH), and hydrochloric hydroxylamine (HH). Toxicity of LOS and its detoxified derivatives was measured on outbred mice which were administered 0.5 ml of actinomycin D intraperitoneally 1 day before immunization. Death of animals was assessed on day 2 after immunization. Polyacrylamide gel electrophoresis was used for study the influence of detoxifying agents on physico-chemical properties of LOS. RESULTS: As a result of treatment of NTHi No.45 LOS by different detoxifying agents, 3 preparations of detoxified LOS (d-LOS) and 3 preparations from precipitates (nd-LOS) were obtained. Preparation d-LOSAH was the least toxic. Toxic properties of nd-LOSHH did not reliably change. PAAG electrophoresis showed that virtually all detoxified preparations were characterized by higher migration of lypooligosaccharide components compared to original LOS of NTHi No. 45, which indicates the lowering of LOS molecular weight after treatment by detoxifying agents, associated with elimination of lipid A higher fatty acids. CONCLUSION: Analysis of effects of detoxifying agents indicates the need to select individual conditions for treatment by each of them.

Effects of two pediatric vaccines on autoimmune diabetes in NOD female mice.

The induction or exacerbation of autoimmune diseases is a potential adverse effect of immunostimulating drugs. Vaccines have been suspected of such actions. Epidemiological studies, however, have so far failed to demonstrate any causal relationship between vaccination and autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM). In this study, autoimmune diabetes-prone non-obese diabetic (NOD) mice were treated with two multivalent diphtheria, tetanus, pertussis, poliomyelitis and haemophilus vaccines (diphtheria, tetanus, acellular pertussis, inactivated polio (DTaP-IVP) or DTaP-IVP/Haemophilus influenza type b (Hib)) intraperitoneally at each of 10, 12 and 14 weeks of age. Although non-statistically significant, the incidence of autoimmune diabetes was slightly reduced by the DTaP-IVP vaccine. Blood glucose levels were actually significantly reduced in the mice treated with the DTaP-IVP vaccine relative to the untreated control mice. A slight decrease in blood glucose levels amongst the mice given the DTaP-IVP/Hib vaccine was also noted. Therefore this study does not support previous claims that children's vaccination might be associated with acceleration or exacerbation of IDDM.

Phase I study of a lipooligosaccharide-based conjugate vaccine against nontypeable Haemophilus influenzae.

Nontypeable Haemophilus influenzae (NTHi) accounts for about one-third of purulent otitis media (OM) in children and is a common cause of pulmonary infection in adults with decreased resistance. Based upon sero-epidemiological data in humans and immunochemical data in laboratory animals, a lipooligosaccharide (LOS)-tetanus toxoid (TT) conjugate was prepared and evaluated for its safety and immunogenicity in a Phase I study of 40 healthy adults. The conjugate was injected intramuscularly into all volunteers: 28 of them received a second injection 14 weeks later. Local and systemic reactions were monitored and sera, taken before and 2, 6, 14, 16, and 38 weeks after injection, were assayed for IgG, IgA, and IgM antibodies to the LOS by ELISA and for bactericidal activity. The results indicate that there were no significant local or systemic reactions after either injection. All volunteers had pre-existing IgG anti-LOS. The geometric mean (GM) level rose from 14 to 40 at 2 weeks, remained at 35 at 6 weeks (40 or 35 versus 14, P<0.01) and dropped to 27 at 14 weeks after the first injection. There was also a rise 2 weeks after the second injection (27 versus 37, P<0.05). A total of 52.5% of subjects showed serum-conversion (greater than four-fold increase) after one and two injections. At 38 weeks, the GM IgG anti-LOS was still higher than before initial injection (20 versus 14, P<0.05). A similar pattern of reactivity was observed for IgA and IgM anti-LOS. Similar to that observed in mice, but not in rabbits, the conjugate-induced antibodies did not yield significant bactericidal activity in vitro. The LOS-TT conjugate is well tolerant in adults and a Phase II evaluation of the conjugate in children is planned.

IgA nephropathy in mice following repeated administration of conjugated Haemophilus influenzae type B vaccine (PRP-T).

OBJECTIVE: In this study, the risk of IgA nephropathy in Swiss albino mice following the subcutaneous administration of conjugated Haemophilus influenzae type b vaccine (PRP-T), containing capsular polysaccharide of the organism (PRP) conjugated to tetanus protein (T), was evaluated. METHODS: Three treatment and corresponding control groups, each containing mice, were constituted and given 2, 4, 6 injections of 1/4 HD of PRP-T or placebo, respectively, at 2-week intervals. All mice in each treatment group were sacrificed two weeks from the last injection to examine sequential glomerular changes. RESULTS: The niceoscpic examination of renal tissues revealed mesangial proliferation (6/7; 85%) in the first group given 2 doses of vaccine; mesangial proliferation (5/7; 72%) and increase in matrix (7/7; 100%) in the second group given 4 doses; and mesangial proliferation (7/7; 100%), increase in matrix (7/7; 100%), IgA (7/7; 100%) and C3 (3/7; 42%) deposition within mesangium in the third group given 6 doses. No histopathological changes were detected in the renal tissues of any control mouse. When the experimental groups were compared statistically with their respective controls at the light microscopic level, mesangial proliferation in the first group (p: 0.0047), mesangial proliferation (p: 0.021) and increase in matrix (p: 0.001) in the second group, mesengial proliferation (p: 0.001) and increase in matrix (p: 0.001) in the third group were determined to be significantly different. When study and control groups were compared by immunofluorescence microscopy, only the third group revealed a statistically significant difference with respect to IgA deposition (p: 0.001). C3 deposition was also demonstrated in this group, but it was not significantly different (p: 0.192). However, in no instance was a control mouse found to have any form of immune deposition. CONCLUSION: We concluded that conjugated Haemophilus influenzae type b vaccine, given at two-week intervals to a total of six doses, caused secondary IgA nephropathy in mice.