Acquired immune responses to the seasonal trivalent influenza vaccination in COPD

International audienceEpidemiological data suggest that influenza vaccination protects against all-cause mortality in chronic obstructive pulmonary disease (COPD) patients. However, recent work has suggested there is a defect in the ability of some COPD patients to mount an adequate humoral response to influenza vaccination. The aim of our study was to investigate humoral and cell-mediated vaccine responses to the seasonal trivalent influenza vaccination (TIV) in COPD subjects and healthy controls. Forty-seven subjects were enrolled into the study; 23 COPD patients, 13 age-matched healthy controls (HC ≥ 50) and 11 young healthy control subjects (YC ≤ 40). Serum and peripheral blood mononuclear cells (PBMC) were isolated pre-TIV vaccination and at days 7 and 28 and 6 months post-vaccine for haemagglutinin inhibition (HAI) titre, antigen-specific T cell and antibody-secreting cell analysis. The kinetics of the vaccine response were similar between YC, HC and COPD patients and there was no significant difference in antibody titres between these groups at 28 days post-vaccine. As we observed no disease-dependent differences in either humoral or cellular responses, we investigated if there was any association of these measures with age. H1N1 (r = -0·4253, P = 0·0036) and influenza B (r = -0·344, P = 0·0192) antibody titre at 28 days negatively correlated with age, as did H1N1-specific CD4+ T helper cells (r = -0·4276, P = 0·0034). These results suggest that age is the primary determinant of response to trivalent vaccine and that COPD is not a driver of deficient responses per se. These data support the continued use of the yearly trivalent vaccine as an adjunct to COPD disease management

Prime-boost immunization with DNA, recombinant fowlpox virus and VLPSHIV elicit both neutralizing antibodies and IFN\u3b3-producing T cells against the HIV-envelope protein in mice that control env-bearing tumour cells

Different primings with DNA and fowlpox virus (FP) recombinants or FP alone were used in a preclinical trial to evaluate and compare immunogenicity and efficacy against HIV/SHIV. Three immunization regimens were tested in three groups of mice in which the SIV gag/pol and HIV-1 env transgenes were separately expressed by DNA and FP vectors, followed by VLPSHIV boosting. All of the protocols were effective in eliciting homologous neutralizing antibodies, although the mice immunized with DNA followed by FP recombinants or DNA+FP recombinants showed both high titres of neutralizing antibodies and high frequencies of env-specific IFN\u3b3-producing T lymphocytes. Vaccine efficacy, as demonstrated by growth control of env-expressing tumours, was obtained in both of these two groups of mice. These results establish a preliminary profile for the combined use of these recombinant vectors in protocols to be tested in the SHIV-macaque model of HIV-1 infection

Bare histidine-serine models : implications and impact of hydrogen bonding on nucleophilicity

International audienceA new family of 2-hydroxyalk(en/yn)ylimidazoles has been evaluated as serine–histidine bare dyad models for the ring-opening reaction of L-lacOCA, a cyclic O-carboxyanhydride. These models were selected to unravel the implication of intramolecular hydrogen bonding and to substantiate its influence on the nucleophilicity of the alcohol moiety, as it is suspected to occur in enzyme active sites. Although designed to exclusively facilitate the preliminary step of proton transfer during the studied ring-opening reaction, these minimalistic models depicted a measureable increase in reactivity relative to the isolated fragments. A couple of reliable experimental and theoretical methods have been developed to readily monitor the strength of the intramolecular hydrogen bond in dilute solution. Results show that the folded conformers are the most nucleophilic species because of the intramolecular hydrogen bond