Combination of Pneumococcal Surface Protein A (PspA) with Whole Cell Pertussis Vaccine Increases Protection Against Pneumococcal Challenge in Mice

Streptococcus pneumoniae is the leading cause of respiratory acute infections around the world. In Latin America, approximately 20,000 children under 5 years of age die of pneumococcal diseases annually. Pneumococcal surface protein A (PspA) is among the best-characterized pneumococcal antigens that confer protection in animal models of pneumococcal infections and, as such, is a good alternative for the currently available conjugated vaccines. Efficient immune responses directed to PspA in animal models have already been described. Nevertheless, few low cost adjuvants for a subunit pneumococcal vaccine have been proposed to date. Here, we have tested the adjuvant properties of the whole cell Bordetella pertussis vaccine (wP) that is currently part of the DTP (diphtheria-tetanus-pertussis) vaccine administrated to children in several countries, as an adjuvant to PspA. Nasal immunization of BALB/c mice with a combination of PspA5 and wP or wPlow – a new generation vaccine that contains low levels of B. pertussis LPS – conferred protection against a respiratory lethal challenge with S. pneumoniae. Both PspA5-wP and PspA5-wPlow vaccines induced high levels of systemic and mucosal antibodies against PspA5, with similar profile, indicating no essential requirement for B. pertussis LPS in the adjuvant properties of wP. Accordingly, nasal immunization of C3H/HeJ mice with PspA5-wP conferred protection against the pneumococcal challenge, thus ruling out a role for TLR4 responses in the adjuvant activity and the protection mechanisms triggered by the vaccines. The high levels of anti-PspA5 antibodies correlated with increased cross-reactivity against PspAs from different clades and also reflected in cross-protection. In addition, passive immunization experiments indicated that antibodies played an important role in protection in this model. Finally, subcutaneous immunization with a combination of PspA5 with DTPlow protected mice against challenge with two different pneumococcal strains, opening the possibility for the development of a combined infant vaccine composed of DTP and PspA

コウダイ レンケイ ニ ヨル セツゾクキョウイク プログラム カイハツ ノ ココロミ

高大連携により効率的な接続教育プログラムを開発するため,高校向けアンケートを実施した。職業に就いた際に必要とされるキャリア基礎能力として本学で過去実施したアンケート結果を基にした10 要素,ならびに経済産業省の「社会人基礎力」12 要素の必要性と達成度を設問とした。その結果,社会人にもっとも必要とされるキャリア基礎能力は「コミュニケーション能力」であること,また,高校教科「情報」によりPC 基礎操作能力は十分獲得されていること,がわかった。この結果を踏まえ,高大連携プログラムの一環として高校-大学教員によるコミュニケーション教育研究会を開催し,全12 講からなる接続教育プログラム「コミュニケーションリテラシー」を開講した。Enquiries were made to upper secondary school teachers on basic vocational abilities necessary for thegraduates. Since "information literacy" was introduced recently as compulsory subject in secondary schools, itsrelation with elements necessary for an ordinary person who wishes to work in a company was investigated. Basedon the results, a project was set up with members from secondary school teachers and Shohoku College teachersand library staff. As a result, a novel coordination program, namely, "communication literacy", consisting of 12lessons, was held for secondary school third grade students

Evaluation of anti-PspA5 antibodies in mice immunized with the different vaccine formulations.

<p>Three weeks after the last immunization anti-PspA5 IgG (A), IgG1 and IgG2a (B) in the sera and IgG (C) and IgA (D) in BALF were detected through ELISA. Concentration of antibodies (mean of 6 animals for A and B and 4 animals for C and D) are shown. IgG1∶IgG2a ratios are indicated above the bars (B). Results are representative of two experiments (A and B). Asterisks represent significant differences from control groups or from group immunized with PspA5, when indicated (* <i>P</i><0.05; ** <i>P</i><0.005, Mann-Whitney <i>U</i> test).</p

Pneumococcal loads in lungs and sera.

<p>Lungs (A, C and E) and sera (B, D and F) from non-immunized BALB/c mice (Non) or mice immunized with wP or PspA5-wP were collected at different time points after intranasal challenge with ATCC6303 pneumococcal strain (PspA5). CFU were determined in four mice per group, after plating the samples in blood-agar. Circles represent individual mice and lines represent the mean for each group. (d = days). In conditions where no bacteria were detected, 1 CFU was considered.</p

Survival of BALB/c mice after intranasal challenge with <i>S. pneumoniae</i> ATCC6303 - Combination of PspA3 and wP.

*<p>Fisher exact test.</p

Survival of BALB/c mice after intranasal challenge with <i>S. pneumoniae</i> ATCC6303 - adjuvant properties of wP.

*<p>Fisher exact test. Results are representative of three independent experiments.</p

Binding to pneumococcal surface, complement deposition and passive protection elicited by anti-PspA5 antibodies.

<p>Sera from BALB/c mice immunized with PspA5 (dotted black lines), PspA5-wP (solid black lines) or PspA5-wP_low (solid dark gray lines) were tested for the ability to bind to the pneumococcal surface (A) and to mediate C3 deposition (B). <i>S. pneumoniae</i> ATCC 6303(PspA5) was incubated with 2% (A) or 10% of each group serum (B). Sera from non-immunized animals (gray areas) and immunized with wP (solid light gray lines) or wP_low (dotted light gray lines) were used as control. The median fluorescence of bacteria is shown for each sample. Data are representative of two independent experiments. Naïve mice were inoculated trough the intraperitoneal route with a 1∶100 dilution of each serum 2 h before pneumococcal challenge. Survival was monitored until 10 days after challenge (C). ***<i>P</i><0.001 when compared with control groups and <i>P</i> = 0.004 when compared with mice vaccinated with PspA5 by Fisher exact test. Data were composed with two independent experiments.</p

Induction of anti-PspA5 antibodies in C3H/HePas and C3H/HeJ mice.

<p>C3H/HePas (A) and C3H/HeJ (B and C) were immunized with the different vaccine formulations through the nasal route. Three weeks after the last immunization anti-PspA5 IgG in the sera were detected through ELISA. Concentration of antibodies (mean of 6 animals) is shown. Results are representative of two experiments. Asterisks represent significant differences from control groups or from group immunized with PspA5, when indicated (* <i>P</i><0.05; ** <i>P</i><0.005, Mann-Whitney <i>U</i> test).</p

Survival of C3H/HePas and C3H/HeJ mice after intranasal challenge with <i>S. pneumoniae</i> ATCC6303.

*<p>Fisher exact test.</p