Acquisition and the immunogenicity of the outer membrane FomA protein of Fusobacterium nucleatum / 中华口腔医学杂志

Objective@#To express and purify outer membrane protein FomA of Fusobacterium nucleatum (Fn) through gene recombination technique with Escherichia coli (Ec) expression system, and to detect the immunogenicity and the immune effects of the recombinant protein on gingival tissues.@*Methods@#The gene recombination technique and Ec expression system were used to express and purified the FomA protein. Totally 20 C57 mice were immuned with the protein or the phosphate buffer solution (PBS) buffer by subcutaneous injection (each 10 mice), and the specific FomA antibody was detection in mice serum. The immunogenicity of FomA protein was assessed by comparing the differences between groups. Furthermore, the model of mice gum abscess was constructed with Fn or Fn and Porphyromonas gingivalis (Pg) mixed suspension used the above mice. The score of the gingival abscess was recorded and the interleukin (IL)-1β in gum tissue and mice serum was determined by enzyme-linked immunosorbent assay method, and the differences of the indexes between groups were compared to evaluate the effect of the FomA protein immunization.@*Results@#Totally 1.0-1.5 g FomA protein were successfully obtained and the protein purity was over 90%. The FomA specific antibody was detected in the serum of mice by subcutaneous injection of the protein, and the antibody titer reached the highest level in 2 weeks after secondary immunization. The model of submaxillary gingival abscess was successfully constructed. In the Fn model, the score of the FomA protein immune group was (1.82±0.35), and the PBS control group was (2.62±0.71), with statistically significant difference between the two groups (P=0.049). In the Fn+Pg mixture model, the score of gingival abscess in the FomA immune group (2.31±0.55) was lower than that in PBS group (3.63±0.45), and the difference was statistically significant (P=0.003). Both in Fn and Fn+Pg injection group, the concentration of IL-1β in the serum of FomA immune mice and gingival tissues was lower than that of PBS control mice (P<0.001).@*Conclusions@#The recombinant FomA protein can be acquired by Ec expression system, and it can produce a certain level antibodies in the mice serum. The way of mice subcutaneously injected with the recombinant FomA protein can reduce the severity of periodontal infections caused by Fn and Pg.

Development of a Novel Subunit Vaccine Targeting Fusobacterium nucleatum FomA Porin Based on In Silico Analysis

Selecting an appropriate antigen with optimal immunogenicity and physicochemical properties is a pivotal factor to develop a protein based subunit vaccine. Despite rapid progress in modern molecular cloning and recombinant protein technology, there remains a huge challenge for purifying and using protein antigens rich in hydrophobic domains, such as membrane associated proteins. To overcome current limitations using hydrophobic proteins as vaccine antigens, we adopted in silico analyses which included bioinformatic prediction and sequence-based protein 3D structure modeling, to develop a novel periodontitis subunit vaccine against the outer membrane protein FomA of Fusobacterium nucleatum. To generate an optimal antigen candidate, we predicted hydrophilicity and B cell epitope parameter by querying to web-based databases, and designed a truncated FomA (tFomA) candidate with better solubility and preserved B cell epitopes. The truncated recombinant protein was engineered to expose epitopes on the surface through simulating amino acid sequence-based 3D folding in aqueous environment. The recombinant tFomA was further expressed and purified, and its immunological properties were evaluated. In the mice intranasal vaccination study, tFomA significantly induced antigen-specific IgG and sIgA responses in both systemic and oral-mucosal compartments, respectively. Our results testify that intelligent in silico designing of antigens provide amenable vaccine epitopes from hard-to-manufacture hydrophobic domain rich microbial antigens.

Adult T-cell leukemia/lymphoma / Leucemia/linfoma de células T do adulto

Summary Adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature CD4+ T-cells caused by human T-cell lymphotropic virus type 1 (HTLV-1). Twenty million people are believed to be infected throughout the world, mostly in Japan, Africa, the Caribbean, and South America, particularly in Brazil and Peru. ATL affects about 5% of infected individuals and is classified in the following clinical forms: acute, lymphoma, primary cutaneous tumoral, chronic (favorable and unfavorable), and smoldering (leukemic and non-leukemic). Although it is considered an aggressive disease, there are cases with a long progression. We emphasize the importance of clinical classification as an indispensable element for evaluating prognosis and appropriate therapeutic approach. Since several cases have been published in Brazil and this disease is still poorly known, we decided to make a review paper for dissemination of clinical, hematological and pathological aspects, diagnosis, and therapy. The best way to reduce the occurrence of ATL would be halting the transmission of the virus through breastfeeding.

Resumo A leucemia/linfoma de células T do adulto (LLcTA) é uma neoplasia de células T maduras CD4+ causada pelo vírus linfotrópico para células T humanas tipo 1 (HTLV-1). Acredita-se que existem cerca de 20 milhões de pessoas infectadas em todo o mundo, principalmente no Japão, na África, no Caribe e na América do Sul, particularmen te no Brasil e no Peru. A LLcTA acomete cerca de 5% dos indivíduos infectados e classifica-se nas seguintes formas clínicas: aguda, linfomatosa, tumoral primária de pele, crônica (favorável e desfavorável) e indolente (leucêmica e não leucêmica). Embora seja considerada uma doença agressiva, há casos com longa evolução. Salientamos a importância da classificação clínica como elemento im prescindível para avaliação do prognóstico e conduta terapêutica adequada. Como já foram publicados vários casos no Brasil e essa doença ainda é pouco conhecida, decidimos fazer um trabalho de revisão para divulgar os seus aspectos clínicos, hematológicos, anatomopatológi cos, diagnósticos e terapêuticos. O melhor meio de redu zir a ocorrência de LLcTA seria sustando a transmissão vertical do vírus pela amamentação.