• Journal of Pharmaceutical Investigation
• /
• 제34권1호
• /
• pp.1-14
• /
• 2004

A promising approach to the development of a new single-step vaccine, which would eliminate the requirement for multiple injections, involves the encapsulation of antigens into microspheres. Biodegradable poly(lactide-co-glycolide) (PLGA) microspheres gave us a bright insight for controling antigen release in a pulsatile fashion, thereby mimicking two or tree boosting injections. However, in spite of the above merits, the level of immunization induced by a single-shot vaccination is often lower tan two doses of alum-adsorbed antigen. Therefore, optima modification of the microsphere is essential for the development of single-step vaccines. In the review, we discuss the stability of antigen in microsphere, safety and non-toxic in human and encapsulation technology. Also, we attempted to outline relevant physicochemical properties on the immunogenicity of microsphere vaccine and attainment of pulsatile release pater by combination of different microsphere, as well as to analyze immunological data associated with antigen delivery by microsphere. Although a lot of variables are related to the optimized microsphere formulation, we could conclude that judicious choice of proper polymer type, adjustment of particles size, and appropriate immunization protocol along with a suitable adjuvant might be a crucial factor for the generation of long-lasting immune response from a single-step vaccine formulation employing PLGA microsphere.

• 대한의생명과학회지
• /
• 제12권4호
• /
• pp.443-450
• /
• 2006

To demonstrate their possibilities as an enhanced vaccine delivery system, protein-loaded Poly lactide glycolide copolymer (PLGA) microspheres were prepared with different physical characteristics. Ethyl acetate (EA) solvent extraction process was employed to prepare microspheres and the effects of process parameters on drug release properties were evaluated. The biodeuadability of microspheres was also evaluated by the pH change and GPC (Gel permeation chromatography). Primary IgG antibody responses in BALB/c mice were compared with protein saline solutions as negative controls and adsorbed alum suspensions as positive controls after single subcutaneous injection for in vivo studies. The microspheres showed a erosion with a highly porous structure and did not keep their spherical shape at 45 days and this result could be confirmed by GPC. In vitro release of proteinous drug showed initial burst effect in all batches of microspheres, followed by gradual release over the next 4 weeks. PLGA microspheres were degraded until 45 days and the secondary structure of OVA was not affected by the preparation method. Enzyme-linked immunosorbent assays demonstrated that the single subcutaneous administrations of OVA-loaded PLGA microspheres induced enhanced serum IgG antibody response in comparison to negative and positive controls. These results demonstrated that microspheres providing the controlled release of antigens might be useful in advanced vaccine formulations for the parenteral carrier system.

• Parasites, Hosts and Diseases
• /
• 제45권4호
• /
• pp.287-293
• /
• 2007

The identification and characterization of antigens that elicit human T cell responses is an important step toward understanding of Leishmania major infection and ultimately in the development of a vaccine. Micropreparative SDS-PAGE followed by electro transfer to a PVDF membrane and elution of proteins from the PVDF, was used to separate 2 novel proteins from L. major promastigotes, which can induce antibodies of the IgG2a isotype in mice and also are recognized by antisera of recovered human cutaneous leishmaniasis subjects. Fractionation of the crude extract of L. major revealed that all detectable proteins of interest were present within the soluble Leishmania antigens (SLA). Quantitation of these proteins showed that their expression in promastigotes is relatively very low. Considering the molecular weight, immunoreactivity, chromatographic and electrophoretic behavior in reducing and non-reducing conditions, these proteins are probably 2 isoforms of a single protein. A digest of these proteins was resolved on Tricine-SDS-PAGE and immunoreactive fragments were identified by human sera. Two immunoreactive fragments (36.4 and 34.8 kDa) were only generated by endoproteinase Glu-C treatment. These immunoreactive fragments or their parent molecules may be ideal candidates for incorporation in a cocktail vaccine against cutaneous leishmaniasis.

• Journal of Veterinary Science
• /
• 제21권2호
• /
• pp.22.1-22.9
• /
• 2020

Rabid raccoon dogs (Nyctereutes procyonoides koreensis) have been responsible for animal rabies in South Korea since the 1990s. A recombinant rabies vaccine strain, designated as ERAGS, was constructed for use as a bait vaccine. Therefore, new means of differentiating ERAGS from other rabies virus (RABV) strains will be required in biological manufacturing and diagnostic service centers. In this study, we designed two specific primer sets for differentiation between ERAGS and other RABVs based on mutation in the RABV glycoprotein gene. Polymerase chain reaction analysis of the glycoprotein gene revealed two DNA bands of 383 bp and 583 bp in the ERAGS strain but a single DNA band of 383 bp in the field strains. The detection limits of multiplex reverse transcription polymerase chain reaction (RT-PCR) were 80 and 8 FAID₅₀/reaction for the ERAGS and Evelyn-Rokitnicki-Abelseth strains, respectively. No cross-reactions were detected in the non-RABV reference viruses, including canine distemper virus, parvovirus, canine adenovirus type 1 and 2, and parainfluenza virus. The results of multiplex RT-PCR were 100% consistent with those of the fluorescent antibody test. Therefore, one-step multiplex RT-PCR is likely useful for differentiation between RABVs with and those without mutation at position 333 of the RABV glycoprotein gene.

• Pediatric Infection and Vaccine
• /
• 제22권2호
• /
• pp.63-68
• /
• 2015

목적: 저자들은 2013년 경기 북부의 한 병원에서 경험한 소규모 홍역 유행의 양상을 알아보기 위해 본 연구를 시행하였다. 방법: 2013년 8월부터 10월까지 가톨릭대학교 의정부성모병원에서 홍역으로 확진된 환아 15명의 의무기록을 후향적으로 분석하였다. 결과: 홍역으로 진단된 환아는 모두 15명으로, 신생아 1명, 영아 11명, 유아 3명이었으며 역전사 중합 효소연쇄반응법(RT-PCR)과 혈청 내 홍역 IgM 검사로 확진하였다. 모든 환아는 Measles-Mumps-Rubella (MMR) 접종을 받지 않았다. 홍역으로 확진된 환아의 바이러스 유전형은 모두 B3이었다. 9명(60%)의 환아가 원내 감염에 의해 홍역에 걸렸다. 잠복기는 8-15일이었고 발열은 접촉 후 평균 10일째 발생하여 평균 8일 동안 39도 이상으로 지속되는 양상을 보였다. 발진은 접촉 후 평균 13일째 발생하였다. 40%의 환아가 호흡기 합병증을 보였고 53%의 환아가 설사를 동반하였다. 결론: 우리나라는 꾸준한 접종 사업을 통해 홍역 퇴치 수준에 이르게 되었지만 홍역 재유행, 특히 영아에 대한 위험성을 간과할 수 없게 되었다. 영유아에서 홍역이 의심될 때에는 가속접종, 면역글로불린 투여와 같은 처치를 적극적으로 시행하는 것이 필요하다. 향후 홍역 유행을 막기 위한 첫 번째 단계로, 신생아, 영아, 가임기 여성의 홍역 IgG 항체가 재조사가 필요할 것으로 사료된다.