Mucosal immunity of mannose-modified chitosan microspheres loaded with the nontyepable Haemophilus influenzae outer membrane protein P6 in BALB/c mice.

Nontypeable Haemophilus influenzae (NTHi) is a common opportunistic pathogen that colonizes the nasopharynx. NTHi infections result in enormous global morbidity in two clinical settings: otitis media in children and acute exacerbation of chronic obstructive pulmonary disease (COPD) in adults. Thus, there is an urgent need to design and develop effective vaccines to prevent morbidity and reduce antibiotic use. The NTHi outer membrane protein P6, a potential vaccine candidate, is highly conserved and effectively induces protective immunity. Here, to enhance mucosal immune responses, P6-loaded mannose-modified chitosan (MC) microspheres (P6-MCMs) were developed for mucosal delivery. MC (18.75%) was synthesized by the reductive amination reaction method using sodium cyanoborohydride (NaBH3CN), and P6-MCMs with an average size of 590.4±16.2 nm were successfully prepared via the tripolyphosphate (TPP) ionotropic gelation process. After intranasal immunization with P6-MCMs, evaluation of humoral immune responses indicated that P6-MCMs enhance both systemic and mucosal immune responses. Evaluation of cellular immune responses indicated that P6-MCMs enhance cellular immunity and trigger a mixed Th1/Th2-type immune response. Importantly, P6-MCMs also trigger a Th17-type immune response. They are effective in promoting lymphocyte proliferation and differentiation without toxicity in vitro. The results also demonstrate that P6-MCMs can effectively induce MHC class I- and II-restricted cross-presentation, promoting CD4+-mediated Th immune responses and CD8+-mediated cytotoxic T lymphocyte (CTL) immune responses. Evaluation of protective immunity indicated that immunization with P6-MCMs can reduce inflammation in the nasal mucosa and the lung and prevent NTHi infection. In conclusion, MCMs are a promising adjuvant-delivery system for vaccines against NTHi.

[Platelet HPA Typing of Platelet Donors in Zhangjiakou Area].

OBJECTIVE: To analyze the polymorphism of the HPA1-5,15 system of the donors in Zhangjiakou area. METHODS: DNA was extracted from the blood samples of the donors, PCR- SSP method was used to divide HPA1-6, 15 genotype. The gene frequency and genotype frequency were calculated, compared with the difference and regiahal specificity of the populations in our country and foregiens was compared other populations. RESULTS: The gene expression in the HPA-1, HPA-2 and HPA-4 systems were all homozygous aa, and the donors who expressed homozygous bb was not exessed. Among them, one heterozygous ab expression was found in both HPA-1 and HPA-4 systems (1%), and 14 cases of heterozygous ab expression were found in HPA-2 system (14%). The gene expression in the HPA-5 system was mainly homozygous aa (98%), and a very few expressed homozygous bb (2%) was found. The degree of heterozygosity of gene expression in the HPA-3 and HPA-15 systems was relatively high. The proprotion of the expression of aa, ab and bb in the HPA-3 system was respectively 46%, 40% and 14%, the proprotion of the expression of aa, ab and bb in the HPA-15 system was respectively 21%, 64% and 15%. CONCLUSION: The gene frequency of platelet-specific antigen HPA1-5,15 system in zhangjiakou region shows local characteristics. The heterozygosity degree of gene expression in the HPA-3 and HPA-15 systems are both high, suggesting that they are more likely to result in alloimmunization and ineffective platelet transfusion, which should be pays attention to.