Expression and diagnostic value of HBHA truncated protein / 国际检验医学杂志

Objective To express recombinant HBHAΔC and HBHAΔN protein,and compare the HBHA series protein activity with each other.It will be provide a experimental basis for the research on clinical diagnostic of HBHA.Methods The HBHAΔC and HBHAΔN gene fragments were cloned and expressed by transforming E.coli BL-21.Test the protein heparin binding ability by CL-6B column.And then added protein to the BCG 7H9 culture medium,to observe the induced BCG aggregation.Results nHB-HA,rHBHA and HBHAΔN protein have heparin binding ability.Meanwhile nHBHA,rHBHA and HBHA Δ C protein have in-duced BCG aggregation effect.Conclusion The HBHAΔC and HBHAΔN protein were successfully obtained.It was proved that the HBHA C-terminal could be combined with heparin and the N-terminal involved could induce the aggregation of BCG.This results provide a basis for further study on molecular mechanism of TB infection and clinical application.

Mycobacterial Heparin-binding Hemagglutinin Antigen Activates Inflammatory Responses through PI3-K/Akt, NF-kappaB, and MAPK Pathways

BACKGROUND: Mycobacterium tuberculosis (Mtb) heparin binding hemagglutinin (HBHA) is an Ag known to evoke effective host immune responses during tuberculosis infection. However, the molecular basis of the host immune response to HBHA has not been fully characterized. In this study, we examined the molecular mechanisms by which HBHA can induce the expression of proinflammatory cytokines in macrophages. METHODS: HBHA-induced mRNA and protein levels of proinflammatory cytokines were determined in bone marrow-derived macrophages (BMDMs) using RT-PCR and ELISA analysis. The roles of intracellular signaling pathways for NF-kappaB, PI3-K/Akt, and MAPKs were investigated in macrophage proinflammatory responses after stimulation with HBHA. RESULTS: HBHA robustly activated the expression of mRNA and protein of both TNF-alpha and IL-6, and induced phosphorylation of NF-kappaB, Akt, and MAPKs in BMDMs. Both TNF-alpha and IL-6 production by HBHA was regulated by the NF-kappaB, PI3-K, and MAPK pathways. Furthermore, PI3-K activity was required for the HBHA-induced activation of ERK1/2 and p38 MAPK, but not JNK, pathways. CONCLUSION: These data suggest that mycobacterial HBHA significantly induces proinflammatory responses through crosstalk between the PI3-K and MAPK pathways in macrophages.