Natural Killer and CD8 T Cells Contribute to Protection by Formalin Inactivated Respiratory Syncytial Virus Vaccination under a CD4-Deficient Condition

Respiratory syncytial virus (RSV) causes severe pulmonary disease in infants, young children, and the elderly. Formalin inactivated RSV (FI-RSV) vaccine trials failed due to vaccine enhanced respiratory disease, but the underlying immune mechanisms remain not fully understood. In this study, we have used wild type C57BL/6 and CD4 knockout (CD4KO) mouse models to better understand the roles of the CD4 T cells and cellular mechanisms responsible for enhanced respiratory disease after FI-RSV vaccination and RSV infection. Less eosinophil infiltration and lower pro-inflammatory cytokine production were observed in FI-RSV vaccinated CD4KO mice after RSV infection compared to FI-RSV vaccinated C57BL/6 mice. NK cells and cytokine-producing CD8 T cells were recruited at high levels in the airways of CD4KO mice, correlating with reduced respiratory disease. Depletion studies provided evidence that virus control was primarily mediated by NK cells whereas CD8 T cells contributed to IFN-γ production and less eosinophilic lung inflammation. This study demonstrated the differential roles of effector CD4 and CD8 T cells as well as NK cells, in networking with other inflammatory infiltrates in RSV disease in immune competent and CD4-deficient condition.

Natural Killer and CD8 T Cells Contribute to Protection by Formalin Inactivated Respiratory Syncytial Virus Vaccination under a CD4-Deficient Condition

Respiratory syncytial virus (RSV) causes severe pulmonary disease in infants, young children, and the elderly. Formalin inactivated RSV (FI-RSV) vaccine trials failed due to vaccine enhanced respiratory disease, but the underlying immune mechanisms remain not fully understood. In this study, we have used wild type C57BL/6 and CD4 knockout (CD4KO) mouse models to better understand the roles of the CD4 T cells and cellular mechanisms responsible for enhanced respiratory disease after FI-RSV vaccination and RSV infection. Less eosinophil infiltration and lower pro-inflammatory cytokine production were observed in FI-RSV vaccinated CD4KO mice after RSV infection compared to FI-RSV vaccinated C57BL/6 mice. NK cells and cytokine-producing CD8 T cells were recruited at high levels in the airways of CD4KO mice, correlating with reduced respiratory disease. Depletion studies provided evidence that virus control was primarily mediated by NK cells whereas CD8 T cells contributed to IFN-γ production and less eosinophilic lung inflammation. This study demonstrated the differential roles of effector CD4 and CD8 T cells as well as NK cells, in networking with other inflammatory infiltrates in RSV disease in immune competent and CD4-deficient condition.

Respiratory Syncytial Virus Fusion Protein-encoding DNA Vaccine Is Less Effective in Conferring Protection against Inflammatory Disease than a Virus-like Particle Platform

Formalin-inactivated respiratory syncytial virus (RSV) vaccination causes vaccine-enhanced disease (VED) after RSV infection. It is considered that vaccine platforms enabling endogenous synthesis of RSV immunogens would induce favorable immune responses than non-replicating subunit vaccines in avoiding VED. Here, we investigated the immunogenicity, protection, and disease in mice after vaccination with RSV fusion protein (F) encoding plasmid DNA (F-DNA) or virus-like particles presenting RSV F (F-VLP). F-DNA vaccination induced CD8 T cells and RSV neutralizing Abs, whereas F-VLP elicited higher levels of IgG2a isotype and neutralizing Abs, and germinal center B cells, contributing to protection by controlling lung viral loads after RSV challenge. However, mice that were immunized with F-DNA displayed weight loss and pulmonary histopathology, and induced F specific CD8 T cell responses and recruitment of monocytes and plasmacytoid dendritic cells into the lungs. These innate immune parameters, RSV disease, and pulmonary histopathology were lower in mice that were immunized with F-VLP after challenge. This study provides important insight into developing effective and safe RSV vaccines.

Distinct Effects of Monophosphoryl Lipid A, Oligodeoxynucleotide CpG, and Combination Adjuvants on Modulating Innate and Adaptive Immune Responses to Influenza Vaccination

Monophosphoryl lipid A (MPL) and oligodeoxynucleotide CpG are toll-like receptor (TLR) 4 and 9 agonist, respectively. Here, we investigated the effects of MPL, CpG, and combination adjuvants on stimulating in vitro dendritic cells (DCs), in vivo innate and adaptive immune responses, and protective efficacy of influenza vaccination. Combination of MPL and CpG was found to exhibit distinct effects on stimulating DCs in vitro to secrete IL-12p70 and tumor necrosis factor (TNF)-α and proliferate allogeneic CD8 T cells. Prime immunization of mice with inactivated split influenza vaccine in the presence of low dose MPL+CpG adjuvants increased the induction of virus-specific IgG and IgG2a isotype antibodies. MPL and CpG adjuvants contribute to improving the efficacy of prime influenza vaccination against lethal influenza challenge as determined by body weight monitoring, lung function, viral titers, and histology. A combination of MPL and CpG adjuvants was effective in improving vaccine efficacy as well as in reducing inflammatory immune responses locally and in inducing cellular immune responses upon lethal influenza virus challenge. This study demonstrates unique adjuvant effects of MPL, CpG, and combination adjuvants on modulating innate and adaptive immune responses to influenza prime vaccination.

Characterization of Proinflammatory Responses and Innate Signaling Activation in Macrophages Infected with Mycobacterium scrofulaceum

Mycobacterium scrofulaceum is an environmental and slow-growing atypical mycobacterium. Emerging evidence suggests that M. scrofulaceum infection is associated with cervical lymphadenitis in children and pulmonary or systemic infections in immunocompromised adults. However, the nature of host innate immune responses to M. scrofulaceum remains unclear. In this study, we examined the innate immune responses in murine bone marrow-derived macrophages (BMDMs) infected with different M. scrofulaceum strains including ATCC type strains and two clinically isolated strains (rough and smooth types). All three strains resulted in the production of proinflammatory cytokines in BMDMs mediated through toll-like receptor-2 and the adaptor MyD88. Activation of MAPKs (extracellular signal-regulated kinase 1/2, and p38, and c-Jun N-terminal kinase) and nuclear receptor (NF)-kappaB together with intracellular reactive oxygen species generation were required for the expression of proinflammatory cytokines in BMDMs. In addition, the rough morphotypes of M. scrofulaceum clinical strains induced higher levels of proinflammatory cytokines, MAPK and NF-kappaB activation, and ROS production than other strains. When mice were infected with different M. scrofulaceum strains, those infected with the rough strain showed the greatest hepatosplenomegaly, granulomatous lesions, and immune cell infiltration in the lungs. Notably, the bacterial load was higher in mice infected with rough colonies than in mice infected with ATCC or smooth strains. Collectively, these data indicate that rough M. scrofulaceum induces higher inflammatory responses and virulence than ATCC or smooth strains.

New vaccines against influenza virus

Vaccination is one of the most effective and cost-benefit interventions that prevent the mortality and reduce morbidity from infectious pathogens. However, the licensed influenza vaccine induces strain-specific immunity and must be updated annually based on predicted strains that will circulate in the upcoming season. Influenza virus still causes significant health problems worldwide due to the low vaccine efficacy from unexpected outbreaks of next epidemic strains or the emergence of pandemic viruses. Current influenza vaccines are based on immunity to the hemagglutinin antigen that is highly variable among different influenza viruses circulating in humans and animals. Several scientific advances have been endeavored to develop universal vaccines that will induce broad protection. Universal vaccines have been focused on regions of viral proteins that are highly conserved across different virus subtypes. The strategies of universal vaccines include the matrix 2 protein, the hemagglutinin HA2 stalk domain, and T cell-based multivalent antigens. Supplemented and/or adjuvanted vaccination in combination with universal target antigenic vaccines would have much promise. This review summarizes encouraging scientific advances in the field with a focus on novel vaccine designs.

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.

Depressed CCL5 Expression in Human Pulmonary Tuberculosis

CCL5/regulated on activation, normal T expressed and secreted production (RANTES) is a principal CC chemokine, and can activate macrophages and Th1 lymphocytes, however, little is known about the CCL5 profiles associated with active tuberculosis (TB). In this study, we investigated the production of CCL5 by the peripheral blood mononuclear cells (PBMCs) of patients with active pulmonary TB after stimulation with Triton X-100 soluble proteins (TSP) or the 30-kDa antigen. The profiles of cytokines/chemokines [CXCL8/interleukin (IL)-8, IL-12 p40, and interferon (IFN)-gamma] were also examined by PBMCs from TB patients, and compared with those obtained from healthy tuberculin reactors (HTR). Concordant with earlier studies, IFN-gamma production was significantly depressed in the PBMCs from TB patients compared with those from HTR. In addition, the CCL5, but not CXCL8, levels in the PBMCs from TB patients were significantly depressed after stimulation for 18 hr compared to those in the PBMCs from HTRs. The CCL5 release was not significantly correlated with the release of IFN-gamma in the cells from TB patients and HTRs. Further, inhibitor studies show that the 30-kDa- or TSP-induced CCL5 mRNA expression is sensitive to inhibitors of mitogen-activated protein kinase kinase (MEK) 1/2 and Janus kinase (JAK) 2, but not p38, pathway activation, suggesting a MEK1/2- or JAK2-based mechanism is responsible for modulating of the CCL5 expression in human PBMCs. Collectively, these data suggest that TB patients show depressed production of CCL5 secretion, which can be modulated by MEK- and JAK2-based transcriptional regulatory mechanisms, in response to the mycobacterial antigens.

Elevated Levels of Interferon-inducible Protein-10 (IP)-10/CXCL10, but not of Interferon-gamma, in Patients with Pulmonary Tuberculosis

Mycobacterial strains are potent inducers of cytokines/chemokines by mononuclear phagocytes, which constitute an important cellular component of the first line of defense in the innate immune system. Interferon (IFN)-gamma-inducible protein (IP-10 or CXCL10) is a potent chemoattractant; however, little is known about the IP-10 profiles attributable to the Th1 regulation associated with active tuberculosis (TB). In this study, we investigated the production of IP-10, interleukin (IL)-12 p40, and IFN-gamma by the peripheral blood mononuclear cells (PBMCs) of patients with active pulmonary TB in response to in vitro stimulation with Triton X-100 soluble proteins (TSPs) or the 30-kDa antigen. The TSP antigens used in the present study were isolated and purified from Mycobacterium tuberculosis H37Rv (virulent strain), M. tuberculosis H37Ra (avirulent strain), and Mycobacterium bovis BCG. The results were compared with those obtained for healthy tuberculin reactors (HTRs). Concordant with earlier studies, IFN-gamma production was significantly depressed in the PBMCs from TB patients compared with those in the HTR group. However, the IP-10 levels in the PBMCs from TB patients were significantly elevated 18 h after stimulation compared to those in the PBMCs from HTRs. IP-10 release was correlated in a significant manner with the release of IFN-gamma in the HTRs, but this was not the case for the TB patients. Collectively, these data suggest that TB patients show altered regulation of Th1-driving cytokine and chemokine production in response to a variety of mycobacterial antigens.

The Proportional Mortality Ratios of Specific-cause Mortality by Occupation and Education among Men Aged 20-64 in Korea (1993-2004) / 예방의학회지

OBJECTIVES: This study investigated the relationship of occupational class and educational background with proportional mortality ratios in Korea. METHODS: Mortality was investigated using the entire registered death data from 1993 to 2004, obtained from the Korean National Statistics Office. Proportional mortality ratios (PMRs) for specific diseases were calculated according to the occupational class and educational background of men aged 20-64. RESULTS: Manual workers were found to have higher PMRs for liver disease and traffic accidents, as did the lower educated group. Especially, this study showed trends of an increasing of the wide gap between lower and higher socioeconomic stati for liver disease, traffic accidents, diabetes mellitus and cerebral vascular disease. The mortality for cerebrovascular disease, diabetes mellitus, heart disease, traffic accident and liver disease showed increasing trends according to the calendar year for the lower than the higher social class. CONCLUSIONS: The specific conditions that had higher PMRs in the Korean lower social class were liver disease and traffic accidents. Especially, there was an increasing trend for a widening of the gap between manual and nonmanual groups in relation to mortality from liver disease, diabetes mellitus and traffic accidents.