Plasmacytoid Dendritic Cells Contribute to the Protective Immunity Induced by Intranasal Treatment with Fc-fused Interleukin-7 against Lethal Influenza Virus Infection

Developing a novel vaccine that can be applied against multiple strains of influenza virus is of utmost importance to human health. Previously, we demonstrated that the intranasal introduction of Fc-fused IL-7 (IL-7-mFc), a long-acting cytokine fusion protein, confers long-lasting prophylaxis against multiple strains of influenza A virus (IAV) by inducing the development of lung-resident memory-like T cells, called T(RM)-like cells. Here, we further investigated the mechanisms of IL-7-mFc-mediated protective immunity to IAVs. First, we found that IL-7-mFc treatment augments the accumulation of pulmonary T cells in 2 ways: recruiting blood circulating T cells into the lung and expanding T cells at the lung parenchyma. Second, the blockade of T cell migration from the lymph nodes (LNs) with FTY720 treatment was not required for mounting the protective immunity to IAV with IL-7-mFc, suggesting a more important role of IL-7 in T cells in the lungs. Third, IL-7-mFc treatment also recruited various innate immune cells into the lungs. Among these cells, plasmacytoid dendritic cells (pDCs) play an important role in IL-7-mFc-mediated protective immunity through reducing the immunopathology and increasing IAV-specific cytotoxic T lymphocyte (CTL) responses. In summary, our results show that intranasal treatment with IL-7-mFc modulates pulmonary immune responses to IAV, affecting both innate and adaptive immune cells.

Erratum: Plasmacytoid Dendritic Cells Contribute to the Protective Immunity Induced by Intranasal Treatment with Fc-fused Interleukin-7 against Lethal Influenza Virus Infection

In the publication by Kang et al., typographical error has been detected in acknowledgements.

COMP-Ang1 Potentiates EPC Treatment of Ischemic Brain Injury by Enhancing Angiogenesis Through Activating AKT-mTOR Pathway and Promoting Vascular Migration Through Activating Tie2-FAK Pathway

Successful recovery from brain ischemia is limited due to poor vascularization surrounding the ischemic zone. Cell therapy with strong angiogenic factors could be an effective strategy to rescue the ischemic brain. We investigated whether cartilage oligomeric matrix protein (COMP)-Ang1, a soluble, stable and potent Ang1 variant, enhances the angiogenesis of human cord blood derived endothelial progenitor cells (hCB-EPCs) for rescuing brain from ischemic injury. COMP-Ang1 markedly improved the tube formation of capillaries by EPCs and incorporation of EPCs into tube formation with human umbilical vein endothelial cells (HUVECs) upon incubation on matrigel in vitro. COMP-Ang1 stimulated the migration of EPCs more than HUVECs in a scratch wound migration assay. The transplanted EPCs and COMP-Ang1 were incorporated into the blood vessels and decreased the infarct volume in the rat ischemic brain. Molecular studies revealed that COMP-Ang1 induced an interaction between Tie2 and FAK, but AKT was separated from the Tie2-FAK-AKT complex in the EPC plasma membrane. Tie2-FAK increased pp38, pSAPK/JNK, and pERK-mediated MAPK activation and interacted with integrins alphanubeta3, alpha4, beta1, finally leading to migration of EPCs. AKT recruited mTOR, SDF-1, and HIF-1alpha to induce angiogenesis. Taken together, it is concluded that COMP-Ang1 potentiates the angiogenesis of EPCs and enhances the vascular morphogenesis indicating that combination of EPCs with COMP-Ang1 may be a potentially effective regimen for ischemic brain injury salvage therapy.

In vivo action of IL-27: reciprocal regulation of Th17 and Treg cells in collagen-induced arthritis

Interleukin (IL)-27 is a novel cytokine of the IL-6/IL-12 family that has been reported to be involved in the pathogenesis of autoimmune diseases and has a pivotal role as both a pro- and anti-inflammatory cytokine. We investigated the in vivo effects of IL-27 on arthritis severity in a murine collagen-induced arthritis (CIA) model and its mechanism of action regarding control of regulatory T (Tregs) and IL-17-producing T helper 17 (Th17) cells. IL-27-Fc-treated CIA mice showed a lower severity of arthritis. IL-17 expression in the spleens was significantly decreased in IL-27-Fc-treated CIA mice compared with that in the CIA model. The Th17 population was decreased in the spleens of IL-27-Fc-treated CIA mice, whereas the CD4+CD25+Foxp3+ Treg population increased. In vitro studies revealed that IL-27 inhibited IL-17 production in murine CD4+ T cells, and the effect was associated with retinoic acid-related orphan receptor gammaT and signal transducer and activator of transcription 3 inhibition. In contrast, fluorescein isothiocyanate-labeled forkhead box P3 (Foxp3) and IL-10 were profoundly augmented by IL-27 treatment. Regarding the suppressive capacity of Treg cells, the proportions of CTLA-4+ (cytotoxic T-lymphocyte antigen 4), PD-1+ (programmed cell death protein 1) and GITR+ (glucocorticoid-induced tumor necrosis factor receptor) Tregs increased in the spleens of IL-27-Fc-treated CIA mice. Furthermore, in vitro differentiated Treg cells with IL-27 exerted a more suppressive capacity on T-cell proliferation. We found that IL-27 acts as a reciprocal regulator of the Th17 and Treg populations in CD4+ cells isolated from healthy human peripheral blood mononuclear cells (PBMCs), as well as from humans with rheumatoid arthritis (RA) PBMCs. Our study suggests that IL-27 has the potential to ameliorate overwhelming inflammation in patients with RA through a reciprocal regulation of Th17 and Treg cells.

The Past, Present, and Future of Adoptive T Cell Therapy

Although adoptive T cell therapy (ACT) has become a promising immunotherapeutic regime for cancer treatment, its effectiveness has been hindered by several inherent shortcomings regarding safety and efficacy. During the past few decades, several strategies for enhancing the efficacy of ACT have been developed and introduced in clinic. This review will summarize not only the past approaches but also the latest strategies which have been shown to enhance the anticancer activity of ACT.

Synergistic Effect of Mesenchymal Stem Cells Infected with Recombinant Adenovirus Expressing Human BDNF on Erectile Function in a Rat Model of Cavernous Nerve Injury

PURPOSE: To evaluate the combined role of mescenchymal stem cells (MSCs) infected with recombinant adenoviruses expressing human BDNF (rAd/hBDNF) on the erectile dysfunction in rat with cavernous nerve injury. MATERIALS AND METHODS: Rats divided into 4 groups: control group, bilateral cavernous nerve crushing group (BCNC group), BCNC with MSCs group and BCNC with MSCs infected with rAd/hBDNF group. After 4-week, functional assessment was done. PKH26 and BDNF staining of major pelvic ganglion and masson's trichrome staining of corpus cavernosum were performed. Western blot analysis of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) was done in corpus cavernosum. RESULTS: After 4 weeks, BCNC with MSCs and MSCs infected with rAd/hBDNF groups showed significantly well-preserved erectile function compared with BCNC group. Moreover, the erectile function of MSCs infected with rAd/hBDNF group was significantly well-preserved than BCNC with MSCs group. The smooth muscle of corpus cavernosum was significantly preserved in BCNC with MSCs and MSCs infected with rAd/hBDNF groups compared with BCNC group. More preservation of smooth muscle was observed in rats with MSCs infected with rAd/hBDNF than with MSCs alone. Significant increase expression of eNOS and nNOS was noted in rats with MSCs infected with rAd/hBDNF than with MSCs alone. CONCLUSIONS: The erectile function was more preserved after injection with MSCs infected with rAd/hBDNF in rat with ED caused by cavernous nerve injury. Therefore, the use of MSC infected with rAd/hBDNF may have a better treatment effect on ED cause by cavernous nerve injury.

Co-Immunization of Plasmid DNA Encoding IL-12 and IL-18 with Bacillus Calmette-Guerin Vaccine against Progressive Tuberculosis

PURPOSE: Bacillus Calmette-Guerin (BCG) vaccine has widely been used to immunize against tuberculosis, but its protective efficacy is variable in adult pulmonary tuberculosis, while it is not efficiently protective against progressive infection of virulent Mycobacterium tuberculosis strains. In this study, the protective effects of plasmid DNA vaccine constructs encoding IL-12 or IL-18 with the BCG vaccine were evaluated against progressive infection of M. tuberculosis, using mouse aerosol challenge model. MATERIALS AND METHODS: Plasmid DNA vaccine constructs encoding IL-12 or IL-18 were constructed and mice were immunized with the BCG vaccine or with IL-12 DNA or IL-18 DNA vaccine constructs together with the BCG vaccine. RESULTS: The BCG vaccine induced high level of interferon gamma (IFN-gamma) but co-immunization of IL-12 or IL-18 DNA vaccine constructs with the BCG vaccine induced significantly higher level of IFN-gamma than a single BCG vaccine. The BCG vaccine was highly protective at early stage of M. tuberculosis infection, but its protective efficacy was reduced at later stage of infection. The co-immunization of IL-12 DNA vaccine constructs with the BCG vaccine was slightly more protective at early stage of infection and was significantly more protective at later stage infection than a single BCG vaccine. CONCLUSION: Co-immunization of IL-12 DNA vaccine with the BCG vaccine induced more protective immunity and was more effective for protection against progressive infection of M. tuberculosis.

Transplantation of Muscle-Derived Stem Cells into the Corpus Cavernosum Restores Erectile Function in a Rat Model of Cavernous Nerve Injury

PURPOSE: Muscle-derived stem cells (MDSCs) harvested from skeletal muscles have the advantage of providing easier access and do not pose the immunogenic risks of embryonic stem cells. We investigated the effect of intracavernosal transplantation of MDSCs on erectile function in rats with bilateral cavernous nerve injury. MATERIALS AND METHODS: Adult male white rats underwent experimentation in 3 groups: group I, sham operation; group II, bilateral cavernous nerve injury; group III, bilateral cavernous nerve injury with MDSC injection. MDSCs were harvested from the femoral muscle of rats and were then injected into the cavernosum. Survival of MDSCs and measurement of erectile function was studied after 4 weeks. We checked the intracavernosal pressure (ICP) and obtained penile tissue. The expression of cyclic guanosine monophosphate (cGMP) was analyzed. RESULTS: Four weeks after transplantation, PKH-26-labeled MDSCs were identified in the cavernosal tissues of group III. Peak ICP and the drop rate of group II were 52+/-8.7 mmHg and 34+/-6.5 mmHg/min, respectively, whereas peak ICP and the drop rate of group III were 97+/-15.6 mmHg and 17+/-4.9 mmHg/min, respectively, showing that erectile function improved after MDSC transplantation (p<0.05). The expression of cGMP was significantly lower in group II (21.9+/-5.8 fmol/well) than in group I and group III (70.2+/-10.3 and 58.9+/-10.5 fmol/well, respectively). CONCLUSIONS: In a cavernous nerve injury rat model, intracavernosal transplantation of MDSCs showed acceptable survival of MDSCs as well as improvement of erectile function.

Serum IP-10 Levels Correlate with the Severity of Liver Histopathology in Patients Infected with Genotype-1 HCV

BACKGROUND/AIMS: Interferon-gamma-inducible protein 10 (IP-10) plays important roles in the pathogenesis of hepatitis C virus (HCV) infection. We investigated the association between serum IP-10 levels and liver pathology in patients with chronic HCV infection. METHODS: The serum IP-10 concentration was assessed in 85 patients with chronic HCV infection using a solid phase sandwich enzyme-linked immunosorbent assay, and a liver biopsy specimen was obtained. The pathology was scored using the Knodell histologic activity index (HAI). RESULTS: Of the 85 patients, 58 had genotype 1 HCV infection, 21 had genotype non-1, and 6 were undetermined. The serum IP-10 levels did not differ between patients infected with genotype 1 and genotype non-1 (p=0.472). In patients with genotype 1 infection, the total HAI score and the stage of fibrosis were highly correlated with the serum IP-10 level (r=0.555, r=0.578, p<0.001). Furthermore, the serum IP-10 concentrations of patients with severe fibrosis (stages 3, 4) were higher than those of patients with mild fibrosis (stages 0 to 2; 214.4 vs. 72.3 pg/mL, p=0.002) among patients with genotype 1 infection. However, in patients without genotype 1 infection, the histopathology was not associated with the serum IP-10 level. A multivariate analysis showed that serum IP-10 was an independent predictor of fibrosis (stages 3, 4) in patients with genotype 1 infection (odds ratio, 1.034; 95% confidence interval, 1.006 to 1.064; p=0.018). CONCLUSIONS: Serum IP-10 concentration was significantly correlated with the severity of liver histology in genotype 1 HCV infection.

Codelivery of IL-7 Augments Multigenic HCV DNA Vaccine-induced Antibody as well as Broad T Cell Responses in Cynomolgus Monkeys

BACKGROUND: A crucial limitation of DNA vaccines is its weak immunogenicity, especially in terms of eliciting antibody responses in non-human primates or humans; therefore, it is essential to enhance immune responses to vaccination for the development of successful DNA vaccines for humans. METHODS: Here, we approached this issue by evaluating interleukin-7 (IL-7) as a genetic adjuvant in cynomolgus monkeys immunized with multigenic HCV DNA vaccine. RESULTS: Codelivery of human IL-7 (hIL-7)-encoding DNA appeared to increase DNA vaccine-induced antibody responses specific for HCV E2 protein, which plays a critical role in protecting from HCV infection. HCV-specific T cell responses were also significantly enhanced by codelivery of hIL-7 DNA. Interestingly, the augmentation of T cell responses by codelivery of hIL-7 DNA was shown to be due to the enhancement of both the breadth and magnitude of immune responses against dominant and subdominant epitopes. CONCLUSION: Taken together, these findings suggest that the hIL-7-expressing plasmid serves as a promising vaccine adjuvant capable of eliciting enhanced vaccine-induced antibody and broad T cell responses.

Increase of Plasma IL-12/p40 Ratio Induced by the Combined Therapy of DNA Vaccine and Lamivudine Correlates with Sustained Viremia Control in CHB Carriers

BACKGROUND: We previously reported that IFN-gamma producing T cell responses induced by the combined therapy of DNA vaccine and lamivudine for one year are important for the induction of sustained virological response (SVR). However, IFN-gamma production is not sufficient to predict sustained viremia control in chronic hepatitis B (CHB) carriers treated. METHODS: Twelve CHB carriers were intramuscularly immunized 12 times at a 4-week interval with 8 mg of HBV DNA vaccine during the standard lamivudine treatment (100 mg/daily/1 year). The level of cytokines during and after the combined therapy in plasma of all 12 CHB carriers treated was determined by each ELISA kit. Six out of 12 CHB carriers revisited the clinic, and their HBV DNA levels were examined. RESULTS: The combined therapy increased plasma IL-12 and IL-12/p40 ratio during the treatment (baseline vs. peak level: 41.8+/-8.3 vs. 163.1+/-29.2 pg/ml; p<0.01 and 0.96+/-0.25 vs. 3.58+/-0.86; p<0.01, espectively), and the peak level of plasma IL-12 and IL-12/p40 ratio was evoked at 6 to 10 months during the combined therapy. In particular, CHB carriers with SVR had two and three-fold higher level of the peak plasma IL-12 and plasma IL-12/p40 ratio than non-virological responders (NVRs), respectively (218.0+/-41.4 vs. 108.1+/-28.6 pg/ml; p=0.09 and 5.35+/-1.38 vs. 1.80+/-0.29; p<0.05, respectively), while p40 level was consistent during the combined therapy. In addition, there was no significant temporal correlation between the peak IL-12/p40 ratio and the elevation of serum alanine aminotransferase (ALT) in this study, contrast to IFN-alpha therapy which induced peak IL-12 level following ALT flares. CONCLUSION: Our results indicate that the combined therapy induces the increase of plasma IL-12 and IL-12/p40 ratio, which are associated with long-term SVR in CHB carriers.

Increase of Plasma IL-12/p40 Ratio Induced by the Combined Therapy of DNA Vaccine and Lamivudine Correlates with Sustained Viremia Control in CHB Carriers

BACKGROUND: We previously reported that IFN-gamma producing T cell responses induced by the combined therapy of DNA vaccine and lamivudine for one year are important for the induction of sustained virological response (SVR). However, IFN-gamma production is not sufficient to predict sustained viremia control in chronic hepatitis B (CHB) carriers treated. METHODS: Twelve CHB carriers were intramuscularly immunized 12 times at a 4-week interval with 8 mg of HBV DNA vaccine during the standard lamivudine treatment (100 mg/daily/1 year). The level of cytokines during and after the combined therapy in plasma of all 12 CHB carriers treated was determined by each ELISA kit. Six out of 12 CHB carriers revisited the clinic, and their HBV DNA levels were examined. RESULTS: The combined therapy increased plasma IL-12 and IL-12/p40 ratio during the treatment (baseline vs. peak level: 41.8+/-8.3 vs. 163.1+/-29.2 pg/ml; p<0.01 and 0.96+/-0.25 vs. 3.58+/-0.86; p<0.01, espectively), and the peak level of plasma IL-12 and IL-12/p40 ratio was evoked at 6 to 10 months during the combined therapy. In particular, CHB carriers with SVR had two and three-fold higher level of the peak plasma IL-12 and plasma IL-12/p40 ratio than non-virological responders (NVRs), respectively (218.0+/-41.4 vs. 108.1+/-28.6 pg/ml; p=0.09 and 5.35+/-1.38 vs. 1.80+/-0.29; p<0.05, respectively), while p40 level was consistent during the combined therapy. In addition, there was no significant temporal correlation between the peak IL-12/p40 ratio and the elevation of serum alanine aminotransferase (ALT) in this study, contrast to IFN-alpha therapy which induced peak IL-12 level following ALT flares. CONCLUSION: Our results indicate that the combined therapy induces the increase of plasma IL-12 and IL-12/p40 ratio, which are associated with long-term SVR in CHB carriers.

Enhancement of DNA Vaccine-induced Immune Responses by Influenza Virus NP Gene

DNA immunization induces B and T cell responses to various pathogens and tumors. However, these responses are known to be relatively weak and often transient. Thus, novel strategies are necessary for enhancing immune responses induced by DNA immunization. Here, we demonstrated that co-immunization of influenza virus nucleoprotein (NP) gene significantly enhances humoral and cell-mediated responses to codelivered antigens in mice. We also found that NP DNA coimmunization augments in vivo proliferation of adoptively transferred antigen-specific CD4 and CD8 T cells, which enhanced protective immunity against tumor challenge. Our results suggest that NP DNA can serve as a novel genetic adjuvant in cocktail DNA vaccination.

Increased in vivo immunological potency of HB-110, a novel therapeutic HBV DNA vaccine, by electroporation

Pulse-induced permeabilization of cellular membranes, generally referred to as electroporation (EP), has been used for years as a tool to increase macromolecule uptake in tissues, including nucleic acids, for gene therapeutic applications, and this technique has been shown to result in improved immunogenicity. In this study, we assessed the utility of EP as a tool to improve the efficacy of HB-110, a novel therapeutic DNA vaccine against chronic hepatitis B, now in phase 1 of clinical study in South Korea. The potency of HB-110 in mice was shown to be improved by EP. The rapid onset of antigen expression and higher magnitude of humoral and cellular responses in electric pulse-treated mice revealed that EP may enable a substantial reduction in the dosage of DNA vaccine required to elicit a response similar in magnitude to that achievable via conventional administration. This study also showed that EP-based vaccination at 4-week-intervals elicited a cellular immune response which was about two-fold higher than the response elicited by conventional vaccination at 2-week intervals. These results may provide a rationale to reduce the clinical dose and increase the interval between the doses in the multidose vaccination schedule. Electric pulsing also elicited a more balanced immune response against four antigens expressed by HB-110: S, preS, Core, and Pol.

Enhancement of Transduction Efficiency and Antitumor Effects of IL-12N220L-expressing Adenovirus by Co-delivery of DOTAP

BACKGROUND: Adenovirus (Ad) vectors have been widely used for many gene therapy applications because of their high transduction ability and broad tropism. However, their utility for cancer gene therapy is limited by their poor transduction into cancer cells lacking the primary receptor, coxsackievirus and adenovirus receptor (CAR). METHODS: To achieve CAR-independent gene transfer via Ad, we pretreated Ad with 1,2-dioleoyl-3- trimethylammonium propane (DOTAP) and analyzed their transduction efficiency into cancer cells in vitro and in vivo comparing with the virus alone. RESULTS: Treatment of DOTAP significantly increased adenoviral gene transfer in tumor cells in vitro. Moreover, DOTAP at an optimum dose (10 microngram/ml) enhanced IL-12 transgene expression by fivefold in tumor, and twofold in serum after intratumoral injection of adenovirus expressing IL-12N220L (Ad/IL-12N220L). In addition, cotreatment of DOTAP decreased tumor growth rate in the Ad/IL-12N220L-transduced tumor model, finally leading to enhanced survival rate. CONCLUSION: Our results strongly suggest that DOTAP could be of great utility for improving adenovirus-mediated cancer gene therapy.

B Cells Transduced with HPV16 E6/E7-expressing Adenoviral Vector Can Efficiently Induce CTL-dependent Anti-Tumor Immunity

BACKGROUND: Human papillomavirus (HPV) infection is responsible for cervical cancer, a common cancer in women. Since HPV infection and cancer development are controlled by the host immune system, immunotherapy against HPV can be helpful in preventing or treating HPV-associated cervical cancer. Two oncoproteins of HPV16, E6 and E7, are promising targets for immunotherapy against cervical cancer, because they are constitutively expressed in cervical cancer. METHODS: Since cellular vaccines using B cells as well as dendritic cells offer an efficient approach to cancer immunotherapy, we opted to use B cells. We evaluated the immunogenicity and anti-tumor effects of a B cell vaccine transduced with HPV16 E6/E7-expressing adenovirus. RESULTS: Vaccination with HPV16 E6/E7-transduced B cells induced E6/E7-specific CD8+ T cell-dependent immune responses and generated anti-tumor effects against E6/E7-expressing TC-1 tumor. The anti-tumor effect induced by this B cell vaccine was similar to that elicited by DC vaccine, showing that B cells can be used as an alternative to dendritic cells for cellular vaccines. CONCLUSION: Thisstudy has shown the feasibility of using B cells as immunogenic APCs and the potential for developing prophylactic and therapeutic vaccines against HPV-associated cervical cancer using a B cell vaccine transduced with adenovirus expressing HPV16 E6/E7.

The Th17 and Autoimmune Arthritis

Autoimmune arthritis, such as rheumatoid arthritis (RA), is a chronic inflammatory disorder that primarily affects the joints and then results in their progressive destruction. Effector Th cells have been classified as Th1 and Th2 subsets based on their cytokine expression profiles and immune regulatory function. Another subset of T cells termed Th17 was recently discovered and known to selectively produce IL-17. Also, Th17 was shown to be generated by TGFbeta and IL-6 and maintained by IL-23. IL-17 is a proinflammatory cytokine that is considered to involve the development of various inflammatory autoimmune diseases such as RA, asthma, lupus, and allograft rejection. IL-17 is present in the sera, synovial fluids and synovial biopsies of most RA patient. IL-17 activates RA synovial fibroblasts to synthesize IL-6, IL-8 and VEGF via PI3K/Akt and NF-kappaB dependent pathway. IL-17 increases IL-6 production, collagen destruction and collagen synthesis. In addition, it not only causes bone resorption but also increases osteoclastogenesis and fetal cartilage destruction. Inhibition of the IL-17 production may contribute a novel therapeutic approach along with potent anti-inflammatory effect and with less immunosuppressive effect on host defenses.

Measurement of HIV-1-specific T Cell Immunity by Using Recombinant Gag Protein

BACKGROUND: HIV-specific immunity, such as strong CD4+ helper and CD8+ cytotoxic T lymphocytes (CTL) responses, develops soon after HIV infection, but usually it can not control HIV replication which ultimately results in severe immune deficiency. HIV-specific CTLs, which are induced by HIV-specific CD4+ helper responses, are the key to cellular immune control of HIV. Measurement of HIV-1-specific CTLs using recombinant Gag protein may be very useful, because it is not restricted by HLA haplotype of the infected individual. MATERIALS AND METHODS: Enzyme-linked immunospot (ELISPOT) assays by using recombinant Gag protein were performed to evaluate HIV-1-specific gamma-interferon cellular responses of 25 HIV-1 infected Korean patients, who had been treated at least for the prior 12 months with highly active antiretroviral therapy at Catholic University Kangnam St. Mary's Hospital. RESULTS: The study group consisted of 25 chronically HIV-infected individuals with a median age of 51 years. The median CD4 counts were 556/mm3 (range:369-994/mm3) and HIV RNA titers were < 25 copies/mL (range: <25-180copies/mL). HIV-1-specific ELISPOT assay results range from 0 to 49 SFCs/2 x 10(5) PBMCs (median, 23.5 SFCs/2 x 10(5) PBMCs). CMV pp65-specific ELISPOT assay results range from 5 to 591 SFCs/2 x 10(5) PBMCs (median, 34 SFCs/2 x 10(5) PBMCs). There was no correlation between CD4 counts and HIV-1-specific SFCs measured by ELISPOT using recombinant protein. CONCLUSION: ELISPOT assays by using recombinant Gag protein may be considerable value in the assessment of cell-mediated immunity of HIV-1 infected patients.

Measurement of HIV-1-specific T Cell Immunity by Using Recombinant Gag Protein

BACKGROUND: HIV-specific immunity, such as strong CD4+ helper and CD8+ cytotoxic T lymphocytes (CTL) responses, develops soon after HIV infection, but usually it can not control HIV replication which ultimately results in severe immune deficiency. HIV-specific CTLs, which are induced by HIV-specific CD4+ helper responses, are the key to cellular immune control of HIV. Measurement of HIV-1-specific CTLs using recombinant Gag protein may be very useful, because it is not restricted by HLA haplotype of the infected individual. MATERIALS AND METHODS: Enzyme-linked immunospot (ELISPOT) assays by using recombinant Gag protein were performed to evaluate HIV-1-specific gamma-interferon cellular responses of 25 HIV-1 infected Korean patients, who had been treated at least for the prior 12 months with highly active antiretroviral therapy at Catholic University Kangnam St. Mary's Hospital. RESULTS: The study group consisted of 25 chronically HIV-infected individuals with a median age of 51 years. The median CD4 counts were 556/mm3 (range:369-994/mm3) and HIV RNA titers were < 25 copies/mL (range: <25-180copies/mL). HIV-1-specific ELISPOT assay results range from 0 to 49 SFCs/2 x 10(5) PBMCs (median, 23.5 SFCs/2 x 10(5) PBMCs). CMV pp65-specific ELISPOT assay results range from 5 to 591 SFCs/2 x 10(5) PBMCs (median, 34 SFCs/2 x 10(5) PBMCs). There was no correlation between CD4 counts and HIV-1-specific SFCs measured by ELISPOT using recombinant protein. CONCLUSION: ELISPOT assays by using recombinant Gag protein may be considerable value in the assessment of cell-mediated immunity of HIV-1 infected patients.

Action Mechanism in Immunopathogenesis and Clearance of HBV / 대한간학회지

Hepatitis B virus (HBV) currently infects more than 400 million people worldwide and they are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. The immune response to HBV- encoded antigens is responsible both for viral clearance and for disease pathogenesis during HBV infection. While the humoral antibody response to viral envelope antigens contributes to the clearance of circulating virus particles, the cellular immune responses to the envelope, nucleocapsid, and polymerase antigens were known to eliminate virus in infected hepatocytes through cytolytic as well as noncytolytic mechanisms. Liver injury could be initiated by an immune response against HBV, but mainly resulted from HBV non-specific lymphocytes and macrophages. There are growing evidences that T helper 1 memory T cells play a predominant role in suppressing viral replication mainly by IFN-gamma through noncytolytic antiviral mechanism. Elucidation of the immunological and virological basis for HBV infection may yield effective immunotherapeutic and antiviral strategies to terminate chronic HBV infection.