• IMMUNE NETWORK
• /
• 제10권4호
• /
• pp.126-134
• /
• 2010

Background: $CD8^+$ T cells contribute to the clearance of Hepatitis B virus (HBV) infection and an insufficient $CD8^+$ T cell response may be one of the major factors leading to chronic HBV infection. Since the HBx antigen of HBV can up-regulate cellular expression of several immunomodulatory molecules, we hypothesized that HBx expression in hepatocytes might affect $CD8^+$ T cell activity. Methods: We analyzed the activation and apoptosis of $CD8^+$ T cells co-cultured with primary hepatocytes rendered capable of expressing HBx by recombinant baculovirus infection. Results: Expression of HBx in hepatocytes induced low production of $interferon-{\gamma}$ and apoptosis of CD8+ T cells, with no effect on CD8 T cell proliferation. However, transcriptional levels of H-2K, ICAM-1 and PD-1 ligand did not correlate with HBx expression in hepatocytes. Conclusion: Our results suggest that HBx may inhibit $CD8^+$ T cell response by regulation of $interferon-{\gamma}$ production and apoptosis.

• IMMUNE NETWORK
• /
• 제23권4호
• /
• pp.35.1-35.16
• /
• 2023

Defining the molecular dynamics associated with T cell differentiation enhances our understanding of T cell biology and opens up new possibilities for clinical implications. In this study, we investigated the dynamics of CD5 expression in CD8⁺ T cell differentiation and explored its potential clinical uses. Using PBMCs from 29 healthy donors, we observed a stepwise decrease in CD5 expression as CD8⁺ T cells progressed through the differentiation stages. Interestingly, we found that CD5 expression was initially upregulated in response to T cell receptor stimulation, but diminished as the cells underwent proliferation, potentially explaining the differentiation-associated CD5 downregulation. Based on the proliferation-dependent downregulation of CD5, we hypothesized that relative CD5 expression could serve as a marker to distinguish the heterogeneous CD8⁺ T cell population based on their proliferation history. In support of this, we demonstrated that effector memory CD8⁺ T cells with higher CD5 expression exhibited phenotypic and functional characteristics resembling less differentiated cells compared to those with lower CD5 expression. Furthermore, in the retrospective analysis of PBMCs from 30 non-small cell lung cancer patients, we found that patients with higher CD5 expression in effector memory T cells displayed CD8⁺ T cells with a phenotype closer to the less differentiated cells, leading to favorable clinical outcomes in response to immune checkpoint inhibitor (ICI) therapy. These findings highlight the dynamics of CD5 expression as an indicator of CD8⁺ T cell differentiation status, and have implications for the development of predictive biomarker for ICI therapy.

• 대한바이러스학회지
• /
• 제27권1호
• /
• pp.97-104
• /
• 1997

For 16 years after the finding of HIV as an agent of AIDS in 1981, HIV therapeutic drugs of reverse transcriptase inhibitors (AZT, ddI, ddC, d4T) and protease inhibitors have been developed. Recent studies also were focused on a combination therapy by using HIV therapeutic drugs or natural compounds. Korean red ginseng (KRG) of natural compounds has been well known as a good reinforcement agent in Asia. The percentage of CD3+CD4+ T cell in nine HIV-infected patients without KRG treatment averaged 17.8% on baseline and decreased 15.8% after 6 months, whereas the percentage of the cell in fifteen HIV-infected patients with KRG treatment averaged 15.3% on baseline and increased up to 18.9% after the same period. The average percentage of CD3+CD8+ T cell of KRG-nontreated and KRG-treated HIV patients increased after 6 months 47.8% to 50.7% and 44.7% to 51.4%, respectively; and the average percentage of B and NK cell in the KRG-nontreated and KRG-treated HIV patients decreased 9.4% to 7.9% and 13.0% to 9.7%, 8.9% to 8.5% and 16.2% to 11.6%, respectively. KRG, therefore, didn't have any effects on the CD3+CD8+ T cell, B cell, and NK cell. However, it seems that KRG has a potential activity for stimulatiing the CD3+CD4+ T cell and some inhibition on destroying of this cell with no significance.

• 대한한의학회지
• /
• 제23권1호
• /
• pp.37-49
• /
• 2002

Objectives: Maekmoondong-tang and Jeongcheonhwadamgangki-tang are herbal decoctions which have been used as traditional therapeutic agents for asthma. This study was performed to investigate the effects of Maekmoondong-tang and Jeongcheonhwadamgangki-tang on immune Cell & serum OA-specific 19B in broncho-alveolar lavage fluid (BALF) in rat asthma model. Methods: Rats were sensitized with ovalbumin (OA); at day I the sensitized group and Maekmoondong-tang and Jeongcheonhwadamgangki-tang groups were systemically immunized by subcutaneous injection of 1mg OA and 300mg of $Al(OH)_3$ in a total volume of 2ml. At the same time, 1ml of 0.9% saline containing $6{\times}10^9$ B. pertussis bacilli was injected by i.p. for 14 days. After systemic immunization, the rats received local immunization by inhaling 0.9% saline aerosol containing 2% (wt/vol) OA. A day after local immunization, BAL fluid was collected from the rats. A day after local immunization, rats were orally administered with each of Maekmoondong-tang and Jeongcheonhwadamgangki-tang extract for 14 days. Lymphocyte, CD4+T-cell CD8+ T-cell counts, CD4+/CD8+ ratio in BALF, change of serum OA-specific IgE level, and CD4+T-cell CD8+T-cell percentage in the peripheral blood were measured and evaluated. Results: Maekmoondong-tang and Jeongcheonhwadamgangki-tang showed a suppressive effect on the rat asthma model. Maekmoondong-tang decreased total cell, lymphocyte, CD4+T-cell, CD8+T-cell in BALF, and serum OA specific 19B level as compared with the control group, whereas Maekmoondong-tang decreased CD4+/CD8+ ratio in BALF with statistical nonsignificance as compared with the control group. 1 decreased total cell, CD4+T-cell, CD4+/CD8+ ratio in BALF, and serum OA specific IgE level, whereas Jeongcheonhwadamgangki-tang decreased ymphocyte, and CD8+T-cell in BALF with statistical nonsignificance as compared with the control group. CD4+T-cell and CD8+ T-cell percentage in peripheral blood were not changed significantly in all the experimental groups. Conclusions: This study shows that Maekmoondong-tang and Jeongcheonhwadamgangki-tang have a suppressive effect on asthma. Maekmooruiong-tang and Jeongcheonhwadamgangki-tang would be useful asthma treatment agents.

• Molecules and Cells
• /
• 제39권7호
• /
• pp.515-523
• /
• 2016

Long-term immunity to many viral and bacterial pathogens requires$ CD8^+$ memory T cell development, and the induction of long-lasting$ CD8^+$ memory T cells from a $na{\ddot{i}}ve$, undifferentiated state is a major goal of vaccine design. Formation of the memory$ CD8^+$ T cell compartment is highly dependent on the early activation cues received by $na{\ddot{i}ve}$ $CD8^+$ T cells during primary infection. This review aims to highlight the cellularity of various niches within the lymph node and emphasize recent evidence suggesting that distinct types of T cell activation and differentiation occur within different immune contexts in lymphoid organs.

• Journal of Ginseng Research
• /
• 제47권1호
• /
• pp.155-158
• /
• 2023

In the present study, we investigated whether treatment with KRG improve the parameters of immune activity such as the cytotoxicity, populations of CD4⁺ CD8⁺T cell, CD3^-CD172^-CD8⁺ NK cell and CD172⁺ monocyte as well as natural cytotoxicity receptors such as Nkp46, Nkp44, Nkp30. In results, KRG significantly increased these immune activities. These results indicate that KRG has distinct immuneenhancing effects by increasing the roles of T cells and NK cell in porcine.

• IMMUNE NETWORK
• /
• 제11권5호
• /
• pp.268-280
• /
• 2011

Background: Dengue virus, which belongs to the Flavivirus genus of the Flaviviridae family, causes fatal dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) with infection risk of 2.5 billion people worldwide. However, approved vaccines are still not available. Here, we explored the immune responses induced by alternating prime-boost vaccination using DNA vaccine, adenovirus, and vaccinia virus expressing E protein of dengue virus type 2 (DenV2). Methods: Following immunization with DNA vaccine (pDE), adenovirus (rAd-E), and/or vaccinia virus (VV-E) expressing E protein, E protein-specific IgG and its isotypes were determined by conventional ELISA. Intracellular CD154 and cytokine staining was used for enumerating CD4+ T cells specific for E protein. E protein-specific CD8+ T cell responses were evaluated by in vivo CTL killing activity and intracellular IFN-${\gamma}$ staining. Results: Among three constructs, VV-E induced the most potent IgG responses, Th1-type cytokine production by stimulated CD4+ T cells, and the CD8+ T cell response. Furthermore, when the three constructs were used for alternating prime-boost vaccination, the results revealed a different pattern of CD4+ and CD8+ T cell responses. i) Priming with VV-E induced higher E-specific IgG level but it was decreased rapidly. ii) Strong CD8+ T cell responses specific for E protein were induced when VV-E was used for the priming step, and such CD8+ T cell responses were significantly boosted with pDE. iii) Priming with rAd-E induced stronger CD4+ T cell responses which subsequently boosted with pDE to a greater extent than VV-E and rAd-E. Conclusion: These results indicate that priming with live viral vector vaccines could induce different patterns of E protein-specific CD4+ and CD8+ T cell responses which were significantly enhanced by booster vaccination with the DNA vaccine. Therefore, our observation will provide valuable information for the establishment of optimal prime-boost vaccination against DenV.

• IMMUNE NETWORK
• /
• 제23권2호
• /
• pp.17.1-17.16
• /
• 2023

Latent membrane protein 2A (LMP2A), a latent Ag commonly expressed in Epstein-Barr virus (EBV)-infected host cells, is a target for adoptive T cell therapy in EBV-associated malignancies. To define whether individual human leukocyte antigen (HLA) allotypes are used preferentially in EBV-specific T lymphocyte responses, LMP2A-specific CD8⁺ and CD4⁺ T cell responses in 50 healthy donors were analyzed by ELISPOT assay using artificial Ag-presenting cells expressing a single allotype. CD8⁺ T cell responses were significantly higher than CD4⁺ T cell responses. CD8⁺ T cell responses were ranked from highest to lowest in the order HLA-A, HLA-B, and HLA-C loci, and CD4⁺ T cell responses were ranked in the order HLA-DR, HLA-DP, and HLA-DQ loci. Among the 32 HLA class I and 56 HLA class II allotypes, 6 HLA-A, 7 HLA-B, 5 HLA-C, 10 HLA-DR, 2 HLA-DQ, and 2 HLA-DP allotypes showed T cell responses higher than 50 spot-forming cells (SFCs)/5×105 CD8⁺ or CD4⁺ T cells. Twenty-nine donors (58%) showed a high T cell response to at least one allotype of HLA class I or class II, and 4 donors (8%) had a high response to both HLA class I and class II allotypes. Interestingly, we observed an inverse correlation between the proportion of LMP2A-specific T cell responses and the frequency of HLA class I and II allotypes. These data demonstrate the allele dominance of LMP2A-specific T cell responses among HLA allotypes and their intra-individual dominance in response to only a few allotypes in an individual, which may provide useful information for genetic, pathogenic, and immunotherapeutic approaches to EBV-associated diseases.

• 대한의생명과학회지
• /
• 제13권4호
• /
• pp.325-332
• /
• 2007

Cell-mediated immune response (CMI) is a major immune protective mechanism against tuberculosis (TB) infection. Among several components involved in CMI, recent studies suggest that CD8+ T cells are important in controlling TB infection. In our previous report, we defined four Mycobacterium tuberculosis (MTB) derived epiotpe peptides specific for HLA-A*0201-restricted CD8+ T cells. These four peptides are $PstAl_{75-83}$, $ThyA_{30-38}$, $RpoB_{127-135}$ and $85B_{15-23}$. In this study, these epitope peptides specific CD8+ T cell responses in tuberculous pleurisy were investigated using ex vivo $IFN-\gamma$ elispot assay and intracellular $IFN-\gamma$ staining method. As a result, we observed these epitope peptide specific CD8+ T cell responses are induced in all three patients with tuberculous pleurisy suggesting that CD8+ T cells are involved in protective immune mechanism against MTB infection in tuberculous pleurisy. However, the CMI to mitogens and MTB antigens from pleural fluids of patients with tuberculous pleurisy does not seem to correlate with that from peripheral blood, although the sample size is too small to make any conclusion. In sum, the MHC I restricted CD8+ T cell responses seem to be induced efficiently in the pleural fluids, at the site of TB infection, in which the CMI is actively induced. In addition, these experiments suggest that MHC I restricted CD8+ T cell mediated immune responses are also involved in protective mechanism against MTB infection in extra-pulmonary TB.

• IMMUNE NETWORK
• /
• 제23권1호
• /
• pp.2.1-2.19
• /
• 2023

Immune diversification helps protect the host against a myriad of pathogens. CD8⁺ T cells are essential adaptive immune cells that inhibit the spread of pathogens by inducing apoptosis in infected host cells, ultimately ensuring complete elimination of infectious pathogens and suppressing disease development. Accordingly, numerous studies have been conducted to elucidate the mechanisms underlying CD8⁺ T cell activation, proliferation, and differentiation into effector and memory cells, and to identify various intrinsic and extrinsic factors regulating these processes. The current knowledge accumulated through these studies has led to a huge breakthrough in understanding the existence of heterogeneity in CD8⁺ T cell populations during immune response and the principles underlying this heterogeneity. As the heterogeneity in effector/memory phases has been extensively reviewed elsewhere, in the current review, we focus on CD8⁺ T cells in a "naive" state, introducing recent studies dealing with the heterogeneity of naive CD8⁺ T cells and discussing the factors that contribute to such heterogeneity. We also discuss how this heterogeneity contributes to establishing the immense complexity of antigen-specific CD8⁺ T cell response.