Publications by authors named "Allen K L Cheung"

Epstein-Barr virus is highly associated with nasopharyngeal carcinoma (NPC) with genes expressed for tumor transformation or maintenance of viral latency, but there are certain genes that can modulate immune molecules. Butyrophilin 2A1 (BTN2A1) is an important activating protein for presenting phosphoantigens for recognition by Vγ9Vδ2 T cells to achieve antitumor activities. We have previously shown that Vγ9Vδ2 T cells achieve efficacy against NPC when BTN2A1 and BTN3A1 are upregulated by stimulating EBV gene expression, particularly LMP1.

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The efficacy of dendritic cell (DC)-based cancer vaccines is critically determined by the functionalities of in vitro maturated DCs. The maturation of DCs typically relies on chemicals that are cytotoxic or hinder the ability of DCs to efficiently activate the antigen-specific cytotoxic T-lymphocytes (CTLs) against tumors. Herein, the maturation chemicals are replaced with extracellular silica nanomatrices, fabricated by glancing angle deposition, to promote in vitro maturation of murine bone marrow-derived DCs (mBMDCs).

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Article Synopsis
  • - Mesothelioma is a hard-to-treat cancer that usually gets diagnosed late, leaving patients with limited treatment options; however, new use of γδ T cells in immunotherapy shows promise due to their ability to infiltrate tumors and kill cancer cells.
  • - Researchers expanded human Vδ2 T cells and tested their effectiveness against mesothelioma in lab settings and a mouse model, using a combination treatment of these cells and anti-PD-1 antibodies to enhance the immune response.
  • - Results showed that the combination of Vδ2 T cells and anti-PD-1 treatment led to significant tumor regression in mice, with notable infiltration of the Vδ2 T cells into the tumors, indicating a potential new avenue for effective
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The current COVID-19 vaccination program requires frequent booster vaccination to maintain sufficient neutralization levels against immune evasive SARS-CoV-2 variants. However, prior studies found more potent and durable immune response in convalescing individuals, raising the possibility of less frequent booster vaccination for them. Here, we conducted a longitudinal immunological study based on two prospective cohorts of booster vaccinated convalescing COVID-19 patients or healthcare workers (HCW) without COVID-19 history in Xiangyang, China.

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Nasopharyngeal carcinoma (NPC) is a diverse cancer with no well-defined tumor antigen, associated with oncogenic Epstein-Barr Virus (EBV), and with usually late-stage diagnosis and survival <40%. Current radiotherapy and chemotherapy have low effectiveness and cause adverse effects, which calls for the need of new therapy. In this regard, adoptive immunotherapy using γδ T cells has potential, but needs to be coupled with butyrophilin 2A1 and 3A1 protein expression to achieve tumoricidal effect.

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Background: Human cytomegalovirus (HCMV) is prevalent in human immunodeficiency virus type 1 (HIV-1)-infected individuals but is suppressed by the host immune system bolstered by antiretroviral therapy. During stage 4 of HIV-1 infection, HCMV becomes a major risk factor for end-organ diseases (EODs). However, the implications of detecting HCMV in patients with stage 2/3 HIV-1 infection have not been established.

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The dysfunction of memory CD8 T cell cannot be reverted by successful clearance of hepatitis C virus (HCV) after direct-acting antivirals (DAAs) therapy, increasing the risk of reinfection with HCV. Stem cell-like memory T cells (Tscm) with superior properties of long-lasting, self-renewing, and multipotency contribute to the maintenance of immune function. We investigated the impact of HCV infection on CD8 Tscm, and their possible role in disease progression, by using DAA-naive HCV-infected and human immunodeficiency virus (HIV)/HCV-coinfected cohorts.

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Background: Since the outbreak of COVID-19 has resulted in over 313,000,000 confirmed cases of infection and over 5,500,000 deaths, substantial research work has been conducted to discover agents/ vaccines against COVID-19. Undesired adverse effects were observed in clinical practice and common vaccines do not protect the nasal tissue. An increasing volume of direct evidence based on clinical studies of traditional Chinese medicines (TCM) in the treatment of COVID-19 has been reported.

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Parkinson's Disease (PD) is a neurodegenerative disease that affects the elderly. It is associated with motor dysfunction due to the accumulation of misfolded or aggregated fibrillar alpha-synuclein (α-syn) in the mid-brain. Current treatments are mainly focused on relieving the symptoms but are accompanied by side effects and are limited in halting disease progression.

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Interactions between T follicular helper (Tfh) cells and germinal center B cells are essential for the differentiation of B cells and specific antibody responses against HIV-1 infection. However, the extent to which HIV-1 infection affects the dynamic interplay between these two cell populations in the bloodstream remains unclear. In this study, the dynamics of circulating Tfh (cTfh) and B cells and their relationship in individuals with acute and chronic HIV-1 infection were investigated.

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Cysteine proteases are involved in the digestion of host blood and the degradation of yolk proteins of arthropod ectoparasites. In this study, a cathepsin L-like cysteine proteinase gene (HasCPL) of Hyalomma asiaticum was cloned, and recombinant (r)HasCPL protein was generated for immunization study. Bioinformatic analysis confirmed HasCPL was a member of the papain family (clan CA) and have high sequence identities with CPLs of other Ixodid ticks.

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Article Synopsis
  • The study explores how cytomegalovirus (CMV) latency affects liver graft injury after transplantation, focusing on the role of hepatic stellate cells (HSCs).
  • Findings showed that CMV latency increases cell damage and fibrosis in liver grafts, particularly through a pathway involving CCL19 and CCR7.
  • The research suggests that targeting CMV-associated HSC activation could improve graft protection and patient outcomes in liver transplants.
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This protocol describes how to visualize surface protein-protein co-localization across a cell-cell interface between antigen-presenting γδ-T cells and CD4 T cells. By consolidating immunofluorescence assay, confocal microscopy and 3D imaging analysis, it enables assessment of interaction between cell surface proteins such as Δ42PD1 and TLR4 between co-cultured γδ-T and CD4 T cells. This protocol can be applied to study a surface protein of interest and its potential interaction with a target cell/protein at the cell-cell interface.

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Among bloodsucking arthropods, hard tick is a vector of transmitting the most diverse human and animal pathogens, leading to an increasing number of manifestations worldwide. The development of the anti-tick vaccine has the potential to be an environmentally friendly and cost-effective option for tick management. We have previously demonstrated the induction of both humoral and cellular response against Hyalomma asiaticum (H.

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TIGIT expression on natural killer (NK) cells is associated with dysfunction during chronic HIV infection, but the phenotype and biological functions of these cells in the context of acute HIV-1 infection remain poorly understood. Here, 19 acutely infected HIV-1 patients traced at first, third and twelfth month, and age-matched patients with chronic HIV-1 infection were enrolled to investigate the phenotype and functions of TIGIT expression on NK cells. We found that TIGIT-expressing NK cells did not increase in frequency in the first, third and twelfth month of infection until chronic HIV-1 infection lasted over 2 years.

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TLR ligands can contribute to T cell immune responses by indirectly stimulating antigen presentation and cytokines and directly serving as co-stimulatory signals. We have previously reported that the human endogenous surface protein, Δ42PD1, is expressed primarily on (Vγ9)Vδ2 cells and can interact with TLR4. Since Vδ2 cells possess antigen presentation capacity, we sought to further characterize if the Δ42PD1-TLR4 interaction has a role in stimulating T cell responses.

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Rotaxane dendrimers with hyperbranched macromolecular interlocked structures and size modulation capacity demonstrate drug binding and release ability upon external stimuli. Mass spectrometry imaging (MSI) can offer the high-throughput screening of endogenous/exogenous compounds. Herein, we reported a novel method to display the spatial distribution of label-free monodispersed type III rotaxane dendrimers (RDs) G1 (first generation, size ∼1.

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HIV-1 diversity and latent reservoir are the major challenges for the development of an effective AIDS vaccine. It is well indicated that Gag-specific CD8 T cells serve as the dominant host immune surveillance for HIV-1 control, but it still remains a challenge for vaccine design to induce broader and stronger cytotoxic T cell immunity against the virus. Genetic variation of the HIV-1 gag gene across different clades is one of the reasons for the reduction of antigenic epitope coverage.

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Background: Yunnan has the greatest share of reported human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) cases in China. In recent years, HIV prevalence and incidence remained stubbornly high in men who have sex with men (MSM). To follow the dynamics of the HIV-1 epidemic among MSM, HIV-1 genetic characteristics and genetic transmission networks were investigated.

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Individuals who have been preinfected by human cytomegalovirus (HCMV) are more prone to AIDS disease progression after subsequent HIV-1 infection but the underlying mechanism remains elusive. HCMV is a ubiquitous DNA virus that commonly establishes lifelong latent infection in CD34 progenitor cells, where latency-specific HCMV genes may modulate host restriction to HIV-1 infection. To test this hypothesis, we studied progenitor cells that are known to resist replicative HIV-1 infection because of the intrinsic expression of host restriction factors.

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The innate immune cells underlying mucosal inflammatory responses and damage during acute HIV-1 infection remain incompletely understood. Here, we report a Vδ2 subset of gut-homing γδ T cells with significantly upregulated Δ42PD1 (a PD1 isoform) in acute (~20%) HIV-1 patients compared to chronic HIV-1 patients (~11%) and healthy controls (~2%). The frequency of Δ42PD1Vδ2 cells correlates positively with plasma levels of pro-inflammatory cytokines and fatty-acid-binding protein before detectable lipopolysaccharide in acute patients.

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Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) is one of the common causes of cognitive dysfunction and morbidity among infected patients. However, to date, it remains unknown if a transmitted/founder (T/F) HIV-1 leads to neurological disorders during acute phase of infection. Since it is impossible to answer this question in humans, we studied NOD.

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We recently reported the identification of Δ42PD1, a novel alternatively spliced isoform of human PD1 that induces the production of pro-inflammatory cytokines from human peripheral blood mononuclear cells and enhances HIV-specific CD8(+) T cell immunity in mice when engineered in a fusion DNA vaccine. The detailed functional study of Δ42PD1, however, has been hampered due to the lack of a specific monoclonal antibody (mAb). In this study, we generated 2 high-affinity mAbs, clones CH34 (IgG2b) and CH101 (IgG1), from Δ42PD1-immunized mice.

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Eradicating malignant tumors by vaccine-elicited host immunity remains a major medical challenge. To date, correlates of immune protection remain unknown for malignant mesothelioma. In this study, we demonstrated that antigen-specific CD8(+) T-cell immune response correlates with the elimination of malignant mesothelioma by a model PD-1-based DNA vaccine.

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