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The explicit identification of CD8+ T cell subpopulation is important for deciphering the role of CD8+ T cells for protecting our body against invading pathogens and cancer. Our generated monoclonal antibody (mAb), named FE‐1H10, recognized two novel subpopulations of peripheral blood CD8+ T cells, FE‐1H10+ and FE‐1H10− CD8+ T cells. The molecule recognized by mAb FE‐1H10 (FE‐1H10 molecules) had a higher distribution on effector memory CD8+ T cell subsets. The functions of FE‐1H10− and FE‐1H10+ CD8+ T cells were investigated. T cell proliferation assays revealed that FE‐1H10− CD8+ T cells exhibited a higher proliferation rate than FE‐1H10+ CD8+ T cells, whereas FE‐1H10+ CD8+ T cells produced higher levels of IFN‐γ and TNF‐α than FE‐1H10− CD8+ T cells. In T cell cytotoxicity assays, FE‐1H10+ CD8+ T cells were able to kill target cells better than FE‐1H10− CD8+ T cells. RNA‐sequencing analysis confirmed that these subpopulations were distinct: FE‐1H10+ CD8+ T cells have higher expression of genes involved in effector functions (IFNG, TNF, GZMB, PRF1, GNLY, FASL, CX3CR1) while FE‐1H10− CD8+ T cells have greater expression of genes related to memory CD8+ T cell populations (CCR7, SELL, TCF7, CD40LG). The results suggested that mAb FE‐1H10 identifies two novel distinctive CD8+ T cell subpopulations. The FE‐1H10+ CD8+ T cells carried a superior functionality in response to tumour cells. The uncover of these novel CD8+ T cell subpopulations may be the basis knowledge of an optional immunotherapy for the selection of potential CD8+ T cells in cancer treatment. [ABSTRACT FROM AUTHOR]

CD147 is upregulated in cancers, including aggressive T-ALL. Traditional treatments for T-ALL often entail severe side effects and the risk of relapse, highlighting the need for more efficacious therapies. ADCP contributes to the antitumor response by enhancing the ability of phagocytic cells to engulf cancer cells upon antibody binding. We aimed to engineer CD147KO THP-1 cells and evaluated their differentiation properties compared to the wild type. A humanized anti-CD147 antibody, HuM6-1B9, was also constructed for investing the phagocytic function of CD147KO THP-1 cells mediated by HuM6-1B9 in the phagocytosis of Jurkat T cells. The CD147KO THP-1 was generated by CRISPR/Cas9 and maintained polarization profiles. HuM6-1B9 was produced in CHO-K1 cells and effectively bound to CD147 with high binding affinity (KD: 2.05 ± 0.30 × 10−9 M). Additionally, HuM6-1B9 enhanced the phagocytosis of Jurkat T cells by CD147KO THP-1-derived LPS-activated macrophages (M-LPS), without self-ADCP. The formation of THP-1-derived mMDSC was limited in CD147KO THP-1 cells, highlighting the significant impact of CD147 deletion. Maintaining expression markers and phagocytic function in CD147KO THP-1 macrophages supports future engineering and the application of induced pluripotent stem cell-derived macrophages. The combination of HuM6-1B9 and CD147KO monocyte-derived macrophages holds promise as an alternative strategy for T-ALL. [ABSTRACT FROM AUTHOR]

CD99 was demonstrated to be a potential target for antibody therapy on T-acute lymphoblastic leukemia (T-ALL). The ligation of CD99 by certain monoclonal antibodies (mAbs) induced T-ALL apoptosis. However, the molecular basis contributing to the apoptosis of T-ALL upon anti-CD99 mAb engagement remains elusive. In this study, using our generated anti-CD99 mAb clone MT99/3 (mAb MT99/3), mAb MT99/3 engagement strongly induced apoptosis of T-ALL cell lines, but not in non-malignant peripheral blood cells. By transcriptome analysis, upon mAb MT99/3 ligation, 13 apoptosis-related genes, including FOS, TNF, FASLG, BCL2A1, JUNB, SOCS1, IL27RA, PTPN6, PDGFA, NR4A1, SGK1, LPAR5 and LTB, were significantly upregulated. The epitope of CD99 recognized by mAb MT99/3 was then identified as the VDGENDDPRPP at residues 60–70 of CD99, which has never been reported. To the best of our knowledge, this is the first transcriptome data conducted in T-ALL with anti-CD99 mAb engagement. These findings provide new insights into CD99 implicated in the apoptosis of T-ALL. The identification of a new epitope and apoptosis-related genes that relate to the induction of apoptosis by mAb MT99/3 may serve as a new therapeutic target for T-ALL. The anti-CD99 mAb clone MT99/3 might be a candidate for further development of a therapeutic antibody for T-ALL therapy. [ABSTRACT FROM AUTHOR]

The explicit identification of CD8 + T cell subpopulation is important for deciphering the role of CD8 + T cells for protecting our body against invading pathogens and cancer. Our generated monoclonal antibody (mAb), named FE-1H10, recognized two novel subpopulations of peripheral blood CD8 + T cells, FE-1H10 + and FE-1H10 - CD8 + T cells. The molecule recognized by mAb FE-1H10 (FE-1H10 molecules) had a higher distribution on effector memory CD8 + T cell subsets. The functions of FE-1H10 - and FE-1H10 + CD8 + T cells were investigated. T cell proliferation assays revealed that FE-1H10 - CD8 + T cells exhibited a higher proliferation rate than FE-1H10 + CD8 + T cells, whereas FE-1H10 + CD8 + T cells produced higher levels of IFN-γ and TNF-α than FE-1H10 - CD8 + T cells. In T cell cytotoxicity assays, FE-1H10 + CD8 + T cells were able to kill target cells better than FE-1H10 - CD8 + T cells. RNA-sequencing analysis confirmed that these subpopulations were distinct: FE-1H10 + CD8 + T cells have higher expression of genes involved in effector functions (IFNG, TNF, GZMB, PRF1, GNLY, FASL, CX3CR1) while FE-1H10 - CD8 + T cells have greater expression of genes related to memory CD8 + T cell populations (CCR7, SELL, TCF7, CD40LG). The results suggested that mAb FE-1H10 identifies two novel distinctive CD8 + T cell subpopulations. The FE-1H10 + CD8 + T cells carried a superior functionality in response to tumour cells. The uncover of these novel CD8 + T cell subpopulations may be the basis knowledge of an optional immunotherapy for the selection of potential CD8 + T cells in cancer treatment., (© 2024 John Wiley & Sons Ltd.)

Background: CD4, a leukocyte surface glycoprotein, is mainly expressed on CD4+ T cells, but is also expressed on monocytes. The difference in the expression level and structure of CD4 on T cells and monocytes predicts the different functions of this molecule in both cell types. Although the function of CD4 on T cells is well characterized, little is known about that expressed on primary monocytes., Objective: In this study, we investigated the immunoregulation function of CD4 on peripheral blood monocytes., Methods: Methods: CD4 molecule on monocyte was ligated by anti-CD4 monoclonal antibody (mAb), MT4/3. The effect of mAb MT4/3 on T cell proliferation, cytokine production, the expression of monocyte costimulatory molecules, monocyte migration, and macrophage differentiation were investigated. Moreover, the molecular weight of CD4 on peripheral blood monocyte was carried out by Western immunoblotting., Results: We demonstrated that mAb MT4/3 inhibited anti-CD3 induced T cell proliferation, cytokine production, and the expression of monocyte costimulatory molecules. The ligation of only CD4 on monocytes was sufficient to inhibit T cell activation. Moreover, mAb MT4/3 could inhibit monocyte migration in a transwell migration assay, but not affect the differentiation of monocytes to macrophages. Using purified primary monocytes, the molecular weight of CD4 expressed on monocytes was identified as 55 kDa., Conclusions: The CD4 molecule expressed on monocytes might play an important role in the regulation of immune responses in both innate and adaptive immunity. Understanding the novel role of CD4 on monocytes in immunoregulation is valuable in the development of new therapeutic approaches.

Background: The concept of heterologous vaccination against SARS-CoV-2 infection has been adopted in Thailand with limited data on the induction of humoral and cellular immunity, particularly the CoronaVac/ChAdOx-1 (CoVac/ChAd) regimen in the elderly., Objective: In this study, the immune responses of the elderly induced by heterologous CoVac/ChAd and homologous ChAdOx-1 (ChAd/ChAd) vaccinations were demonstrated., Methods: A prospective observational study involving healthy participants aged ≥ 60 years who received heterologous CoVac/ChAd or homologous ChAd/ChAd vaccination was conducted. Surrogate neutralizing antibody (NAb) and T-cell responses against the SARS-CoV-2 wild type (WT) and variants of concern were determined at pre and post vaccinations., Results: At 4 and 12 weeks after heterologous or homologous vaccination, the NAb levels against WT, Alpha, Beta, and Delta variants between each group were not significantly different, except for significant lower NAb against the Beta variant in heterologous group at 12 weeks after vaccination. The NAb against the Omicron at 4 weeks post-vaccination were below the cutoff level for antibody detection in both groups. However, higher spike-specific CD4 T cell producing IFN-γ and TNF-α in the heterologous than the homologous vaccination were observed. Insignificant difference of cellular immune responses to spike-peptides of Alpha, Beta, and Delta variants and their WT homologues was demonstrated., Conclusions: In the elderly, heterologous CoVac/ChAd vaccination could induce NAb response against the WT and non-Omicron variants not different from the homologous ChAd/ChAd vaccination. Both regimens could not give adequate NAb of the Omicron strain. The heterologous vaccination, however, induced higher spike-specific Th1 cell response.

Background: Soluble CD147 (sCD147) is the shed form of membrane-bound CD147, which is involved in the regulation of cellular functions. The presence of sCD147 in body fluids is associated with several diseases., Objective: In this study, we aimed to establish antibody (Ab) biosensors for the simultaneous differential detection of the general and truncated forms of sCD147., Method: By combining biolayer interferometry technology (BLItz) and different anti-CD147 monoclonal antibodies (mAbs) specific to different extracellular domains of the CD147 molecule, Ab-based biosensors were established to rapidly measure and characterize sCD147 isoforms., Results: Two types of Ab-biosensors, desginated the single Ab-biosensor and double Ab-biosensor, were established for the measurment and characterization of sCD147 isoforms. For the single Ab-biosensor system, monoclonal antibodies specific for CD147 domain 1 (D1) or domain 2 (D2) were immobilized on the sensor tips and used for the quantification of sCD147 using a BLItz optical interferometric biosensor. For the double Ab-biosensor system, following the single Ab-biosensor step, secondary anti-CD147 mAbs specific for each domain of the CD147 molecule were added and monitored by a BLItz biosensor. By combining the results obtained from the single Ab- and double Ab-biosensors, sCD147 isoforms including the general form (D1 linked to D2) and the truncated forms (sCD147 containing D1 or D2) could be determined., Conclusions: This method may be a beneficial tool for the determination of sCD147 isoforms for disease diagnosis and prognosis as well as for the definition of the cellular mechanisms of the immune system.