ABSTRACT
Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.
Subject(s)
Humans , Antibodies, Bacterial/immunology , CD11c Antigen/metabolism , Lipopolysaccharide Receptors/metabolism , CD18 Antigens/metabolism , Apoptosis/immunology , Biological Assay , Cell Differentiation , Cell Line, Tumor , Cholecalciferol/pharmacology , Dimethylformamide/pharmacology , Flow Cytometry , HL-60 Cells , Phagocytosis/immunology , Pneumococcal Vaccines/immunology , Receptors, IgG/metabolism , Receptors, Immunologic/biosynthesis , Respiratory Burst/immunology , Streptococcus pneumoniae/immunology , Tretinoin/pharmacologyABSTRACT
Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.
Subject(s)
Humans , Antibodies, Bacterial/immunology , CD11c Antigen/metabolism , Lipopolysaccharide Receptors/metabolism , CD18 Antigens/metabolism , Apoptosis/immunology , Biological Assay , Cell Differentiation , Cell Line, Tumor , Cholecalciferol/pharmacology , Dimethylformamide/pharmacology , Flow Cytometry , HL-60 Cells , Phagocytosis/immunology , Pneumococcal Vaccines/immunology , Receptors, IgG/metabolism , Receptors, Immunologic/biosynthesis , Respiratory Burst/immunology , Streptococcus pneumoniae/immunology , Tretinoin/pharmacologyABSTRACT
Hairy-cell leukemia-variant (HCL-V) is a rare B-cell disorder which accountsfor 10% of HCL cases. The main features are splenomegaly, lymphocytosis and cytopenias without monocytopenia. The circulating cells have a morphology intermediate between prolymphocytes and hairy cells. The immunophenotype shows a mature B-cell phenotype with expression of B-cell antigens CD11c and CD103 but unlike typical hairy cell the cells are negative for CD25. The histology of bone marrow and spleen shows a pattern of infiltration similar to that in HCL. We present a case of HCL-V in a 66-year-old male. The bone marrow findings, immunophenotypic profile and electron microscopic features are described. The patient underwent splenectomy which also revealed infiltration by leukemia. Patients are resistant to alkylating agents and alpha-interferon (á-IFN). Splenectomy may be beneficial for long-lasting partial responses in some of the patients and is a good palliative treatment.