Expression of CD4 on Epstein-Barr virus-immortalized B cells.
Human antigen presenting cells commonly express CD4 but the significance of this phenomenon has not been clarified. We analyzed a panel of Epstein-Barr virus-immortalized B cells (so called lymphoblastoid cell lines, LCL) by using flow cytometry, DNA-microarray analysis, and reverse transcriptase-polymerase chain reaction (RT-PCR). The number of CD4(+) cells varied from cell line to cell line but expression of CD4 was detected by flow cytometry and RT-PCR in all investigated cell lines. To characterize CD4 expressing LCL in more detail, we separated CD4(+) and CD4(-) cells from single cell lines by using immunomagnetic beads. When we cultured sorted CD4(+) and CD4(-) cells, we observed that CD4 expression was stable for several passages. However, the number of CD4(+) cells decreased with time in culture. We never observed that CD4(-) cell lines returned back to a CD4(+) phenotype. DNA-microarray analysis of isolated CD4(+) and CD4(-) cells indicated that the overall gene expression profile of both cell populations was highly similar. In addition, CD4(+) and CD4(-) cells showed the same allostimulatory capacity. CD4(+) LCL showed a slightly increased interleukin-16 induced chemotaxis. Differences in the gene expression profile of CD4(+) and CD4(-) cell lines suggested that loss of CD4 expression occurred during a differentiation step involving achaete-scute complex homolog-like 1.
Hoennscheidt
C
C
University Clinic and Polyclinic for Child and Adolescent Medicine, Martin-Luther-University Halle-Wittenberg, D-06097 Halle, Germany.
Max
D
D
Richter
N
N
Staege
M S
MS
D015703:Antigens, CD / Q000378:metabolism; D001402:B-Lymphocytes / Q000378:metabolism* / Q000821:virology; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D015704:CD4 Antigens / Q000378:metabolism*; D045744:Cell Line, Tumor; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology; D020869:Gene Expression Profiling; D004854:Herpesvirus 4, Human; D006801:Humans; D019410:Interleukin-16 / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis
D015703:Antigens, CD; D051792:Basic Helix-Loop-Helix Proteins; D015704:CD4 Antigens; D019410:Interleukin-16; C065500:ASCL1 protein, human