Dear Tessa, I'm not able to answer to the first part of Your question, but it seems to me usefull to mention and think about following: normaly two distinct population of NK cells are found in peripheral blood, primarily discovered by their differential ability to adhere on solid surfaces when stimulated with low doses of IL-2 (2-22 nm rIL-2): so called A-NK cells (activated, adherent who are CD56 very dim, CD16 -/dim, CAM bright, CD69 bright, CD57 dim/-) and NA-NK cells (activated, non-adherent showing CD56 bright, CD16+, CAM dim, CD69 non or dim CD57 often positive expression). Normally just a small proportion of adult PB NK cells are CD56 bright. A-Nk cells are promptly adherable and adhesive to solid plates when stimulated, proliferatively active, Good K562 killers, while NA-NK cells are less adherent, low proliferative and good ADCC killers. A-NK cells are derived from their precursors (<26%) in peripheral blood that are characteristically stained positively with mAb against ANK1 epitope of NCAM that are independent of CD56. All those analyses were done after B-cell and T-cell MACS-negative depletion, and are reproducible. CD8 dim/CD3- expression accounts mainly on NK cells, althought this phenomenon is not functionally familiar to me, at least regarding the functionality of NK cells. So, dim CD8 expression that You registered are only (part of) NK cell population. Good explanatory article about that could be found in Current Opinion in Immunology, 1995;7:704-710 byTL Whiteside and M Herbermann or in Methods:A comparison to methods in Enzimology,1996;9:394-408 by our associate Nikola Vujanovic et al. Perhaps, CB derived NK cells are different from adult ones, regarding this things. Also, If CD3 specific staining was below 2% after MACS T cell depletion (check this) it is obscurely possible for that cells to be gamma-delta, because those cells are CD3 positive. What about CB lymphs and so called NT cells that express cd56, Cd16 and alpha-beta TCR? Is there something specific for CB regarding NT cells? Hope this one could help Best regards Viktor •••••••••••• Jovic Viktor MD Institute of oncology and radiology of Serbia Pasterova 14, 11000 Belgrade, Yugoslavia Phone:+381 11 685755 ext. 423 or 426 Fax: +381 11 685300 E-mail: zvecko@drenik.net E-mail 2: vjovic@beotel.yu If not replying send to: vicca@mailcity.com If everything seems to be going so well, you have obviously overlooked something. -----Original Message----- From: tessa kerre [mailto:tessa.kerre@rug.ac.be] Sent: Thursday, March 02, 2000 4:45 PM To: cyto-inbox Subject: CB phenotying Dear flowers, I posted this message some time ago, together with the proposal to send anyone interested a CFSE summary. I got a huge amount of people wanting the summary, but nobody answered my question in the second part. My theory is that people got so enthusiastic about my proposal they didn't look further in the e-mail. So I am sending my questions again, hopin someone would be able to anwser them... I have some questions regarding the phenotype of CB cells. I deplete the fresh or thawed frozen mononuclear cell fraction of human cord blood , and deplete (with magnetic beads) for CD3. I have done some flowcytometrical analysis on these cells, and I have some questions: - I see a CD4low population (monocytes) and a reminescent CD4high, but I see the same phenomenon with CD8 (sometimes there's a nice segregation between the two, but in most cases there isn't): are the CD8low cells NK cells? - In the CD56+ population I also observe 2 intensities: does anyone know what these two populations represent? Is it possible that the CD56high cells are gamma-delta cells? Kind regards, Tessa Tessa Kerre, MD Gent University Hospital Belgium
This archive was generated by hypermail 2b29 : Wed Apr 03 2002 - 11:55:36 EST