Monoclonal antibodies that recognize a broad range of mammalian terminal deoxynucleotidyl transferases

Commercially available rabbit anti-human polyclonal antisera as a useful tool for immune system studies in veterinary species

We have used selected rabbit anti-human polyclonal antibodies as an example of useful and easily available tools for studies on immune system structure and development in important veterinary species, many of which also represent animal models in biomedicine. The cocktail of anti-human Igkappa-FITC/anti-Iglambda-RPE F(ab')(2) fragments was used for two-colour and, in combination with the cross-reactive anti-CD79alpha monoclonal antibody HM-57, for three-colour flow cytometry of canine, feline, bovine and porcine peripheral B-cells. A possible application of such immunoreagents in studies on primary B-cell differentiation has been suggested in pigs; the same approach can be used in other species of interest. Rabbit anti-human lactoferrin-FITC F(ab')(2) fragment was used for visualizing neutrophils in dogs, pigs and cattle and an application for two-colour immunophenotyping of canine granulocyte subsets has been designed. Affinity isolated rabbit anti-human CD3 and anti-human TdT have been shown to represent a ready-to-use tool for in situ studies on primary T-lymphopoiesis in pigs with possible extensions both to the B-lineage development in pigs and other animal models. Altogether, our study show that carefully selected polyclonal antibodies available on the market may possess broad cross-reactivity with important applications in veterinary research.

Terminal deoxynucleotidyl transferase (TdT)-containing peripheral blood mononuclear cells during remission of acute lymphoblastic leukemia: low sensitivity and specificity prevent accurate prediction of relapse

Serial samples of peripheral blood were obtained from 75 children with acute lymphoblastic leukemia in remission. An immunofluorescence assay was used to quantitate TdT-containing (terminal deoxynucleotidyl transferase-containing) cells in the mononuclear leukocyte fraction of these specimens. Nine relapses in 8 patients were preceded by elevations (0.12-0.70%) in peripheral blood terminal deoxynucleotidyl transferase-containing cells noted 1-33 weeks prior to relapse. No such elevations were observed prior to 6 relapses in 4 patients. Peripheral blood terminal transferase deoxynucleotidyl-containing cells were elevated (0.12-0.61%) in 22 children who did not relapse over a 5-82 week period of observation. The sensitivity (67%) and specificity (68%) of this assay are inadequate to establish which patients have minimal residual leukemia.