Early signal protein expression profiles in basophils: a population study

Abstract

IgE-mediated histamine release from peripheral blood basophils is highly variable within the general population. Recent studies have shown that the ability of antiIgE antibody to induce release can be predicted reasonably well by knowing the level of syk expression in the cells. The current study expands a previous survey to include 14 additional early elements known to be involved in activation and deactivation of basophils and showed that with the exception of syk, the variance of expression of 19 other elements (lyn, fyn, csk, cbp/PAG, CIN85, Bob1, c-cbl, SHIP1, SHIP2, p85␣, p110␦, btk, PLC␥1, PLC␥2, SHP-1, PTEN, SOS2, CRACM1, and IL-3R␣) was narrow despite a broad range of functional capability in the basophils under study. With syk as the only element with high variance and well-correlated to maximum histamine release and cellular sensitivity, this survey examined the expression levels of two proteins thought to regulate syk expression: Bob1/OCA-B and CIN85. Expression of CIN85 was not correlated to syk expression, but Bob1 expression was negatively correlated to expression of syk and maximum histamine release. However, the expected behavior for this protein should have been as a protector of post-translational syk loss and therefore, positively correlated. Previous studies suggested that post-translational control mechanisms regulated syk expression. However, in this study, steady-state mRNA levels for syk in resting basophils showed a correlation with syk protein expression levels (rϭ0.593). It is concluded that with the exception of syk expression, the expression of 19 early signaling elements is tightly regulated and that a component of the regulation of syk may be related to control of transcription or processing of syk mRNA. J. Leukoc. Biol. 86: 313-325; 2009.

Individual IL-3 priming is crucial for consistent in vitro activation of donor basophils in patients with chronic urticaria

“…There are several other, mainly intracellular factors playing a role in the basophil activation process. 31 Therefore we investigated the role of IL-3, which activates the Ras pathway through Janus kinase 2/signal transducer and activator of transcription 5 32 and leads to an enhanced basophil degranulation. 28,33 Some authors claim that IL-3 has to be avoided to improve test specificity.…”

Syk expression in peripheral blood leukocytes, CD34+ progenitors, and CD34-derived basophils

“…The measurement of syk protein expression by flow cytometry using the anti-syk antibody 4D10 has been described previously and validated with respect to standard Western blotting [9,18]. This method has been used on impure as well as purified cell fractions with equivalent results.…”

“…Syk protein was measured simultaneously in the peripheral blood leukocytes of 16 donors using a flow cytometric method. Although we have extensively validated the flow cytometric method of measuring syk in basophils [9,18], the method was validated further for other types of leukocytes. In pilot studies, the relative levels of syk measured by flow cytometry were compared with those measured by Western blotting of purified pDCs, basophils, and neutrophils and were found to be the same as those assessed by flow cytometry (Fig.…”

Dependence of Optimal Histamine Release on Cell Surface IgE Density on Human Basophils: Nature of the Stimulus

“…The measurement of SYK protein expression by flow cytometry using the anti-SYK Ab 4D10 has been previously described and validated with respect to standard Western blotting [19, 20]. This method has been used on both impure as well as purified cell fractions with equivalent results.…”