Lewis SL, Van Epps DE. Demonstration of specific receptors for fluoresceinated casein on human neutrophils and monocytes using flow cytometry.
Inflammation 1983;
7:363-75. [PMID:
6317559 DOI:
10.1007/bf00916301]
[Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Casein is chemotactic for human neutrophils (PMNs) and monocytes. The binding of fluorescein (FITC)-conjugated casein (mixture of alpha, beta, and kappa-casein) and purified alpha-casein to PMNs, monocytes, and lymphocytes was analyzed using flow cytometry. These studies demonstrate that 75-95% of PMNs and 46-85% of monocytes have membrane receptors for casein while lymphocytes lack these receptors. The binding of FITC-casein and FITC-alpha-casein was specific and was blocked only by unlabeled casein and alpha-casein, but not by ovalbumin, bovine or human serum albumin, beta-casomorphin, C5a, or formyl-methionyl-leucylphenylalanine (fMLP). The binding of FITC-casein was reversible when PMNs were stained with this fluorescent agent and subsequently incubated with unlabeled casein. Double-labeling studies of mononuclear cells using FITC-casein and the OKM1 monoclonal antibody in conjunction with a rhodamine conjugated anti-Ig second antibody demonstrate that mononuclear cells binding FITC-casein also stain with the OKM1 monoclonal antibody, indicating a specificity for monocytes.
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