Neutrophils receptor states

Relationship of receptor states in intact neutrophils and reconstituted systems... 

Hoffman, J.F., Linderman, J.J., Omann, G.M. (1996). Receptor upregulation, internalization, and interconverting receptor states critical components of a quantitative description of N-formyl peptide-receptor dynamics in the neutrophil. /. Biol. Chem. 271, 18394-18404. 

Sato N, Ahuja SK, Quinones M, et al. CC chemokine receptor (CCR)2 is required for langerhans cell migration and localization of T helper cell type 1 (Thl)-inducing dendritic cells. Absence of CCR2 shifts the Leishmania major-resistant phenotype to a susceptible state dominated by Th2 cytokines, b cell outgrowth, and sustained neutrophilic inflammation. J Exp Med 2000 192(2) 205-218. 

The lateral segregation mechanism of FPR desensitization in neutrophils (Figure 2) may be an attractive model that integrates the receptor-mediated actin polymerization/depolymerization and feed-back regulation of receptor fimction. What do we know about FPR binding to cytoskeletal proteins and membrane disribution of FPR as a function of the activation state of neutrophils to support such an idea ... 

The immune system is also compromised in uremia. That and the use of dialysis catheters and synthetic grafts, the frequent blood transfusions, the exposure to nosocomial organisms during repeated hospitalization, the presence of anemia and malnutrition, and the immunocompromised state associated with certain renal diseases (nephrotic syndrome, lupus erythematosus) all conspire to make infection a major cause of mortality, accounting for 15-20% of uremic deaths. Pyogenic infections are facilitated by impaired neutrophil adherence and chemotaxis (L7, S27), blunted antibody response (B15), and defective phagocytosis by macrophages due to decreased Fc-receptor activity (R19). 

The evidence that precoupled receptor/G-proteins exist in intact neutrophils is circumstantial, but likely to be important for migration. Such a state would provide rapid signaling that is not dependent upon... 

Clark-Lewis, 1., Dewald, B., Geiser, T., Moser, B., and Baggiolini, M. (1993) Platelet factor 4 binds to interleukin 8 receptors and activates neutrophils when its N terminus is modified with Glu-Leu-Arg. ProceedingoftheNationalAcadlemyof Sciences of the United States of America, 90, 3574-3577. 

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