Gap junctions are connexin-formed channels that play an important role in intercellular communication in most cell types. In the immune system, specifically in macrophages, the expression of connexins and the establishment of functional gap junctions are still controversial issues. Macrophages express P2X7 receptors that, once activated by the binding of extracellular ATP, lead to the opening of transmembrane pores permeable to molecules of up to 900 Da. There is evidence suggesting an interplay between gap junctions and P2 receptors in different cell systems. Thus, we used ATP-sensitive and -insensitive J774.G8 macrophage cell lines to investigate this interplay. To study junctional communication in J774-macrophage-like cells, we assessed cell-to-cell communication by microinjecting Lucifer Yellow. Confluent cultures of ATP-sensitive J774 cells (ATP-s cells) are coupled, whereas ATP-insensitive J774 cells (ATP-i cells), derived by overexposing J774 cells to extracellular ATP until they do not display the phenomenon of ATP-induced permeabilization, are essentially uncoupled. Western-blot and reverse-transcription polymerase chain reaction assays revealed that ATP-s and ATP-i cells express connexin43 (Cx43), whereas only ATP-s cells express the P2X7 receptor. Accordingly, ATP-i cells did not display any detectable ATP-induced current under whole-cell patch-clamp recordings. Using immunofluorescence microscopy, Cx43 reactivity was found at the cell surface and in regions of cell-cell contact of ATP-s cells, whereas, in ATP-i cells, Cx43 immunoreactivity was only present in cytosolic compartments. Using confocal microscopy, it is shown here that, in ATP-s cells as well as in peritoneal macrophages, Cx43 and P2X7 receptors are co-localized to the membrane of ATP-s cells and peritoneal macrophages.
Modulation of intercellular communication in macrophages: possible interactions between GAP junctions and P2 receptors Available to Purchase
Fabio S. A. Fortes, Iracy L. Pecora, Pedro M. Persechini, Sandra Hurtado, Vandir Costa, Robson Coutinho-Silva, Mariane B. Melo Braga, Fernando C. Silva-Filho, Rodrigo C. Bisaggio, Fernando Pires de Farias, Eliana Scemes, Antônio C. Campos de Carvalho, Regina C. S. Goldenberg; Modulation of intercellular communication in macrophages: possible interactions between GAP junctions and P2 receptors. J Cell Sci 15 September 2004; 117 (20): 4717–4726. doi: https://doi.org/10.1242/jcs.01345
Download citation file:
Sign in
Client Account
Sign in via your institution
Sign in via ShibbolethAdvertisement
JCS fast-track option

Have a paper that has been reviewed elsewhere? JCS is pleased to consider such manuscripts for fast-tracked decision making. Send us your manuscript together with the full set of reviews and decision letters, and we will make an initial decision within one week.
Special Issue – Cell Biology of Mitochondria

Our special issue on ‘Cell Biology of Mitochondria’ is now complete. Explore this issue and read the Editorial from our Guest Editors Ana J. García-Sáez and Heidi McBride.
Save the date – Imaging Cell Dynamics

We are delighted to announce that we will be hosting a 2026 Imaging Cell Dynamics meeting. This meeting will provide a unique opportunity to bring together experts working at the interface between cell biology and imaging. Save the date for 11-14 May 2026 and register for more information.
Origin and evolution of mitochondrial inner membrane composition

In this Review, Kailash Venkatraman and colleagues provide an examination of the morphological similarities between prokaryotic intracytoplasmic membranes and mitochondrial inner membranes, and whether cristae evolution has driven specialisation of the mitochondrial lipidome.
Resolution in super-resolution microscopy
Super-resolution microscopy (SRM) has emerged as a powerful tool for biological discovery. In this Perspective, Kirti Prakash and colleagues compile expert opinions on crucial, yet often overlooked, aspects of SRM that are essential for maximising its benefits and advancing the field.