Normal Human Immune Peritoneal Cells: Subpopulations and Functional Characteristics

Abstract

Normal human peritoneal cells collected during elective laparatomy from patients with gallbladder stones without clinically detectable inflammatory changes were characterized phenotypically with immunocytochemical method and flow cytometry, with special attention paid to the presence of memory cells. The responsiveness of normal PCs to mitogen and, specifically, the role of peritoneal macrophages in this process was studied. The peritoneal cells consisted of 45% of monocytes/ macrophages (CD68+), as many as CD2+ T lymphocytes, 8% CD57+ NK and K 2% CD22+ B, cells. The CD4/CD8 ratio was 0.4. The peritoneal cells did not express interleukin-2 (CD25+) and transferrin receptors (CD71+) on their surface. Approximately 49% of the peritoneal cells were class II MHC antigen positive cells. Two per cent of S100+ dendritic cells were found. Flow cytometric two-colour analysis revealed that the majority of peritoneal CD4+ (92.4%) and CD8+ (73.1%) lymphocytes, while only 50.2% of CD4+ and 30.1% CD8+ peripheral blood cells expressed simultaneously the CD45R0 (UCHL1) molecule, which is characteristic to the memory/effector T-cell subpopulation. Peritoneal T lymphocytes responded to the mitogens less than peripheral blood lymphocytes of the same individual. Supplementation of cell culture with anti-macrophage (anti-CD68) and anti-HLA-DR MoAb brought about a dose-dependent decrease of proliferative peritoneal cell response to ConA. The authors conclude that human peritoneal cell population comprises a high proportion of T lymphocytes and macrophages capable of presenting antigens to peritoneal lymphocytes. High prevalence of memory lymphocytes points to the preparedness of these cells to react with invading antigens most likely of gut bacterial origin.

Neutrophil and macrophage responses to inflammation in the peritoneal cavity of rainbow trout Oncorhynchus mykiss. A light and electron microscopic cytochemical study

“…Since the mobilization of phagocytes into the peritoneal cavity is similar to that found for tissues (van Furth 1992), the present results indicate, therefore, that in fish, like in mammals (Lehrer et al 1988, Hasslet et al 1989, Silva et al 1989, van Furth 1992, Densen et al 1995, Kubicka et al 1996, macrophages are the tissue resident phagocytes while the neutrophils are present in tissues in significant numbers only in situations of inflammation and only as long as the inflammation persists.…”

“…It is interesting that mammals, teleosts and other higher eukaryotes utilize 2 types of phagocytic cells-neutrophils and macro- 'E-mail: aafonso@gaia.ibmc.up.pt phages-in the defense against infection (Rowley et al 1988, Secombes & Fletcher 1992, Brown 1995. From studies conducted with mammals, data on the behaviour of each of the 2 phagocytes during inflammation, including that caused by infection, can be summarised as follows (Lehrer et al 1988, Haslett et al 1989, Silva et al 1989, van Furth 1992, Densen et al 1995, Kubicka et al 1996. Neutrophils are present in large numbers in blood and hematopoietic organ pools as a reserve, and, under normal conditions, are rare in the tissues and body cavities.…”

Characterization of human peritoneal dendritic cell precursors and their involvement in peritonitis

“…Since some of these cells do not have the phenotypic features of macrophages, a few studies have concluded that the cavity contains a small population of DC representing about 6% of the total cell numbers [13,36]. In this manuscript, we demonstrate for the first time that the peritoneal cavity of both normal human subjects and patients in PD contains a population of CD14 + CD4 + cells that phenotypically, morphologically and functionally fulfills the definition of myeloid DC precursors or pre-DC1.…”

Effective Relief of Malignant Ascites in Patients with Advanced Ovarian Cancer by a Trifunctional Anti-EpCAM × Anti-CD3 Antibody: A Phase I/II Study

“…administration of catumaxomab offers the advantage of a targeted immunotherapy leading to a direct and specific attack on the ascites-causing tumor cells in the peritoneum. Furthermore, all effector cells essential for the antitumor activity of catumaxomab, like T cells and accessory immune cells, are located in the peritoneal cavity (11,12). To target epithelial tumor cells within the peritoneal cavity, EpCAM is an attractive antigen in the otherwise mesenchymal peritoneal compartment.…”