Cells In Intestinal Lamina Propria Research Articles

Differential Suppression of Heat-Killed Lactobacilli Isolated from kimchi, a Korean Traditional Food, on Airway Hyper-responsiveness in Mice

Probiotics have been shown to be effective in reducing allergic symptoms. However, there are few studies to evaluate the therapeutic effects of lactobacilli on allergen-induced airway inflammation. We investigated whether three heat-killed lactobacilli, Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus sakei subsp. sakei, isolated from kimchi, exerted inhibitory effects on airway hyper-responsiveness in a murine asthma model. Heat-killed lactic acid bacteria were orally administered into BALB/c mice, followed by challenge with aerosolized ovalbumin, after which allergic symptoms were evaluated. Airway inflammation was suppressed in the L. plantarum- and L. curvatus-treated mice. Interleukin (IL)-4 and IL-5 levels were significantly lower in the L. plantarum- and L. curvatus-treated mice than in those treated with L. sakei subsp. sakei. Importantly, heat-killed L. plantarum administration induced Foxp3 expression in intestinal lamina propria cells, and heat-killed L. curvatus induced IL-10 as a way of inducing tolerance. Specific strains of lactobacilli isolated from kimchi can effectively suppress airway hyper-responsiveness.

Reduced expression of basal and probiotic-inducible G-CSF in intestinal mononuclear cells is associated with inflammatory bowel disease

Granulocyte-colony stimulating factor (G-CSF) is a pleiotropic cytokine involved in the hematopoiesis of granulocytes, neuroprotection, and immunomodulation. Previously, we have shown that probiotic Lactobacillus rhamnosus GR-1 induces G-CSF production from bone marrow-derived macrophages. Whether this probiotic also induces G-CSF in intestinal mononuclear cells is unknown. G-CSF release in response to L. rhamnosus GR-1 was analyzed in isolated intestinal lamina propria mononuclear cells from inflammatory bowel disease (IBD) and non-IBD patients. The effects of G-CSF on proinflammatory cytokine production in human peripheral blood mononuclear cells and intestinal tissue from C57BL/6 wildtype and G-CSF receptor knockout mice was examined. Normal mouse or human intestinal lamina propria cells constitutively express high levels of G-CSF, of which production was further enhanced by exogenous L. rhamnosus GR-1. However, cells obtained from IBD patients showed reduced G-CSF production under basal conditions and also lower production after exogenous GR-1 treatments. Intestinal tissue samples isolated from G-CSF receptor-deficient mice constitutively expressed higher levels of TNFalpha, IL-23, and IL-12 than those from wildtype mice, and pretreatment of G-CSF suppressed lipopolysaccharide (LPS)-induced IL-23 in human peripheral blood mononuclear cells. These results suggest that high G-CSF production induced by commensals such as L. rhamnosus is important in maintaining normal immunological homeostasis in the intestine and defects in the production of G-CSF are associated with IBD.

IL-2 production by intestinal lamina propria cells in normal inflamed and cancer-bearing colons.

Biologically significant levels of IL-2 activity were produced by isolated lamina propria mononuclear cells (LPMC) from normal intestine (n = 12), cancer-bearing colons (n = 35) and inflammatory bowel disease (IBD) affected tissue (n = 12). The levels of IL-2 produced were similar for all three sources of LPMC (normal 252 +/- 48 U/ml, IBD-affected mucosa 197 +/- 42 U/ml and colon cancer 285 +/- 43 U/ml). These levels were significantly greater than those produced by peripheral blood mononuclear cells (20 +/- 5 U/ml, P less than 0.01) on a per cell basis. In mucosa from cancer-bearing colons the amount of IL-2 produced by LPMC was unaffected by the invasiveness of the colon cancer. LPMC IL-2 production was markedly suppressed by drugs used in IBD therapy. 5-Aminosalicylic acid (5-ASA) reduced activity in a dose-dependent fashion. At a dose equivalent to the faecal therapeutic level of 0.5 mg/ml activity, IL-2 production by LPMC was suppressed to 3.4% of controls. Similarly, exposure of LPMC to cyclosporin A (CyA) and hydrocortisone (HC) at therapeutic levels reduced IL-2 activity to less than 1% of controls. The major producers of IL-2 activity were shown to be CD3+ T lymphocytes and those bearing the activation markers IL-2R and TFR. Suppression of mucosal IL-2 production represents an important therapeutic mechanism of drugs used in the management of IBD including HC, 5-ASA and CyA. These results suggest that mucosal T cells produce appreciable levels of IL-2 activity that may be important in maintaining immune homeostasis in the normal intestine, provide anti-neoplastic cytotoxic activity and contribute to the inflammatory events that characterize the mucosal lesions of IBD.

Comment on “CCR7 Is Critically Important for Migration of Dendritic Cells in Intestinal Lamina Propria to Mesenteric Lymph Nodes”

The recent paper by Jang et al. ([1][1]), highlighted in In This Issue ([2][2]), is part of a recent rediscovery of the myeloid compartment of the intestinal lamina propria, which is probably the largest macrophage population in the body. The authors refer to these cells as dendritic cells, based on

Response to Comment on “CCR7 Is Critically Important for Migration of Dendritic Cells in Intestinal Lamina Propria to Mesenteric Lymph Nodes”

In response to a letter by Dr. David Hume ([1][1]), we would like to point out that the following lines of evidence clearly indicate that the lamina propria dendritic cells (LP-DC) we reported ([2][2]) are indeed DC but not macrophages. As seen in Fig. 1[⇓][3] A in our recent analysis in which we

Mechanism of up‐regulation of immunoglobulin A production in the intestine of mice unresponsive to lipopolysaccharide

The mechanisms by which immunoglobulin A (IgA) production up-regulates in the intestine of Toll-like receptor-4 (TLR4)-mutated mice were investigated. When TLR4-mutated, C3H/HeJ and BALB/lps(d) mice received oral administration of cholera toxin (CT), not only CT-specific IgA levels in the intestinal lavage but also the number of IgA-producing cells in intestinal lamina propria (iLP) significantly increased compared with those of the wild-type C3H/He and BALB/c mice. Interleukin (IL)-5-producing cells and CD86+ cells in iLP also significantly increased in C3H/HeJ mice. The expression of major histocompatibility complex class II and CD86 on cells present in Peyer's patches (PPs) of C3H/HeJ mice was higher than those of C3H/He mice. In non-immunized C3H/HeJ mice, the expression of transforming growth factor-beta (TGF-beta) mRNA and the percentages of IL-10-producing cells in PPs but not in spleen increased when compared with those in C3H/He mice. The suppressor of cytokine signalling-1 (SOCS-1) was expressed in PPs of C3H/He mice but not C3H/HeJ mice. These results indicate that high IgA levels in the intestine of TLR4-mutated mice are due to up-regulation of TGF-beta and IL-10 and the lack of regulation by SOCS-1.

Alterations of the Mucosal Immune System Due toCryptosporidium parvumInfection in Normal Mice

The mechanism with which the immune system of an immunocompetent host responds toCryptosporidium parvuminfection is still poorly understood. We have therefore investigated the immune response of adult immunocompetent C57BL/6 mice at Days 6 and 10 to postinfection during a self-limitingC. parvuminfection. We evaluated the immune changes at the levels of intestinal intraepithelium and lamina propria as well as mesenteric lymph nodes. At Day 6 postinfection, there was a decrease in the production of IFN-γ, IL-5, IL-6, and IL-10 byin vitromitogen-stimulated intraepithelial lymphocytes. Moreover, an increase in the number of γδ-TCR+, CD8+, and cytoplasmic IgE+cells in intestinal lamina propria was found. Concomitantly, a significant decrease in the number of cytoplasmic IgA+and IgG+cells was observed. These phenotypic changes may be associated with the cytokine-producing profile (decreased IL-4, IFN-γ, and IL-10) by lamina propria lymphocytes. At Days 6 and 10 postinfection cytoplasmic IgA+and IgG+cell numbers remained. Nevertheless, the production of IL-5 and IL-10 by intraepithelial lymphocytes was higher than the noninfected control values; these changes may be associated with the decreased CD4+cell numbers. In mesenteric lymphocytes IgG and IgA productionin vitrowas elevated while no changes were observed in cytokine production except for a significant decrease in IL-5. In conclusion, our results demonstrate that an immunocompetent defense mechanism leading to a successful recovery fromC. parvuminfection involved changes of TH1- or TH2-type cytokine production as well as alterations of the lymphocyte subpopulation at mucosal-associated lymphoid tissues.

IL-6-deficient mice exhibit normal mucosal IgA responses to local immunizations and Helicobacter felis infection.

Using IL-6-deficient (IL-6 -/-) or wild-type mice, we investigated whether IL-6 is involved in the intestinal adjuvant activity of cholera toxin (CT) and to what extent IL-6 is required for mucosal IgA responses against soluble protein Ags or live Helicobacter felis infection. In naive IL-6 -/- mice we found normal total IgA levels in serum, bronchial and intestinal lavage and unaltered frequencies of IgA plasma cells in intestinal lamina propria. In Peyer's patches (PP) and mesenteric lymph nodes (MLN) IgA-producing cells were as frequent in IL-6 -/- as in wild-type mice. Immunohistochemical analysis of PP revealed germinal centers that co-localized IgA+ cells, indicating B cell activation and isotype switching in situ in the intestinal immune inductive site. Phenotypic analysis of the distribution of conventional B-2 cells (B220+CD5-/Mac-1-) and B-1 cells (B220+, CD5+/Mac-1+) in intestine-associated tissues gave comparable results in IL-6 -/- and wild-type mice. The ability to respond with mucosal IgA following oral and intranasal immunization with specific Ag, KLH or OVA, in the presence of CT adjuvant or to live H. felis infection was similar in IL-6 -/- and wild-type mice. CT exerted strong and comparable adjuvant functions in IL-6 -/- and wild-type mice. Repeated oral immunizations with CT alone stimulated immune protection against CT-induced diarrhea in ligated loops that was of similar magnitude in IL-6 -/- and wild-type mice. We conclude that, although IL-6 has been ascribed a crucial role in terminal differentiation of IgA B cells in vitro, we found no evidence to support the notion that IL-6 is critically required for IgA B cell development or specific mucosal IgA responses in vivo.

Identification and characterization of rat intestinal lamina propria cells: consequences of microbial colonization

Germ-free (GF) animals exhibit an abnormally diminished, cell-mediated immune response which can be rapidly normalized by bacterial colonization of the intestine. This conventionalization suggests that the development and/or regulation of the immune system is dependent upon intestinal bacteria or their products. Here we consider the ontogeny of gut-associated lymphoid tissue (GALT) immunocytes by isolating and characterizing the intestinal lamina propria cells (LPC) of GF rats responding to bacterial colonization or an irrelevant protein antigen, and compared to LPC of specific pathogen-free (SPF) rats which were conventionalized (CV) from birth. Isolation of cells was accomplished by successive EDTA washings of small intestine to remove the epithelium, and enzymatic digestion of the tissue generating single-cell suspensions. Resulting cell suspensions were characterized by monoclonal antibodies directed against leukocyte epitopes using flow cytometry. Functional characterization was measured by the tritiated thymidine proliferation assay with concanalin A (Con A) and lipopolysaccharide (LPS) as co-stimulators. Germ-free and SPF rats had fewer total LPC than CV rats. Antibody staining revealed that GF rats had fewer total leukocytes than CV and SPF rats, and that CV rats had a greater percentage of T-cells and cells positive for the C3 receptor than GF rats. Co-stimulation of LPC with mitogens only increased proliferation of cells from CV rats compared to GF and SPF rats. In addition, spleen cells from CV rats demonstrated significantly enhanced proliferative responses compared to spleen cells from GF rat and were more analogous to spleen cells from SPF rats in their ability to proliferate in vitro, with and without mitogens. We conclude that T-cells and CD35-positive (C3BR+) cells are recruited and/or proliferate in response to intestinal bacteria and/or their products, and that this results in the induction of immune competency.

Immunohistochemical Study of Intestinal Lamina Propria Cells in the Rat, with Special Reference to Ia Antigen Expression

A previous study by Osogoe and Yanagi (1987a) has demonstrated that a large proportion of the lamina propria cells (LPC), mostly reticulum cells, in the core of the rat jejunal villi exhibit a strong labeling with [14C]adenine [( 14C]A). To obtain further information on such LPC, immunohistochemical detection of either Ia antigen or IgA on intestinal LPC was carried out in adult rats. It was found that almost all the LPC in the villous core of the small intestine express Ia antigen, and that in this area IgA-containing B cells also occur in unexpectedly large numbers. However, the number of Ia-positive non-B cells was greater than that of IgA-containing B cells which are also Ia-positive. Since the Ia-positive non-B cell population is composed mostly of reticulum cells, the above findings indicate that a large number of LPC, mostly reticulum cells, not only exhibit a strong labeling with [14C]A but also express Ia antigen. The biological significance of Ia antigen expression is discussed in relation to the proliferative activity of the cells.

Effects of Rat and Human Intestinal Lamina Propria Cells on Viability and Muscle Establishment of Trichinella spiralis Newborn Larvae

Although eosinophils and other inflammatory cells from the circulation and peritoneal cavity can damage Trichinella spiralis newborn larvae (NBL) in vitro, the cytotoxic potential of cells from the intestinal lamina propria, a site that may be the first line of defense against NBL migration, is unknown. Accordingly, we examined the interaction between NBL and isolated intestinal lamina propria cells (ILPC), including an enriched eosinophil population, from rats and humans. Rat ILPC killed NBL in vitro only after a prolonged incubation of 6 days. However they strongly adhered to NBL after only 4 hr incubation and prevented muscle establishment of NBL injected intravenously. Human ILPC showed similar adherence as rat ILPC but no killing was seen at the incubation time tested (36 hr).

Genetic differences in the histochemically defined structure of oligosaccharides in mice.

A wide range of tissues from three interfertile species of mice and an interspecific hybrid was examined with lectins conjugated to peroxidase to localize specifically glycoconjugates containing terminal alpha-N-acetylgalactosamine, alpha-galactose, and alpha-fucose, and the terminal disaccharide galactose-(beta 1----3)-N-acetylgalactosamine. This battery of lectins disclosed marked heterogeneity of glycoconjugates in different histological sites in a given animal and even between cells in a presumably homogeneous cell population within an organ. No variation with any lectin was observed between individuals of two closely related inbred strains of Mus domesticus at any specific histological or cytological site. In contrast, littermates of an outbred strain of Mus castaneus differed in binding of certain lectins at various sites, attesting to a genetic basis for individual variation. Hybrids between castaneus and domesticus mice also showed individual variation. Moreover, extensive differences between the mouse species were demonstrable with every lectin in glycoconjugates of stored secretions, Golgi cisternae, and apical or basolateral plasmalemma in many cell types. Totaling the differences in tabulated staining intensities for each possible species pair gave a measure of the overall extent of difference at 53 histological sites. According to this measure, the three species are about equally divergent from one another. Some differences between species appeared to depend on histological rather than histochemical variation, as, for example, a greater abundance of granular duct cells in the sublingual and submandibular glands in Mus hortulanus. Other differences were apparently derived from pathological change, as exemplified by casts and lymphoid infiltrates in kidney and structurally atypical submandibular gland lobules in Mus castaneus, and possibly by infiltrating cells in intestinal lamina propria and epithelium in Mus castaneus and hortulanus.

Isolation and characteristics of small intestinal lamina propria cells from normal and nematode (Nippostrongylus brasiliensis)-infected rats.

Intestinal lamina propria (LP) cells were isolated from normal or nematode (Nippostrongylus brasiliensis)-infected rats. At certain times after infection (days 11-17), viable cell recoveries from infected rats were lower, whereas at other times (days 20-50), they were significantly greater than those from normal rats. The frequencies of lymphocytes, plasma cells, eosinophils, mast cells and macrophages from LP differed between normal and infected rats, and the histamine content did also. However, spontaneous 3H-uridine and 3H-thymidine incorporation and the number of cells with cytoplasmic immunoglobulin were similar. LP cells from normal rats were unresponsive to the mitogens phytohemagglutinin, concanavalin A and pokeweed. 125I-deoxyuridine-radiolabeled LP lymphoblasts from normal rats were widely distributed in recipients 22-24 h after transfer and showed no selective predilection to return to the intestine. The isolation procedure can be used to study intestinal LP cells from normal or diseased animals.

Determinants of the localization, magnitude, and duration of a specific mucosal IgA plasma cell response in enterically immunized rats.

The origin and fate of specific IgA plasma cells in intestinal lamina propria were studied in rats immunized enterically with cholera toxin (CT). Our major goal was to define how an anti-CT response is focused and sustained at the site of antigen challenge. To distinguish antigen-dependent from antigen-independent mechanisms, CT exposure was restricted to defined portions of intestine and, in some studies, the distribution of antitoxin-containing plasma cells (ACC) was examined in nonimmune adoptive recipients of post-challenge thoracic duct lymphocytes. After enteric priming and challenge, ACC appeared throughout the gut, but were most numerous at the challenged site. About 25% of ACC appearing at the site of jejunal challenge were due to antigen-driven proliferation of memory cells within the lamina propria; the remainder arose elsewhere, apparently in mucosal follicles or mesenteric lymph nodes, and migrated systemically as antitoxin-containing plasmablasts before homing to the lamina propria. The homing of these migrating ACC precursors was not affected by mucosal exposure to CT, nor did they undergo appreciable antigen-driven division after arrival in gut lamina propria. However, homing was specific for the organ from which they arose, i.e., precursors arising from duodenal challenge homed selectively to jejunum, whereas those from colonic challenge homed to the colon. The organ specificity of homing was determined during the challenge response and was independent of the origin of memory cells participating in the response. The survival of migrating ACC precursors did not differ in segments of gut exposed or nonexposed to CT. However, CT exposure at the time of their migration evoked another secondary-type response, due to stimulation of comigrating memory cells, thus sustaining the secondary response at a high level. These results and those in a previous report identify important mechanisms that affect the localization, magnitude, and duration of a specific IgA response, at least in the intestine. These include: 1) organ-specific homing of migrating IgA plasmablasts, 2) antigen-driven generation of IgA plasma cells from memory cells within the lamina propria, 3) enhanced memory at the site of mucosal priming compared to that a distant mucosae, and 4) regeneration of memory cells during the secondary response.

Tissue origins of human polymeric and monomeric IgA.

Human tissues were examined for their ability to produce monomeric and polymeric forms of IgA in vitro. Mononuclear cells were examined for the presence of cytoplasmic immunoglobulins and J chain (by immunofluorescence) and for the amounts and molecular forms of intracellular and secreted IgA (by radioimmunoassay). Cultured bone marrow cells were the largest producers of total IgA, and approximately 90% of the secreted IgA was monomeric. Spleen cells also produced predominantly monomeric IgA. Intestinal lamina propria cells secreted the greatest amounts of polymeric IgA, but also produced significant amounts of monomeric IgA. Tonsillar, lymph node, and peripheral blood cells produced approximately equal proportions of monomeric and polymeric IgA. These results suggested that bone marrow may be a major source of serum monomeric IgA, and that lymphoid tissues associated with secretory surfaces may provide a greater proportion of polymeric IgA than other lymphoid tissues. There was a positive correlation between the production of polymeric IgA and the presence of cytoplasmic J chain; tissues that produced predominantly monomeric IgA generally displayed fewer cells containing cytoplasmic J chain.