Gut- and bronchus-associated lymphoid tissue.

Bronchus-associated and gut-associated lymphoid tissues (BALT and GALT) have both functional and morphologic similarities and are involved in seeding lung, gut, and other mucosal sites with predominantly IgA-containing B cells. Both types of lymphoid tissue are engaged in the regulation and the controlled amplification of immune responses, which vary from positive mucosal responses in both mucosae and peripheral tissues to local mucosal responses and systemic tolerance. Their further involvement in provision of cells destined to reside in the epithelial compartment of the body appears likely but requires further investigation.

Mast cell heterogeneity.

Increasing evidence for the existence of inter- and intra-species mast cell heterogeneity has expanded the potential biological role of this cell. Early studies suggesting that mast cells at mucosal sites differ morphologically and histochemically from connective tissue mast cells have been confirmed using isolated intestinal mucosal mast cells in the rat and more recently in man. These studies also established that mucosal mast cells are functionally distinct from connective tissue mast cells.

Mucosal mast cells. III. Effect of quercetin and other flavonoids on antigen-induced histamine secretion from rat intestinal mast cells.

Quercetin, a naturally occurring flavonol structurally related to the antiallergic drug disodium cromoglycate inhibits anaphylactic histamine release from MMC isolated from the small bowel LP of the rat previously infected with the nematode Nippostrongylus brasiliensis. This contrasts with our previous observation that cromoglycate is inactive in this system. The present effect is immediate and does not decrease on preincubation with the drug.

Glycosaminoglycan profiles in cloned granulated lymphocytes with natural killer function and in cultured mast cells: their potential use as biochemical markers.

Proteoglycans from three cloned, granulated lymphocyte cell lines with natural killer (NK) function (NKB61A2, HY-3, H-1) and one mast cell line (PT-18) were labeled with [35S]sulfate. [35S]proteoglycans were extracted in 1 M NaCl with protease inhibitors to preserve their native structure and were separated from unincorporated [35S]sulfate by Sephadex G-25 chromatography. [35S]proteoglycans from all four cell lines were chromatographed over Sepharose 4B and were found to have a similar range of m.

Platelet activating factor: regulation by mast cells and aspirin.

We have investigated some aspects of the regulation of production of rat platelet activating factor (PAF)2 in vitro. Suspensions of unseparated (PLC1), mast cell-depleted (PLC2), or mast cell (MC)-enriched rat peritoneal lavage cells (PLC) were analyzed for PAF content by extraction at alkaline pH. PAF activity extracted from PLC1 varied inversely with viable cell concentration: at 1 X 10(6) cells/ml, 32 +/- 9.

Clinical associations of fibroblast growth promoting factor in scleroderma.

Normal adult human dermal fibroblasts were cultured in the presence of sera from 142 subjects. Results of a fibroblast proliferation assay revealed that 16 of 42 patients with scleroderma, 1 of 25 with rheumatoid arthritis, 3 of 10 with systemic lupus erythematosus, 2 of 3 with mixed connective tissue disease and 0 of 42 normal controls had values outside the normal range. The activity of fibroblast growth promoting factor (FGPF) in the scleroderma group correlated with the skin involvement but not with involvement of any other organ system.

The mucosal immune system in health and disease, with an emphasis on parasitic infection.

This article briefly describes the network of immunity involving selected humoral and cellular elements shared between mucosal surfaces that are both exposed to and remote from antigen challenge. The mechanisms promoting the production, concentration, and secretion of specific antibody isotypes, as well as the migration and localization of various lymphoid cell populations, have been discussed with regard to host mucosal protection against pathogenic agents and other potentially harmful macromolecules.Although certain aspects of the mucosal immune system may be viewed as separate from the systemic immune system, they are not exclusively so.

The lung as an immunologic organ.

Considerable information exists and is reviewed and summarized to support the suggestion that the lungs are a major contributor to immunity. The immune response differs in quantity and quality in different parts of the lung and this response depends in magnitude and type on a number of factors such as previous exposure, nature of the antigen, amount, etc. The ways in which these pulmonary immune responses are regulated and may be augmented and harnessed are discussed.

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.

Regulation of lymphoblast traffic and localization in mucosal tissues, with emphasis on IgA.

A fundamentally important factor in the expression of immunity at mucosal sites is the migration of primed lymphocytes to, from, and among mucosal tissues. Despite considerable information in recent years on the selective localization of B lymphoblasts, especially those destined to make IgA antibodies in mucosal tissues, the basis for this remains obscure. Several cell-associated factors such as surface characteristics, histo-compatibility type, and organ derivation of the cells play a significant role for T and B lymphoblast localization.

Basophil/mast cell precursors in human peripheral blood.

Semisolid (methylcellulose) hemopoietic cultures revealed the presence of histamine-containing granulocyte colonies derived from precursors (CFU-C) present in human peripheral blood. Light microscopy and histochemical studies of cells in individual histamine-containing colonies demonstrated homogeneous populations of metachromatic basophil/mast cells (BMC) at various stages of maturation. By inverted microscopy, pure BMC colonies were more often found to have the overall appearance of the previously described "eosinophil" (type II), rather than "neutrophil-macrophage" (type I), colony type.

Canalicular function during herpetic keratoconjunctivitis in rabbits.

Canalicular function during acute herpetic keratoconjunctivitis was investigated in rabbits. Evidence of partial obstruction of the duct was obtained in the infected as compared with the mock-infected eyes. Direct damage of the ductal epithelium by virus could not be demonstrated by histologic and immunofluorescent studies.

Characteristics of natural killer cells in the murine intestinal epithelium and lamina propria.

Highly purified populations of lymphocytes were obtained from the murine intestinal mucosa using EDTA-collagenase isolation procedures in combination with discontinuous density centrifugation. Intraepithelial lymphocytes (IEL) were separated from lamina propria lymphocytes (LPL) and, within these two populations, fractions enriched or depleted in gut granular lymphocytes (gGL) were obtained. Using these cells in cytotoxic assays, it was shown that both IEL and LPL possess natural killer (NK) activity, and this was associated with gGL.

Mucosal mast cells. II. Effects of anti-allergic compounds on histamine secretion by isolated intestinal mast cells.

Functional mast cells have been isolated from the lamina propria of the small intestine of rats infected with the nematode Nippostrongylus brasiliensis. The cells released histamine on challenge with specific antigen, anti-rat IgE, concanavalin A, and calcium ionophores but were less responsive than peritoneal mast cells (MMC) from the same animals. Intestinal mucosa mast cells (PMC) were refractory to the action of the basic secretagogues peptide 401 from bee venom and compound 48/80.

Mucosal mast cells. I. Isolation and functional characteristics of rat intestinal mast cells.

We have developed a procedure for the dispersion of mast cells from the intestinal lamina propria (LP) and epithelium of rats infected with the intestinal nematode, Nippostrongylus brasiliensis. The dispersed cells are morphologically and histochemically similar to intestinal mucosal mast cells (MMC) in situ and are distinguishable from peritoneal mast cells (PMC). MMC derived from the LP or epithelium of parasitized animals secrete histamine in response to the specific parasite antigens as well as anti-IgE.