CD3+, CD4+, CD8-, Ia- T cells adoptively transfer murine experimental hypersensitivity pneumonitis

Experimental hypersensitivity pneumonitis: role of MCP-1

Inhalation of Saccharopolyspora rectivirgula causes "farmer's lung" disease, a classic example of hypersensitivity pneumonitis (HP). Monocyte chemoattractant protein-1 (MCP-1) is increased in the bronchoalveolar lavage fluid of mice challenged with S rectivirgula, and S rectivirgula induces MCP-1 secretion by alveolar macrophages. We tested the hypothesis that MCP-1 and its receptor CC chemokine receptor-2 (CCR2) are essential to the development of experimental HP by treating mice with MCP-1 antibody and using CCR2(-/-) mice. Administration of anti-MCP-1 did not change the response to intratracheally administered S rectivirgula. CCR2(-/-) animals responded in a fashion similar to that of wild-type animals to intratracheally administered.S rectivirgula. To determine the influence of the MCP-1-CCR2 interaction in vitro, we transferred S rectivirgula-cultured spleen cells from S rectivirgula-sensitized mice, to naïve recipients. Later, challenge of the recipients with intratracheal S rectivirgula and examination of both lung histology and bronchoalveolar lavage fluid characteristics were used to determine whether adoptive transfer had occurred. We found that cultured cells from CCR2(-/-) animals were fully capable of adoptive transfer. We conclude that interaction of MCP-1 with CCR2 is not necessary for the development of pulmonary inflammation in response to intratracheally administered S rectivirgula or cells able to adoptively transfer experimental HP.

Is IL12 necessary in experimental hypersensitivity pneumonitis?

Inhalation of Saccharopolyspora rectivirgula (SR) can cause the disease Farmer's Lung, a classic example of hypersensitivity pneumonitis. Th1, but not Th2, cell lines can adoptively transfer experimental hypersensitivity pneumonitis (EHP). Substantial amounts of IL12 appear in bronchoalveolar lavage fluid (BALF) after a single intratracheal (IT) injection of SR, and SR-induced IL12 secretion by both a macrophage cell line and alveolar macrophages. We tested the hypothesis that IL12 is essential for the development of EHP by addition of anti-IL12 to cultured cells, and adoptive transfer of EHP in IL12p40-/- animals. We transferred SR cultured spleen and lung associated lymph node cells from SR sensitized mice (both IL12p40-/- and wild type), to naïve recipients (both wild type and IL12p40-/-). The addition of anti-IL12 to cultures of sensitized cells could not ablate the ability of these cells to transfer EHP. Cultured cells from IL12p40-/- animals were fully capable of transferring EHP. In contrast, IL12p40-/- recipients of both wild type and IL12p40-/--cultured cells were less able to express EHP (lung histology and BALF characteristics) than wild type mice, and had more eosinophils in both lung tissue and BALF. We conclude that IL12 is not necessary for development of cells able to adoptively transfer EHP, but that it is required for full expression of EHP in recipient animals.

Experimental hypersensitivity pneumonitis: influence of Th2 bias

Cultured murine CD4+ cells from Saccharopolyspora rectivirgula sensitized C3H/HeJ (Th1 bias) donors can adoptively transfer murine experimental hypersensitivity pneumonitis (EHP). We sensitized BALB/c mice (Th2 bias) with S. rectivirgula, obtained spleen and lung associated lymph node (LALN) cells, cultured the cells with specific antigen, and attempted adoptive transfer of EHP. We also treated both C3H/HeJ and BALB/c donor mice with IL4 and anti-IFNgamma before exposure to S. rectivirgula and then cultured cells from both spleen and LALN before attempted transfer of EHP. We found that cultured spleen and lung associated lymph node cells can adoptively transfer EHP in both C3H/HeJ and BALB/c mice as demonstrated by infiltration of the recipient lungs with CD4+ lymphocytes. Treatment of both mouse strains with IL4 and anti-IFNgamma did not change the ability of cultured cells to adoptively transfer EHP. We conclude that EHP induced by S. rectivirgula can occur in animals with either a Th1 or a Th2 bias and is not altered by treatment with IL4 and anti-IFNgamma. This suggests that attributes of the antigen and not genetic background or cytokine environment at the site of initial sensitization determines the results of exposure to S. rectivirgula.

Lung lymphocytes proliferate minimally in the murine pulmonary immune response to intratracheal sheep erythrocytes

The importance of in situ lymphocyte proliferation for net accumulation of lung lymphocytes during pulmonary immune responses and in immunologic lung diseases remains uncertain. Accordingly, we studied the experimental pulmonary immune response of antigen-primed C57BL/6 mice to intratracheal challenge with the particulate antigen sheep red blood cells. Uptake of nucleotide analogs (bromodeoxyuridine in vivo and tritiated thymidine in vitro), expression of the cell activation antigens CD25 and CD69 by flow cytometry, and response to the antimitotic agent hydroxyurea (in vivo) were measured. Although many lung lymphocytes and CD4+ T cells were CD25+ and CD69+, indicating recent activation, all techniques demonstrated that lung lymphocytes proliferated minimally in vivo. Blockade of cell division by hydroxyurea administration for 24 h did not significantly decrease lung lymphocyte accumulation on Day 3 after challenge. Lung lymphocytes also proliferated minimally in vitro (even on macrophage removal and despite addition of exogenous interleukin [IL]-2 or IL-4). However, lung lymphocytes responded vigorously to mitogens (immobilized anti-CD3, phytohemagglutinin, or concanavalin A), excluding global unresponsiveness to restimulation. Thus, in this model of pulmonary immunity, accumulation of lung lymphocytes does not require local T-cell proliferation and presumably depends instead on recruitment.

Transfer of allergic airway responses with serum and lymphocytes from rats sensitized to dust mite

House dust mite (HDM) antigen is one of the most common allergens associated with extrinsic asthma. In a model of allergic lung disease, Brown Norway (BN) rats sensitized to HDM with alum and Bordetella pertussis adjuvants produce high levels of IgE antibody and experience bronchoconstriction, increased airway hyperresponsiveness (AHR) to acetylcholine (ACh), and pulmonary inflammation after antigen challenge. The purpose of this study was to determine whether these asthmatic symptoms could be transferred from sensitized animals to naive recipients via humoral or cellular factors. Syngeneic recipient rats were injected (intraperitoneally with 4 x 10(7) cells (precultured overnight with either HDM or bovine serum albumin [BSA]) from lymph nodes of sensitized or control rats, respectively. Other groups received a tail-vein injection of serum from either HDM-sensitized or control rats. Antigen challenge in rats injected with sensitized cells caused increases in pulmonary inflammation and in AHR, but no changes in immediate bronchoconstriction as compared with control recipients. Antigen challenge in serum recipients resulted in immediate bronchoconstriction but had no effect on AHR or on pulmonary inflammation. These data show that immune-mediated lung inflammation and AHR are promoted by antigen-specific lymphocytes, whereas immediate allergic responses are caused by serum factors.

Th1 CD4+ cells adoptively transfer experimental hypersensitivity pneumonitis

Cultured cells from Micropolyspora faeni-sensitized donors can adoptively transfer murine experimental hypersensitivity pneumonitis (EHP). To determine whether the CD4+ cells responsible for transfer have characteristics of Th1 or Th2 cells, we established cell lines from lung-associated lymph nodes of M. faeni-sensitized C3H/HeJ mice by culturing with antigen and either IFN-gamma, IL2, and anti-IL4, or IL4. Cell lines were stimulated regularly with antigen, fresh antigen-presenting cells, and the cytokine/anti-cytokine antibody cocktail. At various times after initiation of culture, cells were injected intravenously into recipients, which were then challenged intratracheally with M. faeni and sacrificed and the extent of pulmonary inflammatory response was determined. IFN-gamma, IL4, and IL10 levels were determined in supernatants of cell cultures stimulated with M. faeni to characterize the cell lines as Th1 (IFN-gamma, but low IL4 and IL10 secretion) or Th2 (IL4 and IL10, but low IFN-gamma secretion). Cell lines were differentiated into either Th1 (IFN-gamma = 310 +/- 45 U/ml, IL4 = 0.10 +/- 0.1 U/ml, IL10 = 1750 +/- 75 pg/ ml, >99% CD4+) cell lines by Day 16 of culture or Th2 cell lines (IFN-gamma = 1.8 +/- 1.0 U/ml, IL4 = 830 +/- 388 U/ml, IL10 = 51,700 +/- 10,900 pg/ml, >96% CD4+) by Day 30. Th1 cell lines were able to adoptively transfer EHP whereas Th2 cell lines were unable to adoptively transfer EHP. The ability to transfer EHP was directly related to the amount of IFN-gamma and inversely to the amount of IL4 secreted by antigen-stimulated cells. We conclude that it is possible to produce CD4+ cell lines with either Th1 or Th2 characteristics from lung-associated lymph nodes of mice exposed to M. faeni and that only Th1 CD4+ cell lines can adoptively transfer EHP.

Interleukin-10 is a natural suppressor of cytokine production and inflammation in a murine model of allergic bronchopulmonary aspergillosis

We have used interleukin-10 (IL-10) gene knockout mice (IL-10-/-) to examine the role of endogenous IL-10 in allergic lung responses to Aspergillus fumigatus Ag. In vitro restimulated lung cells from sensitized IL-10-/- mice produced exaggerated amounts of IL-4, IL-5, and interferon-gamma (IFN-gamma) compared with wild-type (WT) lung cells. In vivo, the significance of IL-10 in regulating responses to repeated A. fumigatus inhalation was strikingly revealed in IL-10-/- outbred mice that had a 50-60% mortality rate, while mortality was rare in similarly treated WT mice. Furthermore, IL-10-/- outbred mice exhibited exaggerated airway inflammation and heightened levels of IL-5 and IFN-gamma in bronchoalveolar lavage (BAL) fluids. In contrast, the magnitude of the allergic lung response was similar in intranasally (i.n.) sensitized IL-10-/- and wild-type mice from a different strain (C57BL/6). Using a different route of priming (intraperitoneal) followed by one i.n. challenge we found that IL-10-/- C57BL/6 mice had heightened eosinophilic airway inflammation, BAL-IL-5 levels, and numbers of alphabetaT cells in the lung tissues compared with WT mice. We conclude that IL-10 can suppress inflammatory Th2-like lung responses as well as Th1-like responses given the constraints of genetic background and route of priming.