Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate the role of CD8+ T lymphocytes in recovery from influenza pneumonia, we used transgenic mice either homozygous (-/-) or heterozygous (+/-) for beta 2-microglobulin (beta 2-M) gene disruption. These mice lack major histocompatibility complex-restricted class I (CD8+) T cells. We found that after challenge with a nonlethal influenza virus, the beta 2-M (-/-) mice had significantly delayed pulmonary viral clearance. Furthermore, after challenge with a more virulent influenza virus, the beta 2-M (-/-) mice had a significantly higher mortality rate than did control mice. Thus, CD8+ T cells are important in recovery from virulent influenza infections, but other host defense mechanisms can clear the respiratory tract of more benign infections.
 ...
PMID:Transgenic mice lacking class I major histocompatibility complex-restricted T cells have delayed viral clearance and increased mortality after influenza virus challenge. 155 85

Pulmonary A2 strain respiratory syncytial virus infection of BALB/c laboratory mice persisted for up to 7 days after initial infection with peak virus titres being recovered on day 4. Virus antigen within the lungs was found to be restricted essentially to the alveolar regions. Similarly, pulmonary histopathological changes remained confined to the peri-alveolar regions being consistent with mild pneumonia. Infection was found to elicit a pulmonary major histocompatibility complex-restricted cytotoxic T lymphocyte (CTL) response which was first detectable 6 days after infection and optimal 7 to 9 days after infection. This local CTL response was preceded by a rapid transient virus-specific lymphocyte transformation response which was detectable only 3 days after intranasal infection. In addition, infection induced rapid interferon production within the lungs which was accompanied by an equally rapid rise in pulmonary natural killer (NK) cell cytotoxic activity. Enhanced NK cell cytotoxicity could be detected after only 1 day post-infection and continued to rise to maximum levels on day 3. This response like the acute CTL response was found to be restricted to the lower respiratory tract. IgG was the first class of virus-specific immunoglobulin to be detected in the lungs of infected animals after experimental infection. However, IgG was not detected until day 10 post-infection, 5 days after the initial decline of virus shedding. Virus-specific IgA although detectable did not appear in the lung until day 24.
 ...
PMID:Analysis of the local and systemic immune responses induced in BALB/c mice by experimental respiratory syncytial virus infection. 219 71

The cotton rat Sigmodon hispidus has provided an animal model of adenovirus pneumonia that permits investigation of the viral gene products required to produce the disease and the molecular mechanisms effecting the damage. This study was carried out to test the hypothesis that early region 3 (E3) of the adenovirus genome plays a critical role in pathogenesis of the virus's disease process even though none of its gene products are essential for its replication. Mutants whose E3 region is largely deleted (i.e., H2dl801 and H5dl327) replicated like wild-type virus in the cotton rats' lungs, but the lymphocyte and macrophage/monocyte inflammatory response was markedly increased. Viruses containing mutations that ablated production of the 19-kDa glycoprotein had the same effect as H2dl801 and H5dl327. However, mutants with deletions in the other E3 open reading frames, some of which encode known proteins, did not differ from wild-type virus in their pathogenic properties. The 19-kDa glycoprotein markedly reduces expression of the class I major histocompatibility complex antigens on the surface of infected cells. A complete correlation was found between those mutants that had increased pathogenic effects and those that lost the ability to reduce transport of the class I major histocompatibility complex antigens to surface of infected cells (i.e., all mutants unable to express the 19-kDa glycoprotein). H5sub304, which has a deletion between 83.2 and 85.1 map units in the E3B region and expresses the 19-kDa glycoprotein, did not increase the extent of pneumonia but qualitatively changed the inflammatory response in that increased numbers of polymorphonuclear leukocytes accumulated, often in small foci.
 ...
PMID:Role of early region 3 (E3) in pathogenesis of adenovirus disease. 272 53

Gold salt therapy-induced pneumonitis is a rare complication in patients with rheumatoid arthritis (RA). We studied HLA-A, B, C, D/DR, and complement factor B (Bf) and C4 alleles in 17 patients with RA and gold-induced pneumonitis and found that these patients had strikingly homogeneous major histocompatibility complex (MHC) markers. Eight of them (47 percent) had the alleles HLA-A3 B35 Dwl BfF C4A3,2 (BO), which were shown by family studies of some patients to be inherited as an extended MHC-haplotype with an apparent gene duplication in the C4A locus. The other high-risk phenotype, HLA-B40 with a C4 null allele, was found in eight patients (47 percent). All but three of the 17 patients had at least one of the two high-risk markers, the frequency of these combinations being clearly higher than in the two control groups: patients with RA but with no gold-induced side effects and healthy individuals. Our study shows that use of several MHC markers together results in a strong association between the markers and the disease.
 ...
PMID:Patients with rheumatoid arthritis and gold-induced pneumonitis express two high-risk major histocompatibility complex patterns. 311 96

Plasma concentrations of beta 2 microglobulin (B2M), the light chain of the class I major histocompatibility complex, were measured serially in 26 patients undergoing allogeneic bone marrow transplantation (BMT). The concentrations fell after conditioning treatment, and recovered when the marrow was transplanted. Bacterial infection did not influence B2M concentration, but nine of 22 episodes of acute graft versus host disease were associated with raised concentrations. Increased plasma B2M concentrations were also a feature of eight episodes of chronic graft versus host disease, and these fell after treatment. Reactivation of herpes simplex, varicella zoster, or cytomegalovirus infections were also accompanied by raised B2M concentrations. Three patients with cytomegalovirus pneumonitis had high concentrations of plasma B2M, the rise starting between five and 22 days before onset of symptoms. Although it is non-specific, serial measurement of plasma B2M in patients undergoing BMT may be clinically useful in monitoring chronic graft versus host disease.
 ...
PMID:Changes in plasma beta 2 microglobulin concentrations after allogeneic bone marrow transplantation. 330 8

C2 deficiency was demonstrated in an 11-year-old boy with a past history of recurrent purulent otitis media, pneumonia, H. influenzae meningitis and S. pneumoniae septicaemia. The major histocompatibility complex haplotypes present, A10, B18, DR2, BF*S, C2*QO, C4*A4, C4*B2 and A28, B18, DR2, BF*S, C2*Q0, C4*A4, C4*B2, were in accord with previous observations in C2 deficiency. The concentrations of C1q, C5, factor B and factor D were in the low normal range and the hemolytic activity of the alternative pathway was slightly decreased. In addition, the patient showed moderately low IgG2 concentrations and lacked the IgG2 subclass marker G2m(23). The findings indicate that the patient's susceptibility to bacterial infections may be due to C2 deficiency in combination with the presence of an IgG allotype associated with impaired antibody responses to carbohydrate antigens.
 ...
PMID:C2 deficiency, moderately low IgG2 concentrations and lack of the G2m(23) allotype marker in a child with repeated bacterial infections. 360 75

The pathogenesis of radiation pneumonitis is not completely understood. The long latent period and involvement of unirradiated lung tissue may indicate an immune reaction in the injurious process of irradiated lung. To investigate the role of pulmonary macrophages in radiation pneumonitis, morphology and membrane antigen expression of pulmonary macrophages were studied in irradiated rat lung tissue following 4000 R hemithoracic irradiation. Lungs were explanted at 2, 4, 6, 8, 16, and 28 weeks after irradiation. Cryosections of irradiated lung tissue were immunohistochemically studied, and alveolar macrophages in bronchoalveolar lavage fluid were also analyzed using monoclonal antibodies to rat major histocompatibility complex (MHC) antigens and macrophages with flow cytometry. Macrophage subpopulations were analyzed using a panel of monoclonal antibodies to MHC class I (HAM2), MHC class II (OX6) and macrophage differentiation antigens (ED1, ED2, ED3). Alveolar macrophages in bronchoalveolar lavage were morphologically studied by smear and flow cytometry of forward light scatter and 90 degrees light scatter. At 2 weeks after irradiation, when histological changes did not appear, small lymphocyte-like macrophages and large foamy macrophages were observed in both the smear and histograms by flow cytometry. At 4, 6, and 8 weeks after irradiation, these new populations had markedly increased. However, at 16 and 28 weeks after irradiation, the size and shape of alveolar macrophages had returned to normal. In the expression of macrophage membrane antigens, an increase in the frequency of MHC class II+ cells in lavaged cells appeared at 2 weeks after irradiation, and became significant at 4 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Pulmonary macrophages in rats after hemithoracic irradiation: analysis of morphology and expression of surface antigen]. 823 Aug 92

The purpose of this investigation was to determine whether there is any relationship between different subsets of alveolar macrophages and type of infection or survival from interstitial pneumonitis following bone marrow transplantation (BMT). The population of alveolar macrophages found in bronchoalveolar lavage fluid (BALF) from 16 BMT recipients with 19 episodes of interstitial pneumonitis was investigated, using immunocytochemical methods. Results were compared with those from seven normal volunteers. The results showed that patients with pneumonitis had significantly higher numbers of total cells in BALF than normals but reduced proportions of macrophages, although the absolute numbers were unchanged. Of the cells present which were morphologically macrophages, there were raised proportions of both RFD1+ cells (interdigitating cells) and RFD7+ cells (mature macrophages) in patients compared with normals, but expansion of these two subsets could be explained, in part, by a significant increase in cells positive for both markers (42% in patients compared with 9% in normals). Proportions of cells with the monocyte phenotype (CD14+, UCHM1) were also significantly raised in patients with pneumonitis (17% compared with 6% in normals). These patients, however, had significantly reduced proportions of macrophage-like cells which were positive for the DR antigen (Class II major histocompatibility complex (MHC) antigen) (47% compared with 88% in normals), and this abnormality was greater still in patients who died from pneumonitis (40%) compared with those who survived (52%). The results of this study indicate a breakdown of local immunoregulation, thus contributing to the high incidence of, and mortality from, opportunistic pulmonary infections in this group.
 ...
PMID:Abnormal alveolar macrophage populations in bone marrow transplant recipients with pneumonitis. 828 45

Sendai virus pneumonia in beta 2-microglobulin-deficient [beta 2-m(-/-)] mice lacking CD8+ T cells is characterized by the development of CD4+ cytotoxic T lymphocytes that can be recovered directly from the respiratory tract. These CD4+ cytotoxic T lymphocytes are not found in beta 2-m (+/+) mice, though inflammatory CD4+ T cells from both beta 2-m (-/-) and beta 2-m (+/+) mice produce substantial amounts of tumor necrosis factor alpha. Blocking experiments with a monoclonal antibody that also inhibits tumor necrosis factor beta show that the secreted forms of these two cytokines are not responsible for virus-specific killing of class II major histocompatibility complex-compatible targets. Comparison of electron micrographs indicates that the CD4+ effectors from the beta 2-m (-/-) mice are potent inducers of apoptosis, while this is not the case for the beta 2-m (+/+) CD4+ set. These experiments further define the functional status of virus-specific CD4+ T cells responding in vivo in the presence or absence of CD8+ effectors.
 ...
PMID:Divergence between cytotoxic effector function and tumor necrosis factor alpha production for inflammatory CD4+ T cells from mice with Sendai virus pneumonia. 839 84

A murine model of pneumonia due to the mouse pneumonitis agent (MoPn [murine Chlamydia trachomatis]) in mice deficient in CD4+ T-cell function (major histocompatibility complex [MHC] class II function [class II-/-], CD8+ T-cell function (beta2-microglobulin deficient, MHC class I deficient [Beta2m-/-]), B-cell function (C57BL/10J-Igh(tm1Cgn) [Igh-/-]), and gamma interferon (IFN-gamma) (C57BL/6-Ifg(tm1) [Ifg-/-]) or interleukin-4 (C57BL/6J(tm1Cgn29) [IL4-/-]) production was employed to determine if each of these mechanisms was critical to resistance against reinfection by C. trachomatis or if alternate compensatory mechanisms existed in their absence which could potentially be exploited in vaccine development. Resistance to reinfection with MoPn was heavily dependent on CD4+ T cells. CD4 T-cell-deficient MHC class II-/- mice were very susceptible to reinfection with MoPn, showing the critical importance of this cell to resistance. These mice lacked antibody production but did produce IFN-gamma, apparently by mechanisms involving NK and CD8+ T cells. Neutralization of IFN-gamma in these mice led to a borderline increase in susceptibility, showing a possible role (albeit small) of this cytokine in this setting. Tumor necrosis factor alpha (TNF-alpha) was also present at increased levels in these mice. Igh-/- B-cell-deficient mice which produce no antibody to MoPn were only modestly more susceptible to reinfection than immunized B-cell-intact controls, showing that antibody, including lung immunoglobulin A, is not an absolute requirement for relatively successful host defense in this setting. Levels of lung IFN-gamma and TNF-alpha were elevated in Igh-/- mice compared to those in controls. IL-4-/- mice (deficient in Th2 function) could develop normal resistance to reinfection with MoPn. Conversely, normal mice rendered partially IFN-gamma deficient by antibody depletion were somewhat impaired in their ability to develop acquired immunity to MoPn, again indicating a role for this cytokine in host defense against rechallenge. Of most importance, however, congenitally IFN-gamma-deficient Ifg-/- mice (which have elevated levels of other cytokines, including TNF-alpha and granulocyte-macrophage colony-stimulating factor) are paradoxically more resistant to MoPn rechallenge than controls, showing that IFN-gamma is not an absolute requirement for acquired resistance and implying the presence of very effective compensatory host defense mechanism(s). In vivo depletion of TNF-alpha significantly increased MoPn levels in the lungs in these mice. Thus, resistance to reinfection in this model is flexible and multifactorial and is heavily dependent on CD4+ T cells, with a probable role for IFN-gamma and TNF-alpha and a possible modest role for Th1-dependent antibody. Since IFN-gamma was dispensable in host defense, the highly effective mechanism or mechanisms which can compensate for its absence (which include TNF-alpha) deserve further study.
 ...
PMID:Humoral and cellular immunity in secondary infection due to murine Chlamydia trachomatis. 919 62


1 2 3 4 Next >>