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Biomedical subjects

S Rosseau

Publications and source records attributed to S Rosseau.

At least 19 recordsLinked to original sources
PubMed2006

Allergic lung inflammation induces pulmonary vascular hyperresponsiveness.

Pulmonary arterial vasoconstriction is an important early component of pulmonary hypertension. Inflammatory mechanisms play a prominent role in the pathogenesis of pulmonary hypertension. The present authors investigated the potential role of acute allergic lung inflammation for alterations in pulmonary haemodynamics. BALB/c mice were intraperitoneally sensitised to ovalbumin and challenged by ovalbumin inhalation. Subsequently, lungs were ventilated and perfused ex vivo, and pulmonary arterial pressure (P(pa)) was continuously monitored. Isolated perfused lungs of allergen-sensitised and -challenged mice showed five-fold enhanced P(pa) responses to serotonin, which is reported to be a significant contributor to pulmonary hypertension in humans. This increase in P(pa) was abolished by the serotonin receptor-2A antagonist ketanserin, but not the serotonin receptor-1B antagonist GR127935. Intracellular signalling to serotonin involved phosphatidylcholine-specific phospholipase C and protein kinase C, as well as Rho-kinase, as assessed by employing the specific inhibitors D609, bisindolylmaleimide and Y27632, respectively. In addition to serotonin, impressively enhanced P(pa) increases in allergic lungs were also evoked by the thromboxane receptor agonist U46619, angiotensin II and endothelin-1. In conclusion, allergic lung inflammation was accompanied by impressive pulmonary vascular hyperresponsiveness. These results suggest a possible role for allergic inflammation in the development of pulmonary arterial hypertension.

Animals↗
PubMed2001

Short-term "preconditioning" with inhaled nitric oxide protects rabbit lungs against ischemia-reperfusion injury.

BACKGROUND: Pulmonary edema, owing to an impairment of microvascular barrier function, is an important feature in lung ischemia/reperfusion (IR) injury. Inhalation of nitric oxide (NO) during the period of reperfusion has previously been shown to reduce this leakage response. METHODS: We investigated the impact of short-term (30 min) low-dose (10 ppm) pre-ischemic NO inhalation on IR injury in buffer-perfused rabbit lungs, subsequently undergoing 210 min of warm, anoxic-ventilated ischemia. RESULTS: Far-reaching suppression of the leakage response, reflected by manifold increased capillary filtration coefficients and edema formation, was noted in lungs with pre-ischemic NO administration, corresponding to the beneficial effect of NO inhalation during reperfusion. The effect of NO pre-exposure was not related to vasodilation, because microvascular pressures were unchanged, and was mimicked by pre-ischemic intravascular administration of sodium nitroprusside with subsequent washout of this agent. NO inhalation during reperfusion, but not pre-ischemic, short-term NO administration, provoked a manifold increase in the accumulation of guanosine 3',5'-cyclic monophosphate (cGMP) in the perfusate. The cGMP-analogue, 8-Br-cGMP, mimicked the anti-edematous effect of NO when present during reperfusion, but pre-ischemic, short-term administration of 8-Br-cGMP provided only limited protection. The guanylate cyclase-inhibitor, 1H-[1, 2, 4]-Oxadiazolo-[4,3-a]-quinoxalin-1-one (ODQ), largely antagonized the beneficial effects of NO inhalation during reperfusion but had only minor influence on the effect of NO pre-exposure. CONCLUSIONS: "Preconditioning" of the lung vasculature with short-term NO administration maintains endothelial integrity in a subsequent ischemia/reperfusion maneuver, with nonvasodilatory and non-cGMP-related mechanisms suggested to be largely responsible. This finding may offer interesting perspectives for donor management in clinical lung transplantation.

Administration, Inhalation↗
PubMed2001

Monocytes recruited into the alveolar air space of mice show a monocytic phenotype but upregulate CD14.

The evaluation of monocytes recruited into the alveolar space under both physiological and inflammatory conditions is hampered by difficulties in discriminating these cells from resident alveolar macrophages (rAMs). Using the intravenous injected fluorescent dye PKH26, which accumulated in rAMs without labeling blood leukocytes, we developed a technique that permits the identification, isolation, and functional analysis of monocytes recruited into lung alveoli of mice. Alveolar deposition of murine JE, the homologue of human monocyte chemoattractant protein (MCP)-1 (JE/MCP-1), in mice provoked an alveolar influx of monocytes that were recovered by bronchoalveolar lavage and separated from PKH26-stained rAMs by flow cytometry. Alveolar recruited monocytes showed a blood monocytic phenotype as assessed by cell surface expression of F4/80, CD11a, CD11b, CD18, CD49d, and CD62L. In contrast, CD14 was markedly upregulated on alveolar recruited monocytes together with increased tumor necrosis factor-alpha message, discriminating this monocyte population from peripheral blood monocytes and rAMs. Thus monocytes recruited into the alveolar air space of mice in response to JE/MCP-1 keep phenotypic features of blood monocytes but upregulate CD14 and are "primed" for enhanced responsiveness to endotoxin with increased cytokine expression.

Animals↗
PubMed2000

Infection and activation of airway epithelial cells by Chlamydia pneumoniae.

The activation of primary human airway epithelial cells (HAECs) and of the bronchial epithelial cell line BEAS-2B by Chlamydia pneumoniae, an important respiratory pathogen, was characterized. A time-dependent enhanced release of interleukin (IL)-8 and prostaglandin-E(2) and an increased expression of the epithelial adhesion molecule intercellular adhesion molecule-1 (ICAM-1), followed by subsequent transepithelial migration of polymorphonuclear neutrophils (PMN), were also demonstrated. The transepithelial PMN migration could be blocked by an anti-ICAM-1 monoclonal antibody (MAb) but not by MAbs against IL-8. In addition, there was an enhanced C. pneumoniae-mediated activation of NF-kappaB within 30-60 min in HAECs and BEAS-2B, which was followed by increases in mRNA synthesis of IL-8, ICAM-1, and cyclooxygenase-2, with maximal effects occurring 2 h after infection. Thus, C. pneumoniae infects and activates HAECs and BEAS-2B and therefore may be able to trigger a cascade of pro- and anti-inflammatory reactions during chlamydial infections.

Antibodies, Monoclonal↗
PubMed2000

Monocyte migration through the alveolar epithelial barrier: adhesion molecule mechanisms and impact of chemokines.

Alveolar monocyte influx requires adherence and transmigration through the vascular endothelium, extracellular matrix, and alveolar epithelium. For investigating the monocyte migratory process across the epithelial barrier, we employed both the A549 cell line and isolated human alveolar epithelial cells. Under baseline conditions, spontaneous bidirectional transepithelial monocyte migration was noted, which was dose-dependently increased in the presence of the monocyte chemoattractant protein-1. TNF-alpha stimulation of the alveolar epithelium provoked the polarized apical secretion of monocyte chemoattractant protein-1 and RANTES and up-regulation of ICAM-1 and VCAM-1 expression, accompanied by markedly enhanced transepithelial monocyte traffic in the basal-to-apical direction. Multiple adhesive interactions were noted to contribute to the enhanced monocyte traffic across the TNF-alpha-stimulated alveolar epithelium: these included the beta 2 integrins CD11a, CD11b, CD11c/CD18, the beta 1 integrins very late Ag (VLA)-4, -5, and -6, and the integrin-associated protein CD47 on monocytes, as well as ICAM-1, VCAM-1, CD47, and matrix components on the epithelial side. In contrast, spontaneous monocyte migration through unstimulated epithelium depended predominantly on CD11b/CD18 and CD47, with some additional contribution of VLA-4, -5, and -6. In summary, unlike transendothelial monocyte traffic, for which beta 1 and beta 2 integrins are alternative mechanisms, monocyte migration across the alveolar epithelium largely depends on CD11b/CD18 and CD47 but required the additional engagement of the beta 1 integrins for optimal migration. In response to inflammatory challenge, the alveolar epithelium orchestrates enhanced monocyte traffic to the apical side by polarized chemokine secretion and up-regulation of ICAM-1 and VCAM-1.

Cell Adhesion Molecules↗
PubMed2000

Antisense oligomers for selective suppression of MCP-1 synthesis in human pulmonary endothelial cells.

Endothelial synthesis of the C-C chemokine monocyte chemotactic protein-1 (MCP-1) has been implicated in the regulation of monocyte recruitment for extravascular pools under both physiologic and inflammatory conditions. We designed and characterized five antisense phosphorothioate oligodeoxynucleotides (PS-ODN) targeting MCP-1 secretion by human pulmonary artery endothelial cells (HPAEC) and pulmonary microvascular endothelial cells (HMVEC-L). The most effective PS-ODN (MCP-1 AS 2) dose-dependently suppressed the secretion of MCP-1 but not the secretion of the C-X-C chemokine interleukin-8 (IL-8) in both HPAEC and HMVEC-L in the nanomolar concentration range. Mismatch controls bearing 2 or 4 bp substitutions showed markedly reduced inhibitory capacity. MCP-1 mRNA levels were not affected even at the highest PS-ODN doses employed (ribonuclease protection assay), suggesting a translational arrest of MCP-1 production. Accordingly, PS-ODN exhibited no nonspecific side effects on immediate-early gene regulation of the transcription factor nuclear factor-kappaB (NF-kappaB), as analyzed by gel shift assays. Antisense pretreatment of HPAEC reduced the monocyte chemotactic bioactivity liberated from tumor necrosis factor-alpha (TNF-alpha)-activated endothelial cells (EC) and reduced the TNF-alpha-induced transendothelial monocyte migration. We conclude that nanomolar concentrations of specific antisense oligodeoxynucleotides effectively inhibit human endothelial MCP-1 synthesis and may thus provide a rational approach to modulate monocyte recruitment under inflammatory conditions.

Cell Line↗
PubMed2000

Phenotypic characterization of alveolar monocyte recruitment in acute respiratory distress syndrome.

In 49 acute respiratory distress syndrome (ARDS) patients, the phenotype of alveolar macrophages (AMs) was analyzed by flow cytometry. Bronchoalveolar lavage (BAL) was performed within 24 h after intubation and on days 3-5, 9-12, and 18-21 of mechanical ventilation. The 27E10(high)/CD11b(high)/CD71(low)/ 25F9(low)/HLA DR(low)/RM3/1(low) AM population in the first BAL indicated extensive monocyte influx into the alveolar compartment. There was no evidence of increased local AM proliferation as assessed by nuclear Ki67 staining. Sequential BAL revealed two distinct patient groups. In one, a decrease in 27E10 and CD11b and an increase in CD71, 25F9, HLA DR, and RM3/1 suggested a reduction in monocyte influx and maturation of recruited cells into AMs, whereas the second group displayed sustained monocyte recruitment. In the first BAL from all patients, monocyte chemoattractant protein (MCP)-1 was increased, and AMs displayed elevated MCP-1 gene expression. In sequential BALs, a decrease in MCP-1 coincided with the disappearance of monocyte-like AMs, whereas persistent upregulation of MCP-1 paralleled ongoing monocyte influx. A highly significant correlation between BAL fluid MCP-1 concentration, the predominance of monocyte-like AMs, and the severity of respiratory failure was noted.

Adult↗
PubMed2000

The PDE inhibitor zaprinast enhances NO-mediated protection against vascular leakage in reperfused lungs.

Disruption of endothelial barrier properties with development of noncardiogenic pulmonary edema is a major threat in lung ischemia-reperfusion (I/R) injury that occurs under conditions of lung transplantation. Inhaled nitric oxide (NO) reduced vascular leakage in lung I/R models, but the efficacy of this agent may be limited. We coadministered NO and zaprinast, a cGMP-specific phosphodiesterase inhibitor, to further augment the NO-cGMP axis. Isolated, buffer-perfused rabbit lungs were exposed to 4.5 h of warm ischemia. Reperfusion provoked a transient elevation in pulmonary arterial pressure and a negligible rise in microvascular pressure followed by a massive increase in the capillary filtration coefficient and severe lung edema formation. Inhalation of 10 parts/million of NO or intravascular application of 100 microM zaprinast on reperfusion both reduced pressor response and moderately attenuated vascular leakage. Combined administration of both agents induced no additional vasodilation at constant microvascular pressures, but additively protected against capillary leakage paralleled by a severalfold increase in perfusate cGMP levels. In conclusion, combining low-dose NO inhalation and phosphodiesterase inhibition may be suitable for the maintenance of graft function in lung transplantation by amplifying the beneficial effect of the NO-cGMP axis and avoiding toxic effects of high NO doses.

Animals↗
PubMed1999

Surfactant protein A down-regulates proinflammatory cytokine production evoked by Candida albicans in human alveolar macrophages and monocytes.

Surfactant protein A (SP-A) has been implicated in the regulation of pulmonary host defense and inflammatory events. We analyzed the impact of SP-A on the Candida albicans-induced cytokine response in human alveolar macrophages (AM) and its precursor cells, the monocytes, which rapidly expand the alveolar mononuclear phagocyte pool under inflammatory conditions. Both recombinant human SP-A and natural canine SP-A were employed. SP-A dose-dependently down-regulated the proinflammatory cytokine response of AM and monocytes to both viable and nonviable Candida, including TNF-alpha, IL-1beta, macrophage inflammatory protein-1alpha, and monocyte chemoattractant protein-1. In contrast, SP-A did not affect the baseline liberation of these cytokines. The release of the antiinflammatory cytokines IL-1 receptor antagonist and IL-6 was not inhibited by SP-A under baseline conditions and in response to fungal challenge. The inhibitory effect of SP-A on proinflammatory cytokine release was retained upon reassembly of the apoprotein with natural surfactant lipids and in the presence of serum constituents, for mimicry of plasma leakage into the alveolar space. It was not reproduced by the homologous proteins complement component C1q and type IV collagen. It was independent of Candida-SP-A binding and phagocyte C1q receptor occupancy, but apparently demanded SP-A internalization by the mononuclear phagocytes, effecting down-regulation of proinflammatory cytokine synthesis at the transcriptional level. We conclude that SP-A limits excessive proinflammatory cytokine release in AM and monocytes confronted with fungal challenge in the alveolar compartment. These data lend further credit to an important physiological role of SP-A in regulating alveolar host defense and inflammation.

Blood Proteins↗
PubMed1999

Surfactant abnormalities in idiopathic pulmonary fibrosis, hypersensitivity pneumonitis and sarcoidosis.

Bronchoalveolar lavage fluids (BALF) from patients with idiopathic pulmonary fibrosis (IPF; n=36), hypersensitivity pneumonitis (HP; n=32) and sarcoidosis (n=44) were investigated for their surfactant properties and compared to healthy control subjects (n=29). The phospholipid (PL) and protein concentration, the PL:protein ratio, PL subclasses, and the surfactant apoproteins (SP)A and SP-B were quantified in BALF. Large surfactant aggregates (LSA) were measured by means of ultracentrifugation and assayed for surface activity using the pulsating bubble surfactometer. As compared to controls, SP-A concentrations, LSA content and PL:protein ratios were significantly decreased in all groups, whereas PL and SP-B concentrations remained unchanged. Changes in the phospholipid profile, with reduced percentages of phosphatidylcholine (not significant) and phosphatidylglycerol and increased fractions of phosphatidylinositol and sphingomyelin (p<0.05), occurred more in IPF than in HP, and not in sarcoidosis. Surface activity was found to be severely impaired in IPF (minimum surface tension (gamma min) approximately 15-20 mN x m(-1)), but only modestly affected in HP and sarcoidosis (gamma min approximately 5 mN x m(-1)) compared to controls (gamma min approximately 0 mN x m(-1)). Reconstitution of pelleted surfactant material with soluble BALF proteins further increased gamma min values. In conclusion, moderate changes in biochemical and physical surfactant properties are encountered in hypersensitivity pneumonitis and sarcoidosis, but pronounced disturbances occur in idiopathic pulmonary fibrosis.

Adolescent↗
PubMed1999

Expression of mucosa-related integrin alphaEbeta7 on alveolar T cells in interstitial lung diseases.

The expression of alphaEbeta7 integrin has been related to the selective retention of lymphocytes in mucosal tissues of gut, urogenital tract and lung. To identify potential disease-associated alphaEbeta7 expression patterns on cells accounting for lymphocytic alveolitis in interstitial lung disease (ILD), alphaE expression on CD4+ and CD8+ T cell subsets was evaluated by dual-colour flow cytometry in peripheral blood and bronchoalveolar lavage fluid (BALF) of patients with idiopathic pulmonary fibrosis (IPF; n = 18), hypersensitivity pneumonitis (HP; n = 20) and sarcoidosis (n = 44) in comparison with healthy controls (n = 15). In both healthy individuals and all patient groups the proportion of alphaE-bearing T cells in peripheral blood was < 2%, whereas the vast majority of alveolar CD8+ T cells consistently co-expressed alphaE. Absolute alveolar CD8+alphaE+ cell numbers/ml were up to 30-fold increased in HP patients. Proportions of alphaE-bearing CD4+ cells in BALF were significantly elevated in IPF (74.0 +/- 2.7%) and HP (70.0 +/- 2.4%) compared with normals (30.0 +/- 1.8%) (mean +/- s.e.m.; P < 0.01). In sarcoidosis, the alphaE expression on BALF CD4+ cells displayed subgroup dependency: proportions significantly lower than normal were noted in chest radiographic stage I (14.3 +/- 1.5%), but increased proportions in stages II (50.0 +/- 3.8%) and III (64.0 +/- 4.8%). Correlations between common markers of T cell activation or BALF transforming growth factor-beta (TGF-beta ) bioactivity and alphaE expression were not noted. We conclude that the vast majority of alveolar CD8+ T cells consistently express alphaEbeta7 and that distinct patterns of alphaEbeta7 expression on alveolar CD4+ lymphocytes in sarcoidosis are related to the diverse manifestations of the sarcoid inflammatory process in the lung.

Adolescent↗
PubMed1999

Cationic lipids employed for antisense oligodeoxynucleotide transport may inhibit vascular cell adhesion molecule-1 expression in human endothelial cells: a word of caution.

Antisense oligodeoxynucleotides (ODN) have become a powerful tool to achieve specific gene inhibition in various cell types, including endothelial cells. The low spontaneous cellular uptake of ODN, however, usually requires the employment of transmembrane carriers, such as the positively charged liposome formulation dioleyloxypropyltrimethyl ammonium chloride/dioleoylphosphatidylethanolamine (DOTMA/DOPE). In the present study, we observed that DOTMA/DOPE per se interferes with the inducible expression of vascular cell adhesion molecule-1 (VCAM-1) in human pulmonary artery endothelial cells (HPAEC). By RT-PCR analysis, a dose-dependent suppression of VCAM-1 but not intracellular adhesion molecule-1 (ICAM-1) mRNA levels in tumor necrosis factor-alpha (TNF-alpha)-challenged HPAEC pretreated with DOTMA/DOPE (5-20 microg/ml) was demonstrated. Correspondingly, a strong reduction of TNF-alpha-induced VCAM-1 but not ICAM-1 cell surface expression on HPAEC was observed. These DOTMA/DOPE-induced changes were not due to alterations in VCAM-1 mRNA stability, nor did DOTMA/DOPE inhibit TNF-alpha-induced NF-kappaB-like binding activity in nuclear extracts of HPAEC, as analyzed by electrophoretic mobility shift assay. In contrast, DOTMA/DOPE effected a dose-dependent increase in AP-1-like binding activity in nuclear extracts of HPAEC, as analyzed by Western blotting and EMSA. We conclude that positively charged liposome preparations may per se inhibit TNF-alpha-induced endothelial VCAM-1 expression, and this may be related to changes in AP-1 but not NF-kappaB-dependent transcriptional control. Notably, when used at concentrations below 5 microg/ml, DOTMA/DOPE may be employed for specific antisense-mediated downregulation of VCAM-1 in the absence of vehicle-related side effects on adhesion molecule transcription.

Blotting, Western↗
PubMed1999

Evidence for a role of protein kinase C in hypoxic pulmonary vasoconstriction.

Hypoxic pulmonary vasoconstriction (HPV) matches lung perfusion to ventilation, thus optimizing gas exchange. NADPH oxidase-related superoxide anion generation has been suggested as part of the signaling response to hypoxia. Because protein kinase (PK) C activation can occur during hypoxia and PKC activation is known to be critical for NADPH oxidase stimulation in different cell types, we probed the role of PKC in hypoxic vasoconstriction in intact rabbit lungs. Control vasoconstrictor responses were elicited by angiotensin II (ANG II) and the stable thromboxane analog U-46619. Portions of the experiments were performed while NO synthesis and prostanoid generation were blocked with NG-monomethyl-L-arginine and acetylsalicylic acid to avoid confounding effects due to interference with these vasoactive mediators. The PKC inhibitor H-7 (10-50 microM) caused dose-dependent inhibition of HPV, but this agent lacked specificity because ANG II- and U-46619-induced vasoconstrictions were correspondingly suppressed. In contrast, low concentrations of the specific PKC inhibitor bisindolylmaleimide I (BIM; 1-15 microM) strongly inhibited the hypoxic vasoconstriction without any interference with the responses to the pharmacological agents. Superimposable dose-inhibition curves were also obtained for BIM when lung NO synthesis and prostanoid generation were blocked throughout the experiments. Under either condition, BIM did not affect normoxic vascular tone. The PKC activator farnesylthiotriazole (FTT), ascertained to stimulate rabbit NADPH oxidase by provocation of alveolar macrophage superoxide anion generation in vitro, caused rapid-onset, transient pressor responses in normoxic lungs. After FTT, the hypoxic vasoconstrictor response was totally suppressed, in contrast to the largely maintained pressor responses to ANG II and U-46619. The lungs became refractory even to delayed hypoxic challenges after FTT application. In conclusion, these data support the concept that activation of PKC is involved in the transduction pathway forwarding pulmonary vasoconstriction in response to alveolar hypoxia.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1998

Expression of pro-inflammatory cytokines by flow-sorted alveolar macrophages in severe pneumonia.

The aim of the present study was to further characterize the role of alveolar macrophages (AM) in acute human lung inflammation by evaluating their capacity to produce pro-inflammatory cytokines such as tumour necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-8. Patients with severe community-acquired pneumonia (CAP; n=12) and healthy volunteers (n=10) underwent bronchoalveolar lavage (BAL). AM were separated to high purity (>96%) using fluorescence-activated cell sorting. We determined the TNF-alpha, IL-6 and IL-8 cytokine gene expression in AM ex vivo using semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). Moreover, we measured in vitro unstimulated, lipopolysaccharide (LPS)- and LPS/interferon-gamma inducible TNF-alpha, IL-6 and IL-8 cytokine release and evaluated samples of BAL fluids for the same pro-inflammatory cytokines using an enzyme-linked immunosorbent assay (ELISA). We found increased TNF-alpha, IL-6 and IL-8 messenger ribonucleic acid (mRNA) levels in AM from CAP patients that were significantly elevated only for IL-8. When challenged with endotoxin in vitro, AM obtained from CAP patients showed a strongly reduced potential to release TNF-alpha and IL-6 compared to healthy controls, whereas IL-8 secretion did not differ significantly between groups. Moreover, stimulation of AM from CAP patients with LPS plus IFN-gamma augmented TNF-alpha and IL-6 cytokine release to near normal levels. Interestingly, no TNF-alpha protein was measured in BAL samples from CAP patients, whereas IL-6 and IL-8 protein levels were found to be significantly increased. Together, highly purified alveolar macrophages from community-acquired pneumonia patients show relatively low ex vivo tumour necrosis factor-alpha and interleukin-6 but not interleukin-8 messenger ribonucleic acid levels that are associated with a decreased pro-inflammatory cytokine release in vitro which, however, can be restored by concurrent interferon-gamma stimulation.

Adult↗
PubMed1997

Phagocytosis of viable Candida albicans by alveolar macrophages: lack of opsonin function of surfactant protein A.

Surfactant protein A (SP-A) contributes to host defense by opsonizing microbial organisms for phagocytosis by alveolar macrophages (AM). The role of SP-A as opsonin for phagocytosis of Candida albicans was analyzed. AM in suspension exhibited no phagocytosis of nonopsonized yeast. This was not increased by SP-A, whether provided for preincubation of AM or yeast or present during coincubation. However, the engulfment of serum-opsonized yeast by AM in suspension was inhibited by SP-A. This inhibitory effect was mimicked by complement subcomponent C1q and concanavalin A but not by type IV collagen. SP-A did not interfere with phagocytosis of serum-opsonized yeast by adherent AM, monocytes, neutrophils, or peritoneal macrophages. SP-A lacks function as an opsonin for the phagocytosis of C. albicans by AM but interferes with binding of yeast to AM, inhibiting subsequent ingestion. The role of SP-A as an alveolar space opsonin may thus critically depend on the microbial species involved.

Animals↗