Treatment with IgM-enriched intravenous immunoglobulins (IgM-IVIg) enhances clearance of stroke-associated bacterial lung infection

Post-stroke infection is a common complication of stroke that is associated with increased mortality and morbidity. We previously found that experimental stroke induces an ablation of multiple sub-populations of B cells and reduced levels of IgM antibody that coincide with the development of spontaneous bacterial pneumonia. Reduced circulating IgM concentrations were also observed in acute stroke patients. The loss of IgM antibody after stroke could be an important determinant of infection susceptibility and highlights this pathway as an important target for intervention. We treated mice with a low (replacement), dose of IgM-enriched intravenous immunoglobulin (IgM-IVIg) prior to and 24 h after experimental stroke induced by middle cerebral artery occlusion (MCAO) or sham surgery, then recovered mice for 2 d or 5 d. The effect of treatment on lung bacterial burden, lung pathology, brain infarct volume, antibody levels and both lung and systemic cellular and cytokine immune profiles was determined. Treatment with IgM-IVIg enhanced bacterial clearance from the lung after MCAO and improved pathology but did not impact infarct volume. IgM-IVIg treatment induced immunomodulatory effects systemically including rescue of splenic plasma B cell numbers and endogenous mouse IgM and IgA circulating immunoglobulin concentrations that were reduced by MCAO, and treatment also reduced concentrations of pro-inflammatory cytokines in the lung. The effects of MCAO and IgM-IVIg treatment on the immune system were tissue specific as no impact on B cells or mouse immunoglobulins were found within the lung. However, the presence of human immunoglobulins from the IgM-IVIg treatment led to increased total lung immunoglobulin concentration. IgM-IVIg treatment did not increase the number of lung mononuclear phagocytes or directly modulate macrophage phagocytic capacity but enhanced their capability to phagocytose Staphylococcus aureus bioparticles in vitro by increasing opsonisation. Low dose IgM-IVIg contributes to increased clearance of spontaneous lung bacteria after MCAO likely via increasing availability of antibody in the lung to enhance phagocytic activity. Immunomodulatory effects of IgM-IVIg treatment, including reduced pro-inflammatory cytokine production, may also contribute to reduced levels of damage in the lung after MCAO. IgM-IVIg shows promise as an antibacterial and immunomodulatory agent to use in the treatment of post-stroke infection.

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The Asparaginyl Endopeptidase Legumain after Experimental Stroke

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2010.39 ◽

2010 ◽

Vol 30 (10) ◽

pp. 1756-1766 ◽

Cited By ~ 17

Author(s):

Taku Ishizaki ◽

Agnes Erickson ◽

Enida Kuric ◽

Mehrdad Shamloo ◽

Ikuko Hara-Nishimura ◽

...

Keyword(s):

Immune Cell ◽

Infarct Volume ◽

Recovery Period ◽

Gene Array ◽

Stroke Recovery ◽

Experimental Stroke ◽

Post Stroke ◽

Asparaginyl Endopeptidase ◽

Infarct Area ◽

Deficient Mice

Various proteases in the brain contribute to ischemic brain injury. We investigated the involvement of the asparaginyl endopeptidase legumain after experimental stroke. On the basis of gene array studies and in situ hybridizations, we observed an increase of legumain expression in the peri-infarct area of rats after transient occlusion of the middle cerebral artery (MCAO) for 120 mins with a maximum expression at 24 and 48 h. Immunohistochemical analyses revealed the expression of legumain in Iba1+ microglial cells and glial fibrillary acidic protein-positive astrocytes of the peri-infarct area in mice after MCAO. Post-stroke recovery was also studied in aged legumain-deficient mice (45 to 58 weeks old). Legumain-deficient mice did not show any differences in physiologic parameters compared with respective littermates before, during MCAO (45 mins), and the subsequent recovery period of 8 days. Moreover, legumain deficiency had no effect on mortality, infarct volume, and the neurologic deficit determined by the rotating pole test, a standardized grip strength test, and the pole test. However, a reduced number of invading CD74+ cells in the ischemic hemisphere indicates an involvement in post-stroke inflammation. We conclude that legumain is not essential for the functional deficit after MCAO but may be involved in mechanisms of immune cell invasion.

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Short-duration hypothermia completed prior to reperfusion prevents intracranial pressure elevation following ischaemic stroke in rats

Scientific Reports ◽

10.1038/s41598-021-01838-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Daniel Omileke ◽

Sara Azarpeykan ◽

Steven W. Bothwell ◽

Debbie Pepperall ◽

Daniel J. Beard ◽

...

Keyword(s):

Intracranial Pressure ◽

Ischaemic Stroke ◽

Short Duration ◽

Infarct Volume ◽

Arterial Occlusion ◽

Reperfusion Therapy ◽

Artery Occlusion ◽

Experimental Stroke ◽

Stroke Patients ◽

Post Stroke

AbstractReperfusion therapies re-establish blood flow after arterial occlusion and improve outcome for ischaemic stroke patients. Intracranial pressure (ICP) elevation occurs 18–24 h after experimental stroke. This elevation is prevented by short-duration hypothermia spanning the time of reperfusion. We aimed to determine whether hypothermia-rewarming completed prior to reperfusion, also prevents ICP elevation 24 h post-stroke. Transient middle cerebral artery occlusion was performed on male outbred Wistar rats. Sixty-minute hypothermia to 33 °C, followed by rewarming was induced prior to reperfusion in one group, and after reperfusion in another group. Normothermia controls received identical anaesthesia protocols. ΔICP from pre-stroke to 24 h post-stroke was measured, and infarct volumes were calculated. Rewarming pre-reperfusion prevented ICP elevation (ΔICP = 0.3 ± 3.9 mmHg vs. normothermia ΔICP = 5.2 ± 2.1 mmHg, p = 0.02) and reduced infarct volume (pre-reperfusion = 78.6 ± 23.7 mm3 vs. normothermia = 125.1 ± 44.3 mm3, p = 0.04) 24 h post-stroke. There were no significant differences in ΔICP or infarct volumes between hypothermia groups rewarmed pre- or post-reperfusion. Hypothermia during reperfusion is not necessary for prevention of ICP rise or infarct volume reduction. Short-duration hypothermia may be an applicable early treatment strategy for stroke patients prior to- during-, and after reperfusion therapy.

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Hypothermia and rewarming prior to reperfusion, prevents intracranial pressure elevation after ischaemic stroke in rats: an investigation to define the importance of cooling during reperfusion

10.21203/rs.3.rs-846595/v1 ◽

2021 ◽

Author(s):

Daniel Omileke ◽

Sara Azarpeykan ◽

Steven W Bothwell ◽

Debbie Pepperall ◽

Daniel J Beard ◽

...

Keyword(s):

Intracranial Pressure ◽

Ischaemic Stroke ◽

Short Duration ◽

Infarct Volume ◽

Arterial Occlusion ◽

Reperfusion Therapy ◽

Artery Occlusion ◽

Experimental Stroke ◽

Stroke Patients ◽

Post Stroke

Abstract Reperfusion therapies re-establish blood flow after arterial occlusion and improve outcome for ischaemic stroke patients. Intracranial pressure (ICP) elevation occurs 18–24 h after experimental stroke. This elevation is prevented by short-duration hypothermia spanning the time of reperfusion. We aimed to determine whether hypothermia-rewarming completed prior to reperfusion, also prevents ICP elevation 24 h post-stroke. Transient middle cerebral artery occlusion was performed on male outbred Wistar rats. Sixty-minute hypothermia to 33℃, followed by rewarming was induced prior to reperfusion in one group, and after reperfusion in another group. Normothermia controls received identical anaesthesia protocols. ΔICP from pre-stroke to 24 h post-stroke was measured, and infarct volumes were calculated. Rewarming pre-reperfusion prevented ICP elevation (ΔICP = 0.3 ± 3.9 mmHg vs. normothermia ΔICP = 5.2 ± 2.1 mmHg, p = 0.02) and reduced infarct volume (pre-reperfusion = 78.6 ± 23.7 mm3 vs. normothermia = 125.1 ± 44.3 mm3, p = 0.04) 24 h post-stroke. There were no significant differences in ΔICP or infarct volumes between hypothermia groups rewarmed pre-or post-reperfusion. Hypothermia during reperfusion is not necessary for prevention of ICP rise or infarct volume reduction. Short-duration hypothermia is a broadly applicable potential early treatment strategy for stroke patients prior to- during-, and after reperfusion therapy.

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Abstract 43: Neuroprotective Effects of Inhibition of α5β1 Integrin Following Experimental Stroke: A Dual Center Pre-Clinical Study

Stroke ◽

10.1161/str.48.suppl_1.43 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Danielle Edwards ◽

Biav Reber Kittani ◽

Gillian Grohs ◽

Mhairi Macrae ◽

Justin F Fraser ◽

...

Keyword(s):

Ischemic Stroke ◽

Functional Recovery ◽

Infarct Volume ◽

Experimental Stroke ◽

Β1 Integrin ◽

Integrin Receptor ◽

Post Stroke ◽

Enhanced Mri ◽

Bbb Permeability ◽

Α5β1 Integrin

Blood-brain barrier (BBB) dysfunction after ischemic stroke exacerbates brain damage by contributing to edema and inflammation. The β1 integrin receptor family may contribute to this dysfunction via alteration of BBB-forming tight junction proteins. We hypothesize that inhibition of the β1 integrin receptor subtype α5β1, which is acutely expressed in infarct and peri-infarct vasculature after experimental stroke, reduces BBB permeability, reduces infarct volume, and improves functional recovery. A randomized and blinded trial was conducted using transient middle cerebral artery occlusion (MCAO) in mice (60 min; n=8) and rats (90 min; n=15) in two independent laboratories. ATN-161 (α5β1 inhibitor; 1 mg/kg) was administered IV immediately upon reperfusion and on post-stroke day 1 and 2. Infarct volume was determined by cresyl violet (mice) and T 2 weighted MRI (rat) at day 3 post MCAO. Steady state contrast enhanced MRI was used to assess BBB breakdown in rats at day 3. ATN-161 resulted in a significant reduction in infarct volume in both mice and rats when measured at post-stroke day 3 (p<0.001). BBB permeability was decreased upon ATN-161 treatment in vivo as determined by reduced IgG and claudin-5 immunostaining in mice and reduced extent of Gadolinium enhanced MRI signal change in rats. Behavioral tests (open field, rotorod, sticky label and 28 point neuroscore), demonstrated significantly improved functional recovery in both mice and rats following treatment with ATN-161. Finally, in vitro studies where stroke was simulated using oxygen and glucose deprivation or TNF-α, ATN-161 (10 μM) treatment demonstrated decreased barrier permeability as measured by trans-endothelial cell electrical resistance, FITC-dextran permeability, and claudin-5 immunocytochemistry. Collectively, our results demonstrate that post-stroke inhibition of α5β1 integrin with the small peptide ATN-161 profoundly reduces infarct volume, improves functional outcome and decreases BBB permeability in both mice and rats using two different ischemic stroke models. Therefore, inhibition of α5β1 by ATN-161 could represent a novel stroke therapeutic target worthy of further investigation.

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Abstract WP151: Rapamycin Improves Post-Recanalization Blood Flow After Acute Experimental Stroke in Rats

Stroke ◽

10.1161/str.51.suppl_1.wp151 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Anna Maria Schneider ◽

Daniel Beard ◽

Alastair Buchan

Keyword(s):

Blood Flow ◽

Infarct Volume ◽

Mammalian Target Of Rapamycin ◽

Volume Measurement ◽

Artery Occlusion ◽

Experimental Stroke ◽

Stroke Outcome ◽

Doppler Flowmetry ◽

Rapamycin Treatment ◽

Post Stroke

Background and Purpose: In the era of thrombectomy, there is evidence suggesting that successful recanalization is not always accompanied by complete reperfusion, the so called “no-reflow phenomenon”. Given the importance of reperfusion as a predictor of stroke outcome, this represents a potential target for stroke therapy. Rapamycin, a clinically approved inhibitor of Mammalian Target of Rapamycin (mTOR) has been shown to improve cerebral blood flow (CBF) in Alzheimer’s disease. However, there has been little investigation into the effect of rapamycin on post-stroke microvascular perfusion. The aim of this study was to investigate the effects of rapamycin treatment on post-recanalisation CBF and stroke outcome in an experimental animal model of stroke. Methods: Male Wistar rats (300-350g) were subjected to 90min of transient middle cerebral artery occlusion (tMCAo) followed by randomized administration of 250μg/kg intravenous rapamycin (n=8) or vehicle (n=6), 30min after the onset of MCAo. Laser Doppler flowmetry was used to continuously measure changes in MCA perfusion during MCAo and for min after recanalisation. Neurobehavioral tests were performed 24hrs after MCAo before tissue was collected for infarct volume measurement. Results: MCAo was confirmed by a 70% reduction in MCA perfusion. Rapamycin treatment significantly improved post-recanalization CBF at 55min after recanalization (p<0.01). Rapamycin significantly increased average CBF during the 60min post-recanalization period (p<0.01). Rapamycin showed a trend towards reduced final infarct volume. Rapamycin significantly improved neuroscores (p<0.05). Post-recanalization CBF was significantly inversely correlated with infarct volume (R 2 =0.4994, p<0.05). Conclusion: Rapamycin significantly improved post-recanalization CBF and behavioural outcomes after MCAo. These results suggest that rapamycin may be an effective acute intervention to improve post-recanalisation blood flow to improve stroke outcome. However, further studies are need to determine the mechanism of improved CBF and if improvements in post-stroke CBF and neurological outcome are sustained long-term post-stroke.

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IL-10-producing B-cells limit CNS inflammation and infarct volume in experimental stroke

Metabolic Brain Disease ◽

10.1007/s11011-013-9413-3 ◽

2013 ◽

Vol 28 (3) ◽

pp. 375-386 ◽

Cited By ~ 69

Author(s):

Sheetal Bodhankar ◽

Yingxin Chen ◽

Arthur A. Vandenbark ◽

Stephanie J. Murphy ◽

Halina Offner

Keyword(s):

B Cells ◽

Infarct Volume ◽

Experimental Stroke ◽

Cns Inflammation

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Decreased Intracranial Pressure Elevation and Cerebrospinal Fluid Outflow Resistance: A Potential Mechanism of Hypothermia Cerebroprotection Following Experimental Stroke

Brain Sciences ◽

10.3390/brainsci11121589 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1589

Author(s):

Daniel Omileke ◽

Steven W. Bothwell ◽

Debbie Pepperall ◽

Daniel J. Beard ◽

Kirsten Coupland ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Intracranial Pressure ◽

Ischaemic Stroke ◽

Infarct Volume ◽

Artery Occlusion ◽

Experimental Stroke ◽

Outflow Resistance ◽

Hypothermia Treatment ◽

Post Stroke ◽

Intracranial Pressure Elevation

Background: Elevated intracranial pressure (ICP) occurs 18–24 h after ischaemic stroke and is implicated as a potential cause of early neurological deterioration. Increased resistance to cerebrospinal fluid (CSF) outflow after ischaemic stroke is a proposed mechanism for ICP elevation. Ultra-short duration hypothermia prevents ICP elevation 24 h post-stroke in rats. We aimed to determine whether hypothermia would reduce CSF outflow resistance post-stroke. Methods: Transient middle cerebral artery occlusion was performed, followed by gradual cooling to 33 °C. At 18 h post-stroke, CSF outflow resistance was measured using a steady-state infusion method. Results: Hypothermia to 33 °C prevented ICP elevation 18 h post-stroke (hypothermia ∆ICP = 0.8 ± 3.6 mmHg vs. normothermia ∆ICP = 4.4 ± 2.0 mmHg, p = 0.04) and reduced infarct volume 24 h post-stroke (hypothermia = 78.6 ± 21.3 mm3 vs. normothermia = 108.1 ± 17.8 mm3; p = 0.01). Hypothermia to 33 °C did not result in a significant reduction in CSF outflow resistance compared with normothermia controls (0.32 ± 0.36 mmHg/µL/min vs. 1.07 ± 0.99 mmHg/µL/min, p = 0.06). Conclusions: Hypothermia treatment was protective in terms of ICP rise prevention, infarct volume reduction, and may be implicated in CSF outflow resistance post-stroke. Further investigations are warranted to elucidate the mechanisms of ICP elevation and hypothermia treatment.

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Neurofilament Proteolysis after Focal Ischemia; When Do Cells Die after Experimental Stroke?

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-199906000-00008 ◽

1999 ◽

Vol 19 (6) ◽

pp. 652-660 ◽

Cited By ~ 41

Author(s):

Jaroslaw Aronowski ◽

Ki-Hyun Cho ◽

Roger Strong ◽

James C. Grotta

Keyword(s):

Time Course ◽

Infarct Volume ◽

Focal Ischemia ◽

Cellular Damage ◽

Experimental Stroke ◽

Infarct Core ◽

Similar Time ◽

The Core ◽

Tetrazolium Staining ◽

Previous Demonstration

To determine the occurrence and time-course of presumably irreversible subcellular damage after moderate focal ischemia, rats were subjected to 1, 3, 6, 9, or 24 hours of permanent unilateral middle cerebral and common carotid occlusion or 3 hours of reversible occlusion followed by 3, 6, or 21 hours of reperfusion. The topography and the extent of damage were analyzed with tetrazolium staining and immunoblot using an antibody capable of detecting breakdown of neurofilament. Neurofilament proteolysis began after 3 hours in the infarct core but was still incomplete in penumbral regions up to 9 hours. Similarly, tetrazolium-staining abnormalities were observed in the core of 50% of animals after 3 hours of ischemia. At 6 hours of permanent ischemia, infarct volume was maximal, and further prolongation of occlusion to 9 or 24 hours did not increase abnormal tetrazolium staining. In contrast to permanent ischemia and in agreement with the authors' previous demonstration of “reperfusion injury” in this model, prolongation of reperfusion from 3 hours to 6 and 21 hours after 3 hours of reversible occlusion gradually augmented infarct volume by 203% and 324%, respectively. Neurofilament proteolysis initiated approximately 3 hours after ischemia was quantitatively greatest in the core and extended during reperfusion to incorporate penumbra with a similar time course to that of tetrazolium abnormalities. These data demonstrate that, at least as measured by neurofilament breakdown and mitochondrial failure, extensive cellular damage is not present in penumbral regions for up to 9 hours, suggesting the potential for rescuing these regions by appropriate and timely neuroprotective strategies.

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Stem cell treatment improves post stroke neurological outcomes: a comparative study in male and female rats

Stroke and Vascular Neurology ◽

10.1136/svn-2020-000834 ◽

2021 ◽

pp. svn-2020-000834

Author(s):

Koteswara Rao Nalamolu ◽

Bharath Chelluboina ◽

Casimir A Fornal ◽

Siva Reddy Challa ◽

David M Pinson ◽

...

Keyword(s):

Stem Cells ◽

Sex Differences ◽

Motor Function ◽

Infarct Volume ◽

Female Rats ◽

Human Umbilical Cord ◽

Male And Female ◽

Post Stroke ◽

Male And Female Rats ◽

Males And Females

Background and purposeThe therapeutic potential of different stem cells for ischaemic stroke treatment is intriguing and somewhat controversial. Recent results from our laboratory have demonstrated the potential benefits of human umbilical cord blood-derived mesenchymal stem cells (MSC) in a rodent stroke model. We hypothesised that MSC treatment would effectively promote the recovery of sensory and motor function in both males and females, despite any apparent sex differences in post stroke brain injury.MethodsTransient focal cerebral ischaemia was induced in adult Sprague-Dawley rats by occlusion of the middle cerebral artery. Following the procedure, male and female rats of the untreated group were euthanised 1 day after reperfusion and their brains were used to estimate the resulting infarct volume and tissue swelling. Additional groups of stroke-induced male and female rats were treated with MSC or vehicle and were subsequently subjected to a battery of standard neurological/neurobehavioral tests (Modified Neurological Severity Score assessment, adhesive tape removal, beam walk and rotarod). The tests were administered at regular intervals (at days 1, 3, 5, 7 and 14) after reperfusion to determine the time course of neurological and functional recovery after stroke.ResultsThe infarct volume and extent of swelling of the ischaemic brain were similar in males and females. Despite similar pathological stroke lesions, the clinical manifestations of stroke were more pronounced in males than females, as indicated by the neurological scores and other tests. MSC treatment significantly improved the recovery of sensory and motor function in both sexes, and it demonstrated efficacy in both moderate stroke (females) and severe stroke (males).ConclusionsDespite sex differences in the severity of post stroke outcomes, MSC treatment promoted the recovery of sensory and motor function in male and female rats, suggesting that it may be a promising treatment for stroke.

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Immunomodulatory effects of different intravenous immunoglobulin preparations in chronic lymphocytic leukemia

Scientific Reports ◽

10.1038/s41598-021-92412-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ana Colado ◽

Esteban Enrique Elías ◽

Valeria Judith Sarapura Martínez ◽

Gregorio Cordini ◽

Pablo Morande ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

Chronic Lymphocytic Leukemia ◽

T Cell Activation ◽

Cell Activation ◽

Lymphocytic Leukemia ◽

Immunomodulatory Effects ◽

Immunoglobulin Preparations

AbstractHypogammaglobulinemia is the most frequently observed immune defect in chronic lymphocytic leukemia (CLL). Although CLL patients usually have low serum levels of all isotypes (IgG, IgM and IgA), standard immunoglobulin (Ig) preparations for replacement therapy administrated to these patients contain more than 95% of IgG. Pentaglobin is an Ig preparation of intravenous application (IVIg) enriched with IgM and IgA (IVIgGMA), with the potential benefit to restore the Ig levels of all isotypes. Because IVIg preparations at high doses have well-documented anti-inflammatory and immunomodulatory effects, we aimed to evaluate the capacity of Pentaglobin and a standard IVIg preparation to affect leukemic and T cells from CLL patients. In contrast to standard IVIg, we found that IVIgGMA did not modify T cell activation and had a lower inhibitory effect on T cell proliferation. Regarding the activation of leukemic B cells through BCR, it was similarly reduced by both IVIgGMA and IVIgG. None of these IVIg preparations modified spontaneous apoptosis of T or leukemic B cells. However, the addition of IVIgGMA on in vitro cultures decreased the apoptosis of T cells induced by the BCL-2 inhibitor, venetoclax. Importantly, IVIgGMA did not impair venetoclax-induced apoptosis of leukemic B cells. Overall, our results add new data on the effects of different preparations of IVIg in CLL, and show that the IgM/IgA enriched preparation not only affects relevant mechanisms involved in CLL pathogenesis but also has a particular profile of immunomodulatory effects on T cells that deserves further investigation.

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