Modulation of host immune status by cryptococcus co-infection during HIV-1 pathogenesis and its impact on CD+4 cell and cytokines environment

A reproducible murine model of studying HIV-associated brain damage in stroke

BACKGROUND

Emerging clinical and epidemiological data indicates that human immunodeficiency virus (HIV) is associated with an increased risk of stroke and aggravated brain damage. We aimed to develop a reproducible murine model of photothrombotic-stroke with HIV infection that mimics the clinical situation.

METHOD

To evaluate the impact of HIV infection on stroke, male C57BL/6 mice were infected with EcoHIV (p24 2-4 × 106/mouse; i.v.) or mock control. Four weeks post-infection, a stroke was induced by the photothrombotic method (pt-MCAO). After 72 h, a catwalk test was performed for gait impairments, and mice were euthanized for stroke outcomes.

RESULTS

EcoHIV-infection exhibited a larger infarction, brain edema, higher IgG extravasation, hemorrhagic transformation, and gait impairments following pt-MCAO vs mock control. EcoHIV-infected mice showed higher levels of IFN-y and lower levels of IL-6, indicating immune activation without affecting IL-1β and MCP-1 in plasma and brain compared to mock pt-MCAO, suggesting unaltered inflammation. EcoHIV-infection showed increased oxidative stress markers (nitrotyrosine, and 4-hydroxynonenal) and thioredoxin interacting protein expression. Further, EcoHIV-infection significantly activated the microglia and astrocyte cells.

CONCLUSIONS

This animal model would be reliable and clinically relevant to future studies investigating pathophysiological mechanisms and developing new therapeutic approaches in stroke patients with HIV conditions.

Harnessing the Potential of Multiomics Studies for Precision Medicine in Infectious Disease

The field of infectious diseases currently takes a reactive approach and treats infections as they present in patients. Although certain populations are known to be at greater risk of developing infection (eg, immunocompromised), we lack a systems approach to define the true risk of future infection for a patient. Guided by impressive gains in "omics" technologies, future strategies to infectious diseases should take a precision approach to infection through identification of patients at intermediate and high-risk of infection and deploy targeted preventative measures (ie, prophylaxis). The advances of high-throughput immune profiling by multiomics approaches (ie, transcriptomics, epigenomics, metabolomics, proteomics) hold the promise to identify patients at increased risk of infection and enable risk-stratifying approaches to be applied in the clinic. Integration of patient-specific data using machine learning improves the effectiveness of prediction, providing the necessary technologies needed to propel the field of infectious diseases medicine into the era of personalized medicine.

Cryptococcus neoformans Δsgl1 Vaccination Requires Either CD4+ or CD8+ T Cells for Complete Host Protection

Cryptococcus neoformans is a fungal pathogen causing life-threatening meningoencephalitis in susceptible individuals. Fungal vaccine development has been hampered by the fact that cryptococcosis occurs during immunodeficiency. We previously reported that a C. neoformans mutant (Δsgl1) accumulating sterylglucosides (SGs) is avirulent and provides complete protection to WT challenge, even under CD4+ T cell depletion, an immunodeficient condition commonly associated with cryptococcosis. We found high levels of SGs in the lungs post-immunization with Δsgl1 that decreased upon fungal clearance. Th1 cytokines increased whereas Th2 cytokines concurrently decreased, coinciding with a large recruitment of leukocytes to the lungs. Depletion of B or CD8+ T cells did not affect either Δsgl1 clearance or protection from WT challenge. Although CD4+ T cell depletion affected clearance, mice were still protected indicating that clearance of the mutant was not necessary for host protection. Protection was lost only when both CD4+ and CD8+ T cells were depleted, highlighting a previously unexplored role of fungal-derived SGs as an immunoadjuvant for host protection against cryptococcosis.

Evaluation of the effect of Dahuang-Mudan decoction on TNBS-induced colitis using UPLC-QTOF/MS-based metabolomic analysis

Dahuang-Mudan decoction (DMD) is a formula that has been widely used as a complementary treatment for inflammatory bowel disease (IBD). However, the mechanism of action of DMD in IBD has not been clearly elucidated. Therefore, we developed a metabolomics-based method to evaluate the effects and potential mechanisms of DMD in a 2,4,6-trinitobenzene sulfonic acid (TNBS)-induced colitis model. The ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS) method combined with multiple analysis approaches including principal component analysis, partial least square discriminant analysis and orthogonal partial least square discriminant analysis were used to investigate the different urinary metabolites. We identified 29 potential biomarkers of TNBS-induced colitis that returned to normal conditions after DMD administration. Pathway analysis indicated that changes in these metabolites were associated with cysteine and methionine metabolism, citric acid cycle, glycolysis and glycolic regeneration, pyruvate metabolism, biosynthesis of valine, leucine and isoleucine, biosynthesis of primary bile acids, glycine, serine and threonine metabolism, caffeine metabolism, arginine and proline metabolism and phenylalanine metabolism. It is worth noting that DMD has potential therapeutic effects on TNBS-induced colitis, which functions by restoring the balance of multiple disturbed pathways to a normal condition. This study suggests the reliability of metabolomics-based approaches to identifying biomarkers and pathways, which facilitate further investigation of the potential mechanisms of DMD.