Biology subjects

Castillo, J. R.

Publications and source records attributed to Castillo, J. R..

6 recordsLinked to original sources

bioRxiv2024

Targeting CCRL2 enhances therapeutic outcomes in a tuberculosis mouse model

Tuberculosis (TB) remains among the leading infectious causes of death. Due to the limited number of antimicrobials in the TB drug discovery pipeline, interest has developed in host-directed approaches to improve TB treatment outcomes. C-C motif chemokine-like receptor 2 (CCRL2) is a unique seven-transmembrane domain receptor that is upregulated by inflammatory signals and mediates leucocyte migration. However, little is known about its role in the setting of TB infection. Here, we show that Mycobacterium tuberculosis (Mtb) infection increases CCRL2 protein expression in macrophages and in mouse lungs. To target selectively CCRL2-expressing cells in vivo, we developed a novel mouse anti-CCRL2 antibody-drug conjugate (ADC) linked with the cytotoxic drug SG3249. We tested its adjunctive therapeutic efficacy against TB when combined with the first-line regimen for drug-susceptible TB (isoniazid, rifampin, pyrazinamide, ethambutol; RHZE). The anti-CCRL2 ADC treatment potentiated RHZE efficacy in Mtb-infected mice and decreased gross lung inflammation. CCRL2 expression in lung dendritic cells and alveolar macrophages was lower in mice receiving anti-CCRL2 ADC treatment + RHZE compared to those receiving RHZE alone or the control group, although the total innate cell populations did not differ across treatment groups. Interestingly, neutrophils were completely absent in the anti-CCRL2 ADC treatment + RHZE group, unlike in the other treatment groups. IFN-{gamma}+ and IL17-A+ T-cell responses, which are associated with optimal TB control, were also elevated in the anti-CCRL2 ADC treatment + RHZE group. Collectively, our findings suggest that CCRL2-targeting approaches may improve TB treatment outcomes, possibly through selective killing of Mtb-infected innate immune cells.

immunology↗

bioRxiv2024

Therapeutic DNA Vaccine Targeting Mycobacterium tuberculosis Persisters Shortens Curative Tuberculosis Treatment

Mycobacterium tuberculosis (Mtb) is one of the leading infectious causes of death worldwide. There is no available licensed therapeutic vaccine that shortens active tuberculosis (TB) disease drug treatment and prevents relapse, despite the World Health Organizations calls. Here, we show that an intranasal DNA vaccine containing a fusion of the stringent response relMtb gene with the gene encoding the immature dendritic cell-targeting chemokine, MIP-3/CCL20, shortens the duration of curative TB treatment in immunocompetent mice. Compared to the first-line regimen for drug-susceptible TB alone, our novel adjunctive vaccine induced greater RelMtb-specific T-cell responses associated with optimal TB control in spleen, blood, lungs, mediastinal lymph nodes, and bronchoalveolar lavage (BAL) fluid. These responses were sustained, if not augmented, over time. It also triggered more effective dendritic cell recruitment, activation, and colocalization with T cells, implying enhanced crosstalk between innate and adaptive immunity. Moreover, it potentiated a 6-month TB drug-resistant regimen, rendering it effective across treatment regimens, and also showed promising results in CD4+ knockout mice, perhaps due to enhanced Rel-specific CD8+ T-cell responses. Notably, our novel fusion vaccine was also immunogenic in nonhuman primates, the gold standard animal model for TB vaccine studies, eliciting antigen-specific T-cell responses in blood and BAL fluid analogous to those observed in protected mice. Our findings have critical implications for therapeutic TB vaccine clinical development in immunocompetent and immunocompromised populations and may serve as a model for defining immunological correlates of therapeutic vaccine-induced protection. One sentence summaryA TB vaccine shortens curative drug treatment in mice by eliciting strong TB-protective immune responses and induces similar responses in macaques.

immunology↗

bioRxiv2024

Contribution of telacebec to novel drug regimens in a murine tuberculosis model

The clinical efficacy of combination drug regimens containing the first generation diarylquinoline (DARQ) bedaquiline in the treatment of multidrug-resistant tuberculosis has validated ATP synthesis as a vulnerable pathway in Mycobacterium tuberculosis. New DARQs in clinical development may be even more effective than bedaquiline, including against emerging bedaquiline-resistant strains. Telacebec (T) is a novel cytochrome bc1:aa3 oxidase inhibitor that also inhibits ATP synthesis. Based on its demonstrated efficacy as a monotherapy in mice and in a phase 2a clinical trial, we used an established BALB/c mouse model of tuberculosis (TB) to test the contribution of T to novel combination therapies against two strains of M. tuberculosis (H37Rv and HN878) in an effort to find more effective regimens. Overall, T was more effective in regimens against the HN878 strain than against the H37Rv strain, a finding that supports the greater vulnerability of the former strain to T and to genetic depletion of QcrB. Against both strains, combinations of a DARQ, clofazimine (CFZ), and T were highly bactericidal. However, only against HN878 did T contribute synergistically, whereas an antagonistic effect was observed against H37Rv. These results demonstrate the therapeutic potential of T and highlight how differences in the susceptibility of M. tuberculosis strains could lead to different conclusions about a drugs potential contribution to novel drug regimens.

microbiology↗

bioRxiv2024

A mouse model of TB-associated lung fibrosis reveals persistent inflammatory macrophage populations during treatment

Post-TB lung disease (PTLD) causes a significant burden of global disease. Fibrosis is a central component of many clinical features of PTLD. To date, we have a limited understanding of the mechanisms of TB-associated fibrosis and how these mechanisms are similar to or dissimilar from other fibrotic lung pathologies. We have adapted a mouse model of TB infection to facilitate the mechanistic study of TB-associated lung fibrosis. We find that the morphologies of fibrosis that develop in the mouse model are similar to the morphologies of fibrosis observed in human tissue samples. Using Second Harmonic Generation (SHG) microscopy, we are able to quantify a major component of fibrosis, fibrillar collagen, over time and with treatment. Inflammatory macrophage subpopulations persist during treatment; matrix remodeling enzymes and inflammatory gene signatures remain elevated. Our mouse model suggests that there is a therapeutic window during which adjunctive therapies could change matrix remodeling or inflammatory drivers of tissue pathology to improve functional outcomes after treatment for TB infection.

microbiology↗

bioRxiv2024

Pharmacological inhibition of macrophage triglyceride biosynthesis pathways does not improve Mycobacterium tuberculosis control in infected mice

Triglyceride rich macrophages (foam cells) are a hallmark of necrotic granulomas in tuberculosis, and multiple antimicrobial functions are down-regulated in these cells. In this study, we assessed the ability of two different compounds to reduce triglyceride content and intracellular burden in Mycobacterium tuberculosis (Mtb)-infected macrophages: A-922500 (DGATi), an inhibitor of diacylglycerol acyltransferase 1, an enzyme involved in triglyceride synthesis; and LY2584702 (p70S6Ki), an inhibitor of p70 S6 kinase, a serine/threonine kinase involved in mTORC-1dependent lipid biogenesis. Additionally, we evaluated the adjunctive activity of these inhibitors as host-directed therapies against chronic Mtb infection in C3HeB/FeJ mice. DGATi and p70S6Ki significantly reduced the lipid content and bacillary burden in Mtb-infected human monocyte-derived macrophages. In Mtb-infected mice, each inhibitor reduced the triglyceride content (P[≤] 0.0001) in cells from bronchoalveolar lavage samples. Adjunctive treatment of DGATi with isoniazid and p70S6Ki monotherapy reduced the lipid droplet content (P[≤] 0.05) within lung macrophages of Mtb-infected mice. However, neither inhibitor reduced the lung bacterial burden in Mtb-infected mice alone or in combination with isoniazid, and they did not alter lung inflammation. These findings provide further insights into the role of foam cells in tuberculosis pathogenesis and the utility of interventions targeting these cell populations as adjunctive host-directed therapies.

pharmacology and toxicology↗

bioRxiv2022

Wolbachia endosymbionts manipulate GSC self-renewal and differentiation to enhance host fertility

The alphaproteobacterium Wolbachia pipientis infects arthropod and nematode species worldwide, making it a key target for host biological control. Wolbachia-driven host reproductive manipulations, such as cytoplasmic incompatibility (CI), are credited for catapulting these intracellular bacteria to high frequencies in host populations. Positive, perhaps mutualistic, reproductive manipulations also increase infection frequencies, but are not well understood. Here, we identify molecular and cellular mechanisms by which Wolbachia influences the molecularly distinct processes of GSC self renewal and differentiation. We demonstrate that wMel infection rescues the fertility of flies lacking the translational regulator mei-P26, and is sufficient to sustain infertile homozygous mei-P26-knockdown stocks indefinitely. Cytology revealed that wMel mitigates the impact of mei-P26 loss through restoring proper pMad, Bam, Sxl, and Orb expression. In OreR files with wild-type fertility, wMel infection elevates lifetime egg hatch rates. Exploring these phenotypes through dual-RNAseq experiments revealed that wMel infection rescues and offsets many gene expression changes induced by mei-P26 loss at the mRNA level. Overall, we show that wMel infection beneficially reinforces host fertility at mRNA, protein, and phenotypic levels, and these mechanisms may promote the emergence of mutualism and the breakdown of host reproductive manipulations. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=92 SRC="FIGDIR/small/520626v2_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@151904corg.highwire.dtl.DTLVardef@1d86e41org.highwire.dtl.DTLVardef@2e768eorg.highwire.dtl.DTLVardef@697109_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights[bullet] The wMel strain of Wolbachia restores fertility in females and males deficient for the essential translational regulator meiotic-P26 [bullet]Mei-P26s germline maintenance and oocyte cyst differentiation functions are genetically rescued by wMel infection [bullet]Perturbed pMad, Sxl, Bam, and Orb protein expression are mitigated by wMel infection [bullet]wMel infection elevates lifetime egg lay and hatch rates in OreR flies [bullet]Ovary transcriptomes reveal wMel infection restores or offsets changes in gene expression induced by the loss of functional mei-P26 Significance StatementWolbachia bacterial symbionts are being harnessed as biological control agents through the use of their costly manipulations to host fertility. Here, we reveal that the wMel strain can have a beneficial impact on fruit fly development in both mutant and wild-type flies. This phenotype is essential to the long-term use of these bacteria for host population control.

evolutionary biology↗