About

Emma Camacho, PhD, is an Assistant Research Professor at Johns Hopkins Bloomberg School of Public Health, affiliated with the Department of Molecular Microbiology and Immunology and the Johns Hopkins Malaria Research Institute. Her research explores strategies to modify melanin production in organisms that may pose a threat to human health, including malaria-transmitting mosquitoes and human fungal pathogens. Her work focuses on expanding knowledge in cellular biology related to color and melanin across evolutionary distant organisms, employing multidisciplinary approaches to investigate ways to boost or impair melanin production, particularly in organisms affecting underprivileged communities. Dr. Camacho's academic background includes a PhD from the Venezuelan Institute for Scientific Research and a Bachelor's degree from the University of the Andes. Her research emphasizes the biological functions of melanins, their architecture, and their interaction with surrounding components, with applications spanning radioprotection, light harvesting, therapeutics, and drug delivery. She has received several honors, including a postdoctoral fellowship at Johns Hopkins Malaria Research Institute and scholarships from international scientific organizations. Her contributions advance understanding of the cellular and molecular mechanisms of melanization in fungi and mosquitoes, with implications for public health and disease control.

Research topics

• Biology
• Genetics
• Botany
• Cell biology
• Biochemistry
• Microbiology
• Biotechnology

Selected publications

• Metabolic plasticity and virulence of <i>Cryptococcus neoformans</i> are regulated by mitochondrial homeostasis

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-02-10

  articleOpen access

  Abstract The mitochondrion is a versatile organelle involved in diverse processes, such as cell death, metal homeostasis, plasma membrane and cell wall integrity, stress response, oxygen concentration, temperature, and metabolic adaptation, in addition to its role in generating energy. Consequently, mitochondrial fitness is essential for the pathogenicity of various organisms, including fungi. Cryptococcus neoformans is a fungal pathogen responsible for over 180,000 HIV-related deaths each year. In this study, we analyzed C. neoformans metabolic plasticity when grown with non-fermentable carbon sources and their impact on virulence and mitochondrial homeostasis. Growth on non-fermentable carbon sources increased thermotolerance, glucuronoxylomannan (GMX) content in the capsule, melanization rate, urease activity, biofilm formation, and virulence. Moreover, cells grown on non-fermentable carbon sources manifested increased mitochondrial number and activity. Conversely, mutants of the master regulator of mitochondrial biogenesis, the Hap complex, the catalytic subunit 1 of protein kinase A, or media supplementation with antioxidants, decreased the use of alternative carbon sources, capsule formation, melanin synthesis, urease activity, mitochondrial number, and resistance to both fluconazole and macrophage killing. Our results implicate mitochondrial homeostasis in virulence regulation via the PKA pathway, suggesting that targeting fungal mitochondrial homeostasis could be a therapeutic approach for cryptococcosis.

  PublisherOA PDFDOI

• <i>Lomentospora prolificans</i> synthesizes several types of melanin

  mSphere · 2025-04-04 · 3 citations

  articleOpen access

  ABSTRACT Lomentospora prolificans is a filamentous fungus with a global distribution, exhibiting a particularly higher prevalence in human-impacted environments. Melanins are biological compounds with important functions that contribute to the virulence of many pathogenic fungi. Like many fungi, L. prolificans produces melanin, but little is known about its structure and composition. In the current study, we characterized L. prolificans -associated melanin using chemical, biological, biophysical, and structural techniques while also assessing the impact of inhibitors of distinct melanization pathways. Our results reveal that this pathogenic fungus produces multiple types of melanin pigments and suggest the possibility of a new type of melanin, which is synthesized together with a mixture of DHN-, DOPA-, and pyomelanin types. IMPORTANCE This fungal species is associated with a wide spectrum of human infections, especially in immunosuppressed individuals, for whom it causes severe and debilitating illnesses with high morbidity and mortality that are compounded by its pan-resistant profile with respect to antifungal drugs. Melanin is a ubiquitous pigment among fungi with a broad range of actions that include promoting fungal virulence. Although melanin is one of the most studied virulence factors in pathogenic fungi, relatively little is known about the chemistry of this pigment in L. prolificans . These insights enhance our understanding of L. prolificans’ virulence mechanisms, paving the way for potential therapeutic interventions.

  PublisherDOI

• Interdisciplinarity at the nexus of biomedical science training: The R3 Center for Innovation in Science Education

  iScience · 2025-06-01

  articleOpen access

  The R³ Center for Innovation in Science Education (R³ISE), established at Johns Hopkins Bloomberg School of Public Health, addresses critical gaps in scientific education by instilling the core values of rigorous research, reproducible methods, and scientific responsibility in our students. Through graduate- and professional-level courses, certificate programs, workshops, and open-access resources, R³ISE fosters critical thinking, communication, leadership, and other skills essential for scientists. In this Backstory piece, faculty, students, alumni, and network partners reflect on their experiences with R³ISE, which were highlighted in the past year's annual symposium. In this symposium, themes such as ethical leadership, translating classroom theory into practice, and strategies to combat misinformation highlighted R³ISE sustained efforts and proposed further directions. These reflections exemplify how the R³ISE community continues to grow—fostering scientific integrity, resilience, and empathy within a global network committed to excellence and responsibility in the biomedical sciences.

  PublisherOA PDFDOI

• Metabolic Profiling of Brain Tissue and Brain‐Derived Extracellular Vesicles in Alzheimer's Disease

  Journal of Extracellular Vesicles · 2025-02-01 · 12 citations

  articleOpen access

  Alzheimer´s disease (AD) is the most frequent neurodegenerative disorder in the world and is characterised by the loss of memory and other cognitive functions. Metabolic changes associated with AD are important players in the development of the disease. However, the mechanism underlying these changes is still unknown. Extracellular vesicles (EVs) are nano-sized particles that play an important role in regulating pathophysiological processes and are a non-invasive manner to obtain information of the cell that is secreting them. The analysis of brain-derived EVs (bdEVs) will provide new insights in the metabolic processes associated with AD. To characterize bdEVs in AD, we optimised a method to isolate them from tissue of different brain regions, obtaining the highest enrichment in isolations from the temporal cortex. We performed unbiased untargeted metabolomics analysis on post-mortem human temporal cortex tissue and bdEVs from the same region of AD patients and healthy controls. Both, univariate and multivariate statistical analysis were used to determine the metabolites that influence the separation between AD patients and controls. Interestingly, a clear separation between control and AD groups was obtained with bdEVs, which allowed to select 12 relevant features by a validated PLS-DA model. Furthermore, comparison of tissue and bdEVs identified 68 common features. The pathway enrichment analysis of the common metabolites showed that the alanine, aspartate and glutamate pathway and the arginine, phenylalanine, tyrosine pathway were the most significant ones in the separation between the AD patients and controls. The phenylalanine, tyrosine and tryptophan pathway, still had a very high influence in the separation between groups, albeit not significant. Notably, some metabolites were identified for the first time in bdEVs. For example, the N-acetyl aspartic acid (NAA) metabolite present in bdEVs was suitable to differentiate AD patients from healthy controls. Furthermore, the analysis of the hippocampus, midbrain, temporal and entorhinal cortex and their respective bdEVs indicated that the metabolic profiles of different brain areas were distinct and showed some correlation between the metabolome of the tissue and its respective bdEVs. Thus, our study highlights the potential of bdEVs to understand the metabolic fingerprint associated with AD and their potential use as diagnostic and therapeutic targets.

  PublisherOA PDFDOI

• Dietary L-3,4-dihydroxyphenylalanine (L-DOPA) augments cuticular melanization in Anopheles mosquitos reducing their lifespan and malaria burden

  Nature Communications · 2025-08-27 · 4 citations

  articleOpen access1st authorCorresponding

  L-3,4-dihydroxyphenylalanine (L-DOPA), a naturally occurring tyrosine derivative, is prevalent in environments that include mosquito habitats, potentially serving as part of their diet. Given its role as a precursor for melanin synthesis we investigate the effect of dietary L-DOPA on mosquito physiology and immunity to Plasmodium falciparum and Cryptococcus neoformans infection. Dietary L-DOPA is incorporated into mosquito melanin via a non-canonical pathway and has a profound transcriptional effect associated with enhanced immunity, increased pigmentation, and reduced lifespan. Increased melanization results in an enhanced capacity to absorb electromagnetic radiation that affects mosquito temperatures. Bacteria in the mosquito microbiome act as sources of dopamine, a substrate for melanization. Our results illustrate how an environmentally abundant amino acid analogue can affect mosquito physiology and suggest its potential usefulness as an environmentally friendly vector control agent to reduce malaria transmission, warranting further research and field studies. Malaria control and elimination require environmentally safe strategies. Here, the authors propose L-DOPA, a naturally occurring tyrosine derivative, as a mosquito dietary intervention that can shorten lifespan and reduce malaria parasite burden of female Anopheles gambiae mosquitoes.

  PublisherOA PDFDOI

• <i>Cryptococcus neoforman</i> s rapidly invades the murine brain by sequential breaching of airway and endothelial tissues barriers, followed by engulfment by microglia

  mBio · 2024-03-21 · 29 citations

  articleOpen access

  ABSTRACT Cryptococcus neoformans causes lethal meningitis and accounts for approximately 10%–15% of AIDS-associated deaths worldwide. There are major gaps in our understanding of how this fungus invades the mammalian brain. To investigate the dynamics of C. neoformans tissue invasion, we mapped fungal localization and host cell interactions in infected brain, lung, and upper airways using mouse models of systemic and airway infection. To enable this, we developed an in situ imaging pipeline capable of measuring large volumes of tissue while preserving anatomical and cellular information by combining thick tissue sections, tissue clarification, and confocal imaging. We confirm high fungal burden in mouse upper airway after nasal inoculation. Yeast in turbinates were frequently titan cells, with faster kinetics than reported in mouse lungs. Importantly, we observed one instance of fungal cells enmeshed in lamina propria of the upper airways, suggesting penetration of airway mucosa as a possible route of tissue invasion and dissemination to the bloodstream. We extend previous literature positing bloodstream dissemination of C. neoformans , by finding viable fungi in the bloodstream of mice a few days after intranasal infection. As early as 24 h post systemic infection, the majority of C. neoformans cells traversed the blood-brain barrier, and were engulfed or in close proximity to microglia. Our work presents a new method for investigating microbial invasion, establishes that C. neoformans can breach multiple tissue barriers within the first days of infection, and demonstrates microglia as the first cells responding to C. neoformans invasion of the brain. IMPORTANCE Cryptococcal meningitis causes 10%–15% of AIDS-associated deaths globally. Still, brain-specific immunity to cryptococci is a conundrum. By employing innovative imaging, this study reveals what occurs during the first days of infection in brain and in airways. We found that titan cells predominate in upper airways and that cryptococci breach the upper airway mucosa, which implies that, at least in mice, the upper airways are a site for fungal dissemination. This would signify that mucosal immunity of the upper airway needs to be better understood. Importantly, we also show that microglia, the brain-resident macrophages, are the first responders to infection, and microglia clusters are formed surrounding cryptococci. This study opens the field to detailed molecular investigations on airway immune response, how fungus traverses the blood-brain barrier, how microglia respond to infection, and ultimately how microglia monitor the blood-brain barrier to preserve brain function.

  PublisherDOI

• Dietary L-3,4-dihydroxyphenylalanine (L-DOPA) augments cuticular melanization in Anopheles mosquitos while reducing their lifespan and malaria parasite burden

  Research Square · 2024-10-16 · 1 citations

  preprintOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Scientific civility and academic performance

  Research Square · 2024-01-24

  preprintOpen access1st authorCorresponding

  Abstract In modern science, interdisciplinary and collaborative research is encouraged among scientists to solve complex problems. However, when the time comes to measure an individual’s academic productivity, collaborative efforts are hard to conceptualize and quantify. In this study, we hypothesized that a social behavior coined “scientific civility”, which encompasses civility, collaboration, cooperation, or a combination of these, enhances an individual’s productivity influencing their academic performance. To assess the value of collaborative efforts and research output to a scientist’s academic performance, we developed a new indicator: the C score. We examined publicly available data from 1000 academic scientists at the individual-level, focusing on their scholarly output and collaborative networks as a function of geographic distribution and time. Our findings strongly suggest that the C score supports an integrative and holistic assessment of an individual’s academic performance. This indicator may be used as a decision-making tool to track career advancement within the academic environment.

  PublisherOA PDFDOI

• New Insights Into The Melanin Structure Of <i>Lomentospora prolificans</i>

  bioRxiv (Cold Spring Harbor Laboratory) · 2024-11-01 · 2 citations

  preprintOpen access

  Abstract Lomentospora prolificans is a filamentous fungus with a global distribution, manifesting particularly higher prevalence in human-impacted environments. This organism is associated with a wide spectrum of human infections, especially in immunosuppressed individuals, for whom it causes severe and debilitating illnesses with high morbidity and mortality that are compounded by its pan-resistant profile with respect to antifungal drugs. Melanin is a ubiquitous pigment among fungi with a broad range of actions that include promoting fungal virulence. Although melanin is one of the most studied virulence factors in pathogenic fungi, relatively little is known about the chemistry of this pigment in L. prolificans. In the current study we characterized L. prolificans -associated melanin using chemical, biological, biophysical and structural techniques, also assessing the impact of inhibitors of distinct melanization pathways. Our results reveal that this pathogenic fungus makes multiple types of melanin pigments and suggests the possibility of a new type of melanin, which is synthesized together with a mixture of DHN-, DOPA- and pyomelanin types. These insights enhance our understanding of L. prolificans’ virulence mechanisms, paving the way for potential therapeutic interventions.

  PublisherOA PDFDOI

• Dietary L-3,4-dihydroxyphenylalanine (L-DOPA) augments cuticular melanization in <i>Anopheles</i> mosquitos while reducing their lifespan and malaria parasite burden

  bioRxiv (Cold Spring Harbor Laboratory) · 2024-09-30 · 1 citations

  preprintOpen access1st author

  ABSTRACT L-3,4-dihydroxyphenylalanine (L-DOPA), a naturally occurring tyrosine derivative, is prevalent in environments that include mosquito habitats, potentially serving as part of their diet. Given its role as a precursor for melanin synthesis we investigate the effect of dietary L-DOPA on mosquito physiology and immunity to Plasmodium falciparum and Cryptococcus neoformans infection. Dietary L-DOPA is incorporated into mosquito melanin via a non-canonical pathway and has a profound transcriptional effect associated with enhanced immunity, increased pigmentation, and reduced lifespan. Increased melanization results in an enhanced capacity to absorb electromagnetic radiation that affects mosquito temperatures. Bacteria in the mosquito microbiome act as sources of dopamine, a substrate for melanization. Our results illustrate how an environmentally abundant amino acid analogue can affect mosquito physiology and suggest its potential usefulness as an environmentally friendly vector control agent to reduce malaria transmission, warranting further research and field studies.

  PublisherDOI

Frequent coauthors

• Martin L. Olsson

  Lund University

  69 shared

• Jill R. Storry

  69 shared

• C. Ellen van der Schoot

  Sanquin

  69 shared

• Masja de Haas

  Leiden University Medical Center

  69 shared

• Irena Svobodová

  University of Veterinary Sciences Brno

  68 shared

• Neil D. Avent

  68 shared

• Tracey E. Madgett

  University of Plymouth

  68 shared

• Pavel Jinoch

  68 shared

Education

• PhD in Microbiology, Department of Molecular Microbiology and Immunology

  Venezuelan Institute for Scientific Research

  2011

• Bs in Medical Laboratory, School of Pharmacy and Bioanalysis

  University of the Andes

  2004

Awards & honors

• Postdoctoral Fellowship - Johns Hopkins Malaria Research Ins…
• Scholarship - Young International Society for Human and Anim…
• Excellence Scholarship - Venezuelan Institute for Scientific…
• Individual Scholarship - National Endowment for Science Tech…
• Honored as Best Molecular Biophysics article selected for co…