2016 IARS Mentored Research Award Recipient Interview: Angela Meier, MD, PhD

Sex Differences in Bacterial Burden and Mortality in a Murine Model of Experimental Pneumonia

Abstract Presentation:

Poster Session E on Sunday, May 3, 2026, 10:00 am – 11:00 am, in Square Dorchester + Place du Canada, Convention Level at the Fairmont The Queen Elizabeth, during the 2026 Annual Meeting, Presented by IARS and SOCCA

During Angela Meier, MD, PhD’s postdoctoral training in Marcus Altfeld’s lab at Massachusetts General Hospital over 15 years ago, she was intrigued by how biological sex shapes immune responses and influences outcomes in infectious diseases. This would begin her fruitful, decades-long research investigation into sex differences in immune responses. Now a Professor of Clinical Anesthesiology, University of California, San Diego, Dr. Meier continues to explore these differences across multiple pathways, focusing today on bacterial pneumonia and understanding how sex-specific immune responses influence disease severity and outcomes. She hopes these insights might reveal new therapeutic opportunities. Reaching this pivotal point in her career was aided by the support of a 2016 IARS Mentored Research Award for her research on “Anesthesia and Sex Specific, Immune Dependent Impact on Cancer Progression,” providing essential support that enabled her to sustain a dual clinical and research trajectory and establishing the foundation for long-term research development in anesthesiology. On Sunday, May 3, at Poster Session E, during the 2026 Annual Meeting, presented by IARS and SOCCA, Dr. Meier will share the results of her current research which is focused on proteomic differences that may reveal actionable pathways underlying these sex-specific immune responses. Below, she discusses how her research interests have developed over time, how the IARS Annual Meeting has become an opportunity to connect with her extended professional family and her hopes for her investigations in the future.

1. For this research, you are…

Principal Investigator

2. What inspired you to pursue this area of research, and how has your focus evolved over time?

My interest in sex differences in immune responses began during my postdoctoral training in Marcus Altfeld’s lab at Massachusetts General Hospital over 15 years ago. At that time, I became intrigued by how biological sex shapes immune responses and influences outcomes in infectious diseases. This has remained a central theme throughout my career. In collaboration with Victor Nizet, I have continued to explore these differences across multiple pathogens. My current work focuses specifically on bacterial pneumonia, where we aim to understand how sex-specific immune responses influence disease severity and outcomes, and how these insights might reveal new therapeutic opportunities.

3. What key question or challenge does your current research aim to address?

Pneumonia remains a leading cause of mortality worldwide, responsible for over 2.5 million deaths annually, and is one of the most common reasons for hospitalization in the United States. Notably, both the incidence and mortality of community-acquired pneumonia are higher in men than in women, yet the biological basis for this disparity remains poorly understood and is likely multifactorial. Our murine model of Pseudomonas aeruginosa pneumonia recapitulates this clinical pattern: female mice exhibit significantly improved survival compared to males. This raises a central question—what mechanisms enable female hosts to clear infection more effectively? We are investigating differences in immune signaling, cytokine profiles, and proteomic expression between sexes to better understand these divergent outcomes. Ultimately, our goal is to translate these insights into strategies that modulate the immune response and improve survival in patients with pneumonia.

4. What are the most important findings or insights from your work so far?

Our work has identified meaningful sex-based differences in cytokine responses and proteomic signatures during bacterial pneumonia. These findings suggest that immune regulation—not simply pathogen burden—plays a critical role in determining outcomes. In parallel, prior work from Brant M. Wagener and colleagues demonstrated that outcome disparities following bacterial pneumonia in the setting of traumatic brain injury can be mitigated by estrogen, highlighting a potential hormonal contribution. Building on this, our group is focusing on proteomic differences that may reveal actionable pathways underlying these sex-specific immune responses.

5. How could your research, whether through direct clinical application or by advancing foundational knowledge, impact the field of anesthesiology and ultimately improve patient care?

As a clinician-scientist, my goal is to generate insights that ultimately translate into improved patient care. Understanding sex-specific differences in immune responses may help identify novel therapeutic targets and inform more personalized approaches to treating pneumonia and critical illness. Equally important, I hope this work raises broader awareness within the anesthesiology and critical care communities about the importance of incorporating sex as a biological variable in both research and clinical practice.

6. What does presenting your abstract at the IARS Annual Meeting mean to you, and how does it support your professional growth?

Presenting at the IARS Annual Meeting is always an honor. It feels like reconnecting with an extended professional family. I value the opportunity to engage with colleagues, exchange ideas, and discuss emerging research in anesthesiology with both familiar and new collaborators.

7. How has receiving the 2016 IARS Mentored Research Award shaped your career path, research opportunities, or collaborations?

Receiving the IARS Mentored Research Award in 2016 was pivotal for my career. It provided essential support that enabled me to sustain a dual clinical and research trajectory. Importantly, it helped establish the foundation for subsequent funding and long-term research development in anesthesiology.

8. In what ways has your earlier IARS-supported research (e.g., IMRA) influenced your current work?

My earlier IARS-supported work also focused on sex differences in immune-mediated outcomes. It built directly on my prior research in HIV immunology and provided a strong conceptual and experimental foundation for the studies I am presenting this year. In many ways, my current work represents a natural continuation and expansion of those earlier efforts.

9. What advice would you offer to early-career researchers or future IARS award applicants?

Pursuing a research career in anesthesiology is not always straightforward, particularly in today’s environment where clinical work is in high demand and well compensated. That said, research remains essential to advancing our field. I would strongly encourage early-career investigators to stay committed to their scientific interests. The path can be challenging, but the impact of your work—on patients and on the future of our specialty—is incredibly meaningful. Don’t give up.

10. Is there anyone you would like to acknowledge as part of this work?

I am fortunate to work with an outstanding team both clinically and in the laboratory. I would especially like to thank Victor Nizet, my research mentor, and Ruth Waterman, our department chair, for their continued support, inspiration, and generosity.