# Improved Therapeutics and Diagnostics for Pneumocystis Pneumonia

> **NIH NIH R01** · TULANE UNIVERSITY OF LOUISIANA · 2024 · $474,108

## Abstract

Pneumocystis (PC) pneumonia remains a serious complication of HIV infection and other immunocompromised
states. Recent ICD9/10 data show that since 2008 there are consistently 14-15,000 hospitalizations per year
with an average cost of close to $1B per annum in the US alone. Moreover treatment for PCP has not changed
in 25 years and there is concern of anti-microbial resistance and drug:drug interactions with TMP-SMX (the
frontline therapy for PCP). The well-known inverse relationship between CD4+ lymphocyte count and the risk
of PC infection does not hold all of the answers to mechanisms of host defense against this infection. In the prior
funding period, we made significant progress on defining the Pneumocystis transcriptome in both ascus and
trophozoite forms as well as the surface proteome of both forms through surface labeling of the fungus using
techniques that were developed for Candida. We identified troph proteins such as Meu10, a GPI-anchored
protein, as well as ascus specified proteins such as glucan synthetase 1 (GSC1). We were able to clone and
express the GSC1 ectodomain in yeast, and immunization of mice with GSC1 resulted in antibodies that stain
the surface of the ascus and prevent transmission of Pneumocystis in cohousing experiments. We also made
significant progress on diagnostic assays to discriminate colonization from infection. Several groups ae now
using quantitative PCR with copy number thresholds, which may be a valid approach. In the prior funding period
developed and validated a troph specific assay that selectively eradicates the ascus. Furthermore, RNAseq
analysis revealed the troph to be much more metabolically active than the ascus. Thus, we have developed life-
form specific assays that will be tested in clinical specimens. We hypothesize that GSC1 immunization can
prevent pneumocystis transmission and that mucosal immunization is superior to subcutaneous immunization.
We also predict that GSC1 antisera or monoclonal antibodies directed against the GSC1 ectodomain can
mitigate Pneumocystis IRIS. Moreover, as our RNAseq analysis has also revealed that the troph is clearly the
replicative form of the organism in the lung, we hypothesize that an assay to detect troph specific genes will be
diagnostic of PJP due to the detection of the replicative form of the organism. We will also determine the genetic
heterogeneity of these target genes in samples from 4 continents. We will test this hypothesis with the following
specific aims: Aim 1. Determine the immunogenicity and efficacy of systemic (subcutaneous or IM) versus
mucosal GSC1 immunization to prevent PCP. Aim 2. Determine the efficacy of anti-ascus or anti-troph
antibodies to treat established PCP and immune reconstitution syndrome (IRIS). Aim 3. Determine and validate
life-form specific PCR/CRISPR assays in murine and human samples and assess genetic heterogeneity of these
targets in samples from North America, Africa, and western and eastern Asia.

## Key facts

- **NIH application ID:** 10730200
- **Project number:** 5R01AI120033-09
- **Recipient organization:** TULANE UNIVERSITY OF LOUISIANA
- **Principal Investigator:** JAY K KOLLS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $474,108
- **Award type:** 5
- **Project period:** 2016-02-01 → 2026-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10730200

## Citation

> US National Institutes of Health, RePORTER application 10730200, Improved Therapeutics and Diagnostics for Pneumocystis Pneumonia (5R01AI120033-09). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10730200. Licensed CC0.

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