The public mucosal antibody repertoire in HIV-1 infection

Ended Project Grant Awarded Last action

Award ID
R21AI183981
Recipient
Awarding agency
Obligated
$405,600

Award facts

Assistance listing
93.855 Allergy and Infectious Diseases Research
Completion date
Place of performance
Aurora, CO 80045, USA

Award details come from USAspending.gov.

Description

Abstract
Restoring the integrity of the gastrointestinal tract could be key to counteracting the spectrum of inflammation- associated debilitating illnesses and increased mortality among persons living with HIV-1 (PWH) on antiretroviral therapy. This may be accomplished by harnessing pathways that maintain GUT homeostasis, of which IGA- microbiome interactions are emerging as fundamental mechanisms. In fact, using GUT biopsies from an age/SEX- matched cohort of PWH and HIV-1-uninfected individuals, we demonstrated alterations in the IGA repertoire among PWH that associated with specific bacterial taxa. Testing these IGA-microbiome correlations experimentally is a major challenge, as the human antibody repertoire is extremely diverse, with over a trillion distinct antibodies possible. Interestingly, recent high-throughput studies revealed the existence of 'public' antibodies: clonotypes that were shared among unlinked individuals that encode the same v and j genes and highly related CDR3 antigen-binding regions. The biology of public antibodies remains mysterious; statistically, these antibodies should not exist unless there is a shared antigenic history and/or evolutionarily-conserved function. Notably, in inbred, specific-pathogen-free mice, a subset of public IGA interacted with the GUT microbiome, suggesting a potential role in GUT homeostasis. To date, whether these findings extend to humans remains unclear. Using our next-generation sequencing dataset, we uncovered over a dozen public IGA clonotypes specific to PWH versus HIV-1-uninfected controls, and vice versa. As a critical first step in understanding their biology, our main goal in this exploratory study is to prepare recombinant public IGA clonotypes specific to HIV-1-uninfected individuals or PWH, and interrogate their reactivity against fecal bacterial communities and microbial glycans. We will then test if bacteria-reactive public IGA recovered from PWH GUT biopsies influence HIV-1-mediated CD4+ t cell death and inflammation in a robust EX vivo lamina propria aggregate culture model that we developed previously. These studies promise to provide the field with a first look at the nature and immune properties of public IGA clonotypes in the human gastrointestinal tract, that may provide promising leads for therapeutic modulation of mucosal inflammation in chronic HIV-1 infection and a wide variety of medical conditions associated with a 'leaky GUT' syndrome.

Transactions

Action Obligated Date
Amendment $195,000
Original award $210,600

Quick answers

Who received award R21AI183981?

R21AI183981 was awarded to The Regents Of The University Of Colorado by National Institute of Allergy and Infectious Diseases (National Institutes of Health) on August 1, 2024.

How much is award R21AI183981 worth?

$405,600 has been obligated on R21AI183981.

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