Galectin-8 binds HIV envelope glycoproteins with high affinity and promotes viral infectivity
(2026) In Frontiers in cellular and infection microbiology 16.- Abstract
Target cell entry of HIV-1 is dependent on the binding of gp120, the outer component of the viral envelope glycoprotein complex (Env), to CD4 and a coreceptor, preferentially CCR5 or CXCR4. Still, other interactions may also contribute to the infectivity of the virus. One such interaction is between the highly glycosylated gp120 and carbohydrate-binding proteins, such as galectins. Here, we studied the interaction between HIV-1 Env and a panel of galectins and found that galectin-8 (Gal-8), bound with highest affinity (K
D < 1µM) and also interacted with soluble CD4. Detailed analysis using probes for different parts of Gal-8 revealed that it was primarily the N-terminal carbohydrate recognition domain that interacted with HIV-1... (More)Target cell entry of HIV-1 is dependent on the binding of gp120, the outer component of the viral envelope glycoprotein complex (Env), to CD4 and a coreceptor, preferentially CCR5 or CXCR4. Still, other interactions may also contribute to the infectivity of the virus. One such interaction is between the highly glycosylated gp120 and carbohydrate-binding proteins, such as galectins. Here, we studied the interaction between HIV-1 Env and a panel of galectins and found that galectin-8 (Gal-8), bound with highest affinity (K
(Less)
D < 1µM) and also interacted with soluble CD4. Detailed analysis using probes for different parts of Gal-8 revealed that it was primarily the N-terminal carbohydrate recognition domain that interacted with HIV-1 Env expressing sialylated galactosides and both N- and O-linked glycans. Importantly, in cell cultures Gal-8 enhanced the infectivity of HIV-1, including strains with different coreceptor use and subtype origin, as well as HIV-2. This Gal-8 infectivity enhancement was particularly strong (up to 100-fold) at low virus inoculum doses. Next, we compared Gal-8 infectivity enhancement of primary HIV-1 isolates from people living with HIV at different stages of the infection. Of note, the infectivity of HIV-1 isolates obtained during the chronic, relatively immunocompetent phase, was significantly more enhanced by Gal-8 than isolates obtained at late-stage disease during severe immunodeficiency. Taken together, this study reveals novel carbohydrate dependent interactions between Gal-8 and HIV-1 Env, resulting in enhanced infectivity of HIV-1, with particularly strong effects at low dose exposure of strains circulating during the chronic infection phase. These results suggest that Gal-8 is a cell attachment protein that HIV-1 utilizes for optimized infectivity, which may guide the development of novel intervention strategies targeting this interaction.
- author
- Sheik-Khalil, Enas
LU
; Kahl-Knutson, Barbro
LU
; Johansson, Emil
LU
; Karlson, Sara
LU
; Nilsson, Ulf J.
LU
; Leffler, Hakon
LU
and Jansson, Marianne
LU
- organization
- publishing date
- 2026
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Humans, Galectins/metabolism, HIV-1/pathogenicity, HIV Envelope Protein gp120/metabolism, Protein Binding, CD4 Antigens/metabolism, Virus Internalization, HIV Infections/virology, env Gene Products, Human Immunodeficiency Virus/metabolism, Cell Line, HIV-2/metabolism, HEK293 Cells
- in
- Frontiers in cellular and infection microbiology
- volume
- 16
- article number
- 1801072
- pages
- 15 pages
- publisher
- Frontiers Media S. A.
- external identifiers
-
- pmid:41987899
- ISSN
- 2235-2988
- DOI
- 10.3389/fcimb.2026.1801072
- language
- English
- LU publication?
- yes
- additional info
- Copyright © 2026 Sheik-Khalil, Kahl-Knutson, Johansson, Karlson, Nilsson, Leffler and Jansson.
- id
- de75487f-9fde-4514-b97e-d5f30d8f04a9
- date added to LUP
- 2026-04-16 21:49:42
- date last changed
- 2026-04-20 11:25:33
@article{de75487f-9fde-4514-b97e-d5f30d8f04a9,
abstract = {{<p>Target cell entry of HIV-1 is dependent on the binding of gp120, the outer component of the viral envelope glycoprotein complex (Env), to CD4 and a coreceptor, preferentially CCR5 or CXCR4. Still, other interactions may also contribute to the infectivity of the virus. One such interaction is between the highly glycosylated gp120 and carbohydrate-binding proteins, such as galectins. Here, we studied the interaction between HIV-1 Env and a panel of galectins and found that galectin-8 (Gal-8), bound with highest affinity (K<br>
D < 1µM) and also interacted with soluble CD4. Detailed analysis using probes for different parts of Gal-8 revealed that it was primarily the N-terminal carbohydrate recognition domain that interacted with HIV-1 Env expressing sialylated galactosides and both N- and O-linked glycans. Importantly, in cell cultures Gal-8 enhanced the infectivity of HIV-1, including strains with different coreceptor use and subtype origin, as well as HIV-2. This Gal-8 infectivity enhancement was particularly strong (up to 100-fold) at low virus inoculum doses. Next, we compared Gal-8 infectivity enhancement of primary HIV-1 isolates from people living with HIV at different stages of the infection. Of note, the infectivity of HIV-1 isolates obtained during the chronic, relatively immunocompetent phase, was significantly more enhanced by Gal-8 than isolates obtained at late-stage disease during severe immunodeficiency. Taken together, this study reveals novel carbohydrate dependent interactions between Gal-8 and HIV-1 Env, resulting in enhanced infectivity of HIV-1, with particularly strong effects at low dose exposure of strains circulating during the chronic infection phase. These results suggest that Gal-8 is a cell attachment protein that HIV-1 utilizes for optimized infectivity, which may guide the development of novel intervention strategies targeting this interaction.<br>
</p>}},
author = {{Sheik-Khalil, Enas and Kahl-Knutson, Barbro and Johansson, Emil and Karlson, Sara and Nilsson, Ulf J. and Leffler, Hakon and Jansson, Marianne}},
issn = {{2235-2988}},
keywords = {{Humans; Galectins/metabolism; HIV-1/pathogenicity; HIV Envelope Protein gp120/metabolism; Protein Binding; CD4 Antigens/metabolism; Virus Internalization; HIV Infections/virology; env Gene Products, Human Immunodeficiency Virus/metabolism; Cell Line; HIV-2/metabolism; HEK293 Cells}},
language = {{eng}},
publisher = {{Frontiers Media S. A.}},
series = {{Frontiers in cellular and infection microbiology}},
title = {{Galectin-8 binds HIV envelope glycoproteins with high affinity and promotes viral infectivity}},
url = {{http://dx.doi.org/10.3389/fcimb.2026.1801072}},
doi = {{10.3389/fcimb.2026.1801072}},
volume = {{16}},
year = {{2026}},
}