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CCR6 functions as a new coreceptor for limited primary human and simian immunodeficiency viruses.

Islam S, Shimizu N, Hoque SA, Jinno-Oue A, Tanaka A, Hoshino H - PLoS ONE (2013)

Bottom Line: When CCR6 was transduced there, the resultant NP-2/CD4/CCR6 cells became susceptible to HIV-1HAN2, HIV-2MIR and SIVsmE660, indicating coreceptor roles of CCR6.Conversely, CCR6-origin SIVsmE660 clones resulted two amino acid changes in the V1 region and one change in the C2 region.Together, the results describe CCR6 as an independent coreceptor for HIV and SIV in strain-specific manner.

View Article: PubMed Central - PubMed

Affiliation: Department of Virology and Preventive Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.

ABSTRACT
More than 12 chemokine receptors (CKRs) have been identified as coreceptors for the entry of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2), and simian immunodeficiency viruses (SIVs) into target cells. The expression of CC chemokine receptor 6 (CCR6) on Th17 cells and regulatory T cells make the host cells vulnerable to HIV/SIV infection preferentially. However, only limited information is available concerning the specific role of CCR6 in HIV/SIV infection. We examined CCR6 as a coreceptor candidate in this study using NP-2 cell line-based in-vitro studies. Normally, CD4-transduced cell line, NP-2/CD4, is strictly resistant to all HIV/SIV infection. When CCR6 was transduced there, the resultant NP-2/CD4/CCR6 cells became susceptible to HIV-1HAN2, HIV-2MIR and SIVsmE660, indicating coreceptor roles of CCR6. Viral antigens in infected cells were detected by IFA and confirmed by detection of proviral DNA. Infection-induced syncytia in NP-2/CD4/CCR6 cells were detected by Giemsa staining. Amount of virus release through CCR6 has been detected by RT assay in spent culture medium. Sequence analysis of proviral DNA showed two common amino acid substitutions in the C2 envelope region of HIV-2MIR clones propagated through NP-2/CD4/CCR6 cells. Conversely, CCR6-origin SIVsmE660 clones resulted two amino acid changes in the V1 region and one change in the C2 region. The substitutions in the C2 region for HIV-2MIR and the V1 region of SIVsmE660 may confer selection advantage for CCR6-use. Together, the results describe CCR6 as an independent coreceptor for HIV and SIV in strain-specific manner. The alteration of CCR6 uses by viruses may influence the susceptibility of CD4+ CCR6+ T-cells and dendritic cell subsets in vivo and therefore, is important for viral pathogenesis in establishing latent infections, trafficking, and transmission. However, clinical relevance of CCR6 as coreceptor in HIV/SIV infections should be investigated further.

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Sequence analysis of CCR6-using HIV-2MIR and SIVsmE660 isolates.The amino acid alignment of the C2-V3 region of the HIV-2MIR-CCR6 variant has been made with parental HIV-2MIR-CCR5 variant. Similarly, genetic divergence of the V1-V3 region of the SIVsmE660-R6 was determined by the pair-wise comparison to its R5-variant. (A) Each pair of R6 and R5 variants has been aligned. Dots indicate identity and letters represent substitutions in the adapted variants relative to the parental isolate. The positions of the common amino acid changes were marked by ♦. The V3 domain was indicated by dashes. (B) Amino acid sequences of two clones of R6-variant were aligned with two clones of R5-variant in the V1, V2 and V3 domains. The regions equivalent to the V1, V2 and V3 of SIV are indicated by dashes. Dots indicate the identity with the parental isolate; letters represent differences in the adapted variants. The positions of common amino acid changes were marked by ▲.
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pone-0073116-g004: Sequence analysis of CCR6-using HIV-2MIR and SIVsmE660 isolates.The amino acid alignment of the C2-V3 region of the HIV-2MIR-CCR6 variant has been made with parental HIV-2MIR-CCR5 variant. Similarly, genetic divergence of the V1-V3 region of the SIVsmE660-R6 was determined by the pair-wise comparison to its R5-variant. (A) Each pair of R6 and R5 variants has been aligned. Dots indicate identity and letters represent substitutions in the adapted variants relative to the parental isolate. The positions of the common amino acid changes were marked by ♦. The V3 domain was indicated by dashes. (B) Amino acid sequences of two clones of R6-variant were aligned with two clones of R5-variant in the V1, V2 and V3 domains. The regions equivalent to the V1, V2 and V3 of SIV are indicated by dashes. Dots indicate the identity with the parental isolate; letters represent differences in the adapted variants. The positions of common amino acid changes were marked by ▲.

Mentions: Due to the high mutation rate of HIV/SIV, the viral populations of CCR5-user may not be similar to those of CCR6-user. We analyzed the genetic divergence of proviral DNAs of HIV-2MIR and SIVsmE660 propagated in NP-2/CD4/CCR5 and NP-2/CD4/CCR6 cells. For HIV-2MIR, we amplified the C2-V3 region of env genes and sequenced two clones from each of MIR-R5 and MIR-R6 strains. An overall good integrity was observed in the majority of the nucleotide sequences between R5 and R6 MIR strains. There were four common nucleotide substitutions in the C2 region of MIR-R6 compared to MIR-R5, however, no such changes were found inV3 region (Figure S1). The nucleotide substitutions resulted two amino acid substitutions, namely, tryptophan (W) to cysteine (C) and lysine (K) to arginine (R) in the C2 region common in both clones (Figure 4A). Another change of amino acid from lysine (K) to asparagine (N) was found in one clone of R6-MIR but not in other clone. For SIVsmE660, the env gene for the V1-V3 region of R6-variant exhibited six nucleotide substitutions common in two clones relative to that of the parental smE660-R5 ones (Figure S2). Some of the nucleotide substitutions were synonymous that did not result amino acid changes. However, non-synonymous substitutions of nucleotides resulted three amino acid changes such as, arginine (R) to glycine (G) and vice-versa in V1 region, another change from glycine (G) to glutamic acid (E) in C2 region (Figure 4B). Combining, no amino acid substitution were found in the V3 region of either HIV-2MIR or SIVsmE660 while growing through NP-2/CD4/CCR6 cells. In contrast, both of the viruses showed common amino acid substitutions in their C2 regions in using CCR6 as coreceptors.


CCR6 functions as a new coreceptor for limited primary human and simian immunodeficiency viruses.

Islam S, Shimizu N, Hoque SA, Jinno-Oue A, Tanaka A, Hoshino H - PLoS ONE (2013)

Sequence analysis of CCR6-using HIV-2MIR and SIVsmE660 isolates.The amino acid alignment of the C2-V3 region of the HIV-2MIR-CCR6 variant has been made with parental HIV-2MIR-CCR5 variant. Similarly, genetic divergence of the V1-V3 region of the SIVsmE660-R6 was determined by the pair-wise comparison to its R5-variant. (A) Each pair of R6 and R5 variants has been aligned. Dots indicate identity and letters represent substitutions in the adapted variants relative to the parental isolate. The positions of the common amino acid changes were marked by ♦. The V3 domain was indicated by dashes. (B) Amino acid sequences of two clones of R6-variant were aligned with two clones of R5-variant in the V1, V2 and V3 domains. The regions equivalent to the V1, V2 and V3 of SIV are indicated by dashes. Dots indicate the identity with the parental isolate; letters represent differences in the adapted variants. The positions of common amino acid changes were marked by ▲.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3757016&req=5

pone-0073116-g004: Sequence analysis of CCR6-using HIV-2MIR and SIVsmE660 isolates.The amino acid alignment of the C2-V3 region of the HIV-2MIR-CCR6 variant has been made with parental HIV-2MIR-CCR5 variant. Similarly, genetic divergence of the V1-V3 region of the SIVsmE660-R6 was determined by the pair-wise comparison to its R5-variant. (A) Each pair of R6 and R5 variants has been aligned. Dots indicate identity and letters represent substitutions in the adapted variants relative to the parental isolate. The positions of the common amino acid changes were marked by ♦. The V3 domain was indicated by dashes. (B) Amino acid sequences of two clones of R6-variant were aligned with two clones of R5-variant in the V1, V2 and V3 domains. The regions equivalent to the V1, V2 and V3 of SIV are indicated by dashes. Dots indicate the identity with the parental isolate; letters represent differences in the adapted variants. The positions of common amino acid changes were marked by ▲.
Mentions: Due to the high mutation rate of HIV/SIV, the viral populations of CCR5-user may not be similar to those of CCR6-user. We analyzed the genetic divergence of proviral DNAs of HIV-2MIR and SIVsmE660 propagated in NP-2/CD4/CCR5 and NP-2/CD4/CCR6 cells. For HIV-2MIR, we amplified the C2-V3 region of env genes and sequenced two clones from each of MIR-R5 and MIR-R6 strains. An overall good integrity was observed in the majority of the nucleotide sequences between R5 and R6 MIR strains. There were four common nucleotide substitutions in the C2 region of MIR-R6 compared to MIR-R5, however, no such changes were found inV3 region (Figure S1). The nucleotide substitutions resulted two amino acid substitutions, namely, tryptophan (W) to cysteine (C) and lysine (K) to arginine (R) in the C2 region common in both clones (Figure 4A). Another change of amino acid from lysine (K) to asparagine (N) was found in one clone of R6-MIR but not in other clone. For SIVsmE660, the env gene for the V1-V3 region of R6-variant exhibited six nucleotide substitutions common in two clones relative to that of the parental smE660-R5 ones (Figure S2). Some of the nucleotide substitutions were synonymous that did not result amino acid changes. However, non-synonymous substitutions of nucleotides resulted three amino acid changes such as, arginine (R) to glycine (G) and vice-versa in V1 region, another change from glycine (G) to glutamic acid (E) in C2 region (Figure 4B). Combining, no amino acid substitution were found in the V3 region of either HIV-2MIR or SIVsmE660 while growing through NP-2/CD4/CCR6 cells. In contrast, both of the viruses showed common amino acid substitutions in their C2 regions in using CCR6 as coreceptors.

Bottom Line: When CCR6 was transduced there, the resultant NP-2/CD4/CCR6 cells became susceptible to HIV-1HAN2, HIV-2MIR and SIVsmE660, indicating coreceptor roles of CCR6.Conversely, CCR6-origin SIVsmE660 clones resulted two amino acid changes in the V1 region and one change in the C2 region.Together, the results describe CCR6 as an independent coreceptor for HIV and SIV in strain-specific manner.

View Article: PubMed Central - PubMed

Affiliation: Department of Virology and Preventive Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.

ABSTRACT
More than 12 chemokine receptors (CKRs) have been identified as coreceptors for the entry of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2), and simian immunodeficiency viruses (SIVs) into target cells. The expression of CC chemokine receptor 6 (CCR6) on Th17 cells and regulatory T cells make the host cells vulnerable to HIV/SIV infection preferentially. However, only limited information is available concerning the specific role of CCR6 in HIV/SIV infection. We examined CCR6 as a coreceptor candidate in this study using NP-2 cell line-based in-vitro studies. Normally, CD4-transduced cell line, NP-2/CD4, is strictly resistant to all HIV/SIV infection. When CCR6 was transduced there, the resultant NP-2/CD4/CCR6 cells became susceptible to HIV-1HAN2, HIV-2MIR and SIVsmE660, indicating coreceptor roles of CCR6. Viral antigens in infected cells were detected by IFA and confirmed by detection of proviral DNA. Infection-induced syncytia in NP-2/CD4/CCR6 cells were detected by Giemsa staining. Amount of virus release through CCR6 has been detected by RT assay in spent culture medium. Sequence analysis of proviral DNA showed two common amino acid substitutions in the C2 envelope region of HIV-2MIR clones propagated through NP-2/CD4/CCR6 cells. Conversely, CCR6-origin SIVsmE660 clones resulted two amino acid changes in the V1 region and one change in the C2 region. The substitutions in the C2 region for HIV-2MIR and the V1 region of SIVsmE660 may confer selection advantage for CCR6-use. Together, the results describe CCR6 as an independent coreceptor for HIV and SIV in strain-specific manner. The alteration of CCR6 uses by viruses may influence the susceptibility of CD4+ CCR6+ T-cells and dendritic cell subsets in vivo and therefore, is important for viral pathogenesis in establishing latent infections, trafficking, and transmission. However, clinical relevance of CCR6 as coreceptor in HIV/SIV infections should be investigated further.

Show MeSH
Related in: MedlinePlus