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The Two-Phase Emergence of Non Pandemic HIV-1 Group O in Cameroon.

Leoz M, Feyertag F, Kfutwah A, Mauclère P, Lachenal G, Damond F, De Oliveira F, Lemée V, Simon F, Robertson DL, Plantier JC - PLoS Pathog. (2015)

Bottom Line: Our findings show that although this evolutionary pattern is specific to HIV-1 group O, it paralleled the early spread of HIV-1 group M in the Democratic Republic of Congo.Both viral lineages are likely to have benefited from similar epidemiological contexts.The relative role of virological and social factors in the distinct epidemic histories of HIV-1 group O and M needs to be reassessed.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Virologie, CHU Charles Nicolle, Rouen, France; EA 2656 GRAM, Université de Rouen, Rouen, France.

ABSTRACT
Unlike the pandemic form of HIV-1 (group M), group O viruses are endemic in west central Africa, especially in Cameroon. However, little is known about group O's genetic evolution, and why this highly divergent lineage has not become pandemic. Using a unique and large set of group O sequences from samples collected from 1987 to 2012, we find that this lineage has evolved in successive slow and fast phases of diversification, with a most recent common ancestor estimated to have existed around 1930 (1914-1944). The most rapid periods of diversification occurred in the 1950s and in the 1980s, and could be linked to favourable epidemiological contexts in Cameroon. Group O genetic diversity reflects this two-phase evolution, with two distinct populations potentially having different viral properties. The currently predominant viral population emerged in the 1980s, from an ancient population which had first developed in the 1950s, and is characterized by higher growth and evolutionary rates, and the natural presence of the Y181C resistance mutation, thought to confer a phenotypic advantage. Our findings show that although this evolutionary pattern is specific to HIV-1 group O, it paralleled the early spread of HIV-1 group M in the Democratic Republic of Congo. Both viral lineages are likely to have benefited from similar epidemiological contexts. The relative role of virological and social factors in the distinct epidemic histories of HIV-1 group O and M needs to be reassessed.

No MeSH data available.


Related in: MedlinePlus

Estimates of group O tMRCA.The marginal posterior density curves obtained using four different population growth models are shown. Different colours identify the distribution of tMRCA estimates for global group O (black), subgroup H (green), and subclusters H1, H2 and H3 (blue, red and yellow, respectively).
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ppat.1005029.g002: Estimates of group O tMRCA.The marginal posterior density curves obtained using four different population growth models are shown. Different colours identify the distribution of tMRCA estimates for global group O (black), subgroup H (green), and subclusters H1, H2 and H3 (blue, red and yellow, respectively).

Mentions: We used 154 sequences for which all three gene fragments were obtained from a single sample of known sampling time to investigate group O origins and dynamics over time. Different coalescent population growth models (constant size, exponential growth, logistic growth and Bayesian skyline) gave consistent estimates for group O’s time to most recent common ancestor (tMRCA) of around 1930 (Fig 2, black curves), with 95% highest posterior densities (95% HPD) ranging from 1914 to 1944. Interestingly, Bayesian Skyline Plots showed that group O genetic diversity had gone through an alternation of slow and fast growth phases (Fig 3A). Two waves of exponential growth were observed, the first around 1950 and the second, longer and more important, starting in the late 1970's and ending in the early 1990s. While the first wave could be observed when investigating all of the 154 sequences (Fig 3A), it did not appear when only including the H strains and the two minor subclusters observed among the T strains, T1 and T2 (Fig 3B). These results indicate that the first wave represents the development of an ancestral level of genetic diversity, and the second wave the emergence of subpopulations such as H strains.


The Two-Phase Emergence of Non Pandemic HIV-1 Group O in Cameroon.

Leoz M, Feyertag F, Kfutwah A, Mauclère P, Lachenal G, Damond F, De Oliveira F, Lemée V, Simon F, Robertson DL, Plantier JC - PLoS Pathog. (2015)

Estimates of group O tMRCA.The marginal posterior density curves obtained using four different population growth models are shown. Different colours identify the distribution of tMRCA estimates for global group O (black), subgroup H (green), and subclusters H1, H2 and H3 (blue, red and yellow, respectively).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4524642&req=5

ppat.1005029.g002: Estimates of group O tMRCA.The marginal posterior density curves obtained using four different population growth models are shown. Different colours identify the distribution of tMRCA estimates for global group O (black), subgroup H (green), and subclusters H1, H2 and H3 (blue, red and yellow, respectively).
Mentions: We used 154 sequences for which all three gene fragments were obtained from a single sample of known sampling time to investigate group O origins and dynamics over time. Different coalescent population growth models (constant size, exponential growth, logistic growth and Bayesian skyline) gave consistent estimates for group O’s time to most recent common ancestor (tMRCA) of around 1930 (Fig 2, black curves), with 95% highest posterior densities (95% HPD) ranging from 1914 to 1944. Interestingly, Bayesian Skyline Plots showed that group O genetic diversity had gone through an alternation of slow and fast growth phases (Fig 3A). Two waves of exponential growth were observed, the first around 1950 and the second, longer and more important, starting in the late 1970's and ending in the early 1990s. While the first wave could be observed when investigating all of the 154 sequences (Fig 3A), it did not appear when only including the H strains and the two minor subclusters observed among the T strains, T1 and T2 (Fig 3B). These results indicate that the first wave represents the development of an ancestral level of genetic diversity, and the second wave the emergence of subpopulations such as H strains.

Bottom Line: Our findings show that although this evolutionary pattern is specific to HIV-1 group O, it paralleled the early spread of HIV-1 group M in the Democratic Republic of Congo.Both viral lineages are likely to have benefited from similar epidemiological contexts.The relative role of virological and social factors in the distinct epidemic histories of HIV-1 group O and M needs to be reassessed.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Virologie, CHU Charles Nicolle, Rouen, France; EA 2656 GRAM, Université de Rouen, Rouen, France.

ABSTRACT
Unlike the pandemic form of HIV-1 (group M), group O viruses are endemic in west central Africa, especially in Cameroon. However, little is known about group O's genetic evolution, and why this highly divergent lineage has not become pandemic. Using a unique and large set of group O sequences from samples collected from 1987 to 2012, we find that this lineage has evolved in successive slow and fast phases of diversification, with a most recent common ancestor estimated to have existed around 1930 (1914-1944). The most rapid periods of diversification occurred in the 1950s and in the 1980s, and could be linked to favourable epidemiological contexts in Cameroon. Group O genetic diversity reflects this two-phase evolution, with two distinct populations potentially having different viral properties. The currently predominant viral population emerged in the 1980s, from an ancient population which had first developed in the 1950s, and is characterized by higher growth and evolutionary rates, and the natural presence of the Y181C resistance mutation, thought to confer a phenotypic advantage. Our findings show that although this evolutionary pattern is specific to HIV-1 group O, it paralleled the early spread of HIV-1 group M in the Democratic Republic of Congo. Both viral lineages are likely to have benefited from similar epidemiological contexts. The relative role of virological and social factors in the distinct epidemic histories of HIV-1 group O and M needs to be reassessed.

No MeSH data available.


Related in: MedlinePlus