Charlize Theron is chic in smart grey trousers and pumps as she promotes AIDS research

She founded a charitable organization devoted to ending HIV/AIDS in Africa and serves as a United Nations Messenger of Peace.

So Charlize Theron certainly meant business as she attended an AIDS conference at the University of California in Los Angeles on Tuesday.

The 39-year-old actress looked professional and chic as she took to the stage with members of the United Nations Programme on HIV/AIDS (UNAIDS).

The Oscar-winning star sported sleek grey dress pants paired with a black scoop-neck top and black pumps, completing the look with a simple pendant necklace and a gold watch.

She appeared animated on stage, chatting and laughing.

During the event, UNAIDS discussed a fast-track approach to ending the AIDS epidemic by 2030 – averting 28 million new HIV infections and 21 million AIDS-related deaths.

It is a cause that Charlize is passionate about, having founded the Charlize Theron Africa Outreach Project in 2007, which supports African youth in their fight against the disease.

Her organization primarily focuses on her home country of South Africa.

Charlize has a son named Jackson whom she adopted from South Africa in 2012.

Meanwhile, the blonde beauty has just returned to the States, having been filming the upcoming drama The Last Face in South Africa, directed by her boyfriend Sean Penn.

Charlize is starring as the director of an international aid organization ‘doing humanitarian relief work in Africa amidst violent political conflicts in the region,’ according to Deadline.

She then becomes romantically involved with another doctor, played by Javier Bardem, with whom she butts heads in regards to their views on solving the conflict surrounding them, causing their relationship to unravel.

The Last Face is a fitting film for both Charlize and Sean, 54, for the two share a passion and history for humanitarian work.

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