Modifying class property in thread causes interface casting error (Exception from HRESULT: 0x80004002 (E_NOINTERFACE))

When attempting to access my "searchResultCollection" property after modifying it in a separate thread (I've tried both background workers and just threads) I receive the below exception. The exception occurs whether I use the BackgroundWorker e.Result property or just set the classes property directly.

If I do all my processing in a single thread everything is fine.

Removing [STAThread] from my main function fixes the problem, but as I'm using windows forms isn't this bad practice?

What is the proper way to update a windows forms properties via a separate thread?

Exception:

System.InvalidCastException: 'Unable to cast COM object of type 'System.__ComObject' to interface type 'IDirectorySearch'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{109BA8EC-92F0-11D0-A790-00C04FD8D5A8}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).'

Form class:

public partial class ActiveDirectoryDiscovery : Form
    {
        private DirectorySearcher directorySearcher;
        private SearchResultCollection searchResults;
        private BackgroundWorker runSearchWorker;

        public ActiveDirectoryDiscovery()
        {
            InitializeComponent();
        }

        private void button_Start_Click(object sender, EventArgs e)
        {
            runSearchWorker = new BackgroundWorker();
            runSearchWorker.DoWork += RunSearchWorker_DoWork;
            runSearchWorker.RunWorkerCompleted += RunSearchWorker_RunWorkerCompleted;
            runSearchWorker.RunWorkerAsync();
        }

        private void RunSearchWorker_DoWork(object sender, DoWorkEventArgs e)
        {
            string filter = this.textBox_LDAPQuery.Text;
            directorySearcher = new DirectorySearcher(filter);
            this.searchResults = directorySearcher.FindAll();
        }

        private void RunSearchWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            foreach (SearchResult result in this.searchResults) {
                if (!result.Properties["objectclass"].Contains("computer")) {
                    return;
                }
                else {
                    ListViewItem newItem = new ListViewItem((string)result.Properties["cn"][0]);
                    this.listView_SearchResults.Items.Add(newItem);
                }
            }
        }
    }