>>Can THP-1 cell CCR2 expresssion be used as an analog to CD14++CD16- and CD14++CD16+ monocytes?

For me - no.

No they cannot. Classical (CD14++CD16-) and intermediate (CD14++CD16+) monocytes have very similar expression of CCR2, so that marker cannot be used to distinguish between the two. Also, I found that THP-1 had very little expression of CD14 and no expression of CD16. So in my opinion these are still to immature in myelopoeisis to be used as a model of intermediate monocytes. I am not familiar with any cell line that can be used in this way either. Your best opinion is to use primary human monocytes and cell sort for your populations of interest.

I agree with both answers. It is a common mistake and it should be avoided. 

I agree with Dionna Whitney. Additionally, classical and intermediate monocytes have different functions therefore it is difficult to compare with the THP-1. Also, You can obteined this subsets with a monocyte isolation kit.

I also agree with Dionna, and also think primary cells are going to be your best answer. I would add that you need to be careful when using THP-1 cell lines because THP-1 cell lines derived from different laboratories or different conditions can vary greatly in their expression of surface receptors. Therefore you would want to carefully characterize your THP-1's before use.