HIV binds what on T cells?

[md2011]

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page 171 of First Aid for HIV said "Virus binds CXCR4 and CD4 on T cells; binds CCR5 and CD4 on macrophages." If I am right, macrophage has no CD4, what's wrong here? someone help?

 

[Vonsmack]

I don't think you're right. CD4 receptors found on macrophages, T cells, monocytes, dendritic cells. CD8 receptors found on T cells, NK cells. First Aid is correct.

If you don't believe me, do a pubmed search (or google) for macrophage CD4 and you'll probably get a million responses.

 

[ENThopeful]

i may be totally making this up, and im too lazy to check but CD4 is a coreceptor for antigen presenting MHC2. macrophages are antigen presenting, so it probably would have a cd4 receptor

 

[md2011]

First Aid page 199 for "Cell surface proteins" said for macrophages: MHCII, B7, CD40, CD14, receptor for Fc and C3b. CD4 is not there. I think CD4 is T cell specific

 

[md2011]

Here is what said on micro card: "viral gp120 binds CD4 on cell surface-> viral gp120 conformational change-> altered viral gp120 binds co-receptor CXCR4(for T cell infection only) or CCR5 (for T cell or macrophage infection)". It didn't say CD4 on which cell, I assume it also means both T cell and macrophage?

 

[pseudoknot]

Yes, HIV gp120 binds to CD4. It is absolutely required for infection. As others have pointed out, you can easily do a Google search (or, God forbid, pick up a book) and verify that macrophages express CD4. If FA left that out of a table then that is one of FA's numerous and well known errors.

 

[Tiger26]

As I recall, HIV binding CD4 on macraphages allows eventual spread into the CNS . . . . .

 

[ENThopeful]

As I recall, HIV binding CD4 on macraphages allows eventual spread into the CNS . . . . .

eventual spread everywhere.. i dont remember where HIV goes first but i vaguely recall a fact as such.


furthermore, i remember from class that some people have different ccr5 receptor or something causing them to be essential resistant to AIDS (not important for step 1)

 

[AllUpOnYoMama]

"For fusion and translocation of HIV across the cell membrane both a CD4 receptor and a co-receptor, either CCR5 or CXCR4, must be present. These are found on helper T lymphocytes and on macrophages" -CMMRS
So CD4 must be present on both T cells and Macs.
"Patients who fail to produce normal levels of CCR5 proteins appear to be resistant to HIV infection" -CMMRS
Hope this helps man

 

[ENThopeful]

oh haha thats where i got it from. i guess i retained something from that stupid book

 

[turkeyjerky]

Froms this week's NEJM:
http://content.nejm.org/cgi/content/short/360/7/692

They did a bmt on a guy with hiv and leukemia using a donor who had a CCR5 mutation, now he's all good.

 

[windsorMD]

Macrophages are MHC-1 and MHC-2. They have a nucleus (MHC-1 - CD8) and are APC's (MHC-2 - CD4).

 

[ssilver]

In regard to HIV infection, which of the following is the earliest finding?

A. Kaposi sarcoma on the palate

B. Reduced haemoglobin

C. Infection with pneumocystic carinii

D. Reduction in white cells count ?

E. B cell lymphoma

 

[LadyJubilee8_18]

In regard to HIV infection, which of the following is the earliest finding?

A. Kaposi sarcoma on the palate

B. Reduced haemoglobin

C. Infection with pneumocystic carinii

D. Reduction in white cells count ?

E. B cell lymphoma

I would say reduction in white cell count because all of the other problems happen in response to having a lower white cell count. I know B cell lymphoma is a late finding, and pcp infection is an indication of a less than 200 T cell count. The only one I'm not sure about is the reduced haemoglobin.

 

[ssilver]

I would say reduction in white cell count because all of the other problems happen in response to having a lower white cell count. I know B cell lymphoma is a late finding, and pcp infection is an indication of a less than 200 T cell count. The only one I'm not sure about is the reduced haemoglobin.

Thanks LadyJubilee
I appreciate... it 🙂 I guess you're right.

 

[LadyJubilee8_18]

Thanks LadyJubilee
I appreciate... it 🙂 I guess you're right.

no problem 👍