Regarding the infectivity of naked DNA

[Ian A. York]

In article <kirberg-2605950728440001 at seven.bii.ch> kirberg at bii.ch (Jorg Kirberg) writes:
>In article <3pvalu$e33 at cisunix1.dfci.harvard.edu>,
>york at mbcrr.dfci.harvard.edu (Ian A. York) wrote:

>> with MHC II.  The CD4- Th cells are not going to have this restriction, 
>                                      ^^^                ^^^^^^^^^^^^^^^
>why shouldnt they ?
>If commitment to CD4 or CD8 cells is (partially ?) random in the thymus,
>some high affinity/avidity class II restricted cells might make it to
>the periphery without contribution of CD4.

Yes, there are CD8(+) lymphocytes with an MHC II restriction.  
Some guy called J. Kirberg in Switzerland has done some work on this.
(Kirberg J.  Baron A.  Jakob S.  Rolink A.  Karjalainen K.  von Boehmer H.
Thymic selection of CD8+ single positive cells with a class II 
major histocompatibility complex-restricted receptor.
J Exp Med.  180(1):25-34, 1994)

There are also CD8(-) CD4(-) lymphocytes that are MHC II-restricted and 
which have helper function.  

But since CTL can be primed in the absence of MHC II altogether 
(Christensen JP.  Marker O.  Thomsen AR.
The role of CD4+ T cells in cell-mediated immunity to LCMV: studies in 
MHC class I and class II deficient mice.
Scand J Immunol.  40(4):373-82, 1994

 van Eggermond MC.  Rijkers GT.  Kuis W.  Zegers BJ.  van den Elsen PJ.
T cell development in a major histocompatibility complex 
class II-deficient patient.
Eur J Immunol.  23(10):2585-91, 1993)

this is not necessarily relevant to the system is question, is it.  

You seem to have a general disbelief that the immune response could 
possibly be simply to the DNA expressed in the muscle cells.  That's 
fine, but that is still the simplest explanation at this point.  I don't 
deny that other explanations are possible, and I recall that a recent 
paper got much improved responses when they co-injected some cytokines 
(potentially enhancing the local help); but a dogmatic denial is not 
particularly useful.  For example, you might at some point want to post a 
few references.

Ian
-- 
Ian York   (york at mbcrr.harvard.edu)
Dana-Farber Cancer Institute, 44 Binney St., Boston MA 02115
Phone (617)-632-3921     Fax  (617)-632-2627