Newsgroups: alt.drugs.pot,sci.med.immunology
From: [pe 95010] at [sable.ox.ac.uk] (Andy Linkin)
Subject: Re: Does THC suppress the immune system?
Date: Thu, 10 Nov 94 17:29:25 GMT

In article <[1994 Nov 10 112313 19680] at [crosfield.co.uk]>,
Glyn Hanton <[g--n] at [crosfield.co.uk]> wrote:
>Milton Tinkoff ([m--t] at [esd.sgi.com]) wrote:
>: Will smoking marijuana make it harder for the body to fight viral
>: infections?
>
>I've been told by a certain medical student who hangs around here
>that THC is supposed to be a immune system booster in the long term, so
>stoners should be ill for as long.
>
>Care to confirm that Andy.
>
Right, you asked for it..... If you get bored easily, I'd not bother
reading this.

Short answer :  NO

Long answer - immunosuppresive effects have only really been
demonstrated in animals.  These poor lab rats (I'm a bit sick about
this kind of thing) are given doses of THC about 100 times greater
than the normal effective dose per unit body weight in humans.

Consider that the ED50, or normal effective dose is about 1mg/kg in
humans. this basically means that they (the mice) are getting a dose
of about 500mg, or say around about 5 joints worth - all of this in a
lab rat that weighs around 500g, or 1lb for all of you who can't work
out weights in grammes. To my mind, this invalidates this view.


Secondly, only one type of THC receptor has so far been found.  This
only reacts to delta-9THC nad close structural analogues (analogy used
in the FAQ is that of a button). The metabolites can't trigger this
receptor, and so won't have an effect on the macrophage /
kupffer cell/ langerhans cell/ microglial cell / splenocyte /
dendritic cell or any other type of macrophage. (All of these are macrophages)

Basically, this means that the negative effcts only last whilst there
is THC in the blood - ie whilst you are stoned. After this, some
researchers (take this to mean a personal communication with a friend
who is working at a lab in Bristol - who gave me thier lab's current
point of view) believe that there is a rebound period of inmcreased
immunity. Before you all get excited, don't. The concentrations of THC
ion the blood of an average smoker is very low - remember the lucky
lab rats.... So there isn't much effect.

Thirdly, the reticuloendothelial system (I like long words), which is
basically all of the macrophages and PMN (neutrophils) and a few other
cells have absolutely nothing to do with viral infections - they are
good at combatting bacterial infections, though.

Basically, viruses have to replicate inside a host cell, having no
replicative machinery (Sorry if this is too simplistic now) Proteins
from the virus are taken up in molecules called Major
histocompatibility Complex (MHC) class I molecules - expressed on
every cell except neurons. These MHC molecules sample the protein
being produced by the cell, and express them on the cell surface. Now,
a special type of cell called the CD4+ or T helper cell can recognise
these molecules and "Helps" (hence the name) a CD8+ or cytotoxic T
cell to administer a "kiss of death" to the infected cell. (hence the
popular name of killer cells). Basically, there isn't a single
macrophage involved in viral infections until the cells have actually
been killed (they eat all of the debris left)

To summarise, no-one has a clue about effects as far as dope and bacterial
infections (like zits, boils, septicaemia, Legionaires  Disease, etc)
are concerned, and it doesn't have any effect on virus infections (as
far as I'm aware - I haven't read nature or the BMJ for the past few
months...)


Hope that this has muddied the waters a bit, Glyn...

Andy L