Thread: Cells in exhaled air?

Hullo,

Is it possible that endogenous eukaryotic (human) cells might exist in the air exhaled by a human?

I'm guessing it probably is not possible, since there are no reports of this, as far as I can tell.

Assuming that it were possible for such cells to be present in the air exhaled by humans, how long would the cells remain viable ex vivo? If one human were to inhale a cell immediately after it had been exhaled by a second human, would the cell be able to survive and colonise the new respiratory tract environment?

I'm guessing that normal healthy cells would be unable to do so, since detachment from the extracellular matrix usually spells their apoptotic demise, within about 1 hour of detachment.

What if the exhaled cell was transformed, and had multiple genetic hits, inducing anchorage-independence and other phenotypes that would enable it to colonise a foreign environment?

Cancer is not traditionally considered a transmissible disease in humans, except perhaps in the cases of virus-mediated cancers.

My question is: is it possible that human lung cancers might be transmissible by the aerosol route?

Wouldn't any foreign body be attacked and destroyed in the lungs? If another human's cancer cells were to enter the lungs, they wouldn't have any defences that I know of and would be destroyed in short order. No?

Also, even if they survived somehow, they would have different DNA than that of the host, which haven't been noticed before afaik.

I am very far from an expert.

Wouldn't any foreign body be attacked and destroyed in the lungs? If another human's cancer cells were to enter the lungs, they wouldn't have any defences that I know of and would be destroyed in short order. No?

Also, even if they survived somehow, they would have different DNA than that of the host, which haven't been noticed before afaik.

I am very far from an expert.

Yeah, good point Kalster, they probably would be destroyed by the immune system. I wonder if this would still happen in severely immunocompromised individuals?

Is it possible that endogenous eukaryotic (human) cells might exist in the air exhaled by a human?

There are no endogenous eukaryotic HUMAN cells, there are parasites who can live inside cells. These can also be exhaled. But it is very unlikely it resumes to an infection, as eukaryotic cells are not as resilient as prokaryotic cells.

Assuming that it were possible for such cells to be present in the air exhaled by humans, how long would the cells remain viable ex vivo? If one human were to inhale a cell immediately after it had been exhaled by a second human, would the cell be able to survive and colonise the new respiratory tract environment?

Several seconds, probably halftime of 5-10 seconds, under normal conditions. With high humidity, no uv radiation, low temperature (10-20 celcius), they can probably live longer. The chance they can remain infective after this is extremely low.

I'm guessing that normal healthy cells would be unable to do so, since detachment from the extracellular matrix usually spells their apoptotic demise, within about 1 hour of detachment.

No, they would not preform apoptosis, as they would be dead before they would have died due to apoptosis.

What if the exhaled cell was transformed, and had multiple genetic hits, inducing anchorage-independence and other phenotypes that would enable it to colonise a foreign environment?

Most mutations are not simultainous, but slow, and one in a time, preferably 1 nucleotide, or 1 deletion or insertion. This 1 mutation can not protect the cells enough to make them able to colonise a foreign location.

Cancer is not traditionally considered a transmissible disease in humans, except perhaps in the cases of virus-mediated cancers.

My question is: is it possible that human lung cancers might be transmissible by the aerosol route?

This is an interesting question... Direct answer, no.. this is not possible. Mostly because cancer can't form aerosols. Then they can not survive long enough to cross to another organism. But the dead cell, can induce an immune response, the dna can be implemented into ours, and there could be a case of transmittable cancer. However extremely unlikely, the remaining DNA of a dead aerosol cancer can influence lung cells. I doubt this has ever happened, or ever will happen. There is just the theoretic possibility..

Wouldn't necessarily fall foul of the immune system. There are transmissible cancers, such as the Devil facial tunour disease, that manage just fine on that front. Such diseases require close contact however. Violent exhalations, such as coughing and spluttering, undoubtedly contain all sorts of cells. Saliva, of course, has many immune cells in it. I'm sure I read once about PCR contamination from breath.




I wouldn't rule the idea out completely. But if it did happen it's probably an incredibly rare event; one that may not have ever actually happened. With the right mutations, however...




We once had a discussion here about virus transmission by "exhalations from the other end of the tube".

There are no endogenous eukaryotic HUMAN cells, there are parasites who can live inside cells. These can also be exhaled. But it is very unlikely it resumes to an infection, as eukaryotic cells are not as resilient as prokaryotic cells.

Thanks Zwolver for your reply. One question here: how can you know for sure that exhaled air does not contain human cells? Has anybody ever looked to see if this is the case? Human cells are obviously a lot larger than prokaryotic cells that are known to be exhaled in the case of pulmonary infection; the average diameter of a squamous epithelial cell is 40-60um whereas that of Chlamydophila pneumoniae is 0.2-1um. There is also the issue of the mucus lining of the lungs, which in most cases would probably impede escape of detached lung epithelial cells, much in the same way as it captures micro-organisms. Such cells would ordinarily be swallowed or expectorated. However, the transmission of bacterial infection between humans via the aerosol route proves that the mucus system is not infallible. Also - I don’t know the biomechanics involved, but I would guess that the force of coughing sufficient to expel bacteria from the lungs, would also suffice to expel individual detahced epithelial cells from the lung.

Several seconds, probably halftime of 5-10 seconds, under normal conditions. With high humidity, no uv radiation, low temperature (10-20 celcius), they can probably live longer. The chance they can remain infective after this is extremely low.

Are you referring to eukaryotic parasites here? How long do you think an airborne detached human epithelial cell would survive?

No, they would not preform apoptosis, as they would be dead before they would have died due to apoptosis.

How so?

Most mutations are not simultainous, but slow, and one in a time, preferably 1 nucleotide, or 1 deletion or insertion. This 1 mutation can not protect the cells enough to make them able to colonise a foreign location.

I know that most mutations are not simultaneous. What I was envisaging is a single cell that has detached from a clonal expansion (Park et al, 1999) of cancer cells that has evolved over decades to acquire a suite of mutations that confer such transformed phenotypes as: self-sufficiency in growth signals, insensitivity to anti-growth signals, tissue invasion and metastasis, limitless replicative potential; and, evasion of apoptosis (Hanahan & Weinberg, 2000).

Ref.

Hanahan D & Weinberg R (2000) The Hallmarks of Cancer. Cell 100: 57-70

http://www.weizmann.ac.il/home/fedom...e6_Hanahan.pdf
Park I, Wistuba I, Maitra A, Milchgrub S, Virmani AK, Minna JD & Gazdar A (1999) Multiple Clonal Abnormalities in the Bronchial Epithelium of Patients With Lung Cancer. JNCI 91 (21): 1863-1868

Multiple Clonal Abnormalities in the Bronchial Epithelium of Patients With Lung Cancer

This is an interesting question... Direct answer, no.. this is not possible. Mostly because cancer can't form aerosols. Then they can not survive long enough to cross to another organism. But the dead cell, can induce an immune response, the dna can be implemented into ours, and there could be a case of transmittable cancer. However extremely unlikely, the remaining DNA of a dead aerosol cancer can influence lung cells. I doubt this has ever happened, or ever will happen. There is just the theoretic possibility..

How do you know that it is definitely impossible? Note that it wouldn’t require that a cancer form aerosols, only that one single transformed cell be expelled upon violent coughing.

Wouldn't necessarily fall foul of the immune system. There are transmissible cancers, such as the Devil facial tunour disease, that manage just fine on that front. Such diseases require close contact however. Violent exhalations, such as coughing and spluttering, undoubtedly contain all sorts of cells. Saliva, of course, has many immune cells in it. I'm sure I read once about PCR contamination from breath.

Yeah, not to mention that cancer cells typically evolve mechanisms for evading detection by the immune system. The fact that the antigenic profile of the donor cell would be so different from that of the host cell makes me think that it would not stand a good chance of evading the host immune system – although it is less clear what would happen in a severely immunocompromised individual.

I wouldn't rule the idea out completely. But if it did happen it's probably an incredibly rare event; one that may not have ever actually happened. With the right mutations, however...

Yeah, on the whole I would tend to agree with you, Zwirko. It seems, as far as I can tell, that people have assumed the idea too outlandish to bother investigating. However I think it’s too important a question to go so entirely uninvestigated, given the implications if it turned out to be true (for starters, it would require that lung cancer patients be treated in quarantine).

Here's a paper describing the detection of p53 mutations in breath samples:
Detection of p53 gene mutations in exhaled breat... [Lung Cancer. 2004] - PubMed - NCBI

I can't read the paper, so I don't know how the genetic material found it's way into the exhaled breath exactly - as in live cells, cell debris or what? Just mentions PCR on EBC (Exhaled Breath Condensate).

Edit:

The wiki article on Devil facial tumour disease mentions that the tumour cells causing this condition are transmissible between individuals because Tasmanian devils have a low diversity of MHC class I and II genes and so the foreign cells are recognised as self. I've not checked out the other exampels of transmissible cancers, but I'd hazard a guess that similar processes are at work there too.

Thanks Zwirko,

Here is an exerpt from the Materials & Methods section of the Gessner 2004 paper:

2. Material and methods

2.1. EBC collection

EBC was collected using the EcoScreen breath condensate collection device (Jaeger/Toennies, Hoechberg, Germany). Sampling time was 20 min as previously described [14]. EBC was collected from (a) 18 patients with a histologically proven NSCLC and (b) 18 healthy non-smoking volunteers. Main clinicopathologic parameters of investigated NSCLC patients and healthy volunteers are given in Table 1.

From patients with NSCLC tumor tissue was obtained bronchoscopically. Bronchoscopy was performed in NSCLC patients for histological diagnosis of lung cancer.
Approval for this investigation was gained from the ethics committee of the University of Leipzig.

2.2. PCR

Four hundred μl of native EBC was incubated with proteinase K (2 mg/ml) and digestion buffer (5 mM EDTA; 20 mM Tris–HCl pH 8.0; 0.2% SDS) for one hour at 55 °C. Five sections (10 μm each) from tissue embedded in paraffin were also incubated with proteinase K (2 mg/ml) and 300 μl digestion buffer II (0.1 M EDTA; 0.4 M Tris–HCl; 4% SDS) over night at 55 °C. DNA was extracted using the phenol/chloroform method. Dried DNA was solved in 50 μl H₂O.
Amplification was performed for β-actin (control) and p53 exons 5–8. Most genomic mutations of the p53 gene resulting in biological consequences have been localized to exons 5–8 [15], [16] and [17]. DNA was extracted from 400 μl breath condensate and resuspended in 40 μl of water, 3 μl were used for PCR. Alternatively, 3 μl of native breath condensate were used for PCR without further processing. Primer sequences with annealing temperatures are listed in Table 2. PCR was carried out in a final volume of 20 μl, with 3 μl DNA, 200 μM dNTP, 1 U AmpliTaq Gold DNA polymerase (Perkin-Elmer) and 10 pmol of each oligonucleotide primer. PCR for β-actin was performed for 45 cycles with an initial denaturation at 94 °C for 2 min and cycling times of 30 s at 94 °C, 30 s at 55 °C, and 30 s at 72 °C. Nested PCR’s were performed for exons 5–8 of p53 with 40 cycles each and a cycling time of 30 s for all steps. PCR products were analyzed in 2% agarose gels containing ethidium bromid using a Gel Doc System (BioRad)

It still isn't very clear. I took a look at the ECoScreen brochure, available here:

https://docs.google.com/viewer?a=v&q...bDbahAeF8R3pSQ

But it only mentions detection of molecules in the breath condensate (incidentally, it is used in the identification of tumour markers) but the brochure does not mention cells.

Ref.

Gessner C, Kuhn H, Toepfer K, Hammerschmidt S,
Joachim Schauer &
Hubert Wirtz (2003) Detection of p53 gene mutations in exhaled breath condensate of non-small cell lung cancer patients. Lung Cancer 43 (2): 215-222

Done a little more digging with better search terms:

Giovanna E. Carpagnano et al (2005)
3p Microsatellite Alterations in Exhaled Breath Condensate from Patients with Non–Small Cell Lung Cancer
Am. J. Respir. Crit. Care Med.
September 15, 2005 vol. 172 no. 6 738-744


Here's a little excerpt from the "Methods"

In 10 cases with NSCLC, just after collection, an aliquot of EBC was centrifuged and analyzed for cell viability by trypan blue dye assay performed in a Burker chamber. A mean number of 83 × 10^6 cells/ml with a mean of 80% of viable cells were found. A further cytologic examination of EBC showed a lymphomononuclear origin of cells; however, most part of the cells resulted disrupted and from the debris size they appear to be epithelial cells.

Awkward use of English, but I think they are saying here that there are large numbers of cells in the collected EBC samples, many of which are viable.

Quite worried by this What if lung cancers are actually transmissible by aerosol route...

Originally Posted by tridimity

Hullo,

Is it possible that endogenous eukaryotic (human) cells might exist in the air exhaled by a human?

I'm guessing it probably is not possible, since there are no reports of this, as far as I can tell.

Everthing is probable, even if you one does not think so. If you can conceive it something must go that way. Not easy to prove but probable.

Assuming that it were possible for such cells to be present in the air exhaled by humans, how long would the cells remain viable ex vivo? If one human were to inhale a cell immediately after it had been exhaled by a second human, would the cell be able to survive and colonise the new respiratory tract environment?

In actual fact some cells can live quite long outside of the body. There is always a small gap for the abnormal to exist in nature.

I'm guessing that normal healthy cells would be unable to do so, since detachment from the extracellular matrix usually spells their apoptotic demise, within about 1 hour of detachment.

What if the exhaled cell was transformed, and had multiple genetic hits, inducing anchorage-independence and other phenotypes that would enable it to colonise a foreign environment?

Cancer is not traditionally considered a transmissible disease in humans, except perhaps in the cases of virus-mediated cancers.

My question is: is it possible that human lung cancers might be transmissible by the aerosol route?

I am going to climb out on to a fragile limb and say yes. Some of these chemicals were never meant by nature to be directly exposed to human cells, by doing so we encounter genetic mutations that we no longer can control, and so because we do not know how to measure this posibility we call all mutations cancer. I know that some types of cancer is brought about by non spiritual living while others are chemically based. However we tend to treat cancer all the same way.
I am told aids is not transferable by mosqutoes, yet they pass on many blood born deseases.

Everthing is probable, even if you one does not think so. If you can conceive it something must go that way. Not easy to prove but probable.

In actual fact some cells can live quite long outside of the body. There is always a small gap for the abnormal to exist in nature.
I am going to climb out on to a fragile limb and say yes. Some of these chemicals were never meant by nature to be directly exposed to human cells, by doing so we encounter genetic mutations that we no longer can control, and so because we do not know how to measure this posibility we call all mutations cancer. I know that some types of cancer is brought about by non spiritual living while others are chemically based. However we tend to treat cancer all the same way.
I am told aids is not transferable by mosqutoes, yet they pass on many blood born deseases.

Well.. i continue to say no, cancer is not transmittable, but the cause to the cancer might be.. Seen in the Human Papyloma virus.

Several seconds, probably halftime of 5-10 seconds, under normal conditions. With high humidity, no uv radiation, low temperature (10-20 celcius), they can probably live longer. The chance they can remain infective after this is extremely low.

Are you referring to eukaryotic parasites here? How long do you think an airborne detached human epithelial cell would survive?

I was talking there about the human cells, parasites can survive a lot longer. I think i heard about parasites surviving several years outside a body. Guardia is one of them i think, it's not actually a parasite in that order, as it doesn't require a host directly.

No, they would not preform apoptosis, as they would be dead before they would have died due to apoptosis.

How so?

Because apoptosis is a rare cause for cells to die. This only happens when a cell is sick, due to a viral infection, exposed to radiation, etc. Also would take several hours for a cell to preform this. In 1 hours outside the body, the cell is 100% dead. Unless you cough inside a petridish.

Aids does not transfer from mosquito's because the rate of infection in HIV is extremely low (little infective particles per unit of blood). In addition, the virus is highly unstable, it requires a lot of care, care that the stumack of a mosquito can't give it. It's called HUMAN immunodeficiency virus for a reason. There are no animal carriers.

The only way for a cancer to be directly contagious to another system, is by implementation of DNA, which can happen... occasionally..

Originally Posted by Zwolver

Well.. i continue to say no, cancer is not transmittable, but the cause to the cancer might be.. Seen in the Human Papyloma virus.

Several seconds, probably halftime of 5-10 seconds, under normal conditions. With high humidity, no uv radiation, low temperature (10-20 celcius), they can probably live longer. The chance they can remain infective after this is extremely low.

Are you referring to eukaryotic parasites here? How long do you think an airborne detached human epithelial cell would survive?

I was talking there about the human cells, parasites can survive a lot longer. I think i heard about parasites surviving several years outside a body. Guardia is one of them i think, it's not actually a parasite in that order, as it doesn't require a host directly.

No, they would not preform apoptosis, as they would be dead before they would have died due to apoptosis.

How so?

Because apoptosis is a rare cause for cells to die. This only happens when a cell is sick, due to a viral infection, exposed to radiation, etc. Also would take several hours for a cell to preform this. In 1 hours outside the body, the cell is 100% dead. Unless you cough inside a petridish.

Aids does not transfer from mosquito's because the rate of infection in HIV is extremely low (little infective particles per unit of blood). In addition, the virus is highly unstable, it requires a lot of care, care that the stumack of a mosquito can't give it. It's called HUMAN immunodeficiency virus for a reason. There are no animal carriers.

The only way for a cancer to be directly contagious to another system, is by implementation of DNA, which can happen... occasionally..

I am a little cautious of the development of some cells with the introduction of certain chemicals, especially when it comes to transmition outside of the body. There are mutations that can compleatly change the ability of a cell and can allow it to mutate to higher levels of sustainabilty, at least long enough to infect a human. We do see this trend increasing as the chemicals used are helping viruses to cross the human animal barrier. We keep hearing conflicting stories about the aids virus, that is not a so called virus. Does or can animals get aids? Is there scientific reasearch on how cells behave outside of the body in the case of aerosols?

Zwolver, I was referring here specifically to the case in which a live transformed cell derived from an advanced lung cancer us exhaled by the suffer and immefiately - within the space of a few seconds - is inhaled into the lung of a second person. It is therefore less obvious that the cell would die, even by necrosis. I am not talking here about a cell being exhaled onto a work surface where it would die within short order. I don't think that the grounds for dismissing the possibility of such transformed cells remaining viable for a dew seconds outside of the body are very strong. Especially given that the above-cited paper has evidence of cells remaining viable in breath condensate. How would you explain that?Best wishes,Tri