Journal of culture
collections
Volume 4, 2004-2005, pp. 3-16
McCoy and McCoy-Plovdiv Cell Lines
in Experimental and Diagnostic Practice –
Past, Present and perspectives
<=
span
lang=3DEN-US style=3D'font-weight:normal'>Marian Draganov1*, Mar=
ianna
Murdjeva2 and Teodora Michailova-Topalska1
<=
span
lang=3DEN-US style=3D'font-weight:normal'>
1The University of Plovdiv, Developmental
Biology Department, 24 Tzar Assen Str.,
4000 Plovdiv, Bulgaria. e-mail: mmd@pu.ac= ad.bg;
2Medical University, Faculty of Medicine,
Department of Microbiology and Immunology,
15A V. Aprilov Str., 4000 Plovdiv, Bulgar=
ia
The McCoy cell line has almost 50 years
history. The cells are widely applied in the diagnostics and culture of var=
ious
microorganisms with medical importance. The cell line is included in labora=
tory
and diagnostic tests which are the basis for study of interactions between
various pathogens and host cells leading to cytotoxic damage or cell death.
With its importance in experimental and diagnostic laboratories, McCoy cell
line is among the most popular cell cultures – HeLa, HEp-2, Vero, CaC=
o-2,
3T3, MDCK. An alternative for application of McCoy is the serum-free strain
McCoy-Plovdiv. It is cultured in completely defined, serum-and protein-free
medium. It keeps the properties of the parental line but also offers new
opportunities.
McCoy cell line is created i=
n the
Tissue Culture Laboratory, Department of Anatomy, the University of Texas
Medical Branch, Galveston, Texas. In 1957 Pomerat et al. [116] published ow=
n investigations
on radiation influence upon cells in tissue culture conditions. McCoy cells
were among the available cell cultures and they were announced for the first
time in research literature: “Synovial fluid - McC. A strain develope=
d in
this laboratory in October 1955 from cells in synovial fluid from the knee
joint of a patient with a diagnosis of degenerative arthritis”.
By chromosomal
examination of eight cell strains Hsu et al. [63] found that even in more
recently established cell lines such as McCoy, which chromosomes were analy=
zed
approximately half a year after the primary cultures had been made, nearly =
all
the cells showed heteroploid constitution.
In 1960 Defendi et al. [22]
published data concerning identification of cell lines in culture on the ba=
sis
of morphological, immunological and karyological criteria. As a result of t=
hese
studies McCoy cell line, placed at disposal from two different laboratories
(University of Texas, Houston and the Wistar Institute, Philadelphia), show=
ed
distinctions giving grounds to categorize the cell line as McCoy A (human
cells) and McCoy B (mouse cells possessing a marker chromosome, characteris=
tic
for L mouse fibroblasts). There are no data in literature whether any
contamination of the original human cell line McCoy has emerged or when and
under which circumstances an eventual contamination has lead to the peculiar
karyotype and the presence of mouse antigens.
In American Type Culture Col=
lection
(ATCC) the cells have been left by the Center for Disease Control, Cell Cul=
ture
Department, Atlanta, Georgia in March 1984 [2], where they have been regist=
ered
with No CRL-1696. They were described as obtained from a mouse (Mus musculus), from unknown tissue=
, as
adherent cells with fibroblast-like morphology. McCoy B subline is mainly
distributed among the laboratories. This was confirmed also for McCoy, give=
n us
by National Bank of Industrial Microorganisms and Cell Cultures (NBIMCC) in
Bulgaria [29].
Based on information in the =
ATCC
Catalogue [1], Nogueira et al. [102] showed McCoy cell line as “a hyb=
rid
lineage with markers from human cells and mouse cells”, confirming th=
is
with the fact that these cells express human CD4 receptors [101].
McCoy cell line can be cultu=
red in
various media – Minimum Essential Medium (MEM), Dulbecco’s Modi=
fied
Eagle’s Medium (DMEM), Roswell Park Memorial Institute (RPMI) 1640,
medium 199 and others (Table 1). The most commonly used medium is MEM,=
but
it varies in the amount of serum and other supplements.
McCoy cells and microbial culture
McCoy cells are =
applied
for culture of various microorganisms, which are dependent in their develop=
ment
on the eukaryotic host cell. During their interaction with pathogens the ce=
lls
are subjected to various changes leading often to lethality of infected cel=
ls.
Chlamydia trac=
homatis.
At the
beginning of 60s of 20th century, the popularity of McCoy cells =
has
increased considerably after the report of Gordon et al. [51] that cobalt-60
irradiated cultures of synovial fibroblasts strongly rise their susceptibil=
ity
to infection with chlamydial strains. This has been confirmed in another
publication of Gordon et al. [52] and allowed the introduction of McCoy cel=
ls
as a method for diagnosis of genital and ocular infections caused by chlamy=
dia
[59]. Numerous investigations with various
agents followed, aiming the increase of cell susceptibility to infection wi=
th
chlamydial strains. Pretreatment of McCoy =
cells
with diethylaminoethyldextran [20], cycloheximide [143, 15], cytohalasine B
[137], 5-iodo-2-deoxyuridine [75], cycloheximide =
and
centrifugation [151], polybrene [123], mit=
omicin
C [152] fascilitates more successful infection of cell cultures. Inoculation
and isolation of chlamydia in hen embryos has been replaced by cell culture=
s -
commonly McCoy [142]. The attention was driven towards searching new cell l=
ines
which may be used for chlamydial culture with diagnostic purpose or study t=
he
life cycle of bacteria in vitro=
. Croy
et al. [18] examined the susceptibility to infection with trachoma TW-3 (ty=
pe
C) and UW-5 (type E) ofo elev=
en
cell lines - HeLa 229, HeLa M, HEp-
C. trachomatis growth in McCoy cell culture, non-treated with cycloheximide, is de=
eply
influenced by the lack of glucose and minimal changes in aminoacids in the
environment and blood plasma. This is supp=
orted
by the production of abnormal forms with lower infectivity [55]. McCoy cells
show great capacity in terms of aminoacid concentration, which is important=
for
the development of microorganisms [56].
Table 1. Media for culture of McCoy cells=
.
|
Medium |
Supplements |
References |
|
Gey’ salt solution |
45 % human ascitic fluid, 5 % chick emb=
ryonic
extract |
116, 63 |
|
Medium 199 |
1 % horse serum |
22 |
|
MEM |
10 % FCS |
1, 2 |
|
MEM |
5 % FCS, |
25 |
|
MEM |
5 % FCS, 10 mmol/l L-glutamine, 200 U/ml
penicillin, 200 mg/ml streptomycin |
125 |
|
EMEM |
10 % FCS, 10 mg/l gentamicin, |
126 |
|
Eagle’s MEM with Hanks’ sal=
ts |
10 % FCS, 10 mg/ml gentamicin, 50 mg/ml vancomycin, |
10 |
|
EMEM |
10 % FBS, 1 % L-glutamine w/v, 10 % (v/=
v)
non-essential aminoacids and 1 % (w/v) of antibiotic/antibiotic mixture,
containing penicillin, streptomycin and amphotericin B. |
42 |
|
=
GMEM (Glasgow
modification of Eagle’s medium) |
10 % new born calf serum, |
91 |
|
RPMI 1640 |
10 % FCS, 30 mmol/l glucose, 10 =
mg/ml gentamicin, 2 mmol/l L-glutam=
in |
82 |
|
RPMI 1640 |
10 % FCS |
133 |
|
DMEM |
4 % FCS |
138 |
|
DMEM |
10 % FCS |
147 |
|
DMEM-H |
584 mg/l L-glutamine, 4500 mg/l glucose=
, |
127 |
|
Liverpool-Waymouth medium |
10 % FCS |
70 |
|
SF-3 |
|
119 |
|
|
|
|
The cell culture=
serves
as a standard for comparative detection of C.
trachomatis from genital specimens by Polimerase Chain Reaction (PCR),
Ligase Chain Reaction (LCR) and cell culture [132, 99, 66, 80]. With the
encroach of DNA amplification techniques in this field the cell cultures are
applied less frequently, usually in specialized reference laboratories [12].
McCoy cells possess advantages which can not be duplicated by noncultural
techniques, for example the culture may: i. preserve microorganisms and even
allow them to multiply, ii. serve for examination of the interactions micro=
organisms-host
cell which helps studying the bacterial biology and pathological effects as=
a
result of bacterial metabolism, iii. allow testing for susceptibility to
various antimicrobials.
The information = elucidating complex chlamydia-host interactions has been obtained mainly form investigations on cell cultures as an in vitro model of infectious process. Various cell lines (HeLa, HEp2, HeLa 229, CHO, VERO, BGMK) are app= lied now for culture of cells with chlamydia and studying the chlamydial pathogenesis. McCoy remains the leading cell line in these investigations.<= o:p>
The interaction =
between
bacteria and host cells takes place in the following sequence: adhesion of
microorganisms to the eukaryotic cell and entering it, intracellular
development with bacterial amplification and releasing of new chlamydial bo=
dies
out of the cell.
Studying the kin=
etics of
attachment and ingestion of C.
trachomatis serotype L1 by monolayers of McCoy cells Söderlund et =
al.
[135] proved that the accumulation of bacteria in cells needs 3 hours when =
the
incubation is at 37 oC and cannot take place at 4 oC.
They also established that chitobiose and chitotriose reduced association o=
f C. trachomatis with McCoy cells. T=
he
precise mechanism through which the elementary bodies (EBs) attach to the c=
ell
and penetrate into it is not completely understood. Thermolabile proteins
mediate adhesion of many C. trachom=
atis
serotypes to a common receptor on McCoy and HeLa cells [148]. Hodinka et al.
[61] performed ultrastructural studies upon endocytosis of C. trachomatis on McCoy cells. Following attachment to a non-we=
ll
defined receptor on host cell surface, the bacterium internalizes in the ce=
ll.
The internalization of C. trachomat=
is
serotype L2 in McCoy cells may be realized through phagocytosis and pinocyt=
osis
[117]. In cytoplasm the EBs are membrane confined and their aggregation and
fusion take place by means of cytosol anexins which participate selectively=
in
the endosomal aggregation and escape the fusion with lysosomes during
chlamydial infection [84]. In intracellular distribution and localization of
chlamydia-containing vesicles actin and clathrin [83, 85], anexins together
with the level of free intracellular calcium ions [84], and the host cell
cytoskeleton [127] participate. It has been established that the way of
accumulation and development of serotype L in HeLa cells is different from =
the
one of serotype E in McCoy cells. These differences concern the cell types,
respectively epithelial and fibroblast [127]. Entering the cell, bacteria b=
egin
multiplication. Van Ooij et al. [144] found that C. trachomatis serotype LGV L2 fusion does not take place at 32=
oC
in HeLa, McCoy and CHO-K1 cell lines and requires synthesis of bacterial pr=
oteins.
As a result of i=
nfection
with C. trachomatis, McCoy=
cells
produce interferon and nitric oxide in the absence of exogenous cytokines [=
25].
During chlamydial infection in eukaryotic cells, proapoptotic stimuli are
induced, leading to apoptosis in non-infected adjacent cells [126]. The
treatment with antioxidants reduces the degree of apoptosis. HeLa 229, HEp-2
and McCoy have been used by Shaw et al. [133] for characterization of prote=
ases
secreted by chlamydia.
Chlamydia pecorum. McCoy cell line is used for =
culture,
identification and testing of C. pe=
corum
[113, 114].
McCoy cells are applied for =
in vitro investigation of C. trachomatis [8, 9] and C. p=
ecorum
[113] persistence.
Helicobacter pylori. H. pylori participates in the pathogen=
esis of
chronic superficial gastritis and ulcer [36]. Korych et al. [72], using in
vitro cell models as VERO and McCoy cell lines, found that H. pylori strains c=
aused
cytotoxic effect on cells with changes in cell cytoplasm and morphology. The
authors suggested that morphological changes in cell cultures support the i=
dea
for the pathogenic activity of bacterium on gastric mucosa. Similar associa=
tion
between cytotoxic strains and activity of gastritis was established by
Hua-Xiang Xia et al. [64]. They also proved that McCoy cells are more sensi=
tive
than HeLa cells in detection of H. =
pylori
cytotoxicity in vitro.
Gardnerella vaginalis. McCoy cells are applied as an in
vitro cell model for testing the adhesion-receptor mechanism of interac=
tion
between G. vaginalis (a causati=
ve
agent of bacterial vaginosis) and host cells as well as for various factors
that inhibit pathogen adherence [129, 131]. The pathogen adhesion to vaginal
epithelial cells, McCoy cells and red blood cells, was studied by electron
microscopy [130].
Clostridium difficille. C. difficile <=
/span>causes a severe disease of t=
he colon
– pseudomembranous colitis. This bacterium produces two toxins - A an=
d B,
which are the main virulent factors [140]. They do not affect membrane
permeability of intestinal cells and McCoy cells but inhibit protein synthe=
sis
of the latter [96]. In vitro to=
xins A
and B cause cytotoxic effect which is manifested by change in morphology
(shrinkage and roundness) of McCoy cells [5]. During cell intoxication,
reorganization of cytoskeleton microfilaments occurs. The effects are mainly
due to cytotoxin B – 1000 times more toxic than toxin A. Toxin A dama=
ges
phosphorilation of intracellular proteins in contrast to cytotoxin L (relea=
sed
by C. sordelli, a pathogen capa=
ble of
producing gas gangrene in humans). The latter acts through phosphorilation =
of
pp80c on McCoy cells [128].
Various
cell cultures have been used for detection of cytopathic effect of C. difficile. McCoy cells as suspe=
nsion
or monolayer may replace HeLa [86]. Comparative studies on several cell lin=
es:
african green monkey kidney (AGMK), MRC-5, primary rhesus monkey kidney (RM=
K)
and Vero proved that only Vero could be used as equivalent to McCoy in
detection of C. difficile toxin=
from
stool filtrates [87].
The
detection of cytotoxic effect on monolayers of McCoy culture cells is widel=
y applied
in the diagnostics of C. diffi=
cile
infections [13]. This method is evaluated as a standard [23] and helps
elucidation of etiology and pathogenesis of C. difficile -associated
diarrhea [141].
McCoy cells are a comparative
standard for various immunological and molecular methods (TCD Toxin A Enzyme
Immunoassay (EIA), Toxins A/B Enzyme-linked Immuno-sorbent Assay (ELISA), P=
CR)
for detection of C. difficile t=
oxins
[71, 88, 89, 90, 115].
Bacillus cereus and other Ba=
cillus spp. According to Jackson [65] Mc=
Coy cell
line may be a rapid test for screening and detection of enterotoxin-produci=
ng B. cereus as a cause of toxin medi=
ated
foodborne disease. Studying the cultural supernatants of 30 bacteria, the
author established the cytotoxic effect of progressive damaging the McCoy c=
ell
monolayer.
This cell culture system is =
an
excellent opportunity for testing the cytotoxicity of Bacillus isolates but also allows studying the mechanism of act=
ion
of the cytotoxic components. Combining Methylthiazoletetrazolium (MTT)
cytotoxic test, Confocal scanning laser microscopy and Scaning electron
microscopy, Lindsay et al. [79] showed that cytotoxic effects of Bacillus spp. isolates caused for =
three
hours irreversible morphological
changes leading to cell membrane damage, linkage of cell content and necros=
is.
Trichomonas vaginalis. Cli=
nical
isolates and strains of T. vaginali=
s
are successfully maintained in serum-free culture media [26] or as co-cultu=
re
with eukaryotic McCoy cells [47, 15]. The results obtained are similar with
those in conventional conditions of culture. The application of cell cultur=
es
in this field gives the chance to study the contact interaction with its
intimate mechanism between this parasite and the eukaryotic cells. Thus the=
role
of some soluble products of T. vagi=
nalis was
established. The example is the “cell detaching factor” (CDF),
which causes monolayer damage of McCoy, HEp2, CHO cell cultures and human s=
kin
fibroblasts for 6 hours only [45]. The parasite develops in physical contact
with McCoy cells and the cell death is a result of production of
contact-dependent cytotoxicity [46]. In a co-culture of T. vaginalis (a highly vurulent strain) with McCoy Roussel et a=
l.
[121] proved that the cytopathic effect is specifically inhibited by
monosaccharides, N-acetylglucosamine and manose. The researchers suggested =
that
the cytopathic effect is mediated by a manose/N-acetyl-glucosamine-binding
lectin. As it is known, there are molecules in serum, which may interact and
bind directly to T. vaginalis <=
span
style=3D'mso-bidi-font-style:italic'>[112]. Meysick et al. [93] exam=
ined
the growth kinetics of T. vaginalis=
in McCoy cell culture in serum-free conditions. They obtained lower peak of=
T. vaginalis concentration and
prolonged doubling time compared to the serum-containing system and the
conventional culture of the parasite. It has been determined that serum
proteins could interact with enzymes and directly with T. vaginalis
Viruses. According to Consales et al=
., [16]
rabies infected McCoy cells may provide a useful assay system based on
induction of cytopathic effect, high virus production and sensitivity to
interferon. The authors proved cytopathic changes 24 to 72 hours after
infection. The viral titre grew with the number of passages reaching maximum
after the third one. This sensitivity was confirmed by Nogueira [100] in
isolation of Rabies virus from central nervous system of a patient with rab=
ies.
A comparative study proved that McCoy cells are with higher sensitivity and
specificity than N2A cells (a mouse neuroblastoma), which have been accepte=
d as
a reference culture [101]. This implies McCoy cells as an effective model f=
or
Rabies virus isolation.
There are data t=
hat
HIV-1 is success-fully replicated in McCoy cells [102] and the cell line is=
a
suitable model for its isolation. It can be used for studying the dynamics =
of
viral infection together with pharmacological testing of drugs as well as
analysis of the immune response in vaccine therapies.
In
contrast to Rabies virus, Measles virus does not induce cytopathic effect in
McCoy cells but leads to the development of persistent infection which is
maintained by an antiviral factor [125].
McCoy cell cul=
ture and
antibacterial agents
A
number of active substances with various origin are examined in the straggle
against pathogens – plant extracts [145, 24], human defensin and porc=
ine
protegrin [156], microbial producers [62, 67], recombinant mouse
interferon-gamma [25], semisynthetic [24], or synthetic ones [76, 155]. The
ideal agent would be the one with no or minimal cytotoxicity and high
antibacterial activity. This implies the idea that in searching such drugs
combined and parallel investigations for toxicity on eukaryotic cells on one
hand and antimicrobial effect on the other should be performed. The minimal
inhibitory concentration (MIC) of chloramphenicol for C. trachomatis in McCoy cell culture varies widely in term=
s of
antibiotic preparation, duration of treatment and method of infection [60].=
The
considerable variations in accumulation of macrolides depend on the ability=
of
the tested McCoy, HeLa
In vitro studies concerning inhibito=
ry
activity of various antibiotics against C. trachomatis
in McCoy cells give satisfactory prelimenary information about the activity=
of
the tested drugs which may be a basis for further clinical investigations.
Lefevre et al. [78] showed that the lowest MIC values had been established =
for
clarythromycin and sparfloxacin which were with the highest activity in
clinical trials. Moulding in vivo the
in vitro conditions of the cell
culture test system McCoy, Lampe et al. [76] proved that chlorhexidine
gluconate gel killed C. tracho=
matis
serovar D and F at concentrations applicable in genital tract of women.
Electron
microscopic studies on McCoy cells established a realtionship between the
applied concentrations of doxycyclin, erythromycin and ofloxacin and the
changes in cell cycle of C. trachom=
atis [19].
Studying the antichlamydial activity of doxycyclin, erythromycin, ofloxacin=
and
trovafloxacin, Jones et al. [67] established that all 19 strains of C. trachomatis were sensitive to t=
rovafloxacin.
In vitro activity of a new
fluoroquinalone - ABT-492, was examined on
McCoy [54].
The
sensitivity of chlamydia to b-lactam antibiotics is due t=
o the
presence of penicillin-binding proteins (PBPs). Using C. trachomatis 434 serotype L2, cultured in McCoy cell monolaye=
r,
the binding of seven b-lactams to chlamydial PBPs =
and
their antichlamydial activity were examined in
vitro [138].
Mast
acids and monoglycerides inactivate C. trachomatis
in vitro. The highly specific
antichlamydial effect of monocaprin is combined with cytotoxic changes in M=
cCoy
cell monolayer at high concentration whereas at 50 =
mg/ml and lower, lysis has no=
t been
observed [11].
Sokyleszczyrska
et al. [136] studied the effect of antibacterial and antitoxic serum agains=
t C. difficile by neutralization tes=
t on
McCoy cell line. Martirosian et al. [88] moulded the influence of dioctahed=
ral
upon ten toxigenic strains of C.
difficile and eight enterotoxigenic strains of Bacteroides fragilis using McCoy and HT 29/C1 cell lines.
There are microorganisms with ability to
survive and multiply in eukaryotic cells. That is why it is important to kn=
ow
for the antimicrobial agent to have good penetration, accumulation and
intracellular activity. Pascual et al. [=
105]
examined in a series of experiments lomefloxacin and temafloxacin penetrati=
on
in human neutrophils and peripheral macrophages, accumulation of fluconazol=
e in
human polymorphonuclear leucocytes [106], accumulation and intracellular
activity of trovafloxacin, a new ketolide, HMR 3647, obtained by erythromyc=
in A
and linezolid in human phagocytes [107, 108, 109]. This allows elucidating =
the
intracellular activity of antimicrobial agents and enriches the information
about their intracellular pharmacology in macrophages and non-phagocytic ce=
lls
as McCoy cells which are used in the studies as comparative cell culture. It
has been proved that ofloxacin is carried by liposomes and its accumulation=
in
McCoy cells is 2.6 fold higher than the one of free drug [43].
Microbicides are strategy with great pote=
ntial
for prevention of sexually transmitted diseases (STD). An ideal topical
microbicide should not only kill STD-causing pathogens and be potentially
spermicidal, but also should not disrupt the normal flora of the vagina or
rectum and cause cytotoxicity to the vaginal or rectal epithelium [6]. Two
cecropin peptides D2A21 and D4E1 and gel formulations containing 0.1 to 2 %
D2A21 act as effective topical microbicides against two urogenital strains =
of C. trachomais serovars (UW-3/Cx) a=
nd F (UW-6/Cx).
This study was performed on McCoy cell test system combining preinoculation
MCC-tests and postinoculation MIC-test [6].
Long treatment with given antimicrobials =
may
evoke resistance of many microorganisms. In
vitro serial passage of C. =
;trachomatis
and C. pneumoniae with McCoy ce=
ll
monolayer established that increasing the number of passages developed
resistance to the examined fluoro-quinolones only in C. trachomatis [97]. Analysing quinolone resistance
determinating regions of two quinolone-resistant C. trachomatis mutants, the authors proved the presence of a po=
int
mutation in the DNA-girase coding gene. They also assumed other, unknown
mechanisms for the high level of resistance [97].
McCoy cell line - cytotoxicity and cell
compatibility in vitro assessment
Cell
cultures as method for in vitro=
study
of the interaction between various substances and cells have already gone
through a rapid development in the years. Numerous cell test models and met=
hods
for detection of cell response after the treatment have been created. McCoy
cells are the suitable and widely applied in
vitro cell test system for these investigations. McCoy cell culture has
been used for investigation of the inhibitory effects of chloramphenicol [1=
04]
and cephalotin [103].
Using
Neutral Red (NR) and MTT tests, Varanda et al. [145] studied the influence =
of a
new isocoumarin (Paepalantine), isolated by them, with antimicrobial activi=
ty
on McCoy cell line. Devienne et al. [24], applying the same culture test
system, examined in vitro the
cytotoxic effect of natural and semisynthetic isocoumarins of Paepalanthus bromelioides and the
structural parameters influencing the cytotoxicity of isocoumarins, similar=
to
paepalantine.
Vento
et al. [146] studied the effect of dexamethazone on cell division and
macromolecular synthesis in McCoy cell system. Fighetti at al. [41] establi=
shed
that various concentrations of cadmium caused cell damage, induced reductio=
n of
metaphase number and shortened the metaphasic chromosomes.
Microorganisms
produce and secrete in the environment various substances, some of which ca=
use
cytotoxic or necrotic effect on eukaryotic cells. A rapid and easy way for
detecting such virulent factors is the application of in vitro sensitive cell test systems from animal and human cell
lines. Balaji et al. [4] reported a cytopathic effect in monolayers of McCo=
y,
HEp-2, HeLa confluent cultures after treatment with Burkholderia pseudomallei supernatants.
Cytopathic
effect was detected during treatment of McCoy cells with virulent factors,
produced by C. difficile [86], =
B. cereus [65]; hemolysin,
proteases and cytotoxin of Aeromonas
hydrophilia and A. sobria<=
/i>
[7, 81], phenol acids from Scr=
ophularia
frutescens [49].
Examining
48 chemicals on MEIC programme (The Multicenter Evaluation of In Vitro Cytotoxicity), Shrivastav=
a et
al. [134] used cell cultures of primary hepatocytes and McCoy and MDBK cell
lines. They found significant correlation between in vitro and in vivo
values.
Newly
obtained silicone polymers, designed for contact eye lenses, have been
investigated on McCoy cells for cellular compatibility [95].
The
interaction of cells with endoplasmic reticulum and the intercellular
interactions are of great interest concerning the processes of cell
differentiation and signal transduction. Latz et al. [77] studied the adhes=
ion
of McCoy and rabbit lens epithelial (LE) cells on modified acrylic polymers
(EF35) and found different adhesive mechanism in substituted polymers, lead=
ing
to an increased and sustained activation of integrin mediated kinases and
changes in the cytoskeletons of McCoy and rabbit LE cells.
The
culture medium, presence of serum and supplements influence the development=
of
every cell culture. They affect cell growth, cell yield and production of
specific cell products.
Cell culture med=
ia
contain glutamine as a permanent component which is the main energy source =
and
biosynthetic precursor of cell growth. It is believed that adaptation of Mc=
Coy
cells to a medium where glutamine is replaced by glutamate or
2-octa-ketoglutarate, would promote cell yield [57]. The effect of lactat a=
nd
ammonium was studied on McCoy and other eight cell lines. It was confirmed =
that
the cell yield is influenced by the accumulation of ammonium in the medium =
as a
result of glutamine metabolism and its chemical degradation [58]. In
biotechnological aspect the production of biological components can be limi=
ted
by ammonium accumulation. McCoy and MDCK cell lines have been used as model
cultures by McDermott et al. [91] for clarifying the metabolic changes
concerning cell adaptation to glutamine-free medium and the role of
glutamate-transport system.
Hanotte et al. [=
53]
studied the develop-ment of McCoy cells and other animal cell cultures on
microbeads “Cytodex
In
several publications the metabolism of polyamines in McCoy cell culture was
elucidated [38, 39, 40].
The McCoy-Plovdiv cell strain – a s=
erum
free and protein free culture
The
serum-free cell culture McCoy-Plovdiv was derived from the McCoy cell line =
[31].
The cells are cultured solely in HD medium which is chemically defined,
serum-free and does not contain additional proteins. The processes of freez=
ing
and thawing are completed in the same medium [34]. The morphological and
karyological analysis confirmed the origin of McCoy-Plovdiv cell line [29].=
The
cell kinetics [33], the proliferative activity [44], the dynamics of cell
monolayer and the postconfluent culture conditions [30] were studied. It was
experimentally proved that McCoy-Plovdiv cells showed equivalent sensitivity
and specificity as McCoy cells in detection of C. trachomatis from genital specimens of patients [98]. Cytotox=
ic
studies established that McCoy-Plovdiv cells are more susceptible than McCo=
y to
in vitro testing of chemicals [=
27].
The McCoy-Plovdiv cell test system for development of cytotoxic tests with
vital dyes is in progress [94]. There are convincing data about advantages =
of
McCoy-Plovdiv cell system in co-culture with T. vaginalis [3=
2].
Hopeful results have been obtained for McCoy-Plovdiv cells as an appropriate
substrate for antinuclear antibody detection [124] and a protocol for
application of the serum-free cells in the screening of antinuclear antibod=
ies
has been proposed [35].
Additionally,
McCoy-Plovdiv cells might be an adequate cell line for serum-free culture of
nanobacteria, a recently characterized group of extremely small bacteria,
capable of precipitating calcium salts and implicated in the pathogenesis of
human renal and gall stones and calcific atherosclerosis [68; 69]. Now
nanobacteria are cultured by using cell culture media under mammalian cell
culture conditions or 3T6 fibroblast monolayers. It has been established th=
at
the stone formation by nanobacteria is low in the presence of serum in the
culture but extensive and rapid in serum-free conditions [69]. Thus
McCoy-Plovdiv cell line may provide a good opportunity to study nanobacteria
and their interactions with the cells.
Conclusion
<= o:p>
McCoy cell line occupies an
important place among the most popular cell cultures - HeLa, HEp-2, Vero,
CaCo-2, 3T3, MDCK, with its application in experimental and diagnostic
laboratories. As recent reports show the cells are actually important for
culturing viruses, chlamydia, vaccine studies, development of models for C. trachomatis or cytotoxic activi=
ty [4,
48, 101, 102, 139, 154]. A new direction of McCoy application is the creati=
on
of McCoy-Plovdiv serum-free cell line.
Acknowledgments. This work was supported by Grant No 12/2=
002
from the “Scientific and Developmental Work”, University of
Plovdiv.
=
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