Previously, rhesus macaques were inoculated with the macaque adapted H. pylori strain J166 that contained a s1m1 vacA allele and a functional cag PAI that consisted of two fragments, cag1 through cagB and cagA, separated by 12.5 kb of sequence (Supplementary Fig. 2).
Interestingly, studies have shown that s2/m2 VacA is capable of vacuolating activity if the N-terminal extension is removed [7].
Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group.
Indeed, there have been several instances of this reported in the literature in recent years involving acid-response and CrdRS [27], vacA regulation [28], virulence gene regulation in vivo [29], and cagA and vacA expression in response to salt [30].
Currently, there are two presentations available: version 2.0 contains antigens of 19.5, 26.5, 30, 35, 89 (VacA), and 116 (CagA) kDa; and version 2.1 contains antigens of 19.5, 30, 35, 37, 89 (VacA), and 116 (CagA) kDa, the latter version also contains an additional recombinant antigen (∼45 kDa) named the current infection marker (CIM).
Median immunogold particles counts inside at least 100 µm2 PaCS sections ranged from 3.41 (OMPs) to 3.68 (VacA), to 4.33 (urease) per µm2, with a ratio between PaCS and surrounding cytoplasm ranging from 8.5 (OMPs) or 8.6 (VacA) up to 27.1 (urease).
Herein, apoptotic activity of the purified recombinant VacA toxin was detected by incubation of T84 and MDCK cells for 24 h in the presence of 150 µg mL−1 VacA protein and subsequent nuclear staining with DAPI analyzed by fluorescence microscopy.
Forty four percent of the H. pylori strains analyzed in this work (63/143) possessed two or three of the virulence markers analyzed (Table 3): vacA s1 cagA babA2 (9.8%, 14/143), vacA s1 babA2 (4.9%, 7/143), and vacA s1 cagA (29.4%, 42/143).
Strain 60190 expresses an intact and functional cagPaI and possesses an s1/m1 vacA toxin while strain Tx30a expresses s2m2 vacA toxin but does not possess the cagPaI.
Infection by s1m1 vacA genotype was associated with increased antral and corpus gastritis.
The complexes can have a mass of nearly 1000 kDa, indicating that they may contain 12 VacA polypeptides [ 50- 52].
