[Comparing performance of "TB-BIOCHIP", "Xpert MTB/RIF" and "genotype MTBDRplus" assays for fast identification of mutations in the Mycobacterium tuberculosis complex in sputum from TB patients]

The frequency of mutations causing drug resistance in MTB isolates were studied in the respiratory material obtained from TB-patients in the Moscow Region. In izoniazid-resistant isolates, the most prevalent mutation was found to be the Ser315Thr substitution in the katG gene (15.8%) whereas the most frequent mutations in multidrug-resistant isolates were Ser531Leu and Ser315Thr in the rpoB and katG genes (26.3%), or a combination of these two substitutions with a T15 mutation in the inhA gene (5.3%). We compared performance of three molecular assays--"TB-BIOCHIP" ("BIOCHIP-IMB", Ltd, Russia), Xpert MTB/RIF ("Cepheid", USA) and GenoType MTBDRplus ("Hain Life-science", Germany), with the efficiency of luminescent microscopy, and phenotypic drug-suscepibility testing in an automated system BACTEC MGIT 960 (Becton, Disckinson and Company, USA). Xpert MTB/RIF, TB-BIOCHIP and GenoType MTBDRplus detected MTB in sputum in 92, 78 and 49% of all culture-positive cases, respectively. The agreement between standard cultural data and molecular DST results for Xpert MTB/RIF (resistance towards rifampicin), for TB-BIOCHIP and GenoType MTBDRplus (resistance towards rifampicin and izoniazid) amounted to 100, 97 and 100% respectively. Summing up, Xpert MTB/RIF was concluded to be the most efficient assay for primary detection of MTB, whereas the TB-BIOCHIP was shown to be the only molecular assay sensitive enough for simultaneous detection of MTB DNA and for revealing multidrug resistance in sputum (i.e. resistance to both first-line anti-TB drugs, rifampicin and izoniazid).

[Identification of mycobacteria by high-performance liquid chromatography]

AIM

To compare results of mycobacteria identification by bacteriologic methods as well as by high-performance liquid chromatography (HPLC).

MATERIALS AND METHODS

Two hundred and eighty strains of mycobacteria isolated from respiratory specimens and identified by bacteriologic methods and HPLC were studied.

RESULTS

It was established that results of HLPC use were highly correlated with results of microbiologic methods of mycobacteria identification: for identification of M. tuberculosis complex the correlation was 97.0%, for nontuberculous (NTM) slowly growing mycobacteria--95.3%, for quickly growing NTM--96.2% (overall--96.1%). Results of identification of mycobacteria by HPLC were ready in significantly shorter time-frame (during 24 hours).

CONCLUSION

HLPC method could be recommended for identification of mycobacteria in bacteriologic reference laboratories.

[Comparative data on the use of high performance liquid chromatography to identify mycobacteria isolated on liquid and solid media]

Two hundred and forty-two mycobacterial cultures isolated from clinical materials on the Lwenstein-Jensen solid medium and 208 cultures in the automatic Bactec MGIT 960 system (on the modified Middlebrook 7H9 liquid medium) were examined. Of them, there was M. tuberculosis (85 and 82, respectively), M. kansasii (26 and 24), MAC (46 and 38), M. xenopi (24 and 20), M. fortuitum (26 and 22), and M. chelonae/abscessus complex (20 and 18). Identification of mycobacterial cultures isolated on the solid medium by microbiological assay and high performance liquid chromatography (HPLC) showed the agreement of results of the cultures isolated on the liquid medium in 95.5 and 97.2%, respectively; that by these techniques revealed rapidly growing nontuberculosis mycobacteria in 95.8 and 95.2% of cases, respectively; slowing growing mycobacteria in 91.7 and 97.8%, and M. tuberculosis in 96.5 and 97.6%. Mycobacterial isolation on the Middlebrook 7H9 liquid medium in the automatic Bactec MGIT-960 system takes a shorter time than that on the solid (Lwenstein-Jensen) medium. The microbiological identification of mycobacteria lasts as long as 3 weeks while the use of HPLC reduces its time to 24 hours. The efficiency of HPCL does not depend on whether mycobacterial cultures are isolated on the solid or liquid media.

[Use of molecular-biological microchip TB-BIOCHIP-2 for detecting of Mycobacterium tuberculosis with multidrug resistance to fluoroquinolones in patients with new detected and chronic tuberculosis]

At present the left-handed "respiratory" quinolones such as moxifloxacin and levofloxacin are the most promising drugs for therapy of multidrug resistant tuberculosis (MDR). Fast and specific diagnostics of sensitivity of M. tuberculosis (MBT) with MDR to this group of drugs is required for timely prescription of adequate chemotherapy and its correction in case of MBT resistance to fluoroquinolones. A new generation of biological microchips - TB-BIOCHIP-2 makes possible to detect 9 mutation types in quinolones resistant determination region (QRDR) of gene. About 800 samples from 169 patients in Antituberculosis center were studied. In patients with new detected tuberculosis 23.5% MBT resistant to isoniazid and rifampicin (MDR) and sensitive to fluoroquinolones were revealed. In patients with chronic tuberculosis 65.5% MBT-MDR were revealed. Our results were confirmed with detecting ofloxacin resistance on Lowenstein - Jensen. In addition efficiency of TB-BIOCHIP-2 to control drug testing sensitivity of MBT-MDR on fluoroquinolones was confirmed.

Identification of mycobacteria of the MAIS Complex and M. tuberculosis by restriction fragment length polymorphism analysis of hsp65 gene

Restriction fragment length polymorphism analysis of hsp65 gene was performed on museum strains of mycobacteria using Hin6I restrictase. Study of restriction profiles allowed us to distinguish mycobacterial species of the MAIS complex and several strains of nontuberculous mycobacteria.

[Use of molecular genetic studies to determine the species of the mycobacteria mais and M. tuberculosis complex]

The genus Mycobacterium currently comprises more than 90 species of Mycobacterium, of which a third is able to induce human diseases. With a rise in the incidence of diseases induced by non-tuberculosis mycobacteria, tuberculosis caused by M. bovis that is characterized by a severe cause and a high frequency of poor outcomes cannot be remembered. The species of mycobacteria should be identified to establish a diagnosis and to prescribe adequate chemotherapy. For this purpose, cultural, biochemical, chromatographic, and molecular genetic studies are conducted. The present study using the hsp65 gene restriction fragment length polymorphism test on museum mycobacterial strains and strains isolated from the diagnostic material of patients with suspected tuberculosis by means of Hind61 restrictase has provided a clear differentiation of the restriction profiles of MAIS complex mycobacteria and some other species of non-tuberculosis mycobacteria. To determine the species of representatives of M. tuberculosis complex (M. tuberculosis, M. bovis, BCG M. bovis), the authors have successfully used the test system "TUB-dif" developed at the Institute of Molecular Genetics, Russian Academy of Sciences, by applying the chain polymerase reaction of the senX3-regX3 region.

[The centralized mycobacteriological laboratory is a necessary component of a phthisiological service in large towns of Russia]

The paper presents the main points of the authors' own concept of the centralization of mycobacteriological service in large towns of the Russian Federation. The main points of step-by-step organizational and methodological measures required to solve this problem are described in detail. Consecutive measures to realize the proposed mycobacteriological service centralization model originated in January 2004 on a model of the Moscow Eastern Administrative District with 1380 thousand inhabitants are described.

[The characteristics of the sensitivity of Mycobacterium tuberculosis to rifampicin and isoniazid through determination of mutations in the genes rpoB, katG, inhA, oxyR, and kasA by different molecular biological assays]

Two hundred and two patients with different forms of pulmonary tuberculosis were examined to study the characteristics of sensitivity with the signs of multidrug resistance to rifampicin and isoniazid, by using a microbiological assay of the absolute concentrations and determining mutations in the genes rpoB, katG, inhA, oxyR, and kasA, by employing different molecular biological assays. Mycobacterium tuberculosis (MBT) DNA was isolated from both a diagnostic material (such as sputum, bronchial secretion), and clinical MBT isolates. By showing a higher sensitivity and a higher specificity, as cultural techniques, molecular biological assays of MBT drug sensitivity in patients with tuberculosis were ascertained to accelerate its diagnosis until the patient was admitted to a clinic.

[Respiratory tract mycotic infection in phthisiological practice: species composition and susceptibility of the Candida clinical isolates to antifungal agents]

The results of the laboratory diagnosis of respiratory tract candidiasis in patients with tuberculosis of the respiratory organs within 2-year observation in a tuberculosis clinic were generalized. The species composition of 327 isolates of the pathogens of the respiratory tract mycotic infection and the frequency of their detection in the specimens of various clinical material from patients with pulmonary tuberculosis were determined. The data on the resistance of the Candida spp. isolates to 6 antifungal drugs are presented. The number of the strains resistant to azol drugs (intraconazol and fluconazol) amounted to 10% of the total number of the Candida spp. isolates.

[The composition and drug sensitivity of a mycobacterial population in patients with suspected tuberculosis]

By using the diagnostic material (175 sputum samples and 103 bronchoalveolar lavage fluid samples) taken from 39 patients with suspected tuberculous infection during a 2.5-month follow-up, the authors traced the time course of changes in the composition and drug sensitivity of a mycobacterial population to rifampicin. Along with the traditional microbiological studies, the latest molecular biological studies, a TB-BIOCHIP test system (enzyme immunoassay) in particular, were employed to detect the bacterial and L-transformed forms of the causative agent. A molecular biological assay was first developed to detect the drug sensitivity of L-forms of Mycobacterium tuberculosis.

[Role of some representatives of opportunistic microflora in development of secondary infection in patients with pulmonary tuberculosis]

The results of the laboratory diagnosis of secondary (mixed) infection of the respiratory tracts in patients with respiratory tract tuberculosis were summarized. The study was performed for 12 months in a Tuberculosis Clinic. The species of the pathogens and the frequency of their detection in various clinical specimens from pulmonary tuberculosis patients were determined. The data on resistance of the strains of Streptococcus viridans group isolated from the pulmonary tuberculosis patients to various antimicrobials including new fluoroquinolones are presented.

[New technologies in the determination of drug susceptibility in Mycobacterium tuberculosis]

A variety of mutations in the genes rpoB, katG, inhA, ahpC, kasA was studied by using different molecular biological methods (conformational polymorphism of single-chain fragments, heteroduplex analysis, biochips) in rifampicin- and isoniazid-resistant Mycobacterium tuberculosis (MBT) strains isolated from patients with pulmonary tuberculosis. Twenty-nine mutation combinations were identified in the MBT strains. The use of biochips is the most promising method for identifying the type of mutations responsible for the simultaneous resistance to rifampicin and isoniazid. Detection of several MBT strains in one patient requires the use a combination of molecular biological and microbiological studies.

Typing of Mycobacterium tuberculosis strains resistant to rifampicin and isoniazid by molecular biological methods

Mutations in the rpoB, katG, inhA, oxyR/ahpC genes in rifampicin- and isoniazid-resistant M. tuberculosis strains isolated from residents of Moscow, Astrakhan', and Moldova Republic were studied by molecular biological methods (heteroduplex analysis, single strand conformational polymorphism, biochips). Twenty-five combinations of mutations were detected. Some differences in the type distribution of detected mutations were found. The use of biochips is the most perspective method for determining the type of mutation.

[Molecular genetic methods for the detection of rifampicin-resistant Mycobacterium tuberculosis strains]

RCR-heteroduplex (GDA) and chip methods were used to detect rifampricin-resistant (RR) and rifampicin-sensitive (RS) Mycobacterium tuberculosis (MTB) in the samples from patients (sputum) and in the clinical isolates of MTB from these patients (MB/BacT liquid medium and Lowenstein Jensen's (LJ) solid medium. The efficiency of detecting RR and RS of MTB (from the sputum) is 100 and 92.3% in the chip and GDA tests, respectively. Correlations between GDA (sputum) and drug test (LJ) were 91.7%, that of chip (sputum) and drug test LJ, 88.5%, chip (sputum) and chip clinical isolates (LJ), 100%. The efficacy of GDA and chip in the detection of RR of MTB strains is under discussion.

[Automated methods of culture determination of M. tuberculosis in liquid media]

A hundred and seventy respiratory samples from patients with different forms of tuberculosis were used to test the efficiency of the automatic liquid culture systems BACTEC MGIT 960 and MB/BacT with inoculation into the standard dense media. All these media provided 47 M. tuberculous isolates, of them 41 (87.2%), 38 (80.9%), and 76.6% on the BACTER 960, MB/BacT, and dense media, respectively. The average time of detection of mycobacterial growth by means of automatic systems was much shorter and equal to 10.7 days on the BACTEC 960 and 18.7 days on the MB/BacT versus 33.2 days on the standard dense medium. In terms of their sensitivity and detection rate, the automatic systems were superior to the dense media widely used in laboratory practice.

Detection of rifampicin-resistant Mycobacterium tuberculosis strains by hybridization and polymerase chain reaction on a specialized TB-microchip

Two alternative methods for identification of rifampicin-resistant strains of Mycobacterium tuberculosis on biological microchips are developed. The methods are based on detection of point mutations and other rearrangements in the rpoB gene region determining rifampicin resistance. Hybridization on TB-microchip detects 30 mutant variants of DNA in rifampicin-resistant strains (about 95% of all resistant forms). Allele-specific microchip PCR shortens the duration of analysis to 1.5 h. These methods can be used in clinical diagnostic laboratories for evaluating drug resistance/sensitivity of tuberculosis agent and for monitoring of the efficiency of antibiotic therapy.

Application of nested-PCR technique for the diagnosis of tuberculosis

A test-system based on amplification of IS 986 fragment (nested-PCR) was developed for the detection of Mycobacterium tuberculosis and M. bovis in different biological samples. We constructed external primers and selected appropriate amplifications parameters (annealing temperatures for states I and II, the number of cycles for each amplification stage, components of the amplification mixture, and pretreatment conditions for different biological samples). The developed parameters make the detection of mycobacteria more efficient and less expensive compared to commercial Cobas Amplicor system.

[Use of constant electric current in prevention of postoperative bronchopulmonary complications in patients with hiatal hernia]

The prophylactics of bronchopulmonary complications was performed by the authors original method of intrapulmonary electrophoresis. It was shown to be effective and allowed the amount of postoperative bronchitis and pneumonia to be reduced from 15-20% to 4.4%.

[Choice of the method of plasty in hiatal hernia]

Results of operative treatment of patients with esophageal hernias of the diaphragm can be substantially improved in cases of differential approach to choice of the plasty method. Choice of the method of plasty depends on the hernia type, topographic-anatomical structure of the esophageal opening of the diaphragm, concomitant diseases and age of the patient. Preference should be given to methods of non-complete fundoplication performed from the transabdominal access.

[Immunology of tuberculosis: current status]

The paper outlines the high-priority trends in basic and applied investigations of antituberculous immunity. It presents the results obtained from studies of the genetic mechanisms responsible for the control of susceptibility in experimental tuberculosis, from analyses of novel chemical and recombinant tuberculosis vaccines, from examinations of the role of immunological memory in the disease. While describing the results of tuberculosis immunodiagnosis, particular emphasis is laid on its major aspects: on the differential diagnosis of tuberculosis and other lung diseases and on the screening of high-risk group populations for disease progression in order to made further in-depth studies. Current aspects of evaluating the immune status and nonspecific responsiveness in patients with tuberculosis are considered.

[The use of the polymerase chain reaction in the diagnosis of pulmonary tuberculosis]

The data on the use of the polymerase chain reaction (PCR) with primers INS1 and INS2 for the diagnosis of pulmonary tuberculosis are presented. All stages of PCR are described: from the treatment of biological material to the conditions necessary for carrying PCR and the registration of the results. Simultaneously with this reaction, PCR in a Cobas Amplicor apparatus was carried out and Mycobacterium tuberculosis culture was grown in a liquid medium in an MB/BacT apparatus. The study revealed that the method of PCR in pure M. tuberculosis culture made it possible to detect even the DNA of those cells which formed no colonies on Löwenstein--Jensen medium. The detection of M. tuberculosis in clinical samples (sputum, pleural exudate) taken from 31 patients with different pulmonary pathology showed that in 87.1% of cases diagnostics with the use of PCR carried out in a Cobas Amplicor apparatus and with primers INS1 and INS2 yielded similar results. In patients with pulmonary tuberculosis the results of PCR were positive, while the results of the analysis made with use of an MB/BacT apparatus were negative. The proposed primers INS1 and INS2, the conditions of amplification and detection make up the test system for the detection of mycobacteria of the tuberculosis complex.

Capacity of murine T cells to retain long-term responsiveness to mycobacterial antigens is controlled by the H-2 complex

It is firmly established that the allelic composition of the H-2 complex has a prominent impact on the course of tuberculosis (TB) infection in mice, including granuloma formation, mycobacterial spread in the lungs, and the dynamics of mortality. Although intuitively obvious, the role of long-term specific T cell responses in the expression of corresponding phenotypes is poorly understood. In this study we have compared polyclonal lymph node cell response (cell yield, proliferation, surface markers, IL-4/interferon-gamma (IFN-gamma) production) to Mycobacterium tuberculosis H37Rv sonicate in repeated 10-day cycles of stimulation/rest between H-2 congenic IE-negative mouse strains, categorized on the basis of mortality following lethal challenge as TB-susceptible (C57B1/6), TB-resistant (4R) and BCG non-protected (B10.M). The capacity to retain specific responsiveness to repeated stimulation by mycobacterial antigens depended upon both the H-2 haplotype of the host and the immunizing dose of the antigen. 4R lymph node cells following either 50 microg/mouse or 100 microg/mouse immunization constantly responded to sonicate, increased in numbers, and after the third stimulation/rest cycle developed into a stable CD3+CD4+ cell line. B6 cells following either 50 microg/mouse or 100 microg/mouse immunization, and B10.M cells following 100 microg/mouse (but not 50 microg/mouse) immunization, lost the capacity to incorporate methyl-3H-thymidine during the second cycle, and died. Analogous results were obtained in the in vivo experiments, when the dynamics of the response over 12 weeks following a single immunization with the antigen was studied. In response to the antigen, cells from all three mouse strains produced significant amounts of IL-2 and IFN-gamma, but not IL-4, indicating that they belong predominantly to the Th1-like subset. Among noteworthy differences between the mouse strains was a clear deficiency of CD8+ T cells in B6 cultures, and an unusually high proportion of CD3+CD4-CD8- (double-negative) T cells in B10.M cultures following a high-dose immunization.

Influence of the mouse Bcg, Tbc-1 and xid genes on resistance and immune responses to tuberculosis infection and efficacy of bacille Calmette-Guérin (BCG) vaccination

We have studied the role of three mouse distinct non-H-2 genes (Bcg, Tbc-1, xid) in several phenomena of antituberculosis immunity and resistance. On the basis of median survival time (MST) of mice following infection with virulent Mycobacterium tuberculosis H37Rv, Bcg gene did not control resistance to the lethal dose of H37Rv infection in non-vaccinated and Myco. bovis (BCG)-vaccinated mice. However, Bcgr allele, in comparison with Bcgs allele, determined more effective suppression of an early multiplication in spleens of H37Rv mycobacteria after a low dose (5x10(4) colony-forming units (CFU)) injection. CBA/N mice, which are not protected efficiently against tuberculous challenge by BCG vaccination, were characterized by a decreased in vitro proliferation of immune lymph node cells, both spontaneous and stimulated with mycobacterial antigens. The decreased proliferation was due to immunosuppression caused by interactions between responding T cells and CBA/N antigen-presenting cells (APC). We have confirmed that the defective response to BCG-vaccination in CBA/N mice is linked with the X-chromosome and thus is presumably determined by the xid gene itself. I/St mice (Tbc-1s), supersusceptible to H37Rv infection, were not able to restrict the growth of H37Rv mycobacteria in spleens, even following infection with a low dose (5x10(4)), but restricted the growth of Myco.bovis BCG more effectively than Bcgs mice.

[Progress and prospects of tuberculosis immunology and immunogenetics]

Reviews the recent progress in immunopathogenesis, immunogenetics, immunodiagnosis, immunotherapy, and immunoprophylaxis of tuberculosis. The findings of Russian scientists (primarily at the Central Research Institute of Tuberculosis, Russian Academy of Medical Sciences) are compatible to the results of medical centers abroad.

Distinct H-2 complex control of mortality, and immune responses to tuberculosis infection in virgin and BCG-vaccinated mice

We have studied the impact of distinct haplotypes and of different alleles at specific H-2 loci on: (i) the susceptibility to lethal form of experimental tuberculosis; (ii) the level of DTH to mycobacterial antigens; (iii) the efficacy of vaccination with bacille Calmette-Guérin (BCG); and (iv) the IgG production and T cell proliferative response to H37Rv antigens. On the basis of median survival time (MST) following primary inoculation with lethal dose of Mycobacterium tuberculosis, susceptibility to infection associated with I-Ab and Db alleles, host resistance associated with I-Ak and Dd alleles. Mice bearing a disease-resistant phenotype also developed a vigorous DTH response. Vaccination with BCG before H37Rv infection significantly prolonged the survival time of both resistant and susceptible animals, except in B10.M (H-2f) mice. The latter exhibited intermediate resistance to infection before but slight decrease in the MST following a high-dose BCG vaccination. Distinct H-2 regulation of susceptibility to lethal infection and of BCG vaccination efficacy was confirmed in another relatively resistant H-2f-bearing strain A.CA, in which mortality occurred more rapidly in vaccinated compared with primarily infected animals. The expression of the H-2f haplotype was associated with a low DTH response to tuberculin following vaccination and subsequent lethal infection. The lack of BCG protection against Myco, tuberculosis challenge in B10.M mice associated with the high titre of specific IgG. In addition, these mice exhibited a unique ability to respond to 65-kD antigen by both IgG synthesis and T cell proliferation.

Regulation of T-cell proliferative responses by cells from solid lung tissue of M. tuberculosis-infected mice

We have studied proliferative responses to mycobacterial antigen preparation (PPD) and to non-specific stimuli of interstitial cells from the lungs of Mycobacterium tuberculosis-infected CBA mice. PPD-reactive lymphocytes appeared in the lung wall tissue in the course of chronic infection, but their proliferative capacity was totally inhibited by the lung macrophages. The latter were also able to suppress the proliferation of immune lymph node T cells. The mechanism of suppression clearly had two components, one being infection-specific and the other non-specific. Non-specific suppression was mediated mainly by prostaglandin E(PGE), whereas the specific mechanism showed only a weak influence of PGE and depended on the presence of I-J+ Lyt-2- nylon-wool-adherent cells in the responder population. Interstitial lung T or B lymphocytes were not involved in specific suppression.

[The genetic regulation of host response to inoculation with Mycobacterium bovis (BCG) and Mycobacterium tuberculosis H37RV]

Vaccination with M. bovis (BCG) essentially prolonged survival time (ST) of several strain mice, with the exception, of CBA/N, infected with M. tuberculosis H37Rv. ST of CBA/N, differing from CBA by xid mutation, was not prolonged by vaccination. Mouse strains with alternative alleles of BCG gene (s and r) and fzy gene as a genetic marker for Bcg5 were used for segregation analysis. It was shown that ST, the level of DTH reaction of mice infected with M. tuberculosis H37Rv, and protective effect of BCG vaccination did not depend on Bcg gene. However, Bcg gene, apparently, regulate the DTH response to PPD in mice only vaccinated with M. bovis (BCG).

[Cellular mechanisms of suppression of T-lymphocyte proliferation by lung cells in experimental tuberculosis]

The ability of interstitial lung cells from mice, infected with Mycobacterium tuberculosis H37Rv, to suppress proliferative responses of immune lymphocytes to mycobacterial (PPD) and unrelated (Staphylococcus aureus cytoplasm) antigens was studied. Two types of suppression were observed: the specific one, which was characteristic of the PPD-response only; and non-specific. The latter was mediated mainly by prostaglandins, since it could be abolished by indomethacin. Both types of suppression depended on the presence of plastic and nylon wool adherent phagocytes from infected lung. Though the depletion of T or B lymphocytes from the lung cell population have not abrogated the suppressive effect, some intercellular interactions were required for antigen-specific suppression, since the presence of nylon wool adherent cells in the population of responder lymph node cells was necessary for its development.

[Suppression of immune response by lung cells in experimental tuberculosis]

In vitro proliferative response of lung cells from mice infected with Mycobacterium tuberculosis H37Rv against PPD and Con A was studied. It was shown that the infected lung contained immune T cells, but their response in vitro was totally inhibited by plastic and nylon wool adherent suppressor cells. The whole population of lung cells from infected, but not intact mice, efficiently suppressed the proliferative response of immune lymph node cells against various antigens (non-specific suppression). The inhibition of response again depended on the presence of plastic adherent lung cells. Our data suggest that at least two suppressor pathways are induced in the course of tuberculosis infection: one being specific for mycobacterial antigens and other non-specific. Both types of suppressor pathways depend on the plastic adherent lung cells from tuberculosis lesion.

[New alloantisera to antigenic determinant I--J, their specificity and effect on the course of tuberculous infection in mice]

Preparations of anti-I--J alloantisera with higher activity were obtained by a new method, based on induction of expression of the I--J determinant in donor suppressor cells, immunization of mice with such cells, and subsequent elimination of contaminating anti-idiotypic antibodies from antisera by their adsorption on the cells of the recipient murine strain sharing induced idiotype with the donor cells. After adsorption anti-I--J activity remained unchanged. The antisera thus obtained were found active in the standard cytotoxic assay (working dilution greater than or equal to 1:20). The injection of anti-I--Jk antiserum to CBA mice prolonged the survival time of the animals and increased the parameters of the cell-mediated immunity after infection with Mycobacterium tuberculosis virulent strain H37Rv.

[Regulation of antitubercular immunity in mice by genes of the H-2 complex]

Development of DTH reaction and survival time after M. tuberculosis H37Rv infection have been studied in H-2 congenic and recombinant mice pretreated with high doses of BCG vaccine. In addition, in vitro proliferation of lymphocytes from infected CBA, B6 and 4R mice to PPD was studied in the presence of anti-I-A and anti-I-E mAbs. High doses of BCG vaccination (1 mg/mouse) have led to a significant inhibition of DTH and diminution of survival time in B10.M (H-2f) mice only, and to opposite effects in all other strains tested (H-2a, b, d, k, h4). In I-A+, I-E- 4R mice anti-I-Ak mAbs abrogated lymphocyte proliferation to PPD completely, while in I-A+, I-E- CBA mice only the mixture of anti-I-Ak and anti-I-Ek mAbs was effective.

[Na+, K+-ATPase activity in erythrocytes after the effect of laser radiation]

An in vitro single radiation of helium-neon laser (power flux density being 2 mW/cm2 exposure--1 and 3 min) does not change the concentration of Na+ and K+, activity of Na+, K+-dependent ATPase in erythrocytes and does not affect the intensity of active Na transport through their membrane in the donor blood. The 5 min laser action decreases the level of K+ and increases that of Na+ in the erythrocytes, activates Na+, K+-ATPases and intensifies the active Na+ transport.

[Effect of a specific alloantiserum against T-suppressor cells on the resistance of mice to tuberculosis]

Mouse alloantiserum obtained by immunization of/DBA/2X XB10. A (3R)/F1 hybrids with thymic lymphocytes stimulated with Con A of B10.A(%) mice (anti-I-Jk) was tested in the microcytotoxic assay and in functional test of the survival of mice infected with tuberculosis. Serum was found to react with population of the cells from the lymph nodes of A/Sh, A2G, B10.AKM, and A.TL (I-Jk) mice, and was not active with B10.HTT (I-Js), B10 (I-Jb), B10,D2 (R107) (I-Jb), B6-H-2bm3 (I-Jb). Administration of the antiserum to mice infected with tuberculosis made the survival of the I-Jk-bearing strains significantly longer.

[Genetic analysis of the factors determining susceptibility to tuberculosis]

An analysis has been made of the inheritance of factors determining varying survival rate in mice of I/st and A2G lines highly differing in sensitivity to intravenous injection with virulent M. tuberculosis strain H37Rv and by the tuberculin tests. It is considered that there exists a diverse genetic control of sensitivity and resistance to tuberculosis.