♦ Ideal for In Vitro Immunological and Epidemiological Studies ♦ Available in 2mg, 10mg, 200mg sizes
ATCC® offers 24 types of purified pneumococcal polysaccharides that can be used to study pneumococcal disease biology and in immunological research. ATCC's pneumococcal polysaccharides are purified and are the same serotypes found in vaccines against pneumococcal diseases world-wide.
Now Available: Pneumococcal Polysaccharide Type 6 (6A)
Image of Streptococcus pneumoniae courtesy of Dr. Mike Miller, CDC
Background Information
Pneumococcal Diseases
Diseases caused by the common bacterium, Streptococcus pneumoniae (often called pneumococcus), are a major global health problem. Pneumococcus can infect multiple regions of the body, especially the lungs where it causes pneumonia. More than 1 million children die every year of pneumococcal diseases, primarily in developing countries and from pneumonia. In industrialized countries, pneumococcus is the major cause of pneumonia in the elderly. Each year in the United States, pneumococcus causes an estimated 7,000,000 cases of otitis media, 500,000 cases of pneumococcal pneumonia, and 3,000 cases of meningitis.
Nasopharyngeal carriage of pneumococcal serotypes is an important aspect of the severity and progression of disease. There appears to be a relationship between the composition and structure of a pneumococcal strain’s capsule and the success of the serotype during nasopharyngeal carriage to become established. Capsular types with higher ratios of charge to carbon may be physically larger making them more resistant to neutrophil clearance. More prevalent pneumococcal serotypes tend to be more heavily encapsulated hindering clearance. A solid association has been found between increased carriage and resistance to non-opsonic, neutrophil-mediated killing of specific pneumococcal serotypes. Some serotypes have been associated with specific pneumococcal disease syndromes, others with higher hospitalization rates in children, or mortality in adults.
Use of Pneumococcal Polysaccharides in Immunological and Epidemiological Assays
Each polysaccharide antigen is extracted and purified separately making the products specific and useful as antigens in direct enzyme-linked immunosorbent assays (ELISA) and newer multiplex assays. In addition to their use in assaying for type-specific antibody, these antigens are useful in the analysis of other immune responses and immunodeficiency studies. These soluble antigens have been used to detect low levels of immunoglobulin (IgM) specific to the polysaccharide in neonatal and splenectomized adult mice, demonstrating that the spleen plays a major role in the immune response. Use of the pneumococcal vaccine in immunocompromised human beings provides a comparable study model of the human immune response. Many epidemiological studies have been done using pneumococcal polysaccharides as in vitro antigens to quantitate the amount of serotype-specific antibodies in patient sera following vaccination, disease, or exposure to pneumococcus. Different polysaccharide types can be evaluated for their effect on pneumococcal disease biology such as carriage and invasiveness.
Pneumococcal polysaccharides can be used to study the roles of T lymphocytes and B lymphocytes during an immune response and immunosuppression caused by malignancies. Type 3 pneumococcal polysaccharide provides an excellent model system for investigating the initiation and control of antibody responses. In the absence of an adjuvant, type 3 pneumococcal polysaccharide elicits an antibody response restricted to one immunoglobulin class. Pneumococcal immunity has been shown to be dependent on the presence of CD4+ T cells. An important serotype-independent role for Interleukin-17A has been shown in mediating acquired immunity colonization by increasing pneumococcal killing by neutrophils.
Pneumococcal Vaccines
The first approach developed to combat pneumococcal disease was the use of multi-valent vaccines containing polysaccharides isolated from the capsules of different pneumococcus. Some vaccines now use conjugated pneumococcal polysaccharides conjugated to immunostimulatory proteins to elicit an immune response. The pneumococcal capsule, a key virulence factor of pneumococcus, can be serologically differentiated into 91 different types. The 24 serotypes available from ATCC, including type 6 (6A), are found in current commercially available vaccines.
References
- WHO position paper. Pneumococcal vaccines. Wkly Epidemiolog. Rec. 74: 177–183, 1999.
- WHO position paper. Pneumococcal conjugate vaccine for childhood immunization. Wkly Epidemiolol. Rec. 82(12: 93-104, 2007.
- Reinert, RR, Paradiso, P and Fritzell, B. Expert. Rev. Vaccines 9(3): 229-236, 2010.
- Austrian R. The pneumococcus at the millennium: not down, not out. J Infect. Dis. 179 (suppl 20: S338-S341, 1999.
- Ortqvist, A, Hedlund, J, and Kalin, M. Streptococcus Pneumoniae: Epidemiology, Risk Factors, and Clinical Features. Semin. Respir. Crit. Care Med. 26(6): 563-574, 2005.
- Butler JC, Shapiro ED, and Carlone, GM. Pneumococcal vaccines: history, current status, and future directions. Am. J. Med. 107(1A): 69S-76S, 1999.
- WHO position paper. 23-valent pneumococcal polysaccharide vaccine. Wkly Epidemiolog. Rec. 42: 373-384, 2008.
- Jacobson, RM, and Poland, GA. The pneumococcal conjugate vaccine. Minerva Pediatr. 54(40: 295-303, 2002.
- American Academy of Pediatrics Committee on Infectious Diseases. Recommendations for the prevention of Streptococcus pneumonia infections in infants and children: use of 13-valent conjugate vaccine (PCV13) and pneumococcal polysaccharide vaccine (PPSV23). Pediatrics. 126(1): 186-190, 2010.
- Baker, PJ, et al. Regulation of the antibody response to pneumococcal polysaccharide by thymus-derived cells. Rev. Infect. Dis. 3: 332-341, 1981.
- Havas, HF, and G Schiffman. The effect of an IgM plasmacytoma (TEPC-183) on the primary immune response of BALB/c mice. Immunology 34: 1-8, 1978.
- Robbins, JB, et al. Consideration for formulating the second generation pneumococcal capsular polysaccharide vaccine with emphasis on the cross-reactive types within groups. J. Infect. Dis. 148: 1136-1158, 1983.
- Schiffman, G. Immune responses to pneumococcal polysaccharide antigens: a comparison of the murine model and the response in humans. Rev. Infect. Dis. 3: 224-232, 1981.
- Vogel, S, and B Roberson. Phytohemagglutinin stimulation of enhanced immunoglobulin G production in mice inoculated with Type III pneumococcal polysaccharide. Infect. Immun. 3: 901-907, 1978.
- Weinberger, DM, et al. Pnemococcal capsular polysaccharide structure predicts serotype relevance. PLoS Pathogens. 5(6)e1000476, 2009.
- Hausdorff, WP, Feikin, DR, and Klugman, KP. Epidemiological differences among pneumococcal serotypes. Lancet Infect. Dis. 5(2): 82-93, 2005.
- Lu, YJ et al. Interluekin-17A mediates acquired immunity to pneumococcal colonization. PLoS Pathogens. 4(9)e1000159, 2008.
These products are for laboratory use only. Not intended for human or diagnostic use. |